Vascular Infection, Graft/Endograft Infection, Infected Aneurysm, and Aortoenteric Fistula

13.1Definition and presentation

Vascular graft infection, mycotic (infected) native aneurysm, and endovascular infection constitute a single multidisciplinary management domain encompassing prosthetic material, the native arterial wall, adjacent bowel, and overlying soft tissue AHA 2016. Standardized terminology dictates consistent classification across surgical, infectious disease, and imaging disciplines Sörelius 2026.

The ESVS 2026 Clinical Practice Guidelines on Vascular Graft and Endograft Infections update the 2020 guideline. They should be distinguished from the separate Delphi documents on terminology and treatment, and from observational outcome series VGEI Treatment Consensus 2025 · ESVS 2026.

Endograft infection is uncommon but carries substantial early mortality and is frequently delayed. Following endovascular aneurysm repair (EVAR), the incidence of endograft infection is approximately 0.6%, with a mean interval to diagnosis of 22 to 25 months; more than one quarter of presentations involve an aortic fistula EVAR Infection Meta-analysis 2017 · Endograft Infection Cohort 2016. Surveillance encounters late after EVAR or thoracic endovascular aortic repair (TEVAR) require evaluation of new constitutional symptoms, unexplained inflammation, perigraft gas or fluid, or bleeding to differentiate infection from routine aneurysm evolution.

Diagnosis uses the Management of Aortic Graft Infection Collaboration (MAGIC) criteria, integrating clinical, surgical, microbiologic, and imaging inputs. The MAGIC framework serves as a sensitive screen; treating all suspected cases as infected yields sensitivity between 88.2% and 99%, but specificity relies on careful correlation to avoid premature explantation in low-probability scenarios ESVS 2020 · MAGIC Accuracy 2026 · MAGIC Validation 2021.

13.2Microbiology and diagnostic imaging

Appropriate empirical antimicrobial therapy independently predicts survival in hospitalized patients with vascular graft infection VGEI Prognosis 2022. Empiric therapy is anchored to the anatomic site and expected flora. For abdominal disease without aortoenteric fistula, the intended empiric spectrum covers gram-positive cocci, gram-negative bacilli, and anaerobes, with narrowing once operative cultures identify the target organism VGEI Treatment Consensus 2025. The 2025 consensus reserves empirical antimicrobial treatment for complicated infection, such as sepsis or bleeding, or when diagnostic intervention is delayed. Choose the empirical regimen with infectious-disease and microbiology input, using anatomic site, fistula status, severity, previous cultures and local resistance risk. MRSA/MRSE coverage is conditional on risk, not automatic for every infection. Obtain appropriate cultures without delaying treatment of complicated infection, and narrow treatment when results are available; the 2025 consensus distinguishes thoracic from abdominal infection rather than prescribing one fixed combination for both.

Pathogen identity shapes both prognosis and diagnostic suspicion. Candida aortic graft infection establishes a distinct organism category with different counseling implications from non-Candida infection Candida Graft Infection 2023. Fastidious organisms such as Actinomyces require targeted deep cultures and adjustment of antimicrobial assumptions when the clinical course diverges from typical bacterial infection Actinomyces PVGI 2023.

Imaging defines perigraft infection, fluid collections, bowel involvement, and the feasibility of reconstruction. Computed tomography angiography (CTA) maps the operative field but provides modest pooled diagnostic sensitivity (0.67) and specificity (0.63) for vascular graft infection; metabolic and nuclear imaging resolve ambiguity when CTA is equivocal VGEI Imaging Meta-analysis 2018. For patients under late endograft surveillance, structural correlation with focal or heterogeneous uptake is required before committing to reoperation, rather than relying on a single maximum standardized uptake value (SUVmax) threshold PET/CT Endograft Accuracy 2022 · PET/CT Native Aneurysm 2021. Quantitative baseline characteristics and FDG-PET imaging metrics do not reliably predict in-hospital or longer-term survival VGEI Pre-Operative Outcome 2024.

13.3Treatment and reconstruction thresholds

Antimicrobial therapy reduces microbial burden and treats bacteremia, but operative source control is required to remove infected prosthetic material, close fistulas, and debride necrotic tissue VGEI Treatment Consensus 2025 · VGEI Prognosis 2022. Complete excision of infected material with in-situ reconstruction is the standard for patients who can tolerate the physiological burden. Emergency operative timing is an independent predictor of early mortality, prioritizing preoperative physiologic stabilization when feasible Aortic Infection Outcomes 2022.

In-situ reconstruction incorporates aggressive debridement, targeted conduit selection, prolonged antibiotic therapy, and vascularized tissue coverage; omental coverage specifically improves infection clearance and healing Aorta Infections Review 2022. Conduit choices include autogenous femoral vein (neoaortoiliac system, NAIS), cryopreserved allograft, antibiotic-bonded prosthetic, and silver-impregnated prosthetic. NAIS and cryopreserved allografts show no statistically significant difference in 30-day or 1-year mortality for fit patients, though overall morbidity remains high (81%) and recurrent sepsis frequently involves gram-negative and drug-resistant organisms NAIS vs Allograft 2023 · In Situ Reconstruction Outcomes 2023. Peripheral prosthetic infections use the same source-control and follow-up principles IDSA SSTI 2014 · Peripheral PVGI Cohort 2025.

