Evaluation of characteristics of left-sided colorectal perfusion in elderly patients by angiography

BACKGROUND Handling of the inferior mesenteric artery (IMA) and maintaining anastomotic perfusion are important in radical resection of left-sided colorectal cancer. However, the branching of this artery and the drainage patterns of this vein vary among individuals, and the characteristics and perfusion region of this artery in elderly patients remain unclear. AIM To evaluate the characteristics and perfusion region of the IMA in elderly patients using angiography. METHODS We enrolled 154 patients (> 65 years old) who underwent digital subtraction angiography of the IMA. The characteristics, bifurcation, and distribution of the IMA and termination of the anastomotic perfusion of the left colon and rectum were examined using digital subtraction angiography. Collateral arterial arches and the IMA hemoperfusion region were also recorded. Perfusion regions were cross-referenced with clinical and anatomical features by the univariate analysis. RESULTS Of 154 patients, 25 (16.2%) had IMA lesions. The left colic artery arose independently from the IMA in 44.2% of patients, shared a trunk with the sigmoid artery in 35.1%, shared an opening with the sigmoid and superior rectal arteries in 16.9%, and was absent in 5.1%. The IMA perfusion region stopped at the splenic flexure in 50 (32.5%) patients. The collateral circulation existed in the colonic perfusion region, including the marginal artery (Drummond's artery), the ascending branch of the left colonic artery to supply the transverse colon, and the arc of Riolan with a frequency of 100%, 22.7%, and 1.9%, respectively. The IMA perfusion region was independently associated with the comorbidity of atherosclerosis, IMA atherosclerotic lesion, branching pattern, collateral circulation, and marginal artery integrity. CONCLUSION The IMA and its branches are prone to arteriosclerosis, and IMA perfusion may be interrupted at the splenic flexure in elderly patients. The applicability and precision of preoperative angiography for evaluating the IMA branching and perfusion patterns could facilitate geriatric laparoscopic left-sided colorectal cancer surgery with suspicion of poor IMA perfusion.