Feasibility and safety of endoscopic full‐thickness resection for submucosal tumors in the upper gastrointestinal tract, including predominantly extraluminal submucosal tumors (with video)

Objectives Endoscopic full‐thickness resection (EFTR) for submucosal tumors (SMTs) has been technically challenging. This retrospective study aimed to evaluate the feasibility, safety, and efficacy of EFTR for upper gastrointestinal (GI) SMTs, including extraluminal lesions. Methods We retrospectively investigated 232 patients with SMTs who underwent EFTR from January 2014 to August 2023. Clinicopathologic characteristics, procedure‐related parameters, adverse events (AEs), and follow‐up outcomes were assessed in all patients. Results The en‐bloc resection and en‐bloc with R0 resection rates were 98.7% and 96.1%, respectively. The average endoscopic tumor size measured 17.2 ± 8.7 mm, ranging from 6 to 50 mm. The resection time and suture time were 49.0 ± 19.4 min and 22.5 ± 11.6 min, respectively. In all, 39 lesions (16.8%) exhibited predominantly extraluminal growth. Gastrointestinal stromal tumors (GISTs) were the predominant pathology, accounting for 78.4% of the cases. Twenty‐one patients (9.1%) encountered complications, including pneumothorax (1/232, 0.43%), hydrothorax (1/232, 0.43%), localized peritonitis (3/232, 1.29%), and fever (16/232, 6.9%). Although the incidence of postoperative fever was notably higher in the predominantly extraluminal group (7/39, 17.9%) compared to the predominantly intraluminal group (9/193, 4.7%, P = 0.008), there were no significant differences in outcomes of the EFTR procedure. No instances of recurrence were observed during the mean follow‐up period of 3.7 ± 2.3 years. Conclusion EFTR was found to be feasible, safe, and effective for resecting upper GI SMTs, including lesions with predominantly extraluminal growth. Further validation in a prospective study is warranted.