Reverse endoscopic full-thickness resection (R-EFTR) for gastric submucosal tumors with a predominant extraluminal growth pattern

BACKGROUND: Large gastrointestinal stromal tumors (GISTs) exhibiting a predominantly extraluminal growth pattern are characterized by a rich vascular supply and close proximity to adjacent organs, which pose significant challenges for endoscopic full-thickness resection (EFTR). This study aims to evaluate the feasibility and therapeutic outcomes of R-EFTR for gastric GISTs with a predominantly extraluminal growth pattern. METHODS: We conducted a retrospective analysis of 43 consecutive patients who underwent R-EFTR for gastric GISTs exhibiting a predominant extraluminal growth pattern between March 2019 and December 2024. Data on clinicopathologic characteristics, surgical parameters, and follow-up outcomes were collected and analyzed. RESULTS: Tumor sizes ranged from 2.0 to 5.0 cm, and en bloc resection by R-EFTR was successfully achieved in 41 tumors (95.3%). Notably, tumors larger than 3 cm significantly prolonged operative times (P < 0.001). Successful closure of gastric wall defects was accomplished using through-the-scope twin clips in 41.9% of cases, while 58.1% were closed using endoloop-clips. Closure with endoloop-clips was associated with longer procedure time (P = 0.037). The postoperative follow-up completion rate was 100%, achieved through clinic visits combined with endoscopic ultrasound and computed tomography. During the follow-up period, no patients experienced recurrence or metastasis. CONCLUSIONS: The findings of our study suggest that R-EFTR is a viable and effective treatment option for GISTs that exhibit a predominantly extraluminal growth pattern and measure between 2 and 5 cm. Tumor size greater than 3 cm was associated with increased procedural complexity, whereas the association with endoloop-clip closure should be interpreted cautiously.