Novel per‐oral endoscopic myotomy method preserving oblique muscle using two penetrating vessels as anatomic landmarks reduces postoperative gastroesophageal reflux

Background and aim One of the main concerns related to peroral endoscopic myotomy (POEM) is postoperative gastroesophageal reflux (GER). The two penetrating vessels (TPVs) that are found at the boundary between the circular and oblique muscles in the posterior cardia wall have been suggested to be a good indicator of the optimal distal extent of POEM. However, the effect of performing myotomy using the TPVs as an anatomical reference on the frequency of post-POEM GER has not been studied. Methods This study involved consecutive patients who underwent POEM for the treatment of achalasia between April 2015 and June 2017. All enrolled patients underwent POEM in the 5 o'clock position and were divided into two groups: the conventional line group (CL group, n = 31), in which the TPVs were not exposed during submucosal tunnel dissection in the cardia, and the TPVs line group (TPVs group, n = 83), in which the TPVs were exposed and gastric myotomy was performed along the right side of the TPVs to preserve the oblique muscle. Examinations for post-POEM GER were conducted 3 months after the POEM. Results The frequency of grade B or higher reflex esophagitis was 26/83 (31.3%) in the TPVs group and 18/31 (58.1%) in the CL group (P = 0.017). Nine of 83 patients (10.8%) had GER symptoms in the TPVs group, and six of 31 (19.4%) had GER symptoms in the CL group (P = 0.23). Conclusions The novel myotomy method preserving oblique muscle using TPVs as anatomical landmarks significantly reduced the frequency of post-POEM GER.