EP268 - Sigmoid colon cancer and aortoiliac occlusion: a case for prioritizing revascularization

Purpose/Background: The management of colorectal cancer in patients with significant vascular disease poses unique challenges. This case report discusses the preoperative and surgical management of a 64-year-old male with sigmoid colon cancer and severe aortoiliac occlusion.

Methods/Interventions: A 64-year-old male with a history of coronary artery disease, myocardial infarction, hypothyroidism, mild chronic kidney disease, hypertension, hyperlipidemia, and peripheral artery disease presented in April 2024 following a positive Cologuard test. Colonoscopy revealed a 6 cm mass in the descending colon, and biopsy confirmed moderately differentiated adenocarcinoma without evidence of DNA mismatch repair deficiency. Staging CT showed no metastatic disease. Further, it revealed an infrarenal aortic occlusion and bilateral iliac artery occlusions. Collateral circulation to the lower extremities is primarily through the superior mesenteric artery (SMA) via the arc of Riolan, the inferior mesenteric artery (IMA) and the pelvic vasculature. The concern was that an oncologic resection, including high ligation of the IMA, may result in chonic or acute limb threatening ischemia. Conversely, vascular supply to the colorectal anastomosis may be impaired. The femoral and pelvic vasculature are connected through a rich collateral network and it was surmised that preemptive lower extremity revascularization would avert both pelvic and lower extremity ischemia.

Results/Outcomes: The patient first underwent a left axillobifemoral bypass, right iliofemoral endarterectomy, and right renal artery stenting. The postoperative course was uncomplicated, with resolution of claudication symptoms. Six weeks later, the patient underwent an uncomplicated open left hemicolectomy with primary anastomosis. Final pathology revealed pT3N0 moderately differentiated adenocarcinoma, with 0/20 lymph nodes involved, negative margins, and positive lymphovascular invasion. The patient recovered without complication and was treated with adjuvant capecitabine following multidisciplinary tumor board discussion.

Conclusion/Discussion: This case highlights the importance of addressing vascular insufficiency prior to colorectal cancer resection. Performing revascularization prior to colectomy reduced the risk of inducing acute limb threatening ischemia. It also allowed for improved retrograde circulation through the pelvic vasculature to ensure adequate perfusion to the colorectal anastomosis. Successful preoperative vascular intervention can improve surgical outcomes and overall management in patients with concurrent malignancy and significant vascular disease.

Figure 1. CT angiogram
Axial image demonstrating enlarged IMA and arc of Riolan.

Figure 2. Aortoiliac angiogram
Angiogram demonstrating enlarged and tortuous arc of Riolan which goes on to supply circulation to the lower extremities.