Endoscopic Treatment for Gastric Subepithelial Tumor

Advancements in Endoscopic Treatment for Gastric Subepithelial Tumors

Peroral flexible endoscopy is a minimally invasive technique that enables the local resection of gastric subepithelial tumors (SETs) with malignant potential. Resection techniques are mainly chosen on the basis of the lesion size. Minute SETs less than 1 cm should be managed through a watch and wait strategy, with the exception of histologically diagnosed superficial lesions, which require endoscopic mucosal resection or endoscopic submucosal dissection. For 1- to 3-cm small SETs, endoscopic enucleation techniques, such as endoscopic submucosal excavation, submucosal tunneling endoscopic resection, and peroral endoscopic tumor resection, can be used. However, endoscopic full-thickness resection is preferred for histologically complete removal with negative surgical margins. When endoscopic full-thickness resection is considered technically difficult, laparoscopic and endoscopic cooperative surgery (LECS) is a safe and dependable alternative. Moderate-sized SETs (3 to 5 cm) require surgical intervention because the lesions must be removed transabdominally. LECS is a less invasive surgical procedure as it reduces the resection area; however, some LECS techniques that require transoral tumor retrieval are not available. Endoscopic intervention for lesions larger than 5 cm should be used with caution for research purposes. With advancements in endoscopic diagnosis, the indications for endoscopic treatment for SETs are expected to improve, thereby enhancing patients' quality of life.

The maximum transverse diameter: an effective indicator for predicting peroral en bloc retrieval rate of mesenchymal tumors after endoscopic resection

BACKGROUND

Gastrointestinal mesenchymal tumors (GIMTs) are being increasingly resected under endoscopy. Large GIMTs cannot be completely retrieved through the mouth, but the cut-off diameter of peroral en bloc retrieval (PEBR) for GIMTs completely resected is still unknown. This study aimed to investigate the ability of maximum transverse diameter (MTD) to predict the PEBR rate of GIMTs after endoscopic resection (ER).

METHODS

We retrospectively reviewed all patients who underwent ER for upper GIMTs from January 2009 to August 2023. The MTD was measured according to the maximum transverse diameter of specimen immediately retrieved after ER. For the PEBR rate, the independent predictors and optimal cut-off value of MTD were determined by logistic regression analysis and the receiver operating characteristic (ROC) curve analysis. The potential significance of preoperative CT for the evaluation of MTD was also clarified.

RESULTS

A total of 2032 patients were diagnosed with upper GIMTs after en bloc resection under endoscopy. The overall PEBR rate was 98.72% (2006/2032). The PEBR rate was 100% for 1943 GIMTs with MTD < 2.5 cm, 85.71% (60/70) for GIMTs with 2.5 cm but ≤ 3.0 cm, and 15.79% (3/19) for GIMTs with MTD > 3.0 cm, and these rates were significantly different (P < 0.01). In terms of the PEBR rate of GIMTs, the ROC curve revealed that the optimal cut-off MTD value was 3.0 cm, and logistic regression analysis revealed that MTD > 3.0 cm was an independent predictive factor (OR 71.07, 95% CI 9.14-552.43; P < 0.001). The MTD of CT was related to that of the resected specimen (r = 0.7149, P < 0.01), and CT underestimated the mean MTD of upper GIMTs by 0.17 cm (95% CI 0.09-0.24, P < 0.01).

CONCLUSION

MTD is an effective indicator for predicting the PEBR rate of GIMTs after ER. Resected specimens with MTD > 3.0 cm could not be routinely retrieved en bloc. Preoperative CT is suitable for evaluating the MTD of GIMTs, but underestimates the mean MTD of upper GIMTs by 0.17 cm.