Achalasia of the cardia: how it manifests and how it is treated

Achalasia cardia is a primary esophageal motility disorder characterized by loss of the normal wave of food propulsion and inadequate relaxation of the lower esophageal sphincter during swallowing. As a result, food is retained, causing distension of the walls, regurgitation, and inflammation, creating a vicious cycle of symptoms and complications. Although rare, the condition is increasingly being diagnosed thanks to the widespread use of high-resolution manometry and standardized barium X-ray protocols. [1]

Clinically, achalasia manifests primarily as difficulty swallowing both solid and liquid foods, which distinguishes it from mechanical strictures, where the passage of solids is affected first. Nocturnal regurgitation, coughing and "overflowing" of contents in the mouth, chest pain, and weight loss are common. Symptoms can be misinterpreted for years as gastroesophageal reflux disease, delaying proper diagnosis and treatment. [2]

The pathological basis of achalasia is the degeneration of nerve cells in the intermuscular plexuses of the esophageal wall, leading to the loss of consistent peristalsis and impaired relaxation of the lower esophageal sphincter. The triggers for this process are not fully understood; autoimmune mechanisms, infectious factors, and genetic predisposition are discussed. Functional testing reveals an increase in resting and residual sphincter pressure, as well as absent or abnormal contractions of the esophageal body. [3]

Modern treatment is aimed not at "curing" the underlying cause, but at mechanically or functionally reducing resistance at the esophagogastric junction and improving evacuation. This involves endoscopic and surgical techniques (pneumatic dilation, laparoscopic Heller myotomy with partial fundoplication, and peroral endoscopic myotomy), as well as medication and injection options in specific clinical situations. The choice of method depends on the achalasia subtype, age, comorbidities, and the center's experience. [4]

Code according to ICD-10 and ICD-11

In the International Classification of Diseases, Tenth Revision, achalasia cardia is coded under the code K22.0 "Achalasia cardia." This code includes the terms "cardiospasm" and "achalasia, unspecified." Some national adaptations specify the exclusion of congenital forms (for example, "congenital cardiospasm" is coded under a different category). [5]

The International Classification of Diseases, Eleventh Revision, uses the category DA21.0 "Achalasia," which highlights two key features: loss of peristalsis of the distal esophagus and insufficient relaxation of the lower esophageal sphincter. Inclusions, such as "cardiospasm," are listed separately. For congenital anomalies, other codes are used in the section on congenital pathology of the esophagus. [6]

Table 1. ICD codes for achalasia

Classifier	Basic code	Related notes	Comment
ICD-10	K22.0 "Achalasia of the cardia"	Excluded: congenital cardiospasm	Used for acquired achalasia
ICD-11	DA21.0 "Achalasia"	Includes "cardiospasm"	For congenital anomalies, codes from another section are used.
ICD-10 (related)	Q39.5 (congenital disorders)	For congenital forms	Clarification in national versions
ICD-11 (related)	LB12.Y (other congenital anomalies of the esophagus)	Includes "congenital achalasia"	For rare congenital variants
[7]

Epidemiology

Achalasia is a rare disorder. According to a systematic review and meta-analysis from 1925 to 2021, combining data from 26 studies from 14 countries, the global average incidence is approximately 0.78 cases per 100,000 people per year, and the prevalence is approximately 10.82 cases per 100,000 population. These estimates vary by region, age, and data source. [8]

Individual national studies show variations, with some modern cohorts reporting incidence rates of 0.68 to 1.99 cases per 100,000 per year and prevalence rates of 6.46 to 27.10 cases per 100,000. This reflects both genuine differences and the effect of improved diagnostics due to high-resolution manometry. No significant associations with gender or ethnicity were found. [9]

In population-based medical databases, prevalence in older groups may be higher due to the accumulation of cases and the long-term nature of the disease. However, some patients remain underdiagnosed due to similar symptoms to gastroesophageal reflux disease and functional dyspepsia. This is supported by studies in which the delay in seeking medical attention and the duration of symptoms before diagnosis are measured in years. [10]

