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Overview and Recommendations
Background
- •Achalasia is a rare esophageal motility disorder with three interdependent hallmarks: failure of LES relaxation, absent peristalsis, and impaired esophageal emptying, leading to progressive food stasis, esophageal dilation, and malnutrition. The term derives from Greek "chalasis" (loosening) with the prefix "a-" (without).
- •Incidence is 1-1.6 per 100,000 person-years globally, but rising to 2.8 per 100,000 in high-resolution manometry (HRM) era series; prevalence is 10-15 per 100,000 with a slight male predominance (1.2-1.5:1) and peak onset between ages 40-60 years. A US claims analysis found incidence increasing from 0.9 (2001) to 1.8 (2018) per 100,000 among adults under 65.
- •The condition is caused by progressive, immune-mediated destruction of inhibitory neurons in the esophageal myenteric plexus, specifically those releasing nitric oxide (NO) and vasoactive intestinal polypeptide (VIP). This selective neuronal loss leaves unopposed cholinergic tone, producing a hypertensive, non-relaxing LES and aperistalsis. An environmental trigger (likely viral infection, e.g., HSV-1, VZV) is implicated in genetically susceptible individuals (HLA class II associations).
- •Three HRM-based Chicago Classification v4.0 subtypes define prognosis: Type I (classic), 100% failed peristalsis, no pressurization; Type II (panesophageal pressurization), best treatment response; Type III (spastic), requires longer myotomy and responds poorly to pneumatic dilation. EGJ outflow obstruction (EGJOO) is a separate category requiring exclusion of pseudoachalasia.
- •Untreated achalasia carries a 2- to 16-fold increased risk of esophageal squamous cell carcinoma (not adenocarcinoma) due to chronic stasis and inflammation; annual incidence of SCC is approximately 0.64%. All-cause mortality is increased (HR 1.5) compared to the general population in large cohort studies.
- •Chronic opioid use (>90 days) is the strongest modifiable risk factor (OR 5.8 for type III achalasia). Other mimics to exclude: Chagas disease, eosinophilic esophagitis, sarcoidosis, and pseudoachalasia (malignancy, most commonly gastric cardia adenocarcinoma).
Evaluation
- •Suspect achalasia in any patient with dysphagia to both solids and liquids (present from onset), especially when accompanied by regurgitation of undigested food and saliva (often nocturnal, causing coughing/choking), non-cardiac chest pain (especially in type III), and weight loss. Heartburn that is refractory to high-dose PPI is a common misleader.
- •Ask about symptom duration (typically >2 years before diagnosis), adaptive behaviors (eating slowly, drinking large volumes with meals), nocturnal regurgitation with aspiration symptoms, and prior treatments for GERD or dysphagia. Document weight loss (present in 35-50%; more common in type II).
- •Examine for signs of malnutrition (temporal wasting, muscle atrophy), suprasternal fullness or gurgling (indicating a dilated, tortuous esophagus), halitosis from fermentation of retained food, and pulmonary findings (crackles, especially right lower lobe) suggesting recurrent aspiration pneumonia.
- •Order upper endoscopy (EGD) as the first test, but be aware that a normal endoscopy does NOT rule out achalasia. Use the CARS scoring system (Content, Anatomy, Resistance, Stasis): score ≥2 predicts achalasia with 84% sensitivity. Key red flags: retained saliva/food, tight/puckered LES, resistance to scope passage, dilated/sigmoid esophagus. Absence of reflux changes is itself suspicious.
- •Perform high-resolution manometry (HRM) with at least 10 supine and 5 upright swallows. Diagnostic threshold: integrated relaxation pressure (IRP) >15 mmHg supine. Preserved peristalsis with elevated IRP suggests EGJ outflow obstruction, requires exclusion of mechanical causes (stricture, fundoplication, malignancy) before labelling as primary disorder.
- •Classify using Chicago Classification v4.0: Type I (100% failed swallows, no pressurization), Type II (≥20% swallows with panesophageal pressurization >30 mmHg), Type III (≥20% swallows with spastic contractions; distal latency <4.5 s). Subtype assignment is critical because it predicts treatment response.
- •Obtain a timed barium esophagogram (TBE), patient drinks 200 mL dilute barium with radiographs at 1, 2, and 5 minutes. A barium column height >2 cm at 1 minute has 100% sensitivity and 83% specificity for achalasia. A barium tablet challenge (13 mm) showing retention >60 seconds further confirms obstruction. TBE also serves as an objective outcome measure post-treatment.
- •Use functional lumen imaging probe (FLIP) panometry during the index EGD if available, an EGJ-distensibility index (DI) <2.0 mm²/mmHg is 95% specific for achalasia, and abnormal FLIP patterns can expedite diagnosis without awaiting HRM (positive predictive value 91%).
- •Exclude pseudoachalasia in any patient >55 years with symptom duration <6 months, weight loss >10 kg, or a suspicious EGD. Perform EGD with retroflexed view of the gastric cardia and careful biopsy. If clinical suspicion persists despite normal EGD, obtain endoscopic ultrasound (EUS) and CT chest/abdomen to evaluate for submucosal tumors or extrinsic compression (most commonly gastric cardia adenocarcinoma).
- •Consider Chagas serology (T. cruzi antibodies) in patients from endemic regions (Central/South America). Order CBC, albumin, and nutritional labs for baseline status. Serum anti-neuronal antibodies are research tools only and not recommended in routine practice.
- •Calculate the Eckardt score (dysphagia, regurgitation, chest pain, weight loss, each scored 0-3; total 0-12). A score >3 indicates need for therapy and is the standard threshold for initiating treatment.
Management
- •Select definitive therapy based on manometric subtype, age, and patient preference, all three first-line options (PD, LHM with fundoplication, POEM) have comparable long-term success (~80% at 2 years).
- •For Type I or II achalasia: offer pneumatic dilation (PD) using a graded protocol, start with a 30 mm Rigiflex balloon under fluoroscopy; if inadequate response, repeat with 35 mm at 2-4 weeks; if still needed, 40 mm. Inflate to 8-12 psi for 15-60 seconds until the balloon waist disappears. Success: ~66% after one dilation; ~80-90% after up to three dilations. Alternatively, proceed directly to POEM or LHM.
- •For Type III achalasia (spastic): POEM is preferred as first-line therapy because the myotomy can be extended proximally along the spastic segment, achieving success rates of ~80-85% at long-term follow-up. PD has a failure rate >70% in this subtype.
- •For laparoscopic Heller myotomy (LHM): perform a 6-8 cm esophageal myotomy extending 2-3 cm onto the gastric cardia, always combined with a partial fundoplication (Dor or Toupet) to reduce postoperative GERD (from ~30% to ~10%). Success rates ~80-90% at 2 years. Mean hospital stay: 1-2 days.
- •For peroral endoscopic myotomy (POEM): create a submucosal tunnel (12-14 cm total) and perform a myotomy of the circular muscle fibers, short myotomy (8 cm) is non-inferior to long myotomy (13 cm) at 24 months (Eckardt ≤3: 89.9% vs. 87.1%) and reduces post-procedure GERD. Single-dose prophylactic antibiotic (cefazolin 1-2 g IV) is sufficient.
- •For elderly/frail patients (ASA ≥III or age >70): PD is first-line due to lower procedural risk; success rates approach 78% at 2 years with graded protocol. Botulinum toxin (BTX) injection (0.5 mL aliquots of 100 U divided into 4 quadrants at the LES) can be used as a temporizing measure, provides symptom relief in 78% at 1 year but efficacy wanes to 40% at 2 years. BTX should NOT be used in surgical candidates due to fibrosis.
- •What NOT to do: Do NOT use standard balloons for dilation, only dedicated achalasia balloons (30-35-40 mm). Do NOT perform BTX as definitive therapy in surgical candidates. Do NOT omit fundoplication during LHM. Do NOT use a single 30 mm PD as definitive therapy, graded protocol is required.
- •Post-procedural GERD management: All patients after any myotomy (especially POEM) should receive empiric PPI therapy (e.g., omeprazole 20 mg or pantoprazole 40 mg once daily) for at least 8 weeks. Escalate to twice-daily PPI if symptoms persist. Perform endoscopy at 1 year post-myotomy to assess for erosive esophagitis, followed by surveillance every 3 years if GERD is present.
- •Monitoring for treatment failure: Assess Eckardt score at each follow-up (target ≤3). If score >3, obtain timed barium esophagogram, a barium column >5 cm at 5 minutes strongly predicts relapse (HR 3.1). Also consider HRM with rapid drink challenge (200 mL water), maximal pressurization >20 mmHg predicts incomplete emptying with 86% sensitivity.
- •Managing treatment failure after first-line therapy: After failed PD, proceed to POEM or LHM (success ~80% at 5 years). After failed LHM, POEM is superior to repeat PD at 1 year (85% vs. 48%; level 1b). After failed POEM, repeat POEM (Re-POEM) is effective in ~80% of cases.
- •Esophageal perforation: Most feared acute complication of PD (rate ~1.9% per procedure). Suspect if patient has severe chest pain, subcutaneous emphysema, or fever after dilation. Immediate water-soluble contrast esophagram. In stable patients without mediastinal soliage, conservative management with IV antibiotics, nasogastric suction, and endoscopic stent placement is successful in ~75% of cases.
- •Cancer surveillance: Consider screening endoscopy with Lugol chromoendoscopy every 3 years starting 10-15 years after diagnosis, especially in patients with long-standing disease, sigmoid esophagus, or retained food (ESGE conditional recommendation). Lifetime risk of SCC is ~1-3%.
- •Nutritional support: For patients with severe malnutrition or complete esophageal obstruction precluding oral intake, place a nasogastric tube under endoscopic guidance if possible. If not feasible, proceed with urgent POEM or PD for acute decompression. NPO status must be maintained until esophagus is cleared.
- •Referral criteria: Refer to a high-volume esophageal center (≥20 POEM cases/year) for any myotomy procedure, especially in Type III or sigmoid esophagus. Refer to a gastroenterologist with expertise in motility disorders for HRM interpretation. Consider referral to an esophagologist for management of refractory cases and surveillance.
Board Review — High Yield
- •Eckardt score, the validated clinical tool for assessing achalasia severity and treatment response; score >3 indicates need for therapy, ≤3 defines success.
- •Chicago Classification v4.0, HRM-based system that subtypes achalasia into Type I (failed peristalsis, no pressurization), Type II (panesophageal pressurization, best prognosis), and Type III (spastic contractions; needs longer myotomy).
- •Pseudoachalasia, malignancy-mimicking achalasia (most often gastric cardia adenocarcinoma); suspect in patients >55 years with symptom duration <6 months and weight loss >10 kg; requires EGD with retroflexed view and EUS/CT.
- •Opioid-induced esophageal dysfunction (OIED), chronic opioid use (>90 days) produces a manometric pattern mimicking Type III achalasia; OR 5.8 for Type III; partially reversible with opioid cessation.
- •Pneumatic dilation (PD), graded protocol (30→35→40 mm) with Rigiflex balloon; 1.9% perforation rate; success ~80-90% with up to 3 sessions; first-line for elderly/frail patients and Type II achalasia.
- •POEM vs. LHM, POEM has higher post-procedure GERD (30-50% vs. 8-15% with fundoplication); short myotomy (8 cm) non-inferior to long (13 cm) for success, with less GERD.
- •Esophageal squamous cell carcinoma (SCC), risk is increased 10- to 50-fold in long-standing achalasia; consider surveillance with Lugol chromoendoscopy every 3 years starting 10-15 years after diagnosis.
- •Timed barium esophagogram (TBE), objective measure of esophageal emptying; barium column >5 cm at 5 minutes strongly predicts relapse (HR 3.1); tablet retention >60 seconds confirms obstruction.
- •Chagas disease, T. cruzi infection causes achalasia in endemic regions (Central/South America); requires serology and cardiac evaluation before myotomy.
- •Zhongshan POEM Score, predicts failure after POEM: Eckardt >6 (1 point), sigmoid esophagus (1 point), Type I/III (1 point); score 3 predicts 49% success at 5 years.
Deep Dive — Evidence Details
Definition, Classification & Nomenclature
- ▸Achalasia is defined by failure of LES relaxation, absent peristalsis, and impaired esophageal emptying; the term means 'failure to relax' in Greek.
- ▸The Chicago Classification (v4.0) using high-resolution manometry subdivides achalasia into three subtypes (I, II, III) based on integrated relaxation pressure, distal contractile integral, and distal latency, plus EGJ outflow obstruction.
- ▸Subtype classification dictates prognosis and treatment, Type II responds best to any therapy; Type III requires extended myotomy (preferably POEM).
Achalasia is a chronic esophageal motility disorder defined by three interdependent pathophysiologic features: failure of the lower esophageal sphincter (LES) to relax during swallowing, absent peristalsis in the esophageal body, and impaired esophageal emptying that results from the first two derangements [13]D5[25]D5. The term derives from the Greek "chalasis" (loosening) with the prefix "a-" (without), literally meaning "failure to relax."
Also Called / Synonyms
- Esophageal achalasia
- Achalasia cardiae (historically used in Europe)
- Cardiospasm (an outdated term reflecting the mistaken belief that the cardia was in spasm)
- Megaesophagus (end-stage appearance; not a diagnosis and should be avoided as a synonym)
- POEM-eligible disorder (practical term used in endoscopic referral networks)
Defining the Spectrum: The Chicago Classification
High-resolution manometry (HRM) has replaced older classification systems (e.g., conventional manometry Castell criteria) and provides the current diagnostic gold standard through the Chicago Classification, now in version 4.0 (CCv4.0) [13]D5[25]D5[28]B2b. The classification uses three key HRM metrics: integrated relaxation pressure (IRP) (median of the four-second nadir pressure of the LES during swallowing, normally <15 mmHg supine), distal contractile integral (DCI) (a measure of contraction vigor), and distal latency (DL) (time from swallow to the contractile deceleration point).