The operative decision pathway follows a stepwise assessment of fitness, contamination, and source-control feasibility:

1. Baseline operative risk and the feasibility of definitive source control dictate the management pathway.
2. Complete graft excision and in-situ reconstruction (autogenous vein, cryopreserved allograft, or antimicrobial-bonded prosthetic) or extra-anatomic bypass is the standard of care for fit patients with resectable disease.
3. Partial excision or graft preservation with aggressive debridement is reserved for highly selected patients with localized contamination, intact anastomoses, and no fistula, requiring long-term antibiotic commitment.
4. When excision is not undertaken, record whether the goal is suppression, a bridge to reconstruction, or palliation. Drainage can provide microbiological sampling and adjunctive source control, but does not repair a fistula or unstable anastomosis. Recurrent sepsis or bleeding requires reassessment of the original plan VGEI Treatment Consensus 2025.

Anatomic populations must remain separate when counseling about outcomes. A 2025 cohort of selected root, ascending-aortic and arch graft infections reported 82.9% estimated survival over median 4.8-year follow-up among 44 patients managed without graft removal. It excluded descending and endovascular graft infections and cannot establish equivalent outcomes for abdominal EVAR infection or replace definitive source control when required Thoracic Conservative Outcomes 2025.

13.4Aortoenteric fistula and infected native aneurysm

Aortoenteric fistula presents as a hemorrhage and sepsis emergency. Definitive management for secondary aortoenteric fistula is surgical, consisting of complete graft excision combined with either extra-anatomic bypass or in-situ reconstruction and concurrent broad-spectrum antibiotics Secondary AEF Review 2024 · Secondary AEF Case Series 2022 · Autologous AEF Reconstruction 2019. Endovascular repair provides high initial hemodynamic stabilization (approximately 86% in primary fistula) but is followed by a downstream rebleeding or reinfection rate near 42% to 44%, requiring conversion to open repair in up to one-third of patients AEF Stent Graft Systematic Review 2009 · Primary AEF EVAR Review 2022. Preoperative sepsis and a secondary fistula etiology predict worse outcomes. Endovascular therapy is therefore used as a temporizing bridge in unstable patients, not as definitive source control Secondary AEF Systematic Review 2008.

Infected native aortic aneurysms demand a similar distinction between temporization and definitive therapy. Open surgical repair is associated with a lower rate of subsequent graft infection compared to endovascular exclusion (5.4% versus 13.3%), although selection bias heavily favors open repair in fitter patients Infective Native Aneurysm Meta-analysis 2024. Endovascular exclusion serves as a hemorrhage-control or bridging strategy in high-risk patients; it carries a hospital mortality of 11.8%, 1- and 2-year cumulative survival of 86.3% and 80.5%, and a recurrent aortic infection rate of 23.3%, mandating lifelong antibiotics and structured surveillance Infected Aneurysm EVAR 2024.

13.5Postoperative surveillance and antimicrobial suppression

The chosen operative or endovascular strategy determines the postoperative surveillance burden and expected failure modes. Long-term incidence of vascular graft infection is similar following open abdominal aortic aneurysm repair and EVAR, and late mortality remains substantial when infected grafts are not explanted Population VGEI Post-Repair 2023.

Post-treatment surveillance tracks constitutional symptoms, inflammatory markers, operative cultures, perigraft collections, and metabolic imaging trajectory. Anticipated failure modes dictate imaging intervals: endovascular bridges and graft-preservation strategies require monitoring for progressive infection and new fistulization, while in-situ reconstructions require monitoring for reinfection, pseudoaneurysm, and progressive conduit degeneration EVAR Infection Meta-analysis 2017 · In Situ Reconstruction Outcomes 2023 · Primary AEF EVAR Review 2022.

Antimicrobial suppression constitutes active longitudinal therapy. Treatment duration and operative-culture narrowing are guided by multispecialty consensus VGEI Treatment Consensus 2025. Antimicrobial duration depends on source control, conduit and organism rather than a universal lifelong prescription. The 2025 Delphi consensus supports six weeks total treatment after complete removal with autologous vein replacement, with an early oral switch possible when an appropriate bioavailable agent is available. When prosthetic material remains, it generally supports at least 4–6 weeks intravenously followed by oral treatment to a total of 12 weeks. Persistent infection, virulent organisms or incomplete source control may require longer treatment or suppression, decided with infectious-disease expertise. Outpatient parenteral antimicrobial therapy (OPAT) for aortic vascular graft infection introduces substantial treatment intensity and line-related events after hospital discharge, requiring continuous reassessment of the reconstructive plan in response to recurrent sepsis or toxicity OPAT VGEI Cohort 2021 · Endograft Infection Review 2023.

13.6Areas of controversy

The prognostic utility of quantitative metabolic imaging metrics (such as SUVmax cutoffs on 18F-FDG PET/CT) is unestablished for reliably predicting in-hospital mortality, long-term survival, or definitive operative timing in vascular graft infection VGEI Pre-Operative Outcome 2024 · PET/CT Endograft Accuracy 2022 · PET/CT Native Aneurysm 2021.

The comparative durability and equivalence among in-situ reconstruction conduits (autogenous vein, cryopreserved allograft, silver-impregnated prosthetics, and antibiotic-bonded prosthetics) remain heavily confounded by selection bias, with broadly similar pooled reinfection rates but differing availability and operative burdens In Situ Meta-analysis 2018 · NAIS vs Allograft 2023.

The long-term safety of partial graft excision or graft preservation for localized contamination lacks randomized validation; reported survival advantages in small cohorts are recognized as reflections of stringent patient selection rather than equivalence of indication Abdominal Graft NMA 2024 · Graft Preservation Meta-analysis 2023.

Further reading

• Surgical management of abdominal aortic graft infection: network meta-analysis. (2024). Aortic graft infection surgical strategies; network evidence has selection and indirectness limits. Abdominal Graft NMA 2024
• Secondary aortoenteric fistula: a narrative review of the view of the surgeon. (2024). Secondary aortoenteric fistula clinical background. Secondary AEF Review 2024