[Investigation for Arc of Riolan-Conserving High Ligation Using Simulation CT Colonography in Preoperative Colorectal Cancer].

BACKGROUND AND PURPOSE Simulation computed tomography colonography(sCTC), which combines CTC and 3-dimensional vascular imaging, is popular for the surgery of colorectal cancer. We experience anomaly, called arc of Riolan(aR), rarely but its definition and details are unclear. Using sCTC, we identified aR and investigated the simulation of aR-conserving high ligation. PATIENT AND METHOD The patients were 3 cases of sigmoid colorectal cancer with aR in 369 patients who underwent sCTC before colorectal cancer surgery. We identified the running morphology of aR. And we classified Griffiths' point as presence(P)and absence(A). Narrow or mesh-shaped artery which were ischemic risk factors of intestinal tract was P groups and normal artery was A groups in the marginal artery of splenic flexure. We simulated aR-conserving lymph node dissection using sCTC. RESULT Case 1. The patient was 60-year-old man with rectal cancer, cT4aN1M0, Stage Ⅲa. The running morphology of aR was between the left branch of middle colic artery(MCA lt)and LCA. Griffiths point: P. Surgical simulation was D3 lymph node dissection with preservation of aR and high ligation of IMA. Pathological findings was pT3N1M0, Stage Ⅲa. Case 2. The patient was 65-year-old woman with sigmoid colon cancer, cT3N2M0, Stage Ⅲb. The running morphology of aR was between MCA lt and IMA. Griffiths point: P. Surgical simulation was D3 lymph node dissection with preservation of aR and high ligation of IMA. Pathological findings was pT3N2M0, Stage Ⅲb. Case 3. The patient was 75-year-old woman with sigmoid colon cancer, cT1bN0M0, Stage Ⅰ. The running morphology of aR was between first jejunal artery and IMA. Griffiths point: A. Surgical simulation was D3 lymph node dissection with preservation of aR and high ligation of IMA. Pathological findings was pT1bN0M0, Stage Ⅲb. CONCLUSION Using sCTC, we could identify the various running morphology of aR and simulate aR-conserving lymph node dissection in high ligation.