Based on these metrics, CCv4.0 defines three achalasia subtypes and an additional outflow obstruction category:
| Subtype | Key Manometric Feature | Esophageal Body Pattern | Clinical Relevance |
|---|---|---|---|
| Type I (Classic achalasia) | Elevated IRP (>15 mmHg) | 100% failed peristalsis (DCI <100 mmHg·s·cm); no esophageal pressurization above 30 mmHg | Least favorable response to pneumatic dilation; responds well to myotomy [14]B2b |
| Type II (Achalasia with panesophageal pressurization) | Elevated IRP | No peristalsis; panesophageal pressurization to >30 mmHg in ≥20% of swallows | Best treatment response of all subtypes to any therapy, including pneumatic dilation [14]B2b |
| Type III (Spastic achalasia) | Elevated IRP | Spastic contractions (DL <4.5 s) in ≥20% of swallows with preserved DCI (>450 mmHg·s·cm) | Requires longer myotomy to cover the spastic segment; best managed with POEM [6]A1b[14]B2b |
| EGJ outflow obstruction (EGJOO) | Elevated IRP (≥15 mmHg in supine position; ≥12 mmHg in upright) | Preserved peristalsis in ≥20% of swallows (DCI>450 mmHg·s·cm) | A heterogeneous group; must exclude pseudoachalasia and mechanical obstruction (stricture, fundoplication, malignancy) before labeling as a primary disorder [25]D5[28]B2b |
Key Diagnostic Thresholds
- IRP elevation: ≥15 mmHg in supine position is the standard cutoff for abnormal LES relaxation [28]B2b. In the upright position, the threshold is ≥12 mmHg [28]B2b.
- Proximal esophageal pressurization: Panesophageal pressurization ≥30 mmHg in ≥20% of supine swallows defines Type II [14]B2b.
- Distal latency: A DL of <4.5 s defines spastic contractions (Type III) [14]B2b.
- Absence of peristalsis: Failed peristalsis is defined as DCI <100 mmHg·s·cm [14]B2b.
Classification vs. Nomenclature Pitfalls
- False-positive EGJOO: Elevated IRP with intact peristalsis is not automatically achalasia. Causes include obesity, type 2 diabetes, collagen vascular disease, mechanical obstruction (peptic stricture, esophageal web, malignancy), and post-fundoplication state [25]D5[28]B2b. The term "EGJ outflow obstruction" is preferred over "incomplete achalasia" to emphasize the need for exclusion workup.
- Pseudoachalasia: A malignancy (most commonly adenocarcinoma of the cardia or gastric fundus, but also lung cancer, lymphoma, or mesothelioma) that mimics achalasia by infiltrating the LES. Should be suspected in patients over age 60 with short duration of symptoms (<6 months) and weight loss >10% body weight; requires endoscopy with biopsies and cross-sectional imaging [13]D5.
- Post-treatment nomenclature: After successful myotomy (surgical or POEM), the IRP normalizes. A new CCv4.0-based nomenclature for treated achalasia has been proposed: "effective myotomy" (normal IRP with absent peristalsis) vs. "unsuccessful myotomy" (persistent elevated IRP) [24]D5. This distinction guides downstream decisions.
Clinical Significance
Achalasia is a rare disease with an annual incidence of 1 to 1.6 per 100,000 person-years globally, though recent data suggest an increasing trend [41]A1a. The prevalence is approximately 10 to 15 per 100,000 [41]A1a[26]B2b. Although not among the three leading causes of cancer death, untreated achalasia confers a 2-fold to 16-fold increased risk of esophageal squamous cell carcinoma (not adenocarcinoma), likely due to chronic stasis and inflammation [45]B3b[9]B2b. The condition causes severe dysphagia, regurgitation, and weight loss, leading to malnutrition, , and a significantly reduced quality of life if untreated [9]B2b.
Pearl: The Chicago Classification (v4.0) using HRM is the current diagnostic standard for achalasia, and subtype designation (I, II, III, or EGJOO) is critical because it predicts treatment response, Type II has the best outcome to any therapy, while Type III requires a tailored longer myotomy [14]B2b[25]D5.
Pathophysiology & Mechanism
- ▸The core mechanism is immune-mediated destruction of inhibitory (nitrergic) myenteric neurons, causing unopposed cholinergic tone, a non-relaxing LES, and aperistalsis [13, 79].
- ▸The three Chicago Classification subtypes reflect differing degrees of residual esophageal body function: Type I (no pressurization), Type II (panesophageal pressurization, best prognosis), Type III (spastic contractions, worst prognosis) [48, 53].
- ▸Secondary causes of achalasia (opioid-induced, Chagas disease, eosinophilic esophagitis, sarcoidosis, post-fundoplication) must be excluded before assigning a diagnosis of idiopathic achalasia [48, 52, 70].
The core pathogenic event in achalasia is a progressive, immune-mediated destruction of inhibitory neurons in the esophageal myenteric plexus, specifically those that release nitric oxide (NO) and vasoactive intestinal polypeptide (VIP), leading to a failure of lower esophageal sphincter (LES) relaxation and loss of peristalsis [13]D5[79]D5. This selective neuronal loss disrupts the balance of excitatory (cholinergic) and inhibitory (nitrergic) neural input to the esophageal body and LES. The result is unopposed cholinergic tone, causing a hypertensive, non-relaxing LES and aperistalsis due to the inability of the distal esophagus to generate a coordinated propagating contraction wave [13]D5[79]D5. The hypervigilance and symptom-specific anxiety that often accompany achalasia further amplify perceived dysphagia severity, independent of the degree of mechanical obstruction [5]B2b[99]C4[104]B2b.
#### The Neuroinflammatory and Autoimmune Cascade
The prevailing model posits that an environmental trigger, most likely a viral infection (e.g., herpes simplex virus 1, varicella-zoster virus), initiates an aberrant immune response in a genetically susceptible host [79]D5. This response is characterized by:
- T-cell infiltration: A predominantly CD8+ cytotoxic T-cell infiltrate surrounds and invades the myenteric ganglia, driving ganglionitis [13]D5[79]D5.
- Antibody-mediated injury: Serum from achalasia patients contains autoantibodies directed against the myenteric plexus. Ex vivo incubation of normal human fundus with achalasia serum impairs nitrergic relaxation and alters neurochemical coding, reducing VIP and neuronal NOS expression while sparing choline acetyltransferase (ChAT) [17]D5[69]D5. This suggests a pathogenic role for circulating antibodies in propagating neuronal loss.
- Selective nitrergic neuron loss: The hallmark of the disease is the selective destruction of inhibitory motor neurons. Histopathologic studies show a marked reduction or absence of NOS- and VIP-immunoreactive neurons in the LES and esophageal body, while excitatory cholinergic neurons are relatively preserved [96]D5. This explains the classic manometric triad of incomplete LES relaxation, elevated baseline LES pressure, and absent peristalsis.
The inciting antigen remains unidentified, but molecular mimicry between viral peptides and myenteric neuronal proteins is hypothesized [79]D5. Genetic susceptibility may involve HLA class II alleles (e.g., DQA10103, DQB10603), which have been variably associated with achalasia in different populations [13]D5.
#### Resultant Neuromuscular Dysfunction: From Neuron to Manometric Phenotype
The loss of inhibitory innervation directly explains the three Chicago Classification subtypes, each representing a different degree of residual esophageal body function [13]D5[25]D5:
| Phenotype | Pathophysiologic Basis | Manometric Pattern (CCv4.0) |
|---|---|---|
| Type I (Classic) | Complete loss of myenteric neurons in the esophageal body. | Aperistalsis (failed peristalsis) with no pressurization (DCI < 100 mmHg·cm·s). |
| Type II (Compressive) | Preserved but non-peristaltic esophageal body contractility. | Aperistalsis with panesophageal pressurization (> 30 mmHg) in ≥ 20% of swallows. |
| Type III (Spastic) | Residual excitatory neural activity causes premature, simultaneous contractions. | Spastic contractions (DL < 4.5 s) in ≥ 20% of swallows, with impaired EGJ relaxation. |
Type II has the best treatment response, likely because some esophageal muscle function is preserved and can be effectively relieved by myotomy [48]A1c[53]A1a. Type III has the poorest response, as the spastic contractions persist even after LES disruption [48]A1c.
The functional consequence at the esophagogastric junction (EGJ) is quantifiable as reduced EGJ-distensibility index (DI) measured by functional lumen imaging probe (FLIP) panometry. In achalasia, the DI at the EGJ is markedly low (< 2.5 mm²/mmHg), directly correlating with the severity of dysphagia and barium column height on timed esophagram [46]D5[73]B3b[91]A1a. This mechanical obstruction is the immediate cause of food stasis, esophageal dilatation, and symptoms.
#### Secondary Changes and Disease Progression
Chronic obstruction and stasis lead to secondary mucosal and muscular adaptations:
- Esophageal muscle hypertrophy: The esophageal body muscle layer thickens progressively, detectable on high-frequency intraluminal ultrasound [72]D5. This hypertrophy is a compensatory response to impaired emptying but eventually becomes maladaptive, worsening stasis.
- Megaesophagus and sigmoid esophagus: Advanced, untreated disease results in massive esophageal dilatation (> 6 cm diameter) and tortuous deformation (sigmoid esophagus), which often heralds treatment failure [26]B2b[48]A1c. Stasis of food and secretions promotes chronic inflammation of the esophageal mucosa, a risk factor for esophageal squamous cell carcinoma (ESCC) [71]D5[79]D5. The risk of ESCC in achalasia is increased 10- to 50-fold compared with the general population, particularly after 10+ years of disease [71]D5.
- Inflammation and fibrosis: Persistent stasis and reflux of stagnant contents may incite a chronic inflammatory response that contributes to mucosal injury and, in some cases, fibrotic stricture formation at the EGJ, further exacerbating the outflow obstruction [48]A1c.
- Microbial alteration: The stagnant esophageal content may become colonized by a dysbiotic microbiome, which could theoretically perpetuate inflammation, although this is not yet a therapeutic target [48]A1c.
#### Factors That Mimic or Exacerbate the Phenotype
Several conditions can produce a manometric picture indistinguishable from idiopathic achalasia (pseudoachalasia) or exacerbate the underlying process:
- Opioid-induced esophageal dysfunction (OIED): Chronic opioid use (> 90 days) alters neural control of the EGJ, producing impaired LES relaxation, panesophageal pressurization, and spastic contractions without autoimmune myenteric destruction [52]A1a[64]B3b[78]D5. Manometrically, OIED mimics type III achalasia and EGJ outflow obstruction (EGJOO) [75]B3b. The effect is dose-dependent and partially reversible upon opioid cessation [93]C4. requires opioid weaning before procedural therapy [54]B2b.
- : Trypanosoma cruzi infection destroys enteric neurons via toxin-mediated and immune-mediated mechanisms, producing a clinical and manometric picture identical to Type I or Type II achalasia [48]A1c[79]D5. It is the most common cause of achalasia in endemic regions of Latin America.
- Eosinophilic esophagitis (EoE): Eosinophil-derived products (e.g., major basic protein, eosinophil peroxidase) can directly injure myenteric neurons and muscle fibers, causing a reversible achalasia-like motility pattern that resolves with EoE-directed therapy (e.g., ) [70]D5.
- Sarcoidosis and paraneoplastic syndromes: Granulomatous infiltration of the myenteric plexus (sarcoidosis) or anti-neuronal antibodies (paraneoplastic EGJOO, e.g., anti-Hu) can produce secondary achalasia [60]C4[50]D5.
- Post-fundoplication EGJOO: A mechanical, not neuropathic, obstruction at the EGJ caused by a tight wrap, which requires manometry with barium swallow to differentiate from recurrent achalasia [47]A1c.
#### The Role of Esophageal Hypervigilance
Independent of the degree of mechanical obstruction, esophageal hypervigilance and symptom-specific anxiety are major contributors to symptom severity in treated and untreated achalasia [5]B2b[99]C4[104]B2b. The Esophageal Hypervigilance and Anxiety Scale (EHAS) captures this central sensitization, and higher EHAS scores correlate with worse dysphagia and chest pain, even after successful myotomy [99]C4. This explains the discordance sometimes seen between objective EGJ patency (normal DI on FLIP) and persistent patient-reported dysphagia [5]B2b.
Pearl: Achalasia is a selective autoimmune destruction of inhibitory (nitrergic) myenteric neurons, likely triggered by a viral infection in a genetically susceptible host, causing unopposed cholinergic tone, a non-relaxing LES, and absent peristalsis [13]D5[79]D5. The Chicago Classification subtypes (I-III) reflect the degree of residual esophageal body function, while secondary causes (opioids, Chagas, EoE, sarcoidosis) must be excluded before diagnosing idiopathic achalasia [48]A1c[52]A1a[70]D5.
| Phenotype | Pathophysiologic Basis | Manometric Pattern |
|---|---|---|
| Type I (Classic) | Complete loss of myenteric neurons in esophageal body | Aperistalsis with no pressurization (DCI < 100 mmHg·cm·s) |
| Type II (Compressive) | Preserved non-peristaltic contractility | Aperistalsis with panesophageal pressurization (> 30 mmHg) in ≥ 20% of swallows |
| Type III (Spastic) | Residual excitatory neural activity | Spastic contractions (DL < 4.5 s) in ≥ 20% of swallows with impaired EGJ relaxation |
Epidemiology, Etiology & Risk Factors
- ▸Incidence of achalasia is 1-2.8 per 100,000 person-years; prevalence reaches 31 per 100,000 with contemporary diagnostic methods [125, 127].
- ▸Chronic opioid use (>90 days) is the strongest modifiable risk factor, with OR 4.3 for esophageal dysmotility and OR 5.8 for type III achalasia [52].
- ▸Pseudoachalasia from malignancy affects ~5% of newly diagnosed patients; key red flags include age >60 years and rapid weight loss [144].
Global incidence of achalasia is 1.0-2.8 per 100,000 person-years, with prevalence rates steadily rising to 12.8-31.1 per 100,000 in contemporary series [120]B3b[125]B3b[127]B2c. A United States claims-based analysis found incidence increasing from 0.9 per 100,000 in 2001 to 1.8 per 100,000 by 2018 among commercially insured adults under age 65, and a parallel rise in Medicare beneficiaries aged ≥65 from 1.3 to 2.3 per 100,000 over a similar period [125]B3b. The point prevalence in 2018 was 31.1 per 100,000 in the under-65 group and 25.7 per 100,000 in those ≥65 [125]B3b. These figures likely represent under-ascertainment from earlier eras; after the widespread adoption of high-resolution manometry, a tertiary-center study in central Chicago reported an incidence of 2.8 per 100,000 and prevalence of 12.8 per 100,000 for the years 2004-2014 [127]B2c.
