OBJECTIVE: The optimal revascularization modality in secondary abdominal aorto-enteric fistula (SAEF) remains unclear in the literature. The purpose of this investigation was to determine the revascularization approach associated with the lowest morbidity and mortality using real-world data in patients with SAEF.
METHODS: A retrospective, multi-institutional study of SAEF from 2002-2014 was performed using a standardized database. Baseline demographics, comorbidities, operative, and postoperative variables were recorded. The primary outcome was long-term mortality. Descriptive statistics, Kaplan-Meier survival analysis, and univariate and multivariate analyses were performed.
RESULTS: 182 patients at 34 institutions from 11 countries presented with SAEF during the study period (median age 72 years; 79% male). The initial aortic procedures that resulted in SAEF were 138 surgical grafts (76%) and 42 endografts (23%) with 2 unknown. 102 of the SAEF (56%) underwent complete excision of infected aortic graft material, followed by in situ (in-line) bypass (ISB), including antibiotic-soaked prosthetic graft (53), autogenous femoral vein (NAIS) (17), cryopreserved allograft (28), and untreated prosthetic grafts (4). 80 patients (44%) underwent extra-anatomic bypass (EAB) with infected graft excision. Overall median Kaplan-Meier (KM) estimated survival was 319 days (IQR 20, 2410) days. When stratified by EAB versus ISB, there was no significant difference in KM estimated survival (p=0.82). Comparing EAB versus ISB, EAB patients were older (age 74 vs. 70; p=0.01), had less operative hemorrhage (1200mL vs. 2000mL; p=0.04), were more likely to initiate dialysis within 30 days postoperatively (15% vs. 5%, p=0.02), and were less likely to experience aortic-related hemorrhage within 30 days postoperatively (3% aortic stump dehiscence vs. 11% anastomotic rupture, p=0.03). There were otherwise no significant differences in presentation, comorbidities, intra-operative or postoperative variables. Multivariable Cox regression showed the duration of antibiotic use (HR 0.92, 95% CI 0.86-0.98; p = 0.01) and rifampin use at time of discharge (HR 0.20, 0.05-0.86, p = 0.03) independently decreased mortality.
CONCLUSIONS: These data suggest ISB does not offer a survival advantage compared to EAB and does not decrease the risk of postoperative aortic-related hemorrhage. Less than 50% of SAEF patients survive ten months after repair. Each week of antibiotic use decreases mortality by 8%. Further study with risk modeling are imperative for this population.