Endoscopic resection of gastric gastrointestinal stromal tumors originating from the muscularis propria layer in North America: methods and feasibility data.

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. In recent years, endoscopic procedures such as endoscopic enucleation (EN) and endoscopic full-thickness resection (EFTR) have been used to resect GISTs. This study aimed to investigate the clinical efficacy, safety, and feasibility of endoscopic resection of GISTs in a North American population.

METHODS: A total of 25 patients with gastric submucosal lesions (SML) underwent endoscopic resection from December 2014 to April 2016. Data from cases with histologically proven GISTs originating from the muscularis propria layer (MP-GIST) were collected. The main outcome measures were complete resection rate, operative time, postoperative complications, length of hospital stay, narcotic analgesic requirement, and follow-up outcomes. Surveillance was performed with CT abdomen, and/or EGD along with oncology follow-up at 6- to 24-month intervals.

RESULTS: Out of 25 gastric SML, there were 12 histologically proven MP-GIST. Five endophytic MP-GIST were removed by EN, and seven exophytic MP-GIST were removed by EFTR. All lesions were removed en bloc except for one hard to localize exophytic lesion which was completely removed piecemeal. The mean removal time was 79.7 min (range 17-180 min). Nine out of twelve patients required inpatient admission for observation with a mean length of stay of 2.08 days (range 1-4 days). No complications were noted and no narcotic analgesics were required. Pathology reports showed that one GIST was intermediate risk but all others were low-risk lesions. No recurrence has been noted thus far.

CONCLUSION: Endoscopic removal of MP-GIST by a trained endoscopist appears to be safe and feasible in North American population. Further studies with greater sample size are necessary to compare endoscopic versus surgical resection of MP-GIST. Comparison of outcomes may support wider use of endoscopic techniques for GIST removal.