Standardize the Surgical Technique and Clarify the Relevant Anatomic Concept for Complete Mobilization of Colonic Splenic Flexure Using da Vinci Xi® Robotic System.

BACKGROUND: The present study is to set up a standardized approach for complete mobilization of colonic splenic flexure using da Vinci Xi® robotic system, based on clarification of the mesenteric structures of distal transverse colon.

METHODS: The surgical outcomes and relevant anatomic structures of 104 consecutive patients undergoing robotic resection of primary colorectal cancer with the intent of complete mobilization of colonic splenic flexure using da Vinci Xi® robotic system were retrospectively reviewed.

RESULTS: Complete mobilization of colonic splenic flexure can be efficiently performed by the Xi® robotic system, as demonstrated by short operation time, minimal intra-operative blood loss, and few surgical complications. Xi® robotic system has overcome the drawbacks of Si® robotic system for the mobilization of colonic splenic flexure. The present study defined the following anatomic hallmarks for the colonic splenic flexure: (1) The transverse mesocolon distal to the inferior mesenteric vein adheres to the low border of pancreas by the avascular fibrous connective tissues, which have been inappropriately named as "mesenteric root"; (2) The colonic splenic flexure abuts closely to spleen with an acute angle in 78.85% (n = 82/104); (3) Only a minority of patients presented with the Riolan branch (15.38%, n = 16/104) or the Moskowitz artery (8.65%, n = 9/104).

CONCLUSION: With increased maneuverability of Xi® robotic arms and the clarification of relevant anatomic concept, the surgical technique for the complete mobilization of colonic splenic flexure can be standardized; and the standardization of surgical technique is the first step toward the enhanced automation in the rapidly evolving robotic systems.