Evolution and evidence-based adaptations in techniques for peroral endoscopic myotomy for achalasia.

Achalasia is an esophageal motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation and failed peristalsis. Common clinical manifestations include dysphagia to solid and liquid foods, chest pain, regurgitation, and weight loss, resulting in significant morbidity and healthcare burden. Historically, surgical Heller myotomy and pneumatic dilation were the first-line therapeutic options for achalasia. This convention was shaken in 2009 when Inoue and colleagues introduced an endoscopic approach to dissect the muscle fibers of the LES, known as peroral endoscopic myotomy (POEM). Since incorporation of POEM into standard practice, the overall myotomy technique has remained unchanged; however, adaptations in the thickness and length of myotomy have evolved. Full-thickness myotomy is recognized to have similar clinical success and faster procedure times compared with selective circular muscle myotomy. Although myotomy length for type 1 and type 2 achalasia has classically been >6 cm, recent studies demonstrated similar outcomes with reduction of myotomy length to <3 cm. Length of myotomy for type 3 achalasia has been tailored to treat the entire length of spastic muscle segment, and the modality to gauge the optimal thickness and length of myotomy in this group has yet to be established. In addition to changes in POEM technique, the postoperative management of POEM has also changed, favoring reduced postprocedure imaging, antibiotic use, and hospitalizations.