Introduction Full-thickness laparoendoscopic excision could offer an innovative solution for endoscopically irresectible early colonic neoplasia that would otherwise require colectomy. However, accurate preoperative characterisation is needed. This study evaluated the accuracy of CT colonography (CTC) when assessing key anatomical considerations concerning safe laparoendoscopic excision: polyp location in relation to mesenteric vascular supply (‘mesenteric versus anti-mesenteric border of colonic wall’), proportion of colonic circumference involved and polyp diameter.
Method National ethics committee approval was obtained. Between 2006–2014 consecutive patients undergoing CTC examination prior to colonic resection for complex benign polyps or UICC stage 1 cancer were selected from a colorectal database for retrospective review. CTC examinations were interpreted in consensus by two experienced gastrointestinal radiologists, blinded to postoperative histopathological findings (reference). The percentage of cases accurately located was recorded. Kappa statistic (κ) and Spearman’s correlation coefficient (r) were used to compare circumferential involvement and polyp diameter.
Results 20 patients with 20 early colonic neoplasms (2 polyps and 18 UICC stage 1 cancers (median diameter 32.5 mm, range 15–80)) were included. 15 were located on the mesenteric border and 5 on the anti-mesenteric border. All 20 polyps were correctly categorised (mesenteric vs antimesenteric). Consensus agreement on interpretation of proportion of wall circumference involvement was good (17/20 cases, κ 0.76). There was excellent correlation for polyp diameter between radiology and reference (r 0.926).
Conclusion CTC can accurately define local characteristics of colon polyps and early cancers. This is likely to assist in selecting colonic polyps that are suitable for full-thickness laparoendoscopic excision.
Disclosure of interest None Declared.