Demographic Distribution
Achalasia affects both sexes, with a slight male predominance (male-to-female ratio approximately 1.2-1.5:1) [120]B3b[125]B3b. The condition can present at any age, but the peak incidence occurs between the 4th and 6th decades of life; median age at diagnosis in large cohort studies ranges from 48 to 55 years [110]B3b[120]B3b[125]B3b[127]B2c. A smaller second peak is observed in children and young adults [142]B2a. No consistent racial or ethnic predilection has emerged, though one US veterans cohort (predominantly White, 92% male) reported a median age of 55 years at diagnosis [110]B3b.
Temporal Trends and Geographic Variation
The rising incidence over the past two decades likely reflects improved diagnostic sensitivity (increased use of high-resolution manometry) rather than a true increase in disease occurrence [125]B3b[127]B2c. However, a Swedish nationwide cohort observed a stable incidence over 1969-2017 [9]B2b, suggesting that the upward trend in claims-based US data may be partly driven by detection bias. Achalasia occurs worldwide, with no clear geographic predilection. Endemic regions for (Central and South America) harbor a distinct infectious etiology, Trypanosoma cruzi-related achalasia, which may account for up to 10-15% of cases in highly endemic areas but is rarely seen in non-endemic settings [120]B3b.
Risk Factors
| Factor | Odds Ratio / Relative Risk | Evidence Level |
|---|---|---|
| Chronic opioid use (>90 days) | OR 4.3 (95% CI 2.7-6.8) for any esophageal dysmotility; OR 5.8 (95% CI 2.8-12.0) for type III achalasia [52]A1a | Meta-analysis (1a) |
| Prior Heller myotomy failure | Recurrence risk increased 2-fold vs. naïve patients; HR 2.1 (95% CI 1.4-3.0) [53]A1a[137]B2b | Meta-analysis (1a) |
| Genetic variants (LTA/TNFα locus) | rs1800629 (TNFα promoter) OR 1.6 (95% CI 1.3-2.0) [121]B3b | GWAS-level association from three European cohorts |
| Eosinophilic esophagitis | Prevalence up to 7% of EoE patients have achalasia on HRM vs. 0.01% expected [129]C4 | Cross-sectional (4) |
| Male sex | Male-to-female ratio 1.2-1.5:1 [120]B3b[125]B3b | Cohort-based estimates |
| Age 40-65 years | Peak incidence in this age band; OR 3.2 vs. age <40 [120]B3b[127]B2c | Population-based cohort |
Chronic opioid use is the strongest and most modifiable risk factor. A meta-analysis of nine studies found that opioid exposure (duration >90 days) increased odds of esophageal dysmotility by 4.3-fold; specifically, opioid-induced esophageal dysfunction (type III achalasia, esophagogastric junction outflow obstruction, , or hypercontractile esophagus) exhibited an OR of 5.8 [52]A1a. In a tertiary-care cohort, patients on chronic opioids had higher baseline Eckardt scores (mean 7.2 vs. 6.1; P=0.04) and were more likely to have type III achalasia on manometry (32% vs. 11%; P<0.001) [64]B3b. Opioid users undergoing POEM were also less likely to achieve clinical success (Eckardt score ≤3) at 12 months (OR 0.5, 95% CI 0.3-0.9) [54]B2b.
Genetic susceptibility is emerging from case-control and genome-wide association studies. A large European study identified several single nucleotide polymorphisms (SNPs) in the lymphotoxin-α/tumor necrosis factor-α (LTA/TNFα) locus as risk variants, with the strongest signal at rs1800629 (OR 1.6, 95% CI 1.3-2.0) [121]B3b. Achalasia likely fits a multifactorial inheritance model; the absolute lifetime risk for first-degree relatives remains low (<1%), but higher than the general population.
Autoimmune and infectious triggers are discussed in detail in the Pathophysiology & Mechanism section. Briefly, a preceding viral infection (possibly herpesviruses) is postulated to initiate an autoimmune attack on the esophageal myenteric plexus in genetically predisposed individuals. Cohort studies have reported that up to 67% of patients recall an infectious prodrome (e.g., upper respiratory or symptoms) in the months preceding dysphagia onset.
Age, sex, and prior treatment are non-modifiable factors that influence both disease presentation and treatment outcomes. Older age (≥65 years) is associated with a higher risk of post-POEM reflux esophagitis (RR 0.85 for age ≥65 vs. <65, but with a protective direction, likely reflecting lower case numbers) [10]B2b. Prior failed myotomy or dilation reduces the success rate of subsequent therapy; a meta-analysis found that the odds of clinical failure after POEM were 2.1-fold higher in patients with prior treatment compared with treatment-naïve patients [137]B2b.
Pseudoachalasia (Malignancy-Associated)
Pseudoachalasia accounts for approximately 5% of cases presenting with achalasia-like manometric findings [144]B2b. Key clinical clues suggesting pseudoachalasia include: age >60 years, short symptom duration (<6 months), weight loss >10% body weight, and failure of initial endoscopy to show normal mucosa. In a retrospective cohort, malignant pseudoachalasia was identified in 18/333 (5.4%) of consecutively diagnosed patients; the most common underlying malignancy was (61%), followed by lung, esophageal, and pancreatic cancers [144]B2b.
Seasonal and Temporal Variation
No clear seasonal variation in achalasia incidence has been documented. However, some studies have noted a clustering of cases in the months following winter viral epidemics, supporting the infectious trigger hypothesis. This association remains speculative and has not been confirmed in large population-based cohorts.
Pearl: Epidemiologic data from high-resolution manometry era reveal that achalasia is more common than previously recognized (prevalence up to 31 per 100,000), and chronic opioid use is the single strongest modifiable risk factor, increasing the odds of type III achalasia nearly sixfold [52]A1a[125]B3b.
| Factor | Odds Ratio / Relative Risk | Evidence Level |
|---|---|---|
| Chronic opioid use (>90 days) | OR 4.3 (95% CI 2.7-6.8) for any dysmotility; OR 5.8 (95% CI 2.8-12.0) for type III [52]A1a | Meta-analysis (1a) |
| Prior Heller myotomy failure | HR 2.1 (95% CI 1.4-3.0) for recurrence after POEM [53]A1a[137]B2b | Meta-analysis (1a) |
| Genetic variant (TNFα rs1800629) | OR 1.6 (95% CI 1.3-2.0) [121]B3b | GWAS-level (3b) |
| Eosinophilic esophagitis | Prevalence 7% of EoE patients have achalasia [129]C4 | Cross-sectional (4) |
| Male sex | Male-to-female ratio 1.2-1.5:1 [120]B3b[125]B3b | Cohort-based |
| Age 40-65 years | Peak incidence vs. age <40 [120]B3b[127]B2c | Population-based cohort |
Clinical Presentation
- ▸Dysphagia to both solids and liquids from the outset is the sentinel symptom of achalasia, and this feature alone should distinguish it from mechanical causes of esophageal obstruction.
- ▸Nocturnal regurgitation with aspiration, manifesting as chronic cough or recurrent pneumonia, is a high-risk symptom indicating advanced disease and requires urgent decompression.
- ▸Up to 40% of achalasia patients report heartburn, which is a common diagnostic pitfall; this symptom is due to esophageal fermentation, not acid reflux, and does not respond to PPI therapy.
- ▸Achalasia is commonly misdiagnosed as GERD; the key discriminant is dysphagia to liquids present from symptom onset.
The clinical presentation of achalasia is a direct reflection of the underlying pathophysiology: a non-relaxing lower esophageal sphincter (LES) and absent peristalsis. This leads to a predictable, albeit often insidious, constellation of symptoms and signs that progressive worsen over time.
Presenting Symptoms
The hallmark symptom is dysphagia, which occurs in virtually all patients and is the primary driver for seeking medical evaluation [113]B2b. Dysphagia is typically for both solids and liquids from the outset, a key differentiating feature from mechanical obstruction (e.g., peptic stricture, cancer) where liquid dysphagia is a late finding. Patients often describe food "sticking" retrosternally, and many develop adaptive behaviors like eating slowly, drinking large volumes of water with meals, or avoiding certain textures.
As the esophagus dilates due to chronic stasis, regurgitation of undigested food and saliva becomes prominent. Unlike vomiting, regurgitation is effortless and non-projectile, often occurring minutes to hours after a meal or when bending forward or lying supine. Nocturnal regurgitation, with aspiration into the airway, manifests as coughing, choking episodes, or recurrent [155]A1a. Regurgitation is present in 75-90% of patients.
Chest pain (non-cardiac chest pain) is a common but underappreciated symptom, reported in 40-60% of patients, and is especially characteristic of type III achalasia (spastic achalasia) [155]A1a. The pain is typically retrosternal, can mimic angina, and is caused by vigorous, non-peristaltic esophageal contractions against the obstructed LES. It may be exacerbated by eating or stress.
Heartburn is a frequent misleader, occurring in up to 40% of patients [150]D5. This heartburn is not due to acid reflux, the LES is hypertensive and non-relaxing, preventing reflux, but rather due to esophageal distension from retained food and fermentation, causing a burning sensation. This is a critical source of diagnostic delay, as patients are often misdiagnosed with gastroesophageal reflux disease (GERD). A key clinical pearl: if heartburn is refractory to high-dose proton pump inhibitor (PPI) therapy, achalasia must be considered [150]D5.
Weight loss occurs in 35-50% of patients and is more common in type II achalasia compared to other subtypes [155]A1a. It reflects severe dysphagia with reduced caloric intake. In advanced disease, complete esophageal obstruction can lead to profound cachexia. The degree of weight loss correlates with symptom severity and can be quantified using the Eckardt score, a validated patient-reported outcome measure that assesses dysphagia, regurgitation, chest pain, and weight loss [148]D5.
Timeline and Progression
The disease has a characteristic insidious onset, with symptoms often present for 2 to 5 years before diagnosis [139]A1a. The diagnosis of achalasia is typically delayed over 20 months from the first symptom due to the gradual nature of progression and misattribution to GERD or anxiety [139]A1a. Symptoms progress gradually, with dysphagia becoming more prominent, regurgitation more frequent, and chest pain potentially worsening (especially in type III). The severity can wax and wane but overall trends downward.
Physical Examination Signs
Physical examination is often unremarkable in early disease and the diagnosis is made primarily by history. However, certain signs should be sought:
| Sign | Description | Clinical Utility |
|---|---|---|
| Suprasternal fullness or mass | Palpable, often gurgling, fullness in the suprasternal notch | Suggests a massively dilated, tortuous esophagus (sigmoid esophagus) |
| Gurgling on auscultation | Audible gurgling sounds over the suprasternal notch on chest auscultation | Associated with fluid and food stasis; can be provoked by swallowing |
| Foul-smelling breath | Indicative of chronic fermentation of retained food in the esophageal lumen | |
| Pulmonary findings | Crackles or rhonchi on lung auscultation, particularly in the right lower lobe | May indicate recurrent aspiration pneumonia |
| Signs of weight loss/cachexia | Temporal wasting, loss of subcutaneous fat, muscle wasting | Correlates with severe disease and poor nutritional status |
Atypical Presentations: Pseudoachalasia and Triple A Syndrome
Pseudoachalasia, or secondary achalasia, is a mimic that must be excluded in any patient >60 years with rapid symptom onset (<6 months) and significant weight loss [153]A1a. It is most commonly caused by a malignant tumor at the gastroesophageal junction (e.g., gastric cardia adenocarcinoma, pancreatic cancer) that produces a functional obstruction. The key clinical red flags are advanced age, short duration of symptoms, and rapid progression. Manometric findings may be identical to type I achalasia, but the presence of a tumor on CT or EUS should be investigated [153]A1a.
Triple A syndrome (Allgrove syndrome) is a rare autosomal recessive disorder characterized by the triad of achalasia, alacrima (absence of tears), and adrenal insufficiency [156]C4. It presents in childhood, often in the first decade. Neurological features (e.g., autonomic dysfunction, intellectual disability) are present in two-thirds of cases [156]C4. The diagnosis should be considered in any pediatric or young adult patient presenting with achalasia, especially if there is a history of recurrent adrenal crises, dry eyes, or neurological symptoms.
Key Differential Diagnosis
The most important alternative diagnoses to exclude when considering achalasia include:
- Gastroesophageal reflux disease (GERD): Heartburn-dominant, responds to PPI; HRM shows normal peristalsis and normal or hypotensive LES.
- Peptic stricture: Dysphagia primarily to solids; barium swallow shows distal esophageal narrowing; endoscopy reveals inflammation and stricture.
- Eosinophilic esophagitis (EoE): Dysphagia with food impaction, atopic history; endoscopy shows rings, furrows, or strictures; biopsies confirm >15 eosinophils/hpf. Notably, achalasia and EoE can co-exist in up to 5% of patients [129]C4.
- Esophageal cancer: Rapidly progressive dysphagia, weight loss, anorexia; requires careful endoscopic and CT evaluation.
- Post-surgical dysphagia: Occurs after anti-reflux surgery (Nissen fundoplication) or bariatric surgery (sleeve ); HRM may show an obstructive pattern resembling achalasia, with a mechanically narrowed EGJ [20]C4[151]B3b.
Pearl: The classic presentation of achalasia is dysphagia to both solids and liquids from the start, associated with regurgitation and chest pain, with a slow, insidious progression. Any patient with heartburn refractory to PPI therapy should be considered for achalasia [150]D5. Timed barium esophagram showing a dilated esophagus with a smooth "bird-beak" narrowing at the EGJ is highly suggestive and should prompt manometric confirmation [124]B3b[151]B3b.
Diagnosis & Workup (Endoscopy, Imaging & Severity Labs)
- ▸High-resolution manometry with Chicago Classification v4.0 is the gold standard for diagnosing and subtyping achalasia.
- ▸The CARS endoscopic scoring system (Content, Anatomy, Resistance, Stasis) increases recognition of achalasia during routine EGD; a score ≥2 has 84% sensitivity and 80% specificity.
- ▸Pseudoachalasia must be excluded with retroflexed EGD and EUS (or CT) in any patient >55 years old with rapid weight loss or atypical manometry.
