Inter-rater and intra-rater reliability of multi-slice CT and three-dimensional reconstructed imaging analysis of mesenteric vascular anatomy for planning and performing complete mesocolic excision

Aim: Complete mesocolic excision (CME) for colon cancer has been associated with improved oncological outcomes but requires a detailed understanding of complex mesenteric vasculature. Three-dimensional (3D) reconstructed models derived from patient imaging could enhance preoperative anatomical comprehension, enabling safer, precision CME. Methods: In this two-phase, blinded, crossover study, four expert CME surgeons evaluated mesenteric vascular anatomy on CT scans and 3D models. In phase 1, surgeons assessed 66 cases, while 20 were re-evaluated in phase 2. The primary outcome measure was inter-rater reliability by Fleiss's kappa. Secondary outcomes were intra-rater reliability by Cohen's kappa and anatomical accuracy rates measured as a percentage of correct responses on a standardised questionnaire. Results: In phase 1, inter-rater agreement was higher for 3D models (average kappa 0.6, moderate agreement) than for CT scans (average kappa 0.1, poor agreement). Ileocolic vein drainage and ileocolic artery trajectory showed the highest kappa values with 3D imaging (0.85 and 0.93, respectively). Accuracy was also superior with 3D across all surgeons (mean 89.7% correct) versus CT (mean 79.1% correct, P < 0.001). In phase 2, intra-rater reliability remained higher for 3D (average Cohen's kappa 0.61) than CT scans (Cohen's kappa 0.27). Conclusion: 3D mesenteric models significantly improve inter- and intra-rater reliability among CME experts over traditional CT scans while markedly enhancing anatomical comprehension accuracy about critical right-sided colonic vasculature. 3D planning could facilitate CME by enabling superior preoperative visualisation of these vessels.