The Incidence of Para-Anastomotic Aneurysm After Open Repair Surgery for Abdominal Aortic Aneurysm Through Routine Annual Computed Tomography Imaging.

Objective Open repair surgery (ORS) for an abdominal aortic aneurysm (AAA) remains an important treatment option, but the incidence of para-anastomotic aneurysms is unclear. The purpose of this study was to estimate the incidence of para-anastomotic aneurysms and reveal secondary complications through routine annual computed tomography (CT) imaging. Methods One hundred and forty-seven patients who underwent ORS for AAA between January 2006 and December 2015 and received routine CT imaging surveillance were enrolled. Results The follow up period was 7.1 ± 2.7 years. The total follow up time of all patients was 1 041.1 years, and 958 CT images were collected (0.92 CT scans/year/patient). A proximal para-anastomotic aneurysm was detected in five patients (3.4%). Four of the five patients had aneurysmal dilation at the initial ORS (proximal diameter >25 mm), which enlarged during follow up; thus, a de novo proximal para-anastomotic aneurysm was observed in one patient (0.7%). The time between surgery and the diagnosis of all proximal para-anastomotic aneurysms was 5.7 ± 1.4 years, and the de novo proximal para-anastomotic aneurysm was detected at 11.8 years. The incidence of all para-anastomotic aneurysms at five and 10 years was 2.2% and 3.6%, and the incidence of the de novo para-anastomotic aneurysm was 0% at five and 10 years. Nine synchronous thoracic aortic aneurysms (TAAs) and seven metachronous TAAs were detected, and 16 patients (10.9%) had a TAA. Neoplasms were detected in 18 of 147 patients (12.2%), and the most dominant neoplasm was lung cancer. Conclusion The incidence of para-anastomotic aneurysms was low; thus, abdominal and pelvic CT imaging every five years may be sufficient and consistent with the current AAA guidelines. In contrast, TAAs were diagnosed in a high percentage of patients, and based on these observations, routine CT imaging should be expanded to include the chest.