The Extraperitoneal Approach to Left-Sided Colorectal Resections: A Human Cadaveric Study

Area of Science:

• Surgical Innovation
• Minimally Invasive Surgery
• Anatomical Dissection

Background:

• Laparoscopic and robotic anterior resection present challenges in visualizing retroperitoneal structures and the total mesorectal excision (TME) plane.
• Steep head-down positioning, while improving exposure, carries risks like cerebral edema and increased intrapulmonary pressures.

Purpose of the Study:

• To describe and evaluate a novel extra-peritoneal (XP) technique for anterior resection performed in the supine position.
• To assess the feasibility of achieving clear views of key retroperitoneal structures and the TME plane without steep patient positioning.

Main Methods:

• A lateral-to-medial extra-peritoneal (XP) dissection technique was developed and refined in cadaveric workshops.
• Dissection was performed in the left XP space via a skin incision, allowing for laparoscopic or robotic port placement.
• Mobilization of the colon and identification of structures like the inferior mesenteric artery (IMA) pedicle were conducted proximally.

Main Results:

• The technique was tested in eight cadavers, with four procedures performed laparoscopically and four robotically.
• Excellent early visualization of retroperitoneal structures including the IMA pedicle was achieved.
• Anatomical identification of key left-sided structures preceded IMA pedicle ligation in all cases.

Conclusions:

• Performing key steps of anterior resection via the extra-peritoneal (XP) space in the supine position is feasible.
• This approach may reduce the need for steep head-down positioning, offering potential clinical benefits.
• Further prospective clinical studies are necessary to validate this technique in patients.