Combined EUS and CT for evaluating gastrointestinal submucosal tumors before endoscopic resection

Submucosal Tunneling Endoscopic Resection

Minimally invasive endoscopic resection procedures continue to evolve, with submucosal tunneling endoscopic resection (STER) being a durable option for en bloc resection of submucosal tumors. Whether STER can be effectively used for larger (>3.5 cm) lesions remains to be seen. STER-ET is a novel approach for removal of extraluminal tumors, but data are currently limited to support its use.

Outcomes of submucosal tunneling endoscopic resection in upper gastrointestinal sub-epithelial tumors

BACKGROUND

Submucosal tunneling techniques have expanded the horizon of therapeutic endoscopy. One such procedure, submucosal tunneling endoscopic resection (STER), enables the endoscopic removal of gastrointestinal (GI) sub-epithelial tumors. In this study, we aimed to evaluate the safety and efficacy of STER in patients with sub-epithelial lesions localized to the upper GI tract.

METHODS

Consecutive subjects with a sub-epithelial lesion of ≥ 1 cm size in the upper GI tract were enrolled in the study. STER was performed using the standard technique in an endoscopy suite. A modified technique (double-opening STER) was used in cases with difficult en bloc resection of the tumor. Outcome measures included technical success, en bloc resection rates, adverse events, and recurrence.

RESULTS

A total of 104 patients with sub-epithelial tumors were evaluated for STER. Of them, 44 subjects (mean age 44.68 ± 12.82, 52.3% males) underwent standard STER. Majority (31, 70.4%) of the lesions were located in the esophagus and cardia. Technical success and en bloc removal of the tumor were achieved in 97.7% and 88.4% of cases, respectively. There was no major adverse event. Minor adverse events were recorded in 7 (15.9%) cases. Majority (31, 70.4%) of the tumors originated from muscularis propria, followed by submucosa (8, 18.2%) and muscularis mucosa (5, 11.4%). The most common histological diagnosis was leiomyoma (59.1%) followed by GI stromal tumors (20.4%). At a mean follow up of 12.36 ± 7.63 months, there was no incidence of tumor recurrence in en bloc as well as piecemeal resection groups.

CONCLUSION

STER is a safe and efficacious procedure for sub-epithelial tumors in the upper GI tract. Novel strategies need to be developed to ensure en bloc removal of large lesions.

Endoscopic full thickness resection versus submucosal tunneling endoscopic resection for removal of submucosal tumors: a review article

Submucosal tumors (SMT) are protuberant lesions with intact mucosa that have a wide differential. These lesions may be removed by standard polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or surgically. However, in lesions that arise from the muscularis propria, full thickness resection is recommended. This can be completed using either endoscopic full thickness resection (EFTR) or submucosal tunneling endoscopic resection (STER). EFTR can be accomplished by completing a full thickness resection followed by defect closure or by securing gastrointestinal wall patency before resection. STER is an option that first creates a mucosal dissection proximal to the lesion to allow a submucosal tunnel to be created. Using this tunnel, the lesion may be resected. When comparing STER to EFTR, there was no significant difference when evaluating tumor size, operation time, rate of complications, or en bloc resection rate. However, suture time, amount of clips used, and overall hospital stay were decreased in STER. With these differences, EFTR may be more efficacious in certain parts of the gastrointestinal tract where a submucosal tunnel is harder to accomplish.

Endoscopic Full Thickness Resection

Recent advances in minimally invasive endoscopic approaches have pushed the boundaries of well-established resection techniques for therapeutic and diagnostic applications. Endoscopic full thickness resection techniques are a key development in the management of challenging epithelial and subepithelial lesions that are not amenable to conventional endoscopic resection methods and previously required a surgical approach. Endoscopic full thickness biopsy represents a paradigm shift in tissue acquisition and will enhance our understanding of the pathophysiology, and guide therapy, of gastrointestinal neuromuscular diseases, as well as other inflammatory and neoplastic conditions. This review highlights current tools and techniques available for endoscopic full thickness resection and biopsy, as well as outcomes from such interventions.

Submucosal Tunneling Endoscopic Resection (STER) and Other Novel Applications of Submucosal Tunneling in Humans

The submucosal tunneling technique was originally developed to provide safe access to the peritoneal cavity for natural orifice transluminal endoscopic surgery procedures. With this technique, the submucosal tunnel becomes the working space for partial myotomy and tumor resection. The submucosal space has come to represent the "third space" distinguished from gastrointestinal lumen (first space) and peritoneal cavity (second space). New applications continue to be developed and further clinical applications in the future are anticipated. This article summarizes the current applications of submucosal tunneling endoscopic resection for subepithelial tumors and describes other related uses of submucosal tunneling.