Submucosal tunnel endoscopic resection for extraluminal tumors: a novel endoscopic method for en bloc resection of predominant extraluminal growing subepithelial tumors or extra-gastrointestinal tumors (with videos).

BACKGROUND AND AIMS: The management of subepithelial tumors with a predominant extraluminal growth pattern or extra-GI tumors can be challenging and traditionally requires a surgical resection that is not only invasive but may carry a significant risk of morbidity and mortality. We aimed to assess the feasibility, safety, and efficacy of a novel endoscopic technique termed submucosal tunnel endoscopic resection for extraluminal tumors (STER-ET).

METHODS

We prospectively enrolled patients who underwent STER-ET for GI subepithelial tumors with a predominant extraluminal growth pattern or extra-GI tumors located at the level of cardia or the proximal part of the lesser curvature of the stomach seen on cross-sectional imaging between January 2016 and March 2017.

RESULTS

Eight patients underwent STER-ET. The mean (± standard deviation) tumor size was 2.8 ± 0.6 cm and 2.3 ± 0.8 cm in longest and shortest dimension, respectively. The average procedure time was 67 ± 4.4 minutes. The rates of curative en bloc resection and en bloc retrieval was 100% and 87.5%, respectively. On final histology, 6 tumors were GI stromal tumors, 1 was a schwannoma, and 1 was a foregut cyst. Five patients had capnoperitoneum during the procedure and required abdominal decompression. One patient had a small mucosotomy successfully treated with a hemostatic clip. There were no major adverse events or deaths. The median length of hospital stay was 3 days. There was no residual tumor on surveillance imaging after a mean follow-up period of 10.0 ± 2.1 months.

CONCLUSIONS

STER-ET is a novel technique that appears to be safe and effective in achieving a curative resection for GI subepithelial tumors with a predominantly extraluminal growth pattern or extraluminal tumors in a selected group of patients. However, larger studies are required to validate our finding.