The Enigma of Treating Colorectal Cancer and an Abdominal Aortic Aneurysm

As the average lifespan of individuals increases, malignancies and cardiovascular diseases are becoming a common cause of morbidity and mortality. The treatment of abdominal aortic aneurysms (AAAs) with concomitant diagnosis of colorectal cancer (CRC) is challenging. We aim to review the experience of a single tertiary institution in the management of patients with concurrent diagnosis of AAA and CRC hoping to glean information on how better to treat these patients. This is a retrospective review of all individuals treated between 2009 and 2022 at a large tertiary care center who had a documented diagnosis of CRC and AAA. A careful review of 102 patients resulted in a sample of 89 patients. Of the 89 patients in our cohort, 39 (43.8%) were diagnosed with CRC over 1 year before their AAA diagnosis. Fifteen (16.9%) patients were diagnosed with an AAA over 1 year before their CRC diagnosis and 35 (39.3%) were diagnosed concurrently with both CRC and AAA (Fig). In the concurrent subgroup, AAA was found on cancer staging workup CT scans, and we found the following in regard to their treatment: 12 (34.3%) individuals underwent CRC resection and surveillance of an AAA between 3 and 4 cm, 14 (40.0%) underwent CRC resection and surveillance of an AAA between 4 and 5 cm, and 3 (8.6%) had an AAA of over 5 cm and met criteria for repair; however, they had metastatic CRC and passed on hospice. There were no incidents of aneurysm rupture during surveillance. Ultimately, of the 35 individuals with concomitant AAA and CRC, 6 (17.1%) required treatment for both conditions—3 individuals had an endovascular aneurysm repair (EVAR) 4 to 6 months before CRC surgical resection, 2 had an EVAR after completing chemoradiation, and 1 individual had an EVAR 1.5 weeks after fecal diversion for obstructing CRC. In this group, there were no incidents of operative mortality. The treatment of both CRC and AAA has limited guidelines on how to proceed with the Society of Vascular Surgery level 2C recommendation for concomitant treatment. Our retrospective review of a single tertiary center identified 35 patients who were found to have an AAA during CRC workup. Although the majority had a small AAA that could be surveilled, of those who required repair, we found that EVAR was the sole approach. Further studies are needed to assess long-term outcomes with larger patient volumes from multiple institutions to recommend a definitive treatment algorithm.