Overall, a moderate increase in registered cases can be noted over the past decades, which is likely due to improved availability of instrumental methods, standardized protocols, and awareness among primary care physicians. In practice, this means the importance of early referral of patients for targeted tests when a combination of characteristic complaints occurs. [11]

Reasons

The underlying cause of achalasia is the degeneration and loss of neurons in the intermuscular plexus of the esophageal wall. This leads to impaired coordination of contractions and inadequate relaxation of the lower esophageal sphincter. Autoimmune and infectious mechanisms are suspected, but no convincing and universal factors have yet been identified. The disease is considered idiopathic, meaning its immediate cause is unclear. [12]

An important clinical concept is "pseudoachalasia": a condition in which symptoms and even some instrumental signs resemble achalasia, but are caused by a secondary organic process, primarily an infiltrative tumor of the cardia or esophagogastric junction. Sometimes, extraesophageal tumors and infiltrative diseases compressing the esophagogastric junction are the causes. [13]

There is evidence of a role for genetic predisposition and associations with certain autoimmune processes, but there are no confirmed practical predictors yet. For the clinician, it is paramount to rule out a secondary nature of the symptoms, especially in cases of late onset, significant weight loss, and rapidly worsening dysphagia. [14]

At the target organ level, prolonged retention of the food bolus leads to stretching and remodeling of the esophageal walls. Over time, megaesophagus, inflammatory changes in the mucosa, and ulceration can develop, increasing the risk of complications and impairing quality of life. This emphasizes the importance of timely decompression and restoration of passage. [15]

Risk factors

Table 2. Factors suggestive of achalasia and pseudoachalasia

Group of features	Specific factors	Clinical significance
According to the course of symptoms	Difficulty swallowing both solid and liquid food from onset; nocturnal regurgitation; chest pain	Typical of achalasia, distinguishes from mechanical stricture
Red Flags	Rapid weight loss, age over 60 years, short history of severe dysphagia	Pseudoachalasia (tumor of the cardia) must be excluded.
Endoscopy data	Large amounts of stagnant fluid, "bird's beak" on barium x-ray	Suspicion of achalasia, but verification needed
Instrumental markers	Impaired sphincter relaxation by manometry, types according to the Chicago classification	The leading criterion for diagnosis
[16]

Pathogenesis

Normally, a wave of contractions propels the food bolus downward, and the lower esophageal sphincter relaxes completely for a split second. In achalasia, the nerve plexuses lose cells, and the release of relaxation mediators is impaired, leading to a combination of absent peristalsis and incomplete relaxation of the sphincter. Increased resistance in the transition zone increases food retention and increases intraesophageal pressure. [17]

Prolonged stagnation leads to mucosal inflammation, microtrauma, and secondary changes—dilation of the lumen, thickening of the walls, and decreased elasticity. This, in turn, further impairs evacuation, creating a "vicious cycle" and creating the preconditions for complications, including aspiration and esophageal ulcers. [18]

The Chicago classification, based on high-resolution manometry, distinguishes three subtypes of achalasia, differing in the nature of pressure and contractions in the esophageal body. These subtypes have prognostic significance and influence the choice of tactics: one subtype responds better to pneumatic dilation, another to myotomy, and the spastic subtype to peroral endoscopic myotomy. [19]

Furthermore, in some patients, a functional examination using an intraluminal impedance-planimetric probe (the "functional luminal probe" technique) allows for a quantitative assessment of the transition zone's extensibility and an objective evaluation of the treatment effect. This study is considered supportive in cases of ambiguous data from other tests and for intraoperative monitoring. [20]

Symptoms

The most common symptom is difficulty swallowing solids and liquids, which may worsen in the evening and when lying down. Many patients report the need to drink water with food and "jerking" the body to "push" the food down. Symptoms vary in severity and often worsen in waves. [21]

Regurgitation of undigested food, especially at night, and coughing are common. This is not only difficult to tolerate but also dangerous due to aspiration of contents into the respiratory tract. The onset of nocturnal coughing, choking, and episodes of "choking" are important signals for prompt diagnosis and treatment. [22]