The diagnostic yield of any single test for achalasia is insufficient; therefore, the workup proceeds as a deliberate sequence, endoscopy to exclude pseudoachalasia, timed barium esophagogram to assess functional obstruction, and high-resolution manometry (HRM) as the gold standard for confirmation and subtyping [62]D5[79]D5. Incorporating the functional lumen imaging probe (FLIP) during the index endoscopy accelerates the pathway and can identify EGJ outflow obstruction before formal HRM is performed [11]D5[30]B3b[46]D5.
Endoscopy: The First and Most Common Missed Opportunity
Esophagogastroduodenoscopy (EGD) is typically the initial test for dysphagia but detects achalasia in fewer than one-third of cases when performed without systematic attention to subtle features [81]C4[139]A1a. The CARS (Content, Anatomy, Resistance, Stasis) endoscopic scoring system was developed to address this gap: it assigns points for retained salivary or food content (1 point), a tight or puckered EGJ (1 point), resistance to scope passage (1 point), and esophageal dilatation or sigmoid shape (1 point) [81]C4. A CARS score ≥2 has a pooled sensitivity of 84% (95% CI 0.78-0.89) and specificity of 80% (95% CI 0.74-0.85) for predicting achalasia, and a score of 0 essentially rules out the diagnosis (negative likelihood ratio 0.08 at a 5% pretest probability) [139]A1a.
Key endoscopic red flags that mandate manometric evaluation include:
- Retained saliva or food debris in a fasting patient
- A "pop" upon traversing the EGJ (indicating a hypertensive LES)
- Dilated or tortuous (sigmoid) esophageal body
- Normal-appearing squamous mucosa without erosions or rings (absence of reflux changes is itself suspicious)
If any of these features are present, the endoscopist should proceed directly to functional testing rather than diagnosing "normal EGD" [81]C4[150]D5.
Functional Lumen Imaging Probe (FLIP) Panometry: Same-Session Screening
FLIP panometry can be performed during sedated EGD using a 16-cm balloon catheter placed across the EGJ [11]D5. The two key metrics are the EGJ-distensibility index (DI) and the maximum EGJ diameter. An EGJ-DI <2.0 mm²/mm Hg at 40-mL fill is 95% specific for achalasia [29]B3b[73]B3b. The Dallas Consensus provides a standardized four-tier FLIP classification: normal, borderline, abnormal, and inconclusive, with abnormal patterns (absent contractility, spastic-reactive) corresponding to achalasia subtypes [11]D5.
When FLIP panometry demonstrates an abnormal contractile pattern and reduced EGJ opening, the patient can be referred directly for achalasia-directed therapy without awaiting HRM, as the positive predictive value for achalasia is 91% [30]B3b. A combined CARS + FLIP approach increases the pre-HRM diagnostic confidence to >95% [30]B3b.
Timed Barium Esophagogram (TBE): Assessing Functional Severity and Predictor of Response
TBE has a dual role: diagnostic support and objective monitoring of treatment response [12]B2b[21]B2b. The test involves drinking a measured volume of dilute barium (typically 200 mL), with radiographs obtained at 1, 2, and 5 minutes. A barium column height >2 cm at 1 minute is the most discriminative threshold for achalasia, with a sensitivity of 100% and specificity of 83% in one prospective study [12]B2b[19]D5.
TBE also predicts treatment outcome: patients whose 5-minute barium column height fails to fall by >50% after a single pneumatic dilation have a 75% probability of requiring retreatment within 2 years [21]B2b[165]A1b. The addition of a 13-mm barium tablet challenge further improves specificity: tablet retention at the EGJ for >60 seconds suggests outflow obstruction even when liquid emptying is preserved [19]D5.
High-Resolution Manometry (HRM): The Gold Standard
HRM is the definitive diagnostic test for achalasia [62]D5[74]D5[171]A1c. The Chicago Classification v4.0 (CCv4.0) requires incomplete EGJ relaxation (integrated relaxation pressure [IRP] >15 mm Hg in supine position) plus absent peristalsis or spastic contractions [62]D5. The three CCv4.0 subtypes determine prognosis and treatment selection:
| Subtype | Manometric Feature | Percent of Cases | Preferred First-Line Therapy |
|---|---|---|---|
| Type I (Classic) | 100% failed swallows, no panesophageal pressurization | 20-25% | POEM or LHM [164]A1b |
| Type II (With compression) | ≥20% swallows with panesophageal pressurization | 50-70% | PD or POEM (best prognosis) [164]A1b |
| Type III (Spastic) | ≥20% swallows with spastic premature contractions (distal latency <4.5 s) | 5-10% | POEM (longer myotomy often needed) [138]A1a[164]A1b |
Type II achalasia has the highest response rate to any therapy (Eckardt score ≤3 in 96% at 2 years), while type III has the highest failure rate with pneumatic dilation alone (success rate <50%), making POEM the preferred approach for this subtype [164]A1b[167]A1b. HRM should include at least 10 supine and 5 upright swallows; upright IRP measurement can identify clinically significant EGJ outflow obstruction missed in the supine position [183]B3b.
Distinguishing Pseudoachalasia
Pseudoachalasia, a malignancy or infiltrative process mimicking achalasia, must be excluded in every patient. Clinical features that raise suspicion include age >55 years, abrupt symptom onset (<6 months), weight loss >10% of body weight, and absence of typical achalasia findings on TBE (e.g., a dilated esophagus is less common) [144]B2b. In a retrospective cohort of 333 achalasia patients, pseudoachalasia was found in 5.4%, with the most common causes being gastric cardia adenocarcinoma (67%) and pancreatic cancer (11%) [144]B2b.
EGD with retroflexed view of the gastric cardia and careful biopsy of any suspicious area is mandatory [79]D5[144]B2b. Endoscopic ultrasound (EUS) should be performed if the cardia appears nodular, thickened, or fixed; EUS can identify submucosal tumor infiltration not visible on EGD. If EGD and EUS are normal but clinical suspicion remains, CT chest/abdomen with contrast is warranted to evaluate for extrinsic compression from mediastinal masses or pancreatic tumors [144]B2b.
Laboratory Studies: Supportive, Not Diagnostic
No blood test establishes achalasia. However, the following are useful:
- and albumin: Baseline nutritional status; low albumin correlates with worse post-treatment outcomes.
- Serum anti-neuronal antibodies: Research-use only; positive in a minority of patients, supporting an autoimmune etiology [79]D5.
- Chagas serology: Required in endemic regions (Central and South America) or in immigrants from those areas, as T. cruzi infection produces a clinically identical disease [79]D5[162]A1c.
Diagnostic Algorithm
Step 1, with CARS scoring:
- If CARS ≥2 → proceed to FLIP panometry (if available) or directly to HRM.
- If CARS 0 and clinical suspicion persists → proceed to HRM anyway (CARS has a miss rate of ~16% in low-prevalence populations) [139]A1a.
- If retroflexed cardia appears abnormal or age >55 with rapid weight loss → add EUS + CT to rule out pseudoachalasia.
Step 2, FLIP panometry (if equipment available):
- Abnormal FLIP (EGJ-DI <2.0, absent contractility, or spastic pattern) → diagnosis of EGJ outflow obstruction is established; go to Step 4.
- Normal FLIP → HRM still required for subtype classification.
Step 3, High-resolution manometry with CCv4.0 classification:
- IRP >15 mm Hg + absent peristalsis → achalasia confirmed. Classify into Type I/II/III.
- IRP >15 mm Hg + preserved peristalsis → EGJ outflow obstruction (inconclusive); perform TBE to confirm functional significance [180]B2b.
Step 4, Timed barium esophagogram:
- Baseline assessment of esophageal emptying. Barium column >2 cm at 1 minute or tablet retention >60 seconds confirms clinically relevant obstruction.
- Used as the objective endpoint for treatment response (Eckardt score is subjective; TBE adds an objective measure) [12]B2b[21]B2b[165]A1b.
Pearl: The diagnosis of achalasia is made by HRM, but early detection relies on the endoscopist recognizing CARS features during EGD. A normal endoscopy does NOT rule out achalasia, if any red flag is present, proceed to manometry or FLIP [81]C4[139]A1a.
| Subtype | Manometric Feature | Frequency | Preferred First-Line Therapy |
|---|---|---|---|
| Type I (Classic) | 100% failed swallows, no panesophageal pressurization | 20-25% | POEM or LHM [164]A1b |
| Type II (With compression) | ≥20% swallows with panesophageal pressurization | 50-70% | PD or POEM (best prognosis) [164]A1b |
| Type III (Spastic) | ≥20% swallows with spastic premature contractions (distal latency <4.5 s) | 5-10% | POEM (longer myotomy) [138]A1a[164]A1b |
Severity, Staging & Risk Stratification (GI Scores)
- ▸Eckardt score (threshold >3 for treatment, ≤3 for success) is validated across all therapeutic trials, but manometric subtype (type II best, type III worst) independently predicts response and should guide therapy selection [164, 207].
- ▸The Zhongshan POEM Score (Eckardt >6, sigmoid esophagus, type I/III subtype) stratifies risk of clinical failure after POEM: scores 0-1 predict 5-year success >90%, score 3 predicts only 49% [131].
- ▸Achalasia confers a 16.6-fold SIR for esophageal squamous cell carcinoma and 6.0-fold for adenocarcinoma; surveillance is not routinely recommended by ISDE, but clinical suspicion should remain high after 10-15 years of disease [111, 200, 208].
Symptom severity and treatment response in achalasia are quantified with validated instruments, not gestalt. The Eckardt score is the universal gatekeeper: it defines treatment eligibility (score >3), grades severity (0-3 per domain), and anchors clinical success (score ≤3) across all therapeutic trials [164]A1b. Four domains, dysphagia, regurgitation, chest pain, and weight loss, are each scored 0 (absent) to 3 (daily). A composite score of 0-3 = stage I, 4-6 = stage II, 7-9 = stage III, and 10-12 = stage IV. In the European achalasia trial, Eckardt score ≤3 was the sole success criterion, and pretreatment subtype independently predicted response: type II achalasia achieved 96% success with pneumatic dilation versus 56% for type I and 29% for type III [164]A1b. A meta-analysis of 2373 patients confirmed that Eckardt score drops from a mean 6.9 pre-POEM to 0.77 post-POEM, with 98% clinical success (95% CI 97-100%) [56]A1a. Despite its dominance, Eckardt lacks psychometric validation for hypervigilance and anxiety, which substantially distort symptom reporting [5]B2b[148]D5.
Patient-Reported Outcome Measures (PROs)
The Achalasia Patient-Reported Outcomes (APRO) Questionnaire was developed and validated to address this gap. It captures dysphagia, regurgitation, chest pain, early satiety, and global health, and demonstrates convergent validity with the Eckardt score and the Esophageal Hypervigilance and Anxiety Scale (EHAS) [95]C4. The EHAS (15-item; short-form 6-item) assesses cognitive-affective drivers of symptom experience. Patients with elevated EHAS scores report greater dysphagia severity independent of objective manometric findings, explaining variability that Eckardt alone misses [5]B2b[99]C4. The Northwestern Esophageal Quality of Life (NEQOL) Scale is a hybrid measure validated across achalasia, GERD, and eosinophilic esophagitis, providing a cross-disease platform for HRQOL assessment [198]C4. For clinical trials, the ISDE guidelines recommend using Eckardt as the primary outcome with EHAS and NEQOL as secondary endpoints [200]A1c.
Manometric Subtypes as Severity and Prognostic Axes
Chicago Classification v3.0 divides achalasia into three subtypes based on high-resolution manometry, and subtype determines both treatment response and natural history [14]B2b[164]A1b. Type I (classic), no esophageal pressurization, carries the worst response to pneumatic dilation (56% success). Type II (compression), panesophageal pressurization to >30 mmHg, responds best across all modalities: 96% with dilation, equivalent with Heller myotomy, and near-universal with POEM [164]A1b[207]A1a. Type III (spastic), spastic contractions in the distal esophagus, has the poorest outcomes with dilation (29%) and Heller myotomy, but POEM may confer advantage by extending the myotomy proximally [207]A1a. A meta-analysis of 21 studies confirmed type II has the highest pooled success (90.6% at 3.5 years) and type III the lowest (70.1%) [207]A1a. Subtype also predicts technical difficulty during POEM: type III and sigmoid esophagus are independent risk factors for failure and longer procedure time [131]B2b[203]B2b.
Anatomic Staging: Sigmoid Esophagus and Functional Luminal Imaging
With disease progression, esophageal dilation progresses through three radiographic stages: Stage I (nonsigmoid, diameter <4 cm), Stage II (sigmoid, diameter 4-6 cm), and Stage III (advanced sigmoid, >6 cm or tortuous). Sigmoid esophagus is an independent predictor of POEM failure: the Zhongshan POEM Score assigns 1 point for sigmoid changes on barium esophagogram [131]B2b. The EndoFLIP (Functional Luminal Imaging Probe) provides real-time assessment of esophagogastric junction (EGJ) distensibility. A distensibility index (DI) <2.0 mm²/mmHg is diagnostic of EGJ obstruction; post-treatment DI >3.0 mm²/mmHg correlates with clinical success [29]B3b[195]A1b. Combined with the CARS (Contents, Anatomy, Resistance, Stasis) endoscopic motility score, FLIP panometry expedites diagnosis during sedated endoscopy with 90% sensitivity for achalasia versus HRM reference [30]B3b. The rapid drink challenge during HRM, swallowing 200 mL water, amplifies the obstructive pressure pattern; its normalization post-treatment mirrors Eckardt improvement [205]B2b.
Predictive Scores for Treatment Failure
The Zhongshan POEM Score predicts clinical failure after POEM with three weighted risk factors: Eckardt score >6 at baseline (1 point), sigmoid esophagus (1 point), and type I/III subtype (1 point). Scores of 0-1 predict 5-year success >90%; score 2 predicts 78%; score 3 predicts 49% [131]B2b. This score was developed in 1538 patients and internally validated (AUC 0.72). The VA Achalasia Cohort algorithm uses ICD and CPT codes to identify achalasia nationally, achieving a positive predictive value of 96% [26]B2b. The Takahashi body-weight model identifies underweight (BMI <18.5) in 23% of achalasia patients at baseline; persistent underweight after POEM is a marker of residual dysphagia [209]B2b. Conversely, 15.7% are overweight at baseline, and excessive weight gain post-POEM correlates with reflux severity [209]B2b.
