The Safety And Efficacy Of Endoscopic Full-thickness Resection With Over-the-scope Clip(OTSC)for Gastric Submucosal Tumors Originating From The Muscularis Propria

Background: Endoscopic full-thickness resection(EFTR)achieves R0 resection in the most minimally invasive way by actively forming a perforation in the gastrointestinal wall.Therefore,closure of the wall after EFTR is challenging.With the advent of over-the-scope clip(OTSC),EFTR combined with OTSC is gradually applied in the clinic.Aim:To evaluate the safety and efficacy of EFTR using an OTSC.Methods: This prospective,single-center clinical trial was conducted in our department.The study included patients who underwent ETFR treatment from November 2014 to October 2016.They were divided into OTSC and TTSC groups according to the postoperative closure method.We analyzed patient demographics,technical success rate,R0 resection(negative margins)status,adverse events,and 36 months follow-up.Results: There were totally 79 patients in our study.OTSC group contains 63 cases,including 20 males and 43 females,the average age of which is 52.7(52.7±10.2)year-old and the average size of defects is 12.5(12.5±4.3)mm.TTSC group contains16 cases,including 6 males and 10 females,the average age of which is 56.8(56.8±9.9)year-old and the average size of defects is 11.8(11.8±3.4)mm.All tumors were classified according to the lesion location,including 11 cases of cardia,43 cases of fundus,18 cases of gastric body,and 7 cases of antrum.All tumors were classified according to the nature of the lesions: 46 cases of stromal tumor,24 cases of leiomyoma,4 cases of schwannoma,12 cases of ectopic pancreas,and one case each of fibrolipomatous hyperplasia,inflammatory myofibroblastic tumor like hyperplasia and Hyaline degeneration with calcification.Of the patients with GISTs,44 cases had a low or very low-risk and two cases had a moderate risk.All tumors are enucleated completely.R0 resection rate and the closure rate of both groups was 100%.The average days in hospital,the average closure time and the average operative time of OTSC group(4.21±1.17d/38.57±14.82min/4.32±1.27min)were shorter than TTSC group(5.81±1.42d/53.94±17.77min/10.19±2.99min).The hospitalization cost of TTSC group(￥18,610.35±3003.53)was smaller than OTSC group(￥27,184.78±3619.7).There were statistical differences between the two groups(p<0.05),and Cohen’s d values were all> 0.80,which were high level.Mild adverse events including elevated body temperature were observed in 21 patients.The degree of fever was mostly low to moderate fever below 38°C.Five patients(7.9%)in the OTSC group and 2 patients(12.5%)in the TTSC group had a high fever of 38-39°C,and the temperature decreased to normal within 24 hours in both groups.No adverse events such as peritonitis,delayed hemorrhage or delayed perforation occurred.All patients were follow-up for 36 months.There was no recurrence during the follow-up period.22 patients shed their OTSC;one patient developed upper gastrointestinal bleeding,which was stopped using endoscopic therapy.During the follow-up period,all TTSC fell off(100%).The OTSC spontaneous detachment rate was 85.7%(6/7)in the cardia,20.0%(7/35)in the fundus,28.6%(4/14)in the gastric body,and 71.4%(5/7)in the antrum.There was significant difference in terms of location.The spontaneous shedding rate of OTSC was higher in the cardia and antrum.Conclusion: EFTR combined with an OTSC is safe and effective for the treatment of gastric submucosal tumors originating from the muscularis propria.EFTR has a high R0 resection rate and technical success rate.Using an OTSC to close gastric wall defects is simple and reliable,which can shorten hospitalization time and reduce patients’ pain to a certain extent.The spontaneous shedding rate of OTSC is higher in the cardia and antrum.No adverse events have been observed in long-term OTSC indwelling.