Impact of technology on indications and limitations for transanal surgical removal of rectal neoplasms

Abstract

Transanal surgery has and continues to be well accepted for local excision of benign rectal disease not amenable to endoscopic resection. More recently, there has been increasing interest in applying transanal surgery to local resection of early malignant disease. In addition, some groups have started utilizing a transanal route in order to accomplish total mesorectal excision (TME) for more advanced rectal malignancies. We aim to review the role of various transanal and endoscopic techniques in the local resection of benign and malignant rectal disease based on published trial data. Preliminary data on the use of transanal platforms to accomplish TME will also be highlighted. For endoscopically unresectable rectal adenomas, transanal surgery remains a widely accepted method with minimal morbidity that avoids the downsides of a major abdomino-pelvic operation. Transanal endoscopic microsurgery and transanal minimally invasive surgery offer improved visualization and magnification, allowing for finer and more precise dissection of more proximal and larger rectal lesions without compromising patient outcome. Some studies have demonstrated efficacy in utilizing transanal platforms in the surgical management of early rectal malignancies in selected patients. There is an overall higher recurrence rate with transanal surgery with the concern that neither chemoradiation nor salvage surgery may compensate for previous approach and correct the inferior outcome. Application of transanal platforms to accomplish transanal TME in a natural orifice fashion are still in their infancy and currently should be considered experimental. The current data demonstrate that transanal surgery remains an excellent option in the surgical management of benign rectal disease. However, care should be used when selecting patients with malignant disease. The application of transanal platforms continues to evolve. While the new uses of transanal platforms in TME for more advanced rectal malignancy are exciting, it is important to remain cognizant and not sacrifice long term survival for short term decrease in morbidity and improved cosmesis.

Keywords: Transanal surgery, Transanal endoscopic microsurgery, Endoscopic mucosal resection, Transanal total mesorectal excision, Transanal minimally invasive surgery, Robotic transanal surgery, Local excision rectal neoplasms

Core tip: The review summarizes the technology advances and analyzes their impact on the validity of local transanal management of benign vs malignant rectal neoplasms. Current data demonstrate that transanal surgery remains an excellent option for benign disease. As transanal platforms continue to evolve, caution should be used when selecting patients with malignant disease. In view of the fact that the alternative of abdominal oncological procedures (laparoscopic, robotic, open) provide high cure rates, it is important to remain cognizant and not sacrifice long term survival for short term benefits (decrease in morbidity and improved cosmesis).