Complete Mesocolic Excision Is Safe and Results in Increased Lymph Node Harvest: Further Justification for Randomised Trials

Abstract Aim Complete mesocolic excision (CME) for right hemicolectomy encompasses embryonic dissection planes, radical lymphadenectomy and vascular pedicle ligation at the origin. Compared to conventional D2 dissection, CME is associated with increased disease-free survival in population studies. Critics argue that morbidity from CME may be higher. We sought to examine complication rates and specimen oncologic characteristics in a cohort from a single NHS trust. Method We conducted a retrospective cohort study of all right hemicolectomies performed for adenocarcinoma between 3/1/2019 and 15/11/2022. The choice of CME or D2 lymphadenectomy was at the discretion of the operating surgeon. Data were collected from paper notes and electronic records. Statistical analyses used non-parametric testing. Results CME was performed in 30 patients and D2 resection in 99. The CME group were younger (70 vs. 72 years, p = 0.04) and preoperative nodal staging was higher. There were no differences in duration of surgery, estimated blood loss, postoperative haemoglobin or transfusion requirement. Only 20% patients in the CME group had a significant complication compared to 40% of the D2 group (p = 0.05) and length of stay was reduced (5 vs. 7 days, p = 0.02). Nodal harvest was increased in the CME group (24 vs. 19, p = 0.01) with no difference in R0 resection rate. Conclusions CME appears to be safe and does not result in increased complication rates in this single institution cohort. Nodal harvest is increased with comparable margin clearance. Whether this translates to increased disease-free survival is unclear. There is equipoise and randomised studies examining long-term outcomes are justified.