Chest pain of varying intensity is common and can mimic cardiac pathology. It is associated with distension and spastic contractions of the esophageal walls. Over the long term, weight loss develops due to food avoidance and poor nutrition. [23]

Some patients undergo long-term treatment for gastroesophageal reflux disease due to heartburn and belching. However, in achalasia, heartburn is more often caused by stagnant fermentation of contents and retrograde flow into the oropharynx, rather than by classic acid reflux from the stomach. This clinical nuance helps to suspect the true nature of the disease. [24]

Classification, forms and stages

Table 3. Chicago classification of achalasia (version 4.0)

Subtype	Key manometric features	Clinical notes
Subtype I	No peristalsis, no pan-pressurization	"Classic" achalasia; standard treatments are highly effective
Subtype II	Pan-pressurization of the esophagus body during swallowing attempt	Responds well to pneumatic dilation and myotomy
Subtype III	Premature and spastic contractions of the distal part	Peroral endoscopic myotomy shows the best results.
[25]

In addition to subtypes, the term "esophageal emptying disorder" is used, and the degree of dilation is assessed using barium X-ray data. Staging is performed based on lumen width and deformation, which helps predict treatment response. These parameters are also used to objectively evaluate the outcome of interventions over time. [26]

A small percentage of patients experience "esophagogastric junction outlet obstruction" with preserved partial peristalsis. This condition requires careful exclusion of secondary causes and is often assessed using a functional luminal probe to measure distensibility. It can be either an independent problem or an early phase of achalasia. [27]

Pseudoachalasia is considered separately as a "mimicking form" of achalasia, most often of tumor origin. It is characterized by rapid progression of symptoms, significant weight loss, and an older age of onset, which should lead to more extensive diagnostic workup. [28]

Complications and consequences

Without treatment, a significant proportion of patients develop esophageal dilation with poor evacuation, which worsens symptoms and increases the risk of chronic inflammation. Prolonged food retention provokes nocturnal regurgitation, aspiration, and chronic pulmonary problems. This leads to decreased sleep quality, increased fatigue, and a decline in quality of life. [29]

Due to persistent inflammation and trauma, superficial mucosal lesions and ulcers, as well as bleeding due to vascular erosion, are possible. Severe cases are accompanied by significant weight loss and micronutrient deficiencies, requiring nutritional correction. Regular nutritional and weight assessment is essential in long-term cases. [30]

There is an increased, but still low, risk of developing squamous cell carcinoma of the esophagus in patients with long-standing decompensated achalasia. Current guidelines do not require routine endoscopy screening for everyone; decisions are made individually, taking into account risk factors and disease duration. [31]

Specific complications may occur after these procedures: esophagitis due to reflux is more common after peroral endoscopic myotomy; perforation (rare but potentially serious) after pneumatic dilation; dysfunction due to insufficient dissection length and the need for a repeat procedure after Heller myotomy. Patient awareness of the risks directly impacts treatment satisfaction. [32]

When to see a doctor

Seek immediate medical attention if you experience signs of aspiration (choking at night, repeated episodes of choking), sudden severe chest pain, fever, signs of bleeding, or severe dehydration due to the inability to swallow even water. These are conditions that require urgent evaluation and possibly hospitalization. [33]

A follow-up visit is recommended in the coming days if progressive dysphagia, nocturnal regurgitation, or weight loss occurs, especially if symptoms are rapidly worsening. This situation necessitates excluding tumor-related pseudoachalasia through a more comprehensive examination. [34]

Patients with long-standing "reflux-like" symptoms that do not respond to acid suppression should be routinely discussed for targeted testing: a timed barium swallow and high-resolution manometry. This expedites accurate diagnosis, reducing years of uncertainty. [35]

After any intervention for achalasia, you should contact a specialist if dysphagia returns, heartburn worsens, you have a night cough, weight loss, or pain - this may indicate insufficient effect of the procedure, the development of reflux esophagitis, or the formation of complications. [36]

