The Advantage of an Endoscopic Submucosal Tunneling Technique for Rectal Carcinoid Tumors

Endoscopic treatment can be a curative option for small carcinoid tumors with an extremely low risk of metastasis. Since most carcinoid tumors are characterized by a specific growth pattern in the submucosal (SM) layer, specialized endoscopic techniques for deeper resection to achieve clear vertical margins are needed. The endoscopic submucosal dissection (ESD) method in the SM space is superior to conventional endoscopic mucosal resection. However, the standard ESD technique sometimes fails to provide complete deep SM dissection due to insufficient SM lifting. Here, to resolve this problem, we describe our initial experience with an endoscopic SM tunneling technique that is effective for treating rectal carcinoid tumors.

Review of Pure Endoscopic Full-Thickness Resection of the Upper Gastrointestinal Tract

Natural-orifice transluminal endoscopic surgery (NOTES) using flexible endoscopy has attracted attention as a minimally invasive surgical method that does not cause an operative wound on the body surface. However, minimizing the number of devices involved in endoscopic, compared to laparoscopic, surgeries has remained a challenge, causing endoscopic surgeries to gradually be phased out of use. If a flexible endoscopic full-thickness suturing device and a counter-traction device were developed to expand the surgical field for gastrointestinal-tract collapse, then endoscopic full-thickness resection using NOTES, which is seen as an extension of endoscopic submucosal dissection for full-thickness excision of tumors involving the gastrointestinal-tract wall, might become an extremely minimally invasive surgical method that could be used to resect only full-thickness lesions approached by the shortest distance via the mouth. It is expected that gastroenterological endoscopists will use this surgery if device development is advanced. This extremely minimally invasive surgery would have an immeasurable impact with regard to mitigating the burden on patients and reducing healthcare costs. Development of a new surgical method using a multipurpose flexible endoscope is therefore considered a socially urgent issue.