Cancer Risk Stratification
Achalasia carries an elevated risk of esophageal cancer. A Swedish nationwide cohort of 2896 patients reported a standardized incidence ratio (SIR) of 16.6 (95% CI 9.3-27.4) for esophageal squamous cell carcinoma and SIR 6.0 for adenocarcinoma (95% CI 2.0-14.0) [111]B3b. A meta-analysis of 40 studies (11,978 patients) estimated the annual incidence of squamous cell carcinoma at 0.64% and adenocarcinoma at 0.07% [208]A1a. Risk is highest in males, older age, and longer disease duration (>15 years). The ISDE guidelines do not recommend routine surveillance, but clinicians should maintain a low threshold for endoscopy in patients with symptom recurrence or weight loss >15 years post-diagnosis [200]A1c.
Controversies and Guideline Disagreement
| Question | Position A | Position B | Strength | Implication |
|---|---|---|---|---|
| Should cancer surveillance be performed? | ISDE (2018): no routine surveillance; insufficient data to reduce mortality [200]A1c | Some experts: consider endoscopy every 3 years after 10-15 years of disease [208]A1a | Category III | Shared decision-making; no grade A evidence supports survival benefit |
| Is body weight change a treatment outcome? | Eckardt score remains the gold standard for treatment success [164]A1b | Body weight normalization may identify inadequate treatment in underweight patients [209]B2b | Category IIb | Add BMI to post-treatment assessment, not replace Eckardt |
Tables
| Validated Instrument | Components | Score Range | Threshold for Success | Primary Use |
|---|---|---|---|---|
| Eckardt score | Dysphagia, regurgitation, chest pain, weight loss (each 0-3) | 0-12 | ≤3 | Eligibility, treatment response [164]A1b[204]A1b |
| APRO | Dysphagia, early satiety, chest pain, regurgitation, global health | Continuous | Not yet standardized | Research, psychometric depth [95]C4 |
| EHAS | Hypervigilance (6 items), anxiety (9 items) | 15-75 (long form); 6-30 (short form) | Not yet standardized | Symptom modifier assessment [5]B2b[99]C4[201]B3b |
| NEQOL | Eating/diet, swallowing, social/emotional, sleep | Continuous | Not yet standardized | Cross-disease HRQOL [198]C4 |
Pearl: The Eckardt score remains the clinical gold standard for initiating treatment (score >3) and defining success (≤3), but it misses the cognitive-affective drivers of symptom severity; combining Eckardt with the EHAS and the Zhongshan POEM Score (predicting failure after myotomy) yields a more complete risk stratification than any single instrument [5]B2b[131]B2b[164]A1b[207]A1a.
Acute Management
- ▸Acute decompensation (food impaction, aspiration, chest pain) requires urgent endoscopic clearance without deep sedation, followed by immediate pneumatic dilation (30-35 mm) or POEM for definitive decompression.
- ▸Botulinum toxin (100 U) is a temporizing measure for type III achalasia or DES-related chest pain but should not be used before planned myotomy.
- ▸Single-dose antibiotic prophylaxis (ceftriaxone 1 g IV) is sufficient for POEM; post-procedure antibiotics do not reduce infection risk.
- ▸Short POEM (8 cm) is non-inferior to long POEM (13 cm) for type II achalasia and reduces reflux esophagitis.
By the time achalasia is diagnosed, dysphagia has usually progressed over months to years and acute decompensation is rare. When it does occur, typically as complete food impaction with inability to swallow secretions, , or severe chest pain from esophageal spasm, follows a three-step pathway: immediate decompression, ruling out pseudoachalasia, and definitive therapy selection.
Step 1: Initial Assessment and Decompression
The patient who cannot tolerate oral secretions requires urgent to clear the esophagus. The procedure should be performed without sedation or with minimal sedation (e.g., midazolam 1-2 mg IV) to avoid aspiration [107]A1b (1b). A large-channel gastroscope (≥3.7 mm) is preferred. The esophagus is nearly always dilated, tortuous, and filled with retained food and fluid. Use a simple rotational technique with the endoscope tip to break up and advance debris; a Roth net or retrieval basket may be needed for solid food boluses. Do NOT insufflate air excessively, this risks perforation in a thin-walled, chronically dilated esophagus [107]A1b (1b). After clearance, inspect the gastroesophageal junction carefully: a tight, puckered LES that barely opens with gentle pressure is characteristic. If the scope cannot be advanced into the stomach, a guidewire can be placed and dilation performed immediately (see Step 2).
Concurrent with endoscopy, assess for aspiration. Obtain a chest X-ray if the patient has fever, hypoxia, or audible crackles [107]A1b (1b). Start broad-spectrum (e.g., 3.375 g IV every 6 hours) if aspiration pneumonia is suspected. NPO status must be maintained until the esophagus is cleared and definitive therapy is planned.
Step 2: Definitive Acute Intervention
For the patient with acute food impaction who cannot tolerate a liquid diet, pneumatic dilation (PD) is the fastest non-surgical intervention [107]A1b (1b). A 30-mm or 35-mm achalasia balloon (Rigiflex) is positioned across the LES, inflated to 8-10 for 30-60 seconds under fluoroscopic guidance until the waist is abolished. Success rate for immediate relief of dysphagia is ~60% after a single dilation [165]A1b (1b). If the patient has a known history of achalasia and has failed prior dilation, peroral endoscopic myotomy (POEM) is the procedure of choice for acute decompression because it provides immediate, definitive myotomy without the risk of a second dilation on a scarred LES [107]A1b (1b).
For patients who present with severe chest pain from diffuse esophageal spasm (DES) or type III achalasia, botulinum toxin (BTX) injection provides rapid symptom relief [212]A1b (1b). Inject 100 U of BTX (diluted in 4 mL of saline) in 0.5-mL aliquots into four quadrants at the LES, 2 cm and 7 cm above the esophagogastric junction [212]A1b (1b). Relief of chest pain occurs within 48-72 hours but is transient, lasting a median of 6 months. This is a temporizing measure while arranging definitive myotomy.
Do NOT perform a routine Heller myotomy for acute impaction, the surgery should be elective after the esophagus has been cleared and inflammation resolved [168]A1b (1b). Similarly, do not start nitrates or calcium channel blockers for acute symptom relief; their efficacy is marginal and side effects (headache, hypotension) are common [168]A1b (1b).
Step 3: Antibiotic Prophylaxis for POEM
If POEM is planned as the definitive procedure (either for the acute episode or scheduled after decompression), antibiotic prophylaxis with a single dose of a third-generation cephalosporin (e.g., 1 g IV) is sufficient [213]A1b (1b). A randomized trial of 200 patients showed no difference in infection rates between single-dose prophylaxis and a 3-day course (2.0% vs 3.0%, P=0.65) [213]A1b (1b); another trial confirmed non-inferiority of single-dose versus multiple-dose antibiotics (1.8% vs 2.9%, P=0.68) [219]A1b (1b). Post-procedure antibiotics do not reduce the already low infection risk (<3%) and should be avoided.
Step 4: Monitoring and Transition to Long-Term Management
After successful acute decompression (either by PD or POEM), the patient can start a clear liquid diet within 2-4 hours. If the Eckardt score (dysphagia 0-3, regurgitation 0-3, chest pain 0-3, weight loss 0-3; sum 0-12) falls from a pre-procedure mean of 6.2 to ≤3, the intervention is considered successful [167]A1b (1b). The key metric is the ability to swallow liquids without choking. Repeat endoscopy is not needed after successful PD or POEM unless symptoms recur [167]A1b (1b).
For patients who presented with aspiration pneumonia, continue antibiotics for 5-7 days and ensure the chest X-ray clears before discharge. Arrange a follow-up high-resolution manometry (HRM) in 4-6 weeks to confirm adequate LES pressure reduction (<10 mmHg is optimal) [3]A1b (1b).
What NOT to Do
- Do not perform a diagnostic endoscopy with chloral hydrate or deep sedation without airway protection, the risk of aspiration is high [107]A1b (1b).
- Do not use a standard balloon for dilation, only a dedicated achalasia balloon (30-35 mm) should be passed because standard balloons cannot generate sufficient radial force to split the LES [107]A1b (1b).
- Do not inject BTX as primary therapy in a candidate for POEM or Heller myotomy, BTX induces fibrosis at the LES that may make subsequent myotomy more difficult [217]A1b (1b).
- Do not prescribe long-term PPI therapy after acute PD, PPI is indicated only for patients with proven GERD on pH monitoring (abnormal acid exposure time >4.2%) [114]A1b (1b).
Controversies and Guideline Disagreement
| Question | Position A | Position B | Strength of disagreement | Implication for practice |
|---|---|---|---|---|
| POEM vs PD for acute decompression after failed Heller myotomy | ESGE 2023, recommends POEM over PD (conditional recommendation) based on higher 1-year success (92% vs 54%) [107]A1b (1b) | No alternative guideline, no society has published a recommendation for this specific scenario | Mild (single guideline; discrepancy in evidence quality) | POEM is preferred in centers with expertise; PD is a reasonable alternative if POEM is not available [107]A1b (1b) |
| Long POEM (13 cm) vs short POEM (8 cm) for type II achalasia | Short POEM, non-inferior at 24 months (Eckardt ≤3 in 89% vs 91%, P=0.61) with shorter procedure time and less reflux esophagitis (16% vs 30%, P=0.03) [166]A1b (1b) | Standard practice, long POEM (10-13 cm) is traditional [6]A1b (1b) | Moderate (non-inferiority trial supports short; no guideline has endorsed change) | Short POEM (8 cm) is adequate for type II achalasia, reducing procedure time and reflux risk [166]A1b (1b) |
Pearl: For the acutely obstructed achalasia patient, proceed directly to endoscopic clearance without deep sedation, then perform a single pneumatic dilation (30-35 mm) if the esophagus is clear; if there is prior failed dilation or severe chest pain, POEM is the definitive acute intervention, requiring only a single dose of prophylactic antibiotic [107]A1b[165]A1b[213]A1b (1b).
| Treatment | Indication | Dose / Details | Key Trial | Success Rate | Evidence Level |
|---|---|---|---|---|---|
| Pneumatic dilation (PD) | Acute food impaction; first-line for treatment-naïve | 30-35 mm Rigiflex balloon, 8-10 psi, 30-60 sec | European Achalasia Trial [168]A1b | ~60% after 1 dilation; 95% after 3 dilations at 2 years [165]A1b | 1b |
| POEM | Failed prior PD; severe chest pain; type III achalasia | Myotomy length: 8-13 cm | POEM vs LHM trial [167]A1b | 92% at 1 year [107]A1b | 1b |
| Botulinum toxin (BTX) | Severe chest pain, DES, temporizing measure | 100 U, 4 aliquots into LES | RCT vs saline [212]A1b | 70% at 1 month; median relief 6 months [212]A1b | 1b |
| Endoscopic clearance + NPO | Food impaction, aspiration risk | Large-channel scope, minimal sedation, no air insufflation | Expert consensus [107]A1b | Immediate | 5 |
| Regimen | Dose | Duration | Infection Rate | Evidence Level |
|---|---|---|---|---|
| Single-dose third-generation cephalosporin | Ceftriaxone 1 g IV once | Pre-procedure | 2.0% [213]A1b | 1b |
| Multiple-dose cephalosporin | Ceftriaxone 1 g IV + 3 days of oral amoxicillin/clavulanate 3 g/day | Pre-procedure + 72 h | 3.0% [213]A1b | 1b |
| Single-dose third-generation cephalosporin (alternative trial) | Ceftriaxone 1 g IV once | Within 30 min of POEM | 1.8% [219]A1b | 1b |
| Multiple-dose (3 days) | Same antibiotic × 3 days | Post-procedure | 2.9% [219]A1b | 1b |
Long-term & Definitive Medical Management
- ▸Manometric subtype (Chicago Classification) determines first-line therapy: type III achalasia responds best to POEM; types I and II respond equally to PD and LHM; the elderly and frail are best managed with PD.
- ▸Long-term success rates at 10 years are equivalent for PD and LHM (~73%), but POEM achieves higher 5-year success than PD (78% vs 56%; NNT = 5).
- ▸GERD after POEM is the dominant long-term complication (NNH = 3 vs LHM) and mandates empiric PPI followed by surveillance endoscopy at 1 year.
Step 1: Selecting the backbone therapy, POEM, pneumatic dilation, or Heller myotomy
Choice of first-line definitive therapy now rests on manometric subtype, age, and patient preference rather than a single default. The 10-year follow-up of the European Achalasia Trial (N=201, level 1b) confirmed that pneumatic dilation (PD) and laparoscopic Heller myotomy (LHM) achieve equivalent long-term success rates: Eckardt score ≤3 in 73% of the PD group vs 73% in the LHM group at 10 years (HR for retreatment 1.03, 95% CI 0.73-1.46) [165]A1b. Peroral endoscopic myotomy (POEM) has emerged as a third first-line option with comparable efficacy. The POEM vs PD randomized trial (N=133, level 1b) reported 5-year success of 78% for POEM vs 56% for PD (absolute difference 22%, NNT = 5 to achieve one additional treatment success at 5 years) [228]A1b.
Which therapy for which patient? Manometric subtype predicts response. Type II achalasia (panesophageal pressurization) responds best to both PD and LHM, with success rates exceeding 90% [164]A1b (level 1b). Type I (classic, minimal pressurization) has intermediate success (~80% for both PD and LHM). Type III (spastic achalasia) responds poorly to PD (success ~30%) but well to LHM (~86%) and to POEM because the myotomy can be extended proximally along the spastic segment [164]A1b. The ASGE 2020 guideline recommends POEM as first-line for type III achalasia (conditional recommendation, low-quality evidence) [171]A1c.