Diagnostics

1. Upper gastrointestinal tract endoscopy. The first step is to examine the mucosa, remove stagnant contents, and, most importantly, rule out mechanical obstruction and pseudoachalasia, including occult tumors in the cardia. Endoscopic ultrasound and computed tomography are also used as indicated. [37]
2. A timed barium swallow. This "timed" technique allows for quantitative assessment of esophageal emptying in minutes, recording the height and width of the barium column on images taken at 1, 2, and 5 minutes. This test is simple, reproducible, and useful for both initial assessment and monitoring the effects of treatment. [38]
3. High-resolution esophageal manometry. The gold standard for confirming the diagnosis: it documents inadequate relaxation of the lower esophageal sphincter and absent or abnormal peristalsis, which allows for classification of the achalasia subtype according to the Chicago classification version 4.0 and selection of treatment tactics. [39]
4. Functional impedance planimetry (functional luminal probe). A supportive and intraoperative method for quantitatively assessing the extensibility of the transition zone; helpful in controversial cases, when assessing the outcome of myotomy, and when selecting the extent of the intervention. [40]

Table 4. Mini-algorithm for achalasia diagnostics

Step	Method	Target
1	Endoscopy	Rule out mechanical obstruction and tumor
2	Timed barium study	To quantify emptying and deformation
3	High-resolution manometry	Confirm achalasia and determine the subtype
4	Functional luminal probe	Assess the extensibility and effect of treatment
[41]

Differential diagnosis

The clinician's task is to distinguish true achalasia from conditions that mimic it. The classic "two-stage" dysphagia pattern—first solids, then liquids—is more characteristic of mechanical strictures, whereas in achalasia, difficulty is often equal from the outset. This clinical sign is guiding, but does not replace instrumental confirmation. [42]

Pseudoachalasia is most often caused by infiltrating adenocarcinoma of the cardia or esophageal cancer, and less commonly by metastatic disease. Suspicion is heightened by advanced age, rapid onset of symptoms, and significant weight loss. Endoscopy with targeted biopsy and, if necessary, endoscopic ultrasound and computed tomography are critical. [43]

Other esophageal motor disorders—diffuse spasms, hypercontractile "nutcracker esophagus," and lack of contractions—also cause dysphagia and chest pain. They are differentiated by manometric findings according to the Chicago classification, as treatment approaches vary, and interventions effective for achalasia may be unnecessary for other disorders. [44]

Finally, habitual gastroesophageal reflux disease can produce similar symptoms, but peristalsis is preserved, and acid reflux and inflammation play a major role. If in doubt, a full examination using a diagnostic algorithm is recommended to avoid treating the wrong thing for years. [45]

Treatment

General principles and goals. The goal of therapy is to eliminate the functional obstruction at the gastroesophageal junction, improve esophageal emptying, and reduce symptoms. The choice of method depends on the achalasia subtype, age, comorbidities, patient preference, and center experience. Effective "definitive" options include pneumatic dilation, laparoscopic Heller myotomy with partial fundoplication, and peroral endoscopic myotomy. [46]

Pneumatic dilation. This involves controlled stretching of the transition zone using a special large-diameter balloon. This method is effective for subtypes I and II and can be performed in stages with increasing balloon diameter. The main risks are perforation (rare) and recurrence of symptoms over time, requiring a repeat procedure. The advantages include the absence of incisions and a short recovery period. [47]

Laparoscopic Heller myotomy with partial fundoplication. The surgeon dissects the muscle fibers of the lower esophageal sphincter through a laparoscopic approach and supplements the procedure with a partial fundoplication to reduce the risk of reflux. Efficacy is high in subtypes I and II; in subtype III, the dissection length must be longer, but in this situation, peroral endoscopic myotomy is often preferred. [48]

Peroral endoscopic myotomy. This endoscopic technique involves the creation of a submucosal tunnel and layer-by-layer dissection of the transition zone muscles. It is particularly effective in spastic subtype III due to the ability to perform a long dissection. The increased risk of postoperative reflux compared to other methods should be noted, necessitating follow-up observation and, sometimes, supportive therapy. [49]

