OBJECTIVETo evaluate the clinical value of submucosal tunneling endoscopic resection(STER) for gastric submucosal tumor(SMT) originating from the muscularis propria (MP) layer.

METHODSClinicopathological data of 23 cases with gastric SMT originating from the MP layer treated with STER from September 2010 to December 2011 were analyzed retrospectively.

RESULTSThere were 13 males and 10 females. The age ranged from 28 to 73(mean, 52.4) years old. Of the 23 SMTs, 11 were located in the cardia adjacent to the gastric body, 4 in the cardia adjacent to the fundus, 5 in the lesser curvature of gastric body and 3 in the gastric antrum of greater curvature. All the SMTs originating from the MP layer, 14 were located in the superficial MP layer and 9 in the deep MP layer(including 5 gastric SMTs close to serosa). En bloc STER was performed successfully in all the patients. The mean lesion size was 2.1 cm(range 1.5-3.2 cm). The mean procedure time was 54.8 min(range 30-125 min). Pathological examination showed that the lesions were leiomyomas(n=10), stromal tumors(n=8), glomus tumor(n=2), Schwannoma(n=2), and calcifying fibrous tumor(n=1). Both lateral and vertical margins were negative in all the cases. Three patients developed pneumothorax and subcutaneous emphysema and 5 pneumoperitoneum. One patient developed effusion under the left half of the diaphragm and secondary infection. All of them recovered uneventfully after conservative treatments. No delayed bleeding or GI tract leakage was noticed. None of the 23 cases encountered submucosal hematoma or infection. No tumor residual or recurrence was found during the follow up(range, 3-18 months).

CONCLUSIONSSTER is a safe, effective for appropriate lesions in the MP layer of the stomach. En bloc resection and accurate histopathological evaluations can be achieved.