A novel technique for NO.253 lymph node dissection and left colic artery preservation to avoid potential postoperative internal hernia in laparoscopic radical resection for rectal cancer.

Background: The preservation of the left colic artery (LCA) has emerged as a preferred approach in laparoscopic radical resection for rectal cancer. However, preserving the LCA while simultaneously dissecting the NO.253 lymph node can create a mesenteric defect between the inferior mesenteric artery (IMA), the LCA, and the inferior mesenteric vein (IMV). This defect could act as a potential "hernia ring," increasing the risk of developing an internal hernia after surgery. The objective of this study was to introduce a novel technique designed to mitigate the risk of internal hernia by filling mesenteric defects with autologous tissue.

Methods: This new technique was performed on eighteen patients with rectal cancer between January 2022 and June 2022. First of all, dissected the lymphatic fatty tissue on the main trunk of IMA from its origin until the LCA and sigmoid artery (SA) or superior rectal artery (SRA) were exposed and then NO.253 lymph node was dissected between the IMA, LCA and IMV. Next, the SRA or SRA and IMV were sequentially ligated and cut off at an appropriate location away from the "hernia ring" to preserve the connective tissue between the "hernia ring" and retroperitoneum. Finally, after mobilization of distal sigmoid, on the lateral side of IMV, the descending colon was mobilized cephalad. Patients'preoperative baseline characteristics and intraoperative, postoperative complications were examined.

Results: All patients' potential "hernia rings" were closed successfully with our new technique. The median operative time was 195 min, and the median intraoperative blood loss was 55 ml (interquartile range 30-90). The total harvested lymph nodes was 13.0(range12-19). The median times to first flatus and liquid diet intake were both 3.0 days. The median number of postoperative hospital days was 8.0 days. One patient had an injury to marginal arterial arch, and after mobolization of splenic region, tension-free anastomosis was achieved. No other severe postoperative complications such as abdominal infection, anastomotic leakage, or bleeding were observed.

Conclusions: This technique is both safe and effective for filling the mesenteric defect, potentially reducing the risk of internal hernia following laparoscopic NO.253 lymph node dissection and preservation of the left colic artery in rectal cancer surgeries.