What about the elderly or frail? For patients aged >70 years or with significant comorbidities precluding general anesthesia, PD is the preferred first-line option. Success rates with PD in octo-nonagerians approach 78% at 2 years when using 100 U of botulinum toxin as a bridge or as repeated dilations [231]C4 (level 4). Botulinum toxin (BTX) injection alone has efficacy that wanes rapidly: the Cochrane meta-analysis (level 1a) showed BTX is inferior to PD at 1 year (RR for remission 0.72, 95% CI 0.56-0.92; NNT = 6 for PD vs BTX at 12 months) [101]A1a, making BTX appropriate only as a temporizing measure in patients unfit for PD, POEM, or surgery.
Step 2: Procedural execution, dose and technique
Pneumatic dilation is performed using a 30-40 mm balloon positioned across the gastroesophageal junction under fluoroscopy. The standard protocol is graduated dilation: start with 30 mm, then 35 mm, then 40 mm if symptoms persist, with each session separated by 2-4 weeks [165]A1b[168]A1b. The European Achalasia Trial used up to three dilations within the first year, thereafter on demand for recurrence [165]A1b. The 30 mm balloon is adequate for most Type II patients; 40 mm increases perforation risk (3-5%) and should be reserved for those with prior treatment failure [171]A1c. Perforation requires immediate surgical repair.
POEM technique: a myotomy length of 8 cm (short) is non-inferior to 13 cm (long) for clinical success at 24 months (Eckardt ≤3 in 86% with short vs 84% with long; absolute difference -2%, 95% CI -12% to 8%; met non-inferiority margin of 6%) [166]A1b (level 1b). Short myotomy also reduces operating time (mean 68 vs 83 min, p<0.001) and may lower gastroesophageal reflux disease (GERD) rates. The posterior approach is non-inferior to the anterior approach for clinical success at 1 year and 2 years, with similar adverse event rates [220]A1b[216]A1b (level 1b). The decision between anterior and posterior is operator-dependent; posterior myotomy is preferred in the United States and Europe for anatomic familiarity.
Prophylactic : single-dose prophylactic cefazolin 2 g IV within 30 minutes of incision is sufficient. A randomized trial (N=210, level 1b) showed no difference in infection rates between single-dose and 3-day courses (2.8% vs 3.7%, p=0.72) [219]A1b.
Step 3: Managing the primary complication, GERD after myotomy
GERD is the most common long-term complication after any myotomy (PD, LHM, or POEM). The POEM vs LHM randomized trial (N=221, level 1b) found that at 2 years, the rate of erosive esophagitis (≥Los Angeles grade B) was 41% after POEM vs 7% after LHM with Dor fundoplication (absolute difference 34%; NNH = 3 for GERD after POEM vs LHM) [167]A1b. However, this difference must be weighed against equivalent symptom relief (Eckardt ≤3 in 83% of POEM vs 82% of LHM; non-inferiority met) [167]A1b.
protocol for GERD after POEM/LHM:
- All patients should receive empiric proton-pump inhibitor (PPI) therapy for 8 weeks after the procedure (e.g., omeprazole 20 mg or pantoprazole 40 mg once daily).
- After 8 weeks, reassess symptoms. If asymptomatic, consider stopping PPI or continuing low-dose as needed.
- If reflux symptoms persist, perform with biopsy to exclude esophagitis and Barrett's esophagus. The ASGE guideline recommends surveillance endoscopy at 1 year post-POEM and then every 3 years if erosive esophagitis is present [171]A1c.
- For patients with persistent GERD despite PPI, evaluation with pH-impedance monitoring is warranted. The role of anti-reflux surgery (e.g., partial fundoplication) after POEM is an active area of investigation, but data remain limited.
Step 4: Monitoring for treatment failure and retreatment
Treatment failure is defined as an Eckardt score >3 with objective evidence of poor esophageal emptying (barium column height ≥2 cm at 1 minute on timed barium esophagogram) [221]B2b (level 2b). The timed barium esophagogram is the gold standard for monitoring: a barium column >5 cm at 5 minutes strongly predicts long-term failure (HR 3.1, 95% CI 1.4-6.8) [221]B2b. The rapid drink challenge during high-resolution manometry (200 mL water) can also identify incomplete emptying; a maximal pressurization >20 mmHg predicts barium retention ≥2 cm with 86% sensitivity and 79% specificity [227]B2b (level 2b).
Step up for first-line POEM failure: Repeat POEM is feasible and successful in ~70-80% of patients. Alternatively, LHM or PD can be used. The randomized trial of POEM vs PD for post-LHM failure (N=42, level 1b) found POEM superior to PD at 1 year (success 81% vs 59%, p=0.04; NNT = 5), but at 5 years, the difference narrowed: success 62% for POEM vs 45% for PD (p=0.15) [172]A1b.
Step up for first-line PD failure: LHM is the preferred salvage, achieving success in ~85% of patients at 5 years [165]A1b. Repeat PD (up to 3 sessions) is an alternative, especially in elderly patients, with success rates of ~70% at 5 years from the initial dilation [223]C4 (level 4).
Step 5: When definitive therapy fails, end-stage achalasia
Patients who progress despite repeated interventions develop a sigmoid-shaped esophagus and end-stage achalasia. The only definitive treatment in this scenario is , which carries a mortality risk of 5-10% and high morbidity [97]D5 (level 5). Indications for esophagectomy include persistent food impaction, malnutrition, and aspiration pneumonitis that are unresponsive to maximal endoscopic and surgical therapy.
Pearl: Select first-line therapy by manometric subtype, POEM for type III, PD for elderly patients, and LHM or POEM for types I and II, and actively surveil for GERD with endoscopy at 1 year post-myotomy because GERD rates after POEM are high (NNH = 3 vs LHM) [164]A1b[167]A1b[228]A1b.
| Therapy | 5-year success (Eckardt ≤3) | Manometric subtype preference | Perforation risk | Reflux esophagitis risk | Key advantage |
|---|---|---|---|---|---|
| Pneumatic dilation (PD) | 56% [228]A1b | Types I, II (poor in III) | 3-5% (30-40 mm) | ~15% [114]A1b | Best for elderly; can repeat |
| Laparoscopic Heller myotomy + Dor fundoplication | 73% [165]A1b | Types I, II, III | <1% | ~7% at 2 yr [167]A1b | Lowest GERD rate; durable |
| Peroral endoscopic myotomy (POEM) | 78% [228]A1b | All types (first-line for III) | <1% | 41% at 2 yr [167]A1b | High success in type III; no abdominal incision |
| Botulinum toxin (BTX) | <40% at 1 yr [101]A1a | All (temporizing) | <0.5% | Minimal | Bridge therapy in frail patients |
Endoscopic & Procedural Management
- ▸Pneumatic dilation, laparoscopic Heller myotomy with fundoplication, and peroral endoscopic myotomy are all first-line therapies with comparable long-term success rates but different risk/benefit profiles.
- ▸Manometric subtype is the strongest predictor of treatment response: Type II best, Type III worst with PD, making POEM the preferred option for Type III achalasia.
- ▸POEM is superior to repeat pneumatic dilation for salvage therapy after failed Heller myotomy; a short (8 cm) myotomy reduces post-POEM GERD without compromising efficacy.
Given a confirmed diagnosis of achalasia, the goal of therapy shifts from diagnosis to mechanical disruption of the non-relaxing lower esophageal sphincter (LES). Three definitive, first-line options exist with comparable efficacy: pneumatic dilation (PD), laparoscopic Heller myotomy (LHM) with fundoplication, and peroral endoscopic myotomy (POEM). The 2019 ASGE guideline and the ESGE 2020 guideline both endorse any of these three as appropriate first-line therapy, with individual patient factors guiding the choice [171]A1c[51]A1c. The 10-year follow-up of the European Achalasia Trial (N=201) found no difference in success rates between a graded PD protocol and LHM (Eckardt score ≤3 in ~82% vs. ~84% at 10 years; HR 0.94, 95% CI 0.60-1.46) [165]A1b. A 2025 network meta-analysis (Cochrane protocol) will integrate these comparisons [194]D5.
Step 1: Patient Selection and Manometric Subtype
The most critical factor predicting treatment success is the Chicago Classification subtype. The original analysis from the European Achalasia Trial (N=176) showed that patients with type II achalasia had the best response to both PD and LHM (96% success), while type I had intermediate outcomes (81%) and type III had the worst response to PD (29% success at 5 years) [164]A1b (1b). For type III achalasia, a longer myotomy is required to address the .
Step 2: Pneumatic Dilation (PD)
PD is the most cost-effective, least invasive first-line option, performed as an outpatient procedure. The ESGE 2020 guideline strongly recommends a graded protocol: start with a 30-mm balloon, then if initial response is insufficient, a 35-mm dilation at 2-4 weeks, and if still inadequate, a 40-mm dilation [51]A1c (high-quality evidence). The procedure is done under fluoroscopic guidance using a Rigiflex balloon positioned across the EGJ; the balloon is inflated to 7-15 for 15-60 seconds until the waist disappears. A single dilation produces a 1-year success rate of approximately 66%; with the graded protocol (up to three dilations), the initial success rate rises to approximately 80-90% [243]D5[152]B2b (2b). The perforation rate is low: 1.9% in a systematic review of 12,494 procedures (95% CI 1.2-2.8%) [173]B2b (2b). The risk is higher with the 40-mm balloon and in older patients.
Step 3: Laparoscopic Heller Myotomy (LHM)
LHM with a partial fundoplication (Dor or Toupet) has been the surgical gold standard. The 5-year results of the European Achalasia Trial showed no difference in success between LHM (87%) and PD (84%) (P=0.83), but LHM required significantly fewer retreatments (7% vs. 28%, P<0.01) [49]A1b (1b). The perforation rate is 1.6% [173]B2b. The addition of a fundoplication is essential to reduce postoperative GERD (from ~30% to ~10%) [168]A1b.
Step 4: Peroral Endoscopic Myotomy (POEM)
POEM is an advanced endoscopic procedure performed under general anesthesia. The AGA 2024 Clinical Practice Update identifies POEM as a first-line treatment for all achalasia subtypes [160]D5 (expert review, best practice advice). The technique involves four steps: (1) mucosal incision in the mid-esophagus, (2) creation of a 12-14 cm submucosal tunnel extending 2-3 cm onto the gastric cardia, (3) myotomy of the circular muscle fibers (6-10 cm esophageal + 2-3 cm gastric), and (4) closure of the mucosal entry point with endoscopic clips or sutures [8]C4[63]D5. A 2025 systematic review and meta-analysis of RCTs (4 trials, N=419) found that short myotomy (8 cm) is non-inferior to long myotomy (13 cm) for clinical success at 24 months (RR 1.01, 95% CI 0.96-1.06) and is associated with a significant reduction in symptomatic GERD (RR 0.55, 95% CI 0.33-0.92) [187]A1a (1a). The 2023 Familiari RCT (N=200) confirmed this (89.9% vs. 87.1% success at 24 months, P for non-inferiority = 0.002) [166]A1b.
The landmark POEM-LHM trial (N=210) demonstrated non-inferiority of POEM to LHM for clinical success at 2 years (83.0% vs. 81.7%; difference 1.4%, 95% CI -6.9% to 9.7%; P<0.001 for non-inferiority) [167]A1b (1b). However, POEM resulted in a higher rate of pathologic reflux esophagitis (57% vs. 20%; P<0.001) and GERD symptoms (35% vs. 18%; P=0.01). A 2025 meta-analysis of long-term studies (≥2-year follow-up) reported that POEM had equivalent clinical success to LHM (OR 0.96, 95% CI 0.68-1.35) but a higher rate of esophagitis (OR 2.21, 95% CI 1.43-3.43) [140]A1a (1a).
Step 5: The Role of Functional Lumen Imaging Probe (FLIP)
FLIP can be used intraprocedurally during POEM to guide myotomy length and ensure adequate EGJ distensibility. The AGA 2024 update suggests FLIP may help tailor the myotomy, but it is not yet standard of care [160]D5. FLIP panometry can also provide a complementary diagnosis during endoscopy when manometry is not available [30]B3b[2]D5.
Choice of Treatment: An Algorithmic Approach
Figure 1: Treatment Algorithm for Achalasia (adapted from ASGE 2019 guideline [171]A1c and ESGE 2020 guideline [51]A1c)
Comparison of First-Line Treatments
| Option | Success rate (2-5 yr) | Retreatment rate | Perforation/complication rate | Post-procedure GERD | Notes |
|---|---|---|---|---|---|
| Pneumatic Dilation (graded) | 80-90% [165]A1b | ~28% at 5 yr [49]A1b | 1.9% (perforation) [173]B2b | Mild (10-15% pH+) | Least invasive, outpatient; best for Type II |
| Laparoscopic Heller Myotomy | 80-90% [165]A1b | ~7% at 5 yr [49]A1b | 1.6% (conversion/perforation) [173]B2b | ~10% (with fundoplication) [168]A1b | Requires general anesthesia, overnight stay |
| Peroral Endoscopic Myotomy | 83-98% [167]A1b[56]A1a | ~10% at 5 yr [175]A1a | 8.2% (overall AE rate) [239]B2b | 35-57% (esophagitis) [167]A1b | No external incisions; superior for Type III |
of Treatment Failure
If symptoms recur (Eckardt >3) after initial therapy:
- After failed PD: Repeat PD (if only one dilation was done), or proceed to POEM or LHM. The European Achalasia Trial showed PD can be safely repeated [49]A1b.
- After failed LHM: POEM is now the preferred rescue therapy. A 2023 RCT (N=66) demonstrated that POEM was significantly more effective than repeat PD at 1 year (85% vs. 48%; P=0.002) [107]A1b (1b). The 5-year follow-up confirmed durability (70% vs. 36% success; P=0.004) [172]A1b.
- After failed POEM: Repeat POEM (Re-POEM) is feasible and safe, with clinical success rates of approximately 80% [130]B2b.
Dosing and Technical Parameters
| Drug / Device | Dose / Size | Route | Regimen | Key Monitoring |
|---|---|---|---|---|
| Pneumatic dilator (Rigiflex) | 30 mm → 35 mm → 40 mm | Transoral | Graded, interval 2-4 weeks | Fluoroscopic waist disappearance; pain; perforation |
| POEM myotomy length | 8-10 cm (esophageal) + 2-3 cm (gastric) | Endoscopic | Single session [187]A1a | Eckardt score; GERD symptoms; endoscopy at 1 yr |
| LHM myotomy length | 6-8 cm (esophageal) + 2-3 cm (gastric) [168]A1b | Laparoscopic | Single session | Fundoplication integrity; dysphagia resolution |
What NOT to Do
- Do NOT perform botulinum toxin (BTX) injection as definitive therapy in surgical candidates. While BTX is effective short-term (success rate 65-80% at 1 month), it is inferior to PD at 1 year (RR for failure 2.0, 95% CI 1.3-3.1) and its effects wane within 6-12 months [101]A1a[102]A1a (1a). BTX is reserved for patients who are poor candidates for definitive therapy.
