Surgical strategy for treating mycotic aneurysms of thoracic and abdominal aorta and iliac artery: analysis of long-term follow-up data

Resection of Mycotic Iliac Artery Aneurysm with Extra-Anatomic Bypass: An Alternative to Aneurysmorrhaphy in Difficult Situations

Mycotic aneurysms of the iliac and other large arteries are rare and are associated with increased morbidity and mortality. Treatment of mycotic aneurysms usually requires modification of the surgical technique done for cases of degenerative or atherosclerotic aneurysms. Degenerative and atherosclerotic fusiform aneurysms are usually managed with aneurysmorrhaphy using a prosthetic graft, which however is not ideal for mycotic aneurysms. Avoidance of prosthetic material at the site of mycotic aneurysm is a better option with higher chances of resolution of infection and favorable patient outcome.

A Comparison of Surgical Techniques and Outcomes for Primary Infected Abdominal Aortic Aneurysms

BACKGROUND

Primary infected abdominal aortic aneurysms (PIAAAs) are associated with high morbidity and mortality. Three repair approaches include open in-situ repair (OIR), extra-anatomic repair (EAR), and endovascular abdominal aortic aneurysm repair (EVAR). This study is one of the largest single-center case series comparing the outcomes of the different surgical approaches for PIAAA.

METHODS

This is a retrospective cohort study of all patients treated surgically for PIAAA between 2000 and 2021. PIAAA diagnosis was defined as the presence of an abdominal aortic aneurysm with evidence of infection on clinical presentation, laboratory markers, radiology, or surgically. Patients with prior aortic surgery were excluded from this study. Basic demographics were compared across the 3 surgical groups using standard statistical methods. Our primary outcomes included mortality at 1 and 5 years. Kaplan-Meier curves were generated and compared using log-rank testing. Multivariate Cox proportional hazards models were created to assess determinants of mortality.

RESULTS

A total of 43 patients were included in the full cohort. Patients undergoing EVAR more often had diabetes, end-stage renal disease, and coronary artery disease. EVAR was also more often done in patients with a saccular aneurysm rather than fusiform. (93% vs. 70% in EAR and 42% in OIR; P = 0.015). All-cause mortality rates at 1 year were not significantly different between the 3 groups. Survival at 5 years did show a significant benefit of OIR over EVAR and EAR: OIR had an 8% mortality rate with EAR having a 53% rate and EVAR having the highest (72%) mortality rate at 5 years (P = 0.03). Multivariable Cox regression analysis showed that EVAR (aHR 12.1, (95% CI 1.42 to 103.9), P = 0.02) and EAR (aHR 15.1, (95% CI 1.59 to 143.3), P = 0.0.02) had an increased 5-year mortality risk when compared to OIR.

CONCLUSIONS

Repair of primary infected aortic aneurysm is associated with high complication and mortality rates regardless of the approach. In our studied sample, OIR offered an improved long-term survival without added benefits in terms of complication rates. In infected AAA, EVAR should be considered bridging stage between the urgent situation and eventual open repair.