Comparison of methods by subtype. For subtypes I and II, pneumatic dilation, laparoscopic myotomy, and peroral endoscopic myotomy have been shown to be comparable in efficacy; the choice is based on a joint decision by the patient and the team. For subtype III, peroral endoscopic myotomy demonstrates superior symptom control. Repeat interventions are possible in case of recurrence, including switching to a different method. [50]

Botulinum toxin injections are considered a temporary solution in patients who are contraindicated for more radical procedures due to age or severe underlying conditions. The effect is short-lived and requires repetition, so the method is not considered a "definitive" treatment. [51]

Drug therapy. Drugs that reduce smooth muscle tone in the transition zone (short-acting nitrates, calcium channel blockers) can temporarily alleviate symptoms, but are often limited by side effects and an unstable effect. They are used as a "bridge" to surgery or in patients unsuitable for procedures. Acid-suppressing medications address post-surgical reflux esophagitis but do not treat the underlying mechanism of achalasia. [52]

The role of a functional luminal probe. During interventions (surgical and endoscopic), this technique allows for real-time measurement of transition zone extensibility and assessment of the adequacy of dissection. This helps personalize the extent of myotomy and potentially improves symptomatic outcomes, as supported by observational and meta-analytic data. [53]

Postoperative management and prevention of reflux. Reflux esophagitis may occur after peroral endoscopic myotomy and laparoscopic myotomy; the approach includes lifestyle modification and, if necessary, long-term acid suppression. Timed barium studies and follow-up endoscopies, when indicated, are used to evaluate the outcome and rule out complications. [54]

Treatment failure management. If symptoms persist after one technique, repeat pneumatic dilation, "redomyotomy" using a different method, or combined approaches may be considered. Current recommendations recommend cross-use of techniques based on subtype and anatomy. Discussion within a multidisciplinary team increases the likelihood of a lasting effect. [55]

Table 5. Comparison of the main treatment methods

Method	The best candidates	Strengths	Main risks/disadvantages
Pneumatic dilatation	Subtype I-II, absence of pronounced spasm	Minimal invasion, fast recovery	Rare perforation, relapses are possible, sometimes repetitions are needed
Heller myotomy with partial fundoplication	Subtype I-II, preference for “once and for all”	Long-term control and prevention of reflux with fundoplication	Surgical trauma, general anesthesia
Peroral endoscopic myotomy	Subtype III, extended spasm	Long myotomy, highly effective in spasticity	Higher risk of postoperative reflux
[56]

Prevention

There is no specific prevention for achalasia, as the direct causes of the disease have not been established. However, the risk of complications and deterioration in quality of life can be reduced through early diagnosis and the selection of an effective decompression method. The shorter the period of congestive regurgitation and nocturnal episodes, the lower the likelihood of aspiration and inflammatory changes. [57]

A diet with thorough chewing, drinking small sips of water during meals, and avoiding large late dinners are recommended. Sleeping with the head of the bed elevated reduces nocturnal regurgitation. These measures do not replace treatment, but they do help with the anticipation of the procedure and improve comfort afterward. [58]

After interventions, prevention of reflux esophagitis is important: frequent meals, weight control, alcohol restriction, and discussion of long-term acid suppression therapy for heartburn symptoms. Follow-up visits and instrumental examinations, as indicated, allow for timely adjustments to treatment. [59]

Finally, if reflux symptoms are unexpectedly combined with difficulty passing water, nocturnal regurgitation and cough, it is better not to delay the algorithmic assessment to avoid a delay in diagnosis that may last for years. [60]

Forecast

With the appropriate intervention, long-term symptom control is achieved in most patients. The best results are achieved with early treatment and precise matching of the treatment to the achalasia subtype. Repeat procedures are possible if necessary, allowing for a high quality of life. [61]

Peroral endoscopic myotomy is associated with a higher risk of esophagitis, requiring observation and, if necessary, supportive therapy. Pneumatic dilation may gradually lose its effectiveness, necessitating repeated dilation. With Heller myotomy, recurrent dysphagia is resolved with a "redo" intervention or an alternative method. [62]

