Establishment of the hybrid endoscopic full-thickness resection of gastric gastrointestinal stromal tumors.

A prospective observational study was conducted to establish the procedure of hybrid endoscopic full-thickness resection (EFTR) using an existing flexible endoscope. The present study included 16 patients who underwent hybrid EFTR between September 2009 and February 2013 for gastric gastrointestinal stromal tumor (GIST). The patients were selected using the following inclusion criteria for histological findings: Mitotic counts <5/high-power field and immunohistochemical stains positive for KIT or cluster of differentiation 34 (CD34). The mean patient age was 68.2 years (range, 44-81 years); the male-to-female ratio was 6:10; lesion sites at upper (U), middle (M) and lower regions (L) of the stomach were 9/6/1; and the average tumor diameter was 28.3 mm. The mean surgical time was 271 min and the surgical time became progressively faster with each successive surgery. There were 12 and four patients with mitotic counts of <5 and 5-10, respectively, which was significantly different (P=0.01). Immunohistochemical stains showed that tumors from 13 and 10 patients (81.2 and 62.5%, respectively) were positive for KIT and CD34, respectively (P=0.328). All resected surgical margins were negative. According to Fletcher's risk classification, there were five, eight and three patients at an 'extremely low', 'low', and 'intermediate' risk (31.2, 50 and 18.8%, respectively) (P=0.003). The mean postoperative hospital duration was 12.3 days (range, 10-15 days). In conclusion, an ultra-minimally invasive surgery-hybrid EFTR is a safe and established surgical endoscopy procedure.