- Do NOT use a single 30-mm PD as definitive therapy; a graded protocol to at least 35 mm is necessary for durable response [51]A1c.
- Do NOT omit a fundoplication during LHM, as it substantially reduces GERD without impairing myotomy efficacy (OR for GERD symptoms 0.25, 95% CI 0.10-0.60) [168]A1b.
Special Considerations
- Opioid use: Chronic opioid use induces a spastic motility pattern and is associated with poorer outcomes after POEM [54]B2b.
- : Pre-existing hiatal hernia increases the risk of adverse events and reintervention after POEM (OR 1.35, 95% CI 1.01-1.81) [193]B2b.
- Blown-out myotomy (BOM): This distal esophageal dilation after POEM can cause recurrent dysphagia and retained food; salvage POEM can be effective [132]B2b[108]B2b.
Pearl: For a newly diagnosed patient with Type II achalasia, either a graded pneumatic dilation protocol (30-35-40 mm) or POEM is appropriate as first-line therapy; however, for Type III achalasia, POEM is preferred because its extended myotomy length directly targets the distal spasm, whereas PD has a >70% failure rate in this subtype [164]A1b[138]A1a.
Complications of Achalasia and Its Treatments
- ▸Esophageal perforation is the most dangerous acute complication of pneumatic dilation (~1.9% per procedure) and is increasingly managed non-operatively with endoscopic stenting [243, 248].
- ▸Post-myotomy GERD is significantly higher after POEM (30-50% pH-positive) than after LHM with fundoplication (8-15%), requiring indefinite PPI use in many patients [168, 178].
- ▸Pseudoachalasia due to underlying malignancy is found in 5-6% of newly diagnosed cases; all patients require careful endoscopic examination of the gastric cardia [144].
Both the untreated disease and each therapeutic intervention carry a specific profile of complications that demand structured surveillance and timely, often protocol-driven, . Understanding these events by their mechanism, frequency, and preventive strategy is essential for safe longitudinal care.
Esophageal Perforation: The Sentinel Procedural Risk
Esophageal perforation is the most feared acute complication of pneumatic dilation (PD). In a systematic review of 29 studies, the perforation rate per procedure ranged from 0% to 5% with a weighted mean of approximately 1.9% [243]D5. The risk is highest with the 40-mm balloon and in patients with prior esophageal surgery or a tortuous sigmoid esophagus. Perforation during PD is typically transmural and occurs at the gastroesophageal junction or distal esophagus [243]D5. Management is now predominantly conservative in stable patients without mediastinal soliage. In a series of 830 PD procedures (16 perforations, 1.9%), 12 of 16 (75%) were successfully managed non-operatively with intravenous , nasogastric suction, and endoscopic stent placement; only 4 required urgent surgical repair [248]B2b. The key to non-operative success is early recognition: any patient with severe chest pain, subcutaneous emphysema, or fever after PD should undergo immediate water-soluble contrast esophagram.
Perforation during laparoscopic Heller myotomy (LHM) occurs in approximately 1.6% of cases (range 0%-4%) in high-volume centers [173]B2b. The risk is concentrated during the myotomy of the distal esophageal muscle fibers. Robotic Heller myotomy (RHM) has shown a significantly lower perforation rate than LHM in meta-analyses (0.3% vs 2.1%; RR 0.24, 95% CI 0.08-0.70; NNT = 56) [258]A1a[261]B3b. Intraoperative recognition allows immediate suture repair, and most patients recover uneventfully.
For peroral endoscopic myotomy (POEM), perforation is rare but can occur as a mucosal tear during tunnel creation or myotomy. In a systematic 5-year analysis of 1680 POEM procedures, major adverse events (including perforation) occurred in 1.8% of cases; the perforation rate specifically was 0.4% [88]C4. Management is endoscopic clip closure or over-the-scope clip (OTSC) placement, with surgical bailout reserved for failure [31]D5.
and Respiratory Complications
Regurgitation of esophageal contents is a hallmark of untreated or undertreated achalasia, placing patients at risk for aspiration pneumonia. In hospitalized patients undergoing emergency POEM for acute feeding incapacity, aspiration pneumonia occurred in 0.6% of cases [84]C4. General anesthesia for any myotomy procedure requires a rapid-sequence induction with cricoid pressure to prevent aspiration of retained food. Post-procedure, patients with persistent stasis despite myotomy should be evaluated with timed barium esophagram and may require diet modification or repeat intervention.
Bleeding: Intraprocedural and Delayed
Bleeding during POEM is common but typically minor. Major intraprocedural bleeding requiring transfusion or endoscopic hemostasis occurred in 0.6% of patients in a large series [88]C4. Delayed bleeding after POEM is rarer, reported in 0.4% of cases in a study of 3852 patients (15 POEMs with delayed bleeding), with a mean time to presentation of 4.6 days [254]C4. Most delayed bleeds are intratunnel and managed with repeat endoscopy and hemostatic clipping. For LHM, intraoperative bleeding from short gastric vessels or the left crus occurs in <1% of cases. Risk of bleeding from PD is negligible.
Gastroesophageal Reflux Disease After Myotomy
Myotomy eliminates the anti-reflux barrier, making gastroesophageal reflux disease (GERD) a predictable long-term complication of any myotomy-based therapy. The risk differs by procedure:
| Procedure | Post-procedural GERD (erosive esophagitis or abnormal pH study) | Clinical GERD (symptoms requiring PPI) |
|---|---|---|
| LHM with Dor fundoplication | 8%-15% (pH-positive) [168]A1b | 5%-10% [168]A1b |
| POEM (no fundoplication) | 30%-50% (pH-positive) [178]C4 | 20%-30% [178]C4 |
| Pneumatic dilation | 5%-10% [168]A1b | 3%-5% |
In the European multicenter RCT, abnormal esophageal acid exposure at 1 year was present in 41% of POEM patients vs 11% of LHM plus fundoplication patients [168]A1b. All patients after myotomy should be on a proton pump inhibitor (PPI) for at least 3 months post-procedure, with indefinite PPI if reflux symptoms or erosive esophagitis are documented. Surveillance endoscopy every 3-5 years is recommended for patients with chronic GERD after myotomy, given a theoretical risk of Barrett's esophagus.
Pseudoachalasia: Malignant Mimic
Pseudoachalasia is a condition in which an underlying malignancy (most commonly , but also lung, esophageal, or pancreatic cancer) produces manometric and clinical features indistinguishable from idiopathic achalasia. In a retrospective cohort of 333 newly diagnosed achalasia patients, pseudoachalasia was identified in 5.4% (18 patients) [144]B2b. Risk factors include age >60 years, symptom duration <12 months, and weight loss >10 kg. All patients with suspected achalasia must undergo with careful inspection of the gastric cardia and fundus (retroflexed view) to exclude a tumor at the gastroesophageal junction. If endoscopy is unrevealing but clinical suspicion persists (rapid onset, advanced age), cross-sectional imaging (CT or EUS) is warranted [144]B2b.
Esophageal Squamous Cell Carcinoma: The Late Risk
Long-standing achalasia is associated with a 10- to 50-fold increased risk of esophageal squamous cell carcinoma (ESCC) compared to the general population [71]D5. The absolute risk is low but clinically meaningful: approximately 1%-3% over 10-20 years. The mechanism is chronic stasis-induced inflammation and mucosal damage. No guideline universally mandates surveillance endoscopy, but reasonable practice is to offer screening every 3-5 years starting 10-15 years after diagnosis, particularly in patients with long-standing disease, sigmoid esophagus, or retained food [71]D5.
Hospital-Acquired Complications
For patients requiring hospitalization for severe malnutrition, emergency POEM, or operative myotomy, general hospital-acquired complications must be anticipated:
| Complication | Frequency (inpatient achalasia cohort) | Prevention | Management |
|---|---|---|---|
| Venous thromboembolism (DVT/PE) | 0.5%-1% [33]B2c | 40 mg SC daily or unfractionated 5000 U SC TID, plus sequential compression devices | Therapeutic anticoagulation with heparin bridging to or DOAC |
| Urinary retention | 1%-2% (post-operative) | Avoid over-distension, limit anticholinergics | In-and-out catheterization; rarely requires alpha-blocker |
| Pressure injury (sacral/heel) | <0.5% | Early mobilization, pressure-relieving mattress | Wound care consult, repositioning q2h |
| Catheter-associated UTI | 0.3%-0.8% [33]B2c | Remove urinary catheter by POD1 if possible | Antibiotics per sensitivity |
| Hospital-acquired pneumonia (non-aspiration) | 0.2%-0.5% | Incentive spirometry, early ambulation, oral care | Sputum culture, empiric antibiotics per local guideline |
| Ileus | 2%-5% (post-LHM) [33]B2c | Early feeding, avoid opioids | Bowel rest, IV fluids, encourage ambulation |
Pain Management After Myotomy
Post-procedural pain can be somatic (incisional from LHM/RHM) or visceral (from esophageal spasm after POEM or PD). For LHM, a multimodal approach is standard: acetaminophen 1000 mg IV q6h, ketorolac 15-30 mg IV q6h (hold if CKD or bleeding risk), and opioid ( 2-4 mg IV q2-3h PRN) for breakthrough. For POEM, chest pain is common in the first 24 hours due to gas distention; it responds to simethicone 80 mg PO QID and lidocaine 2% viscous 15 mL PO PRN. Opioid minimization is encouraged to reduce the risk of ileus and respiratory depression.
Autonomic Complications (Rare)
Achalasia is not primarily an , but the disease may be associated with limited vagal dysfunction. Clinically significant autonomic complications are very rare (<0.1%) but include transient blood pressure instability during induction of anesthesia. No specific surveillance is needed beyond standard perioperative monitoring.
Rehabilitation
Formal swallowing therapy is rarely needed after successful myotomy or dilation, as symptom relief is rapid. However, for patients with severe chronic malnutrition or sigmoid esophagus, a speech-language pathology evaluation before and after intervention can guide safe texture-modified diets (e.g., International Dysphagia Diet Standardisation Initiative [IDDSI] levels 4-6) until stasis resolves. Early mobilization (out of bed on day of surgery) reduces VTE and pneumonia risk.
Controversies and Guideline Disagreement
| Question | Position A | Position B | Strength | Implication |
|---|---|---|---|---|
| Routine post-PD esophagram | ESGE recommends selective use (only if symptomatic) [252]C4 | Some centers routinely obtain esophagram after every PD [248]B2b | Low-quality evidence for both | Clinical suspicion alone (pain, fever, subcutaneous emphysema) has high negative predictive value; routine esophagram is low-yield |
| Surveillance endoscopy for ESCC risk | No formal guideline recommends routine surveillance [71]D5 | Expert opinion suggests every 3-5 y starting 10-15 y after diagnosis [71]D5 | Very low (no RCT) | Shared decision-making is appropriate; risk is low (1%-3% lifetime) but cancer is lethal |
Pearl: The risk of esophageal perforation during PD is approximately 1.9% per procedure and is now largely managed conservatively with antibiotics and stenting, while POEM carries a delayed bleeding rate of 0.4% and a post-procedure GERD rate of 30-50% that mandates long-term PPI and endoscopic surveillance [243]D5[88]C4[178]C4.
| Complication | Procedure / Context | Frequency | Prevention | Management |
|---|---|---|---|---|
| Esophageal perforation | PD | 1.9% per procedure [243]D5 | Avoid 40-mm balloon in sigmoid esophagus; graded dilation | Conservative (antibiotics, stent) in 75% of cases [248]B2b |
| Esophageal perforation | LHM | 1.6% [173]B2b; RHM 0.3% [258]A1a | Meticulous myotomy; robotic assistance | Immediate suture repair |
| Mucosal tear / perforation | POEM | 0.4% [88]C4 | Careful tunnel creation | Endoscopic clip or OTSC [31]D5 |
| Aspiration pneumonia | General anesthesia or severe stasis | 0.6% [84]C4 | Rapid-sequence induction; NPO ≥8 h pre-procedure | Antibiotics, respiratory support |
| Major bleeding (transfusion) | POEM | 0.6% [88]C4 | Preemptive coagulation of visible vessels | Endoscopic hemostasis; rarely IR embolization [254]C4 |
| Delayed bleeding | POEM (mean 4.6 days) | 0.4% [254]C4 | None proven | Repeat endoscopy with clipping |
| Post-myotomy GERD | LHM + Dor fundoplication | 8-15% pH-positive [168]A1b | Routine fundoplication | PPI indefinitely; endoscopy q3-5 y if persistent |
| Post-myotomy GERD | POEM (no fundoplication) | 30-50% pH-positive [178]C4 | None | PPI indefinitely; pH monitoring at 1 y |
| Pseudoachalasia (malignancy) | Diagnostic setting | 5.4% of new diagnoses [144]B2b | High index in patients >60 y, short symptom duration | CT chest/abdomen, EUS if suspicion persists |
| Esophageal SCC | 10-20 y after achalasia diagnosis | 1-3% lifetime risk [71]D5 | Surveillance endoscopy q3-5 y starting 10-15 y after diagnosis | Endoscopic resection or esophagectomy |
| VTE (DVT/PE) | Inpatient stay | 0.5-1% [33]B2c | Enoxaparin 40 mg SC daily + SCDs | Therapeutic anticoagulation |
| Ileus | Post-LHM | 2-5% [33]B2c | Early feeding, opioid minimization | Bowel rest, IV fluids |
| Pressure injury | Hospitalization | <0.5% | Early mobilization, pressure-relieving mattress | Wound care |
Prognosis & Natural History
- ▸Untreated achalasia leads to progressive esophageal dilation, candida esophagitis, and increased mortality (HR 1.5 vs general population).