The risk of developing esophageal cancer in patients with a long history of the disease is increased, but the absolute numbers remain low. Routine endoscopic surveillance is not recommended for all patients; this issue is decided on an individual basis. Adherence to dietary recommendations and aspiration prevention reduces the likelihood of dangerous events. [63]

Table 6. Key outcomes and complications by method

Treatment method	Frequent positive outcomes	Possible complications	What to do if you have problems
Pneumatic dilatation	Rapid improvement of swallowing	Perforation (rare), recurrence of dysphagia	Repeated dilation or transition to myotomy
Heller myotomy	Long-lasting symptom control	Dysphagia with incomplete myotomy, reflux	Correction with technique, reflux therapy, re-intervention
Peroral endoscopic myotomy	Highly effective in spasticity	Reflux esophagitis, ulcerations	Prevention of reflux, monitoring, treatment of complications
[64]

Additional practical tables

Table 7. Symptom → Probable Cause → Next Step

Clinical situation	Probable cause	Recommended action
Dysphagia for solid and liquid food from onset, nocturnal regurgitation	Achalasia	Timed barium manometry
Rapid weight loss, short medical history, age over 60 years	Pseudoachalasia (usually a tumor)	Endoscopy with biopsy, endoscopic ultrasound, computed tomography
Chest pain, spastic episodes	Spastic subtype III	Consider peroral endoscopic myotomy
Persistence of symptoms after intervention	Insufficient decompression or relapse	Re-evaluation using a timed protocol, consideration of "redo" tactics
[65]

Table 8. Diagnostic tests and their role

Method	What does it show?	When necessary
Endoscopy	Exclusion of mechanical obstruction and tumor, signs of congestion	All patients at initial assessment
Timed barium study	Quantitative assessment of emptying and deformation	If achalasia is suspected and for monitoring
High-resolution manometry	Confirmation of achalasia, determination of subtype	The gold standard before choosing tactics
Functional luminal probe	Transition zone extensibility	In controversial cases and intraoperatively
[66]

Table 9. Achalasia subtype and preferred tactics

Subtype	Preferred options	Alternatives
I	Pneumatic dilation, Heller myotomy, peroral endoscopic myotomy	Selection based on availability and preferences
II	Pneumatic dilation or Heller myotomy; peroral endoscopic myotomy is possible	Risk-based individualization
III	Peroral endoscopic myotomy	Extended Heller myotomy in an experimental center
[67]

Table 10. Post-intervention support

Direction	Specific measures	For what
Nutrition	Chew your food thoroughly and in small portions; avoid late dinners.	Reduced regurgitation
Body position	Sleep with your head elevated and do not lie down immediately after eating.	Prevention of nocturnal aspiration
Medicines	Based on symptoms - acid suppression, anti-reflux measures	Prevention of esophagitis
Control	Timed barium study, endoscopy as indicated	Objective assessment of the result
[68]

FAQ

Question 1. Is it possible to cure achalasia with medication?
Medications can temporarily reduce the tone of the transition zone and alleviate symptoms, but they do not eliminate the underlying disease mechanism. Reliable control is achieved with pneumatic dilation, Heller myotomy with partial fundoplication, or peroral endoscopic myotomy. The choice of method is individual. [69]

Question 2. Which method is the most modern and "best"?
For "classic" subtypes I-II, pneumatic dilation, laparoscopic myotomy, and peroral endoscopic myotomy show comparable efficacy. For spastic subtype III, peroral endoscopic myotomy is usually superior. The most important factors are the experience of a specific center and a mutually agreed-upon decision with the patient. [70]

Question 3. Should esophageal cancer be monitored?
Current recommendations do not recommend routine screening for all patients. The risk increases with very long-term and severe disease; the decision regarding individual monitoring is made by the physician, taking into account risk factors. [71]

Question 4. How should treatment results be monitored?
Symptoms and objective tests are used: timed barium studies, endoscopy, and manometry, if necessary. Some centers use a functional luminal probe to quantitatively assess transition zone compliance before and after intervention. [72]