The Effect of the Degree of Inferior Mesenteric Artery Occlusion on Anastomotic Leakage After Rectal Cancer Surgery

Rectal cancer can be diagnosed either after the onset of symptoms or through screening of asymptomatic individuals. Although surgery remains the cornerstone of curative treatment, rectal cancer may be managed with local excision or radical resection depending on the clinical stage, size, and location of the tumor. In terms of radical resection, patients may undergo low anterior resection or ultra-low anterior resection.

Anastomotic leakage is a serious complication following rectal surgery and is associated with increased morbidity and mortality. Elderly patients and those with comorbidities have a higher risk of death after the occurrence of an anastomotic leak. The main risk factors for anastomotic leakage include male sex, preoperative radiotherapy, low anastomosis (less than 10 cm from the anal verge), a high burden of comorbidities, advanced age, and a history of vascular disease.

Atherosclerosis increases the risk of anastomotic leakage by causing inadequate perfusion of the anastomosis due to tissue ischemia and impaired microcirculation. When atherosclerosis develops, the intima of the arteries thickens, the vessel lumen narrows, blood flow decreases, and the vasomotor function of blood vessels is impaired. In addition, collateral circulation is reduced, thereby increasing the risk of anastomotic leakage.

The superior mesenteric artery and inferior mesenteric artery are primarily responsible for the blood supply to the colorectal region. During colorectal surgery, the normal blood flow to the bowel is disrupted and reduced, which may result in local intestinal ischemia.

The primary aim of our study is to evaluate and grade the diameter of the inferior mesenteric artery using preoperative contrast-enhanced computed tomography, a simple, rapid, and readily available imaging modality routinely performed for staging purposes in patients with rectal cancer. By identifying patients with a high degree of inferior mesenteric artery narrowing or occlusion, we aim to determine whether the creation of a protective stoma should be recommended to reduce the risk of postoperative anastomotic leakage following rectal cancer surgery.