Risk Factors and Outcomes Associated with Infected Lower Extremity Prosthetic Bypasses and Patches.
Yana Etkin, MD1, Benjamin Jackson, MD2, Joanna Fishbein, MPH1, Mark Kissin, MD1, Joseph McGinn, III, MD1, Hana Baig1, Gregg Landis, MD1.
1Northwell Health System, Manhasset, NY, USA, 2Hospital of University of Pennsylvania, Philadelphia, PA, USA.
Prosthetic grafts are often used as alternative conduits in patients with peripheral vascular disease who do not have adequate autologous vein for bypass. However, prosthetic grafts carry increased risk of infection, and associated increased morbidity and mortality. The goal of this study was to identify potential risk factors and subsequent outcomes associated with lower extremity prosthetic graft infections.
272 lower extremity prosthetic bypasses and patches were performed at an academic medical center between 2013 and 2016. A retrospective review of patients’ demographics (age, gender, race, insurance status), co-morbidities (DM, HTN, CAD, ESRD, smoking), BMI, albumin, indication for surgery, type of procedures performed and procedural characteristics (length of surgery, blood transfusions, antibiotics and skin prep) was conducted. Outcomes - including limb loss and mortality - were analyzed.
43 patients (15.8%) with graft infections were identified during mean follow-up of 638 days (±364 days). The median time to graft infection was 43 days (IQR=85). Staphylococcus was the most common bacteria, found in 51.2% of patients. 60% of infected grafts and patches were removed. Infections were associated with 30.2% rate of limb loss and 34.9% rate of mortality. The risk of limb loss was 8.1 times greater (95% CI: 3.5, 18.5) for patients with infections and risk of death was 6.4 times greater (95% CI: 3.3, 12.3) as compared to patients without infection.
Based on univariate analysis, female gender (p=0.013), HTN (p=0.085), albumin level (p=0.017) and redo surgery (p=0.011) were included as potential predictors in a multivariable model. The risk of infection was 2.4 times greater among those with history of redo surgery (95% CI: 1.3, 4.3) and 2.1 times greater in females (95% CI: 1.1, 3.8), by multivariable statistics. A 1 g/dL increase in albumin level was associated with a 33.5% decrease in hazard of infection (HR: 0.67, 95% CI: 0.46, 0.96) in the multivariable model. The estimated cumulative incidence of infection for female patients with HTN and albumin of 3.36 (the mean) undergoing redo surgery was 31.6% at 100 days post-surgery (95% CI: 19.5, 51.4).
Female gender, redo surgery and malnutrition are associated with increased risk of prosthetic graft infections leading to high rate of limb loss and mortality. Endovascular interventions and bypasses with vein conduits should be consider in these patients.
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