Key steps in exposure techniques for robotic total mesorectal excision (TME)

Aim: The use of robotic surgery is increasing significantly. Specific training is fundamental to achieve high quality and better oncological outcomes. This work defines key exposure techniques in robotic total mesorectal excision (TME). Based on a modular approach, macro- and microtractions for exposure in every step of a robotic TME are identified and described. The aim is to develop a step-by-step technical guide of the exposure techniques for a robotic TME.

Methods: Twenty-five videos of robotic rectal resections performed at Champalimaud Foundation (Lisbon, Portugal) with the Da Vinci™ Xi robotic platform were examined. Robotic TME was divided into modules and steps. Modules are essential phases of the procedure. Steps are exposure moments of each module. Tractions are classified as macro- and microtractions. Macrotraction is the grasping of a structure to expose an area of dissection. Microtraction consists in the dynamic grip of tissue to optimize macrotraction in a defined area of dissection.

Results: The procedure videos reviewed showed homogeneity concerning surgical methodology. Eight modules are outlined: abdominal cavity inspection and exposure, approach to and ligation of the inferior mesenteric vessels, medial to lateral dissection of the mesocolon, lateral colon mobilization, splenic flexure takedown, proctectomy with TME, rectal transection, and anastomosis. Each module was divided into steps, with a total of 45 steps for the entire procedure. This manuscript characterizes macrotraction and microtraction fine-tuning, detailing the large-scale macrotractions and the precision of microtractions at each step.

Conclusion: Tissue exposure techniques in robotic TME are key to precise dissection. This modular guide provides a functional system to reproduce this procedure safely; the addition of the exposure techniques could serve as a training method for robotic rectal cancer surgery.