To evaluate the perioperative efficacy, safety and long-term outcome of nerve-sparing sheath outside-sheath separation technique in D3 radical resection for right-sided colon cancer under laparoscope.

The clinical data of 148 patients underwent D3 radical resection for right-sided colon cancer under laparoscop (arterial approach) in Gastrointestinal Cancer Center of Guangdong Hospital of Traditional Chinese Medicine from January 2016 to December 2021 were retrospectively analyzed. According to whether the sheath of superior mesenteric artery was preserved, the patients were divided into inside-sheath separation group (36 cases) and outside-sheath separation group (112 cases). The two groups were matched 1∶1 by the propensity score matching. The operation time, blood loss, intraoperative vascular injury, and postoperative complications were compared and analyzed. Pathological examination of the sheath of the superior mesenteric artery was conducted, and the lymphatic tracer was used in the outside-sheath separation group, and the 3-year survival and 3-year disease-free survival of the two groups were compared and analyzed.

After propensity score matching, thirty-six patients in each group were successfully matched. The baseline characteristics were comparable between two groups (all P＞0.05). The intraoperative blood loss was less in the outside-sheath separation group than in the inside-sheath separation group [45(20.0, 50.0) mL vs. 80(50.0, 100.0) mL, Z=-2.743, P=0.006]. Postoperative duration of hospitalization was shorter [6(5, 9) d vs. 7(6, 10) d, Z=-2.288, P=0.022]; There was no significant difference in the total number of lymph nodes [(22.5±8.3) vs. (19.7±10.0)] and the number of positive lymph nodes [0(0, 1) vs. 0(0, 1)] between outside-sheath separation and inside-sheath separation groups (P＞0.05). The incidence of postoperative diarrhea (11.1% vs. 44.4%, χ²=9.969, P=0.002) and the incidence of lymphatic leakage (8.3% vs. 33.3%, χ²=6.281, P=0.009) were lower in the outside-sheath separation. Pathological examination of the sheath of the superior mesenteric artery showed nerve fibers containing nerve cells in the sheath, but no lymphoid tissue structure was found, and the lymphatic tracer showed no inside-sheath staining. There was no significant difference in 3-year overall survival rate (88.1% vs. 89.5%) and 3-year disease-free survival rate (74% vs. 85.4%) between outside-sheath separation and inside-sheath separation groups (P＞0.05).

The nerve-sparing sheath outside-sheath separation technique in D3 radical resection for right-sided colon cancer under laparoscope is safe and feasible, which can significantly reduce intraoperative blood loss, shorten postoperative duration of hospitalization, reduce postoperative diarrhea and lymphatic leakage, and does not affect the long-term outcomes.