Retroperitoneal Approach to D3-Lymph Node Dissection With Left Colic Artery Preservation in the Treatment of Sigmoid Cancer

BACKGROUND: Laparoscopic approaches and robot-assisted operations are used for colorectal cancer surgery because of their minimal invasiveness. 1 However, changes in intra-abdominal pressure during laparoscopy can lead to cardiovascular complications in compromised patients; 2 obesity and intraabdominal adhesions may further interfere with laparoscopic procedures. The retroperitoneal approach may facilitate minimally invasive surgery, even in patients with comorbidities. The technique for high ligation of the inferior mesenteric artery has been described in left colonic surgeries. 3 However, complete termination of the blood supply through this artery may lead to a higher frequency of anastomotic leakage. 4 IMPACT OF INNOVATION: We present a novel retroperitoneal approach for D3-lymph node dissection with low ligation of the inferior mesenteric artery and preservation of the left colic artery. This method can reduce the duration of laparoscopic procedures for compromised patients and meet the standards for extended lymph node dissection with tumor-specific mesocolic excision. 5,6 TECHNOLOGY MATERIALS AND METHODS: The procedure started with the installation of a paraumbilical optical trocar to introduce a 30-degree optical system. The SILS™ Port (Covidien, Medtronic) was inserted into the retroperitoneal space via a 4-cm incision, made 2 cm below and parallel to the anterior superior iliac spine in the left flank under the control of the optical system. The horizontal aspect of the duodenum served as the cranial landmark during interfascial dissection, with the dissection proceeding in a cranial and medial direction. During the dissection, the left ureter was the primary landmark, passing medial to the gonadal vessels and Gerota's fascia. The aorta was exposed medially and the inferior mesenteric artery was identified. The inferior mesenteric artery was skeletonized from its origin until the branching of the left colic artery and the sigmoid artery. The left colic artery was skeletonized until the passage of the inferior mesenteric vein, and the apical lymphatic nodes with mesocolic tissue were mobilized and excised. The inferior mesenteric artery was cut below the left colic artery. The final step was performed laparoscopically. The parietal fascia along Toldt’s line was cut laterally to complete the mesocolon excision. The parietal fascia was cut along the right side of the aorta to free the mesocolonic medial border. The sigmoid mesocolon was dissected at the proximal and distal resection margins. Following mobilization, the colon was cut 10 cm distal to the tumor margin using a linear stapler. The specimen was then extracted using an SILS incision. The sigmorectal anastomosis was made. Atypical hepatic resection was performed using two additional trocars. PRELIMINARY RESULTS: The incidence of pain syndrome in the early postoperative period was low. Blood loss reached 100 mL. The duration of the surgery was 300 min. The retroperitoneal step took 63 min. Metastases were observed in 7 of the 41 harvested lymph nodes. The patient was discharged on the 8 th postoperative day. CONCLUSIONS AND FUTURE DIRECTIONS: The retroperitoneal technique can be safely performed. Anatomical structures are readily accessible and easily visualized with this approach after special training, enabling extended lymph node dissection.