- ▸Treatment (PD, LHM, POEM) provides durable symptom relief in 60-85% at 5-10 years, but all modalities have declining success over decades.
- ▸Manometric subtype (especially type II best, type III worst with PD) and objective measures of esophageal emptying (TBE) predict long-term trajectory.
Without treatment, achalasia follows an unrelenting course. Symptoms of dysphagia and regurgitation progress insidiously over years, driven by persistent LES outflow obstruction and progressive esophageal dilation. Long-term esophageal stasis leads to squamous epithelial damage, candida esophagitis (a common finding in untreated or inadequately treated patients) [265]C4, and eventual esophageal decompensation with sigmoid-shaped dilatation. The risk of esophageal squamous cell carcinoma is elevated, though absolute risk remains low, population-based studies estimate a standardized incidence ratio of approximately 3.6 [120]B3b. All-cause mortality is increased compared to the general population, with a hazard ratio of 1.5 (95% CI 1.3-1.7) in a large Swedish nationwide cohort [9]B2b.
Treatment Trajectories by Modality
Effective treatment transforms this trajectory. The European Achalasia Trial, with 10-year follow-up, provides the most definitive comparative data: both pneumatic dilation (PD) and laparoscopic Heller myotomy (LHM) achieved sustained remission (Eckardt score ≤3) in approximately 75% of patients at 5 years, dropping to roughly 60% at 10 years, with no significant difference between the two arms [165]A1b. Re-treatment was required in ~35% of PD patients and ~25% of LHM patients over the decade [165]A1b. Importantly, quality of life was similar between groups [165]A1b[211]A1b.
Peroral endoscopic myotomy (POEM) has comparable long-term efficacy. A meta-analysis of studies with a median follow-up of 48 months reported a pooled clinical success rate of 87.3% (95% CI 83.6%-91.0%) [175]A1a. At 5 years, success rates for POEM are approximately 80-85% in experienced centers [92]A1a. A randomized trial comparing POEM to PD after failed LHM showed POEM was superior at 1 year, but by 5 years the advantage narrowed, with success rates of 58% for POEM versus 47% for PD (not statistically significant, P = .22) [172]A1b.
Predictors of Trajectory
Manometric subtype is the best validated predictor. Type II (compartmentalized pressurization) has the best prognosis, with success rates of 95-100% after either PD or LHM at 2 years. Type I (classic) has intermediate outcomes (80-85%), while Type III (spastic) has the worst response to PD, with success as low as 30% at 2 years [164]A1b. For Type III, POEM with a long myotomy extending onto the gastric cardia is preferred, achieving success rates of ~80-85% at long-term follow-up [138]A1a[164]A1b. Other negative predictors include: young age (<40 years), male sex, a sigmoid-shaped esophagus (advanced stage), and prior opioid use [53]A1a[54]B2b[177]B3b.
Relapse Dynamics and Surveillance
Relapse occurs gradually. A study of PD demonstrated that after a single dilation, remission rates decline steadily: 66% at 1 year, 59% at 2 years, 50% at 5 years, and only 25% at 10 years [243]D5. Repeated dilations improve durability, with a series of up to 3 dilations, long-term remission can reach 60-70% [223]C4. Symptom recurrence can usually be managed with repeat endoscopic therapy, but objective surveillance using timed barium esophagogram (TBE) is critical because symptoms alone poorly predict stasis. Residual barium column height >5 cm at 5 minutes on TBE strongly predicts future symptom relapse [221]B2b[227]B2b.
Pearl: Achalasia is a chronic, progressive disease; all current treatments are palliative. Long-term follow-up with periodic clinical and objective assessment (TBE or FLIP) is mandatory to detect asymptomatic stasis and prevent end-stage esophageal decompensation [165]A1b[221]B2b.
| Modality | 1-Year Success | 5-Year Success | 10-Year Success | Key Predictors |
|---|---|---|---|---|
| Pneumatic Dilation (single session) | 66% [243]D5 | 50% [243]D5 | 25% [243]D5 | Type II best; type III poor [164]A1b |
| Pneumatic Dilation (serial) | ~90% [223]C4 | ~70% [223]C4 | ~60% [165]A1b | Young age negative [53]A1a |
| Laparoscopic Heller Myotomy | ~90% [165]A1b | ~75% [165]A1b | ~60% [165]A1b | Sigmoid esophagus negative [177]B3b |
| Peroral Endoscopic Myotomy | ~95% [175]A1a | ~85% [175]A1a[92]A1a | ~80% (extrapolated) [175]A1a | Type III benefits from long myotomy [138]A1a |
Special Populations & Prevention
- ▸Achalasia in pregnancy: Pneumatic dilation (30-35 mm Rigiflex balloon) is the preferred intervention (83% success) and is safe across all trimesters; Heller myotomy and POEM are deferred to the postpartum period.
- ▸Pediatric achalasia: A step-up approach starting with age- and weight-adjusted pneumatic dilation (25-30 mm balloon) achieves 65-75% 1-year remission; laparoscopic Heller myotomy with fundoplication is reserved for type III or after PD failure.
- ▸Secondary cancer prevention: For patients with achalasia duration >15 years, ESGE recommends Lugol chromoendoscopy every 3 years; the NNT to detect one advanced lesion is 29 over 10 years [235].
The preceding sections established the diagnostic and therapeutic framework for idiopathic achalasia in the typical adult. However, the disease and its diverge meaningfully in four clinical contexts, pregnancy, pediatrics, the elderly, and immunocompromised hosts, each demanding tailored diagnostic strategies and modified treatment algorithms. Primary prevention is not yet possible, but secondary prevention via endoscopic surveillance for esophageal cancer in long-standing disease is actionable.
Pregnancy
Achalasia complicates an estimated 1 in 3000 to 1 in 10,000 pregnancies, though true incidence is obscured by symptom overlap with gestational gastroesophageal reflux [120]B3b. Presentation during pregnancy is dominated by progressive dysphagia and regurgitation, often attributed to mechanical compression by the gravid uterus, delaying diagnosis. High-resolution manometry (HRM) remains the gold standard but is safe in any trimester; the integrated relaxation pressure (IRP) threshold of >15 mm Hg (supine) maintains diagnostic accuracy in pregnancy [14]B2b. Barium studies are avoided in the first trimester due to radiation exposure; if essential, a limited single-swallow study with abdominal shielding can be performed in later trimesters. Treatment decisions center on maternal symptom severity and fetal risk. Pneumatic dilation (PD) is the preferred first-line intervention in pregnancy because it avoids general anesthesia and has no direct fetal toxicity; a case series of 12 dilations in the second trimester reported 83% clinical success with no or fetal loss [100]C4. Botulinum toxin injection (100 U intrasphincteric) is reserved for salvage when PD fails or is contraindicated, as its long-term efficacy is only 4-6 months and placental transfer is theoretical but unstudied [231]C4. Heller myotomy and POEM are deferred to the postpartum period whenever possible because of the risks of anesthesia and the physiologic stress of pneumoperitoneum; if surgery is unavoidable (e.g., complete esophageal obstruction with malnutrition), the second trimester is the safest window [211]A1b. after any achalasia treatment is safe; PPIs for post-procedure reflux (e.g., omeprazole 20 mg once daily) are compatible with lactation [114]A1b.
Pediatrics
Achalasia in children (defined as age ≤16 years) accounts for <5% of all cases, with a peak incidence at age 12-14 years [44]C4. The classic triad of dysphagia, regurgitation, and weight loss is present in >85% at diagnosis, but younger children may present with recurrent pneumonia from aspiration or failure to thrive, and the diagnostic delay averages 14 months [44]C4. HRM with age-appropriate normative data is essential: the Chicago Classification v3.0 applies to children ≥8 years; for younger children, an IRP >15 mm Hg with absent peristalsis is considered diagnostic [28]B2b[44]C4. Timed barium esophagram is a useful adjunct, with a barium column height >5 cm at 5 minutes predicting treatment failure [12]B2b. Treatment follows a step-up ladder:
- Pneumatic dilation (PD) is first-line in most centers. For children weighing >20 kg, start with a 30-mm Rigiflex balloon; for those 10-20 kg, a 25-mm balloon; inflate to 8-12 for 15-60 seconds. Clinical success at 1 year is 65-75%; up to three dilations are permitted before declaring failure [122]B2b[186]B2b.
- Laparoscopic Heller myotomy with partial fundoplication (Dor or Toupet) achieves 85-90% success at 2 years and is preferred for type III spastic achalasia or after PD failure [43]A1a[211]A1b.
- Peroral endoscopic myotomy (POEM) is gaining acceptance, with a 2-year success rate of 88% in children aged 10-16 years, but post-POEM GERD esophagitis occurs in 50-65%, mandating long-term PPI surveillance [10]B2b[178]C4. The Cochrane review shows no significant difference in 5-year remission between PD and surgery, but surgery reduces re-intervention rates (NNT = 5) [43]A1a. Growth parameters and nutritional status must be monitored every 6 months post-treatment.
The table below summarizes key distinctions across special populations.
| Population | Diagnostic Pearl | First-Line Therapy (with dose) | Efficacy | Key Modification |
|---|---|---|---|---|
| Pregnancy | HRM safe in any trimester; avoid barium in first trimester | Pneumatic dilation (30-35 mm Rigiflex) | 83% clinical success | Defer surgery to postpartum; botox salvage only |
| Pediatrics | Barium column >5 cm at 5 min predicts failure; HRM norms for age | PD (25-30 mm balloon) | 65-75% at 1 year | Max 3 dilations; fundoplication for type III |
| Elderly (≥65 yr) | Opioid-induced dysmotility mimics type III achalasia | Botox (100 U) for frail; PD if fit | 78% at 1 year for Botox | Post-POEM GERD risk higher (RR 0.85 age ≥65) |
| Immunocompromised | Rule out Chagas (serology), pseudoachalasia (CT) | PD or POEM per standard; Botox for high-risk | Same as immunocompetent | Lower threshold for esophageal cancer screening |
Elderly
Age-related changes in esophageal physiology, decreased amplitude contractions and impaired EGJ compliance, raise the threshold for diagnosing achalasia: an IRP >17 mm Hg (supine) may be more specific in adults ≥65 years [28]B2b[75]B3b. Chronic opioid use, which produces a manometric pattern distinguishable from true achalasia by the presence of some peristaltic reserve on rapid drink challenge, is present in 12-25% of elderly patients referred for dysphagia and must be excluded before committing to myotomy [75]B3b[124]B3b[94]B2b. Treatment decisions are driven by comorbidity burden, not chronologic age:
- For frail patients (ASA ≥III or life expectancy <2 years): Botulinum toxin injection (100 U in 1 mL aliquots into the four quadrants of the LES) produces symptom relief in 78% at 1 year and is repeatable, but efficacy wanes to 40% by 2 years [231]C4.
- For fit elderly patients: Either PD (success 80% at 1 year) or POEM (success 92% at 2 years) is appropriate, with PD carrying less procedural risk for cardiorespiratory compromise [10]B2b[186]B2b. A nationwide cohort showed that age ≥65 years is independently associated with lower risk of post-POEM reflux esophagitis (RR 0.85, 95% CI 0.75-0.96), likely due to reduced gastric acid output [10]B2b. The NNT for POEM over PD to prevent one retreatment at 2 years is 8 in elderly patients [186]B2b.
Immunocompromised Hosts
The immunocompromised population, solid organ transplant recipients, those on chronic corticosteroids or biologics, and patients with HIV, faces three key distinctions: (1) increased susceptibility to infectious esophagitis (Candida, CMV, HSV) that can mimic achalasia on endoscopy; (2) risk of reactivation in patients from endemic areas (Central and South America), which causes achalasia through destruction of the myenteric plexus by Trypanosoma cruzi; and (3) a higher baseline risk for esophageal squamous cell carcinoma (SCC) [235]B2b[45]B3b. Diagnostic workup must include serology for T. cruzi in at-risk patients and, if positive, a cardiac evaluation for Chagas cardiomyopathy before any myotomy. The choice of intervention is not modified by immune status, but perioperative infection prophylaxis is: for POEM, cefazolin 1 g IV (or clindamycin if penicillin-allergic) is given 30 minutes before incision; Heller myotomy requires a single preoperative dose of a second-generation cephalosporin [88]C4[193]B2b. Long-term outcomes are equivalent to immunocompetent individuals, with 2-year POEM success rates exceeding 90% [178]C4. However, post-treatment GERD, which occurs in 50-65% after POEM, mandates PPI therapy (pantoprazole 40 mg once daily) to prevent erosive esophagitis and potential progression to Barrett's esophagus in this vulnerable group [10]B2b[117]B2b.
Prevention Strategies
Primary prevention of idiopathic achalasia is not possible because the inciting viral or autoimmune trigger is unknown, though avoidance of chronic opioid use may prevent one cause of secondary achalasia-like dysmotility [75]B3b. Secondary prevention consists of endoscopic surveillance for esophageal SCC in patients with long-standing achalasia (≥10-15 years). The accumulated risk is 0.4-9.2%, with a standardized incidence ratio of 16.6 for SCC compared with the general population [235]B2b[45]B3b. The European Society of Endoscopy (ESGE) suggests considering screening in patients with achalasia for >15 years, performed every 3 years with Lugol chromoendoscopy to detect dysplastic lesions that are flat and easily missed with white-light endoscopy [235]B2b. If low-grade dysplasia is found, surveillance is intensified to yearly; if high-grade dysplasia or carcinoma is detected, curative treatment (endoscopic resection, ) follows standard oncologic protocols [188]A1c[235]B2b. A retrospective analysis of 230 patients who underwent Lugol chromoendoscopy found low-grade dysplasia in 3.5% and high-grade dysplasia or SCC in 1.3% over a median follow-up of 7 years [235]B2b; the NNT to screen (to detect one advanced lesion) is 29 over 10 years.
Pearl: Achalasia in pregnancy is managed safely with pneumatic dilation [100]C4; in children, a step-up from PD (25-30 mm balloon) to myotomy yields 85-90% success [44]C4; in elderly patients, Botox (100 U) is a reasonable alternative to myotomy for frail candidates [231]C4; and in immunocompromised hosts, Chagas serology and Lugol chromoendoscopy surveillance every 3 years for disease >15 years reduce cancer mortality [235]B2b[45]B3b.
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