Laparoscopic right hemicolectomy for transverse colon cancer with a rare common trunk of the ileocolic and middle colic arteries: a case report

Introduction: A common trunk of the ileocolic artery (ICA) and the middle colic artery (MCA) is an extremely rare vascular variation, occurring in less than 1% of the population. We report a case of transverse colon cancer associated with this anomaly. Case presentation: A 67-year-old woman with right-sided transverse colon cancer underwent laparoscopic right hemicolectomy. Preoperative three-dimensional computed tomography (3D-CT) revealed that the ICA and the right branch of the MCA (rt. MCA) shared a short common trunk arising from the superior mesenteric artery. This finding was confirmed intraoperatively. To ensure oncologic radicality, the ICA and rt. MCA were ligated at the common trunk, with simultaneous lymph node dissection around the common trunk. The pathological diagnosis was p Stage IIIA due to metastases at the rt. MCA root, while common-trunk nodes were negative. Discussion: Complete mesocolic excision with central vascular ligation is the gold standard for radical colon cancer surgery; however, rare vascular variations can complicate oncologically adequate lymph node dissection. In this case, lymph nodes around the common trunk, for which the definition of “main lymph nodes” has not been clearly established, were dissected. Preoperative identification of the vascular anatomy by 3D-CT provided a major advantage in planning and safely performing the dissection. Conclusion: The optimal extent of lymph node dissection in cases involving rare vascular variations requires further discussion. Preoperative 3D-CT is essential for an accurate understanding of the vascular anatomy and for appropriate planning of lymph node dissection.