High-frequency probe EUS-assisted endoscopic mucosal resection: a therapeutic strategy for submucosal tumors of the GI tract.

Background: The aim of this study was to evaluate the efficacy and safety of high-frequency probe EUS (HFPE)-assisted endoscopic mucosal resection in the management of submucosal tumors of the GI tract.

Methods: HFPE-assisted endoscopic mucosal resection was attempted in 28 patients with submucosal tumors less than 2 cm in diameter. HFPE was performed with a 20-MHz "through-the-scope" probe. Saline solution was injected into the submucosa. After confirming detachment of the lesion from the muscularis propria by repeat HFPE, endoscopic mucosal resection was performed with a lift-and-cut or endoscopic mucosal resection cap technique. Follow-up endoscopy was performed in all patients.

Results: Submucosal tumors from the following areas were included: esophagus 3, stomach 4, duodenum 3, and colon 18. The submucosal tumors were located in the upper third (n = 3), middle third (n = 18), and lower third (n = 7) of the submucosa. Twenty-one submucosal tumors were removed by the lift-and-cut technique and 6 by the cap method. One patient required surgical resection after unsuccessful endoscopic mucosal resection. The origin and depth of penetration of all lesions was accurately depicted by HFPE. Median tumor diameter was 9 mm (range 3-20 mm). Resection was successful and complete in 93% of the cases. There were no immediate postprocedure complications (exact 95% CI [0%, 12.3%]). During a median follow-up of 21.5 months (range 2-74 months) no recurrence was found.

Conclusions: HFPE-assisted endoscopic mucosal resection is safe and effective for the management of selected submucosal tumors of the GI tract. A management algorithm based on endoscopic and HFPE findings is proposed.