Comparison of right hemicolectomies with and without complete mesocolic excision (CME)

Abstract Objective Since the concept of complete mesocolic excision (CME) in right hemicolectomies was introduced, it is still under debate if all patients require this radical technique. Methods Patients with adenocarcinoma of the colon undergoing right hemicolectomies at our hospital were retrospectively analyzed and stratified in a non-CME group (08/2014-04/2018) and a CME group (05/2018-11/2021). Patients were compared in regard to clinical, histopathological and prognostic parameters. CME were classified according to Benz et al. Results A total of 130 right hemicolectomies were performed, 33 (25.4%) patients were excluded due to other pathologies or emergency patients. Finally, 97 patients were included (53 in the CME group, 39 in the non-CME group). No difference in patient's characteristics were found except more male patients in the CME group (20 vs. 6; p=0.02). Tumors in the CME group were mainly located in the colon ascendens (66.0%), in the non-CME group in the coecum (48.7%; n.s.). In the CME group, 26 of 53 (49.1%) patients were operated laparoscopically compared to 10 of 39 (25.6%) patients in the non-CME group. Da Vinci system were used exclusively in the CME group (5 of 53 (9.4%); p=0.003). TNM classification, histology and UICC stadium showed no significant difference. In total, 50 (94.3%) surgical specimen were classification either as CME 0 or 1. In average, 35.2 lymph nodes (8.2% positive) were found in the CME group compared to 32.7 (16.2% positive) lymph nodes in the non-CME group (p=0.9). No relevant intraoperative complications occurred in both groups. Distance of the mesocolon were available in 39 (73.6%) patients in the CME group and 34 (37.1%) in the non-CME group; the distance tended to be longer in the CME group (mean 116.0 mm in CME group vs. 96.6 mm in non-CME group; p=0.09). Follow-up were 336.4 days in CME-group and 1210.4 days in the non-CME group. In the follow-up, 2 (5.1%) patients in the non-CME group developed a local recurrence in the smaller pelvis. No local recurrence occurred in the CME group (p=0.18). Distant metastasis occurred in 5 of 53 (9.4%) patients in the CME group and in 2 of 39 (5.4%) patients in the non-CME group (p=0.7). Conclusion This study shows that the benefit for CME in all performed right hemicolectomies is marginal and that the surgical standards was already high in the pre-CME era.