Transcolonic endoscopic appendectomy: a novel natural orifice transluminal endoscopic surgery (NOTES) technique for the sessile serrated lesions involving the appendiceal orifice

With the advancement in endoscopic technology, the discovery of novel endoscopic techniques such as endoscopic full-thickness resection (EFTR) provides new contents for natural orifice transluminal endoscopic surgery (NOTES) and endoscopic therapeutic options for patients with gastrointestinal lesions. Here, we present transcolonic endoscopic appendectomy as an expansion of full thickness resection with extraluminal dissection of the appendix for minimally invasive treatment of the sessile serrated lesions (SSLs) deeply involving the appendiceal orifice; final closure is done by endoloop and clip placement. The procedure was successful in four patients with good follow-up results at the 3 months colonoscopic control. Generally, transcolonic endoscopic appendectomy extends endoscopic resection technique and will promisingly replace combined endoscopic and laparoscopic surgery technique. This technique should be studied further. SSLs are colorectal lesions with malignant potential1 and should be removed as accurately as possible.2 In dilemma, more than half of the appendiceal adenomas are SSLs3 4 and therapeutic methods are controversial: endoscopic resection, extended laparoscopic appendectomy or combined laparoscopic appendectomy is traditionally optional.1 Surgical resection remains the standard and endoscopic resection is sometimes performed as an alternative to surgical intervention. However, conventional endoscopic resection of SSLs involving the appendiceal orifice has very critical limitations: endoscopic resection into the appendiceal orifice deeply itself carries a risk of appendicitis and it cannot guarantee a negative deep margin for lesions growing into the lumen of the appendix.2 To overcome these disadvantages, we present a novel NOTES technique, transcolonic endoscopic appendectomy, for the SSL involving the appendiceal orifice. This technique takes advantage of EFTR technique, which includes the endoscopic full-thickness incision and defect closure techniques. Here, we report a series of patients with the SSLs deeply involving the appendiceal orifice removed by transcolonic endoscopic appendectomy technique (figure 1). Patient demographics, procedure details, outcomes, histology and follow-up after …