Peroral Endoscopic Myotomy (POEM) for Achalasia: Indications, Techniques, and Outcomes

POEM represents a novel endoscopic version of Heller myotomy, the timehonored gold standard for achalasia therapy. POEMrepresents the first successful realization of the NOTES (Natural Orifice Transluminal Endoscopy Surgery) ideal, namely, the minimally invasive “scarless” performance of intrathoracic or intraabdominal surgeries via natural body orifices rather than surgical incisions. This chapter provides an in-depth comprehensive review of POEM with an emphasis on current controversies and areas of intense investigation. Topics to be covered include the broad range of POEM indications in diverse patient populations and conditions extending from achalasia to nonachalasia esophageal motility disorders, POEM technique variations and adjuncts, mid and long term efficacy outcomes, adverse events, and comparative data versus other standard therapies including detailed analysis of reflux after POEM relative to other achalasia treatments. We will address in particular the data that refute the misconception that reflux is much more prevalent after POEM than after Heller myotomy.