Mycotic/Infective Native Aortic Aneurysms: Results After Preferential Use of Open Surgery and Arterial Allografts

Mycotic/infective native aortic aneurysms (INAA) are managed heterogeneously. In the context of disparate literature, this study aimed to assess the outcomes of INAA surgical management and provide comprehensive data in alignment with recent suggestions for reporting standards.

A retrospective review of patients presenting with INAA from September 2002 to March 2020 at two institutions was conducted. In hospital mortality, 90 day mortality, overall mortality, and infection related complications (IRCs) were the study endpoints. Overall survival and IRC free survival were estimated, and predictors of mortality tested using uni- and multivariable analyses.

Seventy patients (60 men [86%], median age 68 years [range 59 - 76 years]) were included. Twenty (29%) were ruptured at presentation. INAA location was thoracic in 11 (16%) cases, thoraco-abdominal in seven (10%), and abdominal in 50 (71%). Half of the abdominal INAAs were suprarenal. Two INAAs were concomitantly abdominal and thoracic. Pathogens were identified in 83%. The bacterial spectrum was scattered, with rare Salmonella species (n = 6; 9%). Open surgical repair was performed in 66 (94%) patients, including five conversions of initially attempted endovascular grafts (EVAR), three hybrid procedures, and one palliative EVAR. Vascular substitutes were cryopreserved arterial allografts (n = 67; 96%), prosthesis (n = 2), or femoral veins (n = 1). Kaplan-Meier estimates of overall survival at 30 and 90 days were 87% (95% confidence interval [CI] 76.6 - 93.0) and 71.7% (95% CI 59.2 - 80.9), respectively. The overall in hospital mortality rate was 27.9% (95% CI 1.8 - 66.5). IRCs occurred in seven (10%) patients. The median follow up period was 26.5 months (range 13.0-66.0 months). Chronic kidney disease (CKD) was independently related to in hospital mortality (odds ratio [OR] 20.7, 95% CI 1.8 - 232.7). American Society of Anesthesiologists score of 3 (OR 6.0, 95% CI 1.1 - 33.9), 4 (OR 14.9, 95% CI 1.7 - 129.3), and CKD (OR 32.0, 95% CI 1.2 - 821.5) were related to 90 day mortality.

Surgical INAA management has significant mortality and a low re-infection rate. EVAR necessitated secondary open repair, but its limited use in this report did not allow conclusions to be drawn.