Background and Purpose: Laparoscopic right hemicolectomy has been widely accepted for locally advanced cancer of the right colon. Three–dimensional computed tomography was reported to be useful to obtain sufficient information regarding arterial and venous distributions for the right colon preoperatively. However, its routine use in clinical practice has several limitations. This study was performed to classify the distribution patterns of arterial branches crossing the superior mesenteric vein (SMV). Patients and Methods: Arterial branches crossing the superior mesenteric vein (SMV) were prospectively recorded in 196 patients (Male/Female=117 /79) who underwent standard right hemicolectomy via conventional open or minilaparotomy approach between 1991.1 and 2009.6. Results: The right branch of the middle colic artery (RBMCA) originated directly from the superior mesenteric artery in 24 cases (12.2 %), while it arouse from the common trunk in 172 cases (87.8%). According to the presence or absence of the right colic artery (RCA) and the site at which the RCA (if present) and ileocolic artery (ICA) crossed the SMV (ventrally or dorsally), cases were classified into 6 types: Type Ia; ICA crossing SMV ventrally (absent RCA) in 27 cases (13.8%), Type Ib: ICA crossing SMV dorsally (absent RCA) in 46 cases (23.5%), Type IIa: ICA and RCA crossing SMV dorsally in 21 cases (10.7%), Type IIb: ICA and RCA crossing SMV ventrally in 50 cases (25.5%), Type IIc: ICA crossing dorsally and RCA crossing ventrally SMV in 50 cases (25.5%), and Type IId: ICA crossing ventrally and RCA crossing dorsally SMV in two cases (1.0%). Conclusion: Surgeons should note the type and frequency of pattern of arterial branches crossing the SMV to perform laparoscopic right hemicolectomy safely.
Program Number: P134