The pocket-creation method facilitates endoscopic submucosal dissection of gastric neoplasms involving the pyloric ring

Abstract

Background and study aims Endoscopic submucosal dissection (ESD) of superficial gastric lesions involving the pyloric ring is difficult. The pocket-creation method (PCM) with a small-caliber-tip transparent hood can overcome this difficulty by compressing the pyloric sphincter applying both traction and counter-traction. The aim of this study is to clarify the usefulness of the PCM for ESD of superficial gastric neoplasms involving the pyloric ring compared to the conventional method (CM). Patients and methods From October 2006 to August 2019, 66 gastric lesions requiring duodenal submucosal dissection beyond the pyloric ring in 66 patients were resected. The CM was mainly performed in the first period (CM group, n = 46) and the PCM in the second period (PCM group, n = 20). We retrospectively reviewed their medical records. Results Although no significant differences were observed in en bloc resection rates between the two groups, the PCM group had a significantly higher R0 resection rate than the CM group (P = 0.047). There were no holes in resected specimens in the PCM group while three specimens in the CM group had a hole. The dissection speed in the PCM group tended to be higher than in the CM group, although it did not reach statistical significance (P = 0.148). No significant differences were observed for the incidence of adverse events. Conclusions This is the first study reporting the advantages of the PCM over the CM for ESD of gastric lesions involving the pyloric ring. We believe that the PCM is an effective strategy to compress the pyloric sphincter and facilitates R0 resection.

The pocket-creation method of endoscopic submucosal dissection

“…Therefore, even if a viscous solution such as sodium hyaluronate is injected, the mucosal elevation cannot last as long as in other organs. In particular, solution injected into the submucosa in the flat area between folds may be dispersed quickly [11] . The minimal mucosal incision performed during PCM prevents leakage of the injected solution from the submucosa and the traction of ST hood stretches the thin submucosa in the pocket.…”

The Pocket-Creation Method Facilitates Endoscopic Submucosal Dissection of Gastric Neoplasms Along the Lesser Curvature at the Gastric Angle

“…The PCM is a simple technique to accomplish sophisticated ESD and is more effective for endoscopists familiar with ESD procedures. The PCM may facilitate gastric ESDs in various locations such as the fornix, along the lesser curvature, and the pyloric ring ( 13 , 16 ).…”

“…Second, careful submucosal dissection is necessary to insert the endoscope tip into the pocket, and the pocket is subsequently enlarged without a circumferential incision to preserve traction and countertraction by the hood tip and prevent dispersion of the injected solution. Third, the pocket is opened entirely from the gravity side once the submucosal dissection under the tumor is completed ( 13 ). For a successful gastric ESD procedure with the PCM, it is critical to aspirate as much gas as possible from the gastric lumen ( 16 ).…”

“…The usefulness of PCM for ESD in the colon and duodenum have been reported ( 9 – 12 ). We have also reported the effectiveness of PCM for ESD of gastric lesions involving the pyloric ring ( 13 ). The PCM offers four distinct advantages: (1) the injected solution is not dispersed due to a minimal incision; (2) both traction and countertraction are obtained simultaneously because the transparent hood stretches the submucosal tissue in the pocket; (3) a vertical approach toward the muscularis can be changed to a tangential approach, and (4) the influence of cardiopulmonary movement is diminished due to synchronization of the endoscope and the pocket ( 14 , 15 ).…”

Effectiveness and safety of endoscopic submucosal dissection using the pocket creation method in the Japanese population: a systematic review and meta-analysis

“…Two studies from our own group [7,8] were excluded due to many patients overlapping with subjects in another study [9]. The eight studies included five retrospective studies [3,[9][10][11][12], two RCTs [13,14] and one prospective study [15]. Overall, eight studies including 1,585 ESDs were analyzed.…”