Is closure of only the mucosal layer really sufficient?

We read with great interest the article by Shi et al.: “Complete closure of large gastric defects after endoscopic full-thickness resection, using endoloop and metallic clip interrupted suture.” The authors presented their experience of closing large gastric defects following endoscopic full-thickness resection (EFTR) for gastric submucosal tumors, using conventional endoloops and metallic clips. In their study, endoloops were anchored with clips to normal mucosa near the proximal and distal resection margins, and tightened slightly to approximate the borders of the defect. This technique closed both sides of the defect but was limited to the mucosal layer and did not involve the full thickness.

Our concern is that the metallic clips might not close the defect firmly enough. Bearing in mind gastric peristalsis and the radial force of the large defect of the gastric wall, closure of the mucosal layer using clips may be not sufficient. Once the clips drop off the mucosal layer, peritonitis could occur.

Renteln and colleagues have reported the closure of natural orifice transluminal endoscopic surgery (NOTES) gastrotomies using either over-the-scope clips (OTSC) or conventional metallic clips. Gastric wall puncture and closure of the incision was carried out in 20 pigs. There were three minor leaks and one major leak in the endoclip closures and then four animals developed peritonitis or gastric abscess. Microscopic examination revealed that the endoclips mostly closed the mucosal layer whereas the OTSCs closed the submucosal or muscular layer. Thus the authors believed that leak rates of the clips seemed to be related to the more superficial closure.

Excellent closure of the defects was obtained in the study by Shi et al. and all the wounds had healed after 1 month. However, in our opinion, the metallic clips are associated with an increased risk of leak and peritonitis. The application of metallic clips should be limited to small perforations or defects. Muscular or full-thickness closure of the gastric wall may provide a more durable closure, especially when the defect is large.

• References

• 1 Shi Q, Chen T, Zhong YS et al. Complete closure of large gastric defects after endoscopic full-thickness resection, using endoloop and metallic clip interrupted suture. Endoscopy 2013; 45: 329-334
• 2 von Renteln D, Vassiliou MC, Rothstein RI. Randomized controlled trial comparing endoscopic clips and over-the-scope clips for closure of natural orifice transluminal endoscopic surgery gastrotomies. Endoscopy 2009; 41: 1056-1061