Myotomy length informed by high-resolution esophageal manometry (HREM) results in improved per-oral endoscopic myotomy (POEM) outcomes for type III achalasia

IntroductionHigh-resolution esophageal manometry (HREM) is essential in characterizing achalasia subtype and the extent of affected segment to plan the myotomy starting point during per-oral endoscopic myotomy (POEM). However, evidence is lacking that efficacy is improved by tailoring myotomy to the length of the spastic segment on HREM. We sought to investigate whether utilizing HREM to dictate myotomy length in POEM impacts postoperative outcomes.MethodsComparative analysis of HREM-tailored to non-tailored patients from a prospectively collected database of all POEMs at our institution January 2011 through July 2017. A tailored myotomy is defined as extending at least the length of the diseased segment, as initially measured on HREM.ResultsForty patients were included (11 tailored versus 29 non-tailored). There were no differences in patient age (p=0.6491) or BMI (p=0.0677). Myotomy lengths were significantly longer for tailored compared to non-tailored overall (16.62.2 versus 13.5 +/- 1.8; p<0.0001), and for only type III achalasia (15.9 +/- 2.4 versus 12.7 +/- 1.2; p=0.0453), likely due to more proximal starting position in tailored cases (26.0 +/- 2.2 versus 30.0 +/- 2.7; p<0.0001). Procedure success (Eckardt<3) was equivalent across groups overall (p=0.5558), as was postoperative Eckardt score (0.2 +/- 0.4 versus 0.8 +/- 2.3; p=0.4004). Postoperative Eckardt score was significantly improved in the tailored group versus non-tailored for type III only (0.2 +/- 0.4 versus 1.3 +/- 1.5; p=0.0435). A linear correlation was seen between increased length and greater improvement in Eckardt score in the non-tailored group (p=0.0170).Conclusions Using HREM to inform surgeons of the proximal location of the diseased segment resulted in longer myotomies, spanning the entire affected segment in type III achalasia, and in lower postoperative Eckardt scores. Longer myotomy length is often more easily achieved with POEM than with Heller myotomy, which raises the question of whether POEM results in better outcomes for type III achalasia, as types I and II do not generally have measurable spastic segments.