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.