Achalasia: Insights into Diagnostic and Therapeutic Advances for an Ancient Disease

Abstract

Achalasia is a chronic idiopathic disease characterized by the absence of esophageal body peristalsis and by defective lower esophageal sphincter (LES) relaxation. The incidence rate ranges from 1.07 to up to 2.8 new cases per year per 100,000 population. Presenting symptoms include dysphagia, regurgitation, vomiting, and weight loss. The diagnosis of achalasia has undergone a revolution in the last decade due to the advent of high-resolution manometry (HRM) and the consequent development of the Chicago Classification. Recent progress has allowed achalasia to be more precisely diagnosed and to be categorized into three subtypes, based on the prevalent manometric features of the esophageal peristalsis. Treatment options are pharmacotherapy, endoscopic management (Botox injection or pneumatic dilation), and surgery, e.g. laparoscopic Heller myotomy (LHM). More recently, a new endoscopic technique, per oral endoscopic myotomy (POEM), has developed as a less invasive approach alternative to the traditional LHM. Since the first POEM procedure was performed in 2008, increasing evidence is accumulating regarding its efficacy and safety profiles. Currently, POEM is being introduced as a reasonable therapeutic option, though randomized controlled trails are still lacking. The current review sheds light onto the diagnosis and management of achalasia, with special focus on the recent advances of HRM and POEM.

Figure 1. Example of High-resolution Manometry with Esophageal Pressure Topography

Single swallow initiated at the upper esophageal sphincter (UES) showing normal esophageal body peristalsis and normal lower esophageal sphincter (LES) relaxation; LES relaxation is measured over a 10 second period as indicated by the black box and calculation of the integrated relaxation pressure (IRP).

Figure 2. Diagnostic Algorithm in Patients with Symptoms of Esophageal Dysphagia

EGD, esophago-gastro-duodenoscopy; EGJ, esophagogastric junction; HRM, high-resolution manometry.

Figure 3. The Chicago Classification Achalasia Subtypes

Achalasia type I is characterized by the total absence of peristalsis for all swallows. In type II the peristalsis is replaced by pan-esophageal pressurizations. Type III is characterized by the presence of premature spastic contraction.

Figure 4. Esophagogastric Outflow Obstruction (EGOO)

Shown is the outflow obstruction at the level of the esophagogastric junction (IRP>15 mmHg), accompanied by normal esophageal body peristalsis. BTT, bolus transit time; CFV, contraction front velocity; DL, distal latency; DCI, distal contractile integrity; PIP, pressure inversion point.