Aortic Graft Infection- Contemporary Management of a Resurgent Problem

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1 Aortic Graft Infection- Contemporary Management of a Resurgent Problem Peter F. Lawrence, MD Professor and Chief Division of Vascular Surgery University of California Los Angeles

2 Incidence of Aortic Graft Infection Meta-analysis - 13 series with 11,526 aortic grafts 1.6% incidence; highest with aortofemoral graft (groin incision) Aortoenteric fistula/erosion % Underestimates true incidence Projected infections - 95,000 grafts x 1.6 =1,520/year Sarfati - Epidemiology of Aortic Graft Infection in Gewertz Surgery of the Aorta

3 Aortic Graft Infection Morbidity/Mortality High mortality: One year survival - 65%; 5 year survival - 55% Early mortality- sepsis, MSOF, hemorrhage, renal failure, MI Late mortality- Graft related(recurrent infection), CV disease Mortality declining Morbidity Limb loss - 20% Pneumonia, renal failure, cardiac - 60% Reoperation - 20% Re-infection of new graft 20-60% Occlusion of new graft - 25%

4 Endograft Infection: The New Epidemic? Increasing reports of endograft infection (~35 papers since 2005) Incidence ranges from 0.2 to 0.7% 1431 aortic endografts placed evaluated with 11 endograft infections (EVAR + TEVAR)= 0.6% Ducasse et al Ann Vasc Surg 2004 Hobbs et al J Cardiovs Sur 2010 Sharif et al JVS 2007 Cernohorsky JVS 2011

5 Treatment Less Invasive Approaches IV / topical antibiotics Muscle coverage without graft excision Drainage with Abx irrigation VAC Replacement with Abx bonded femoral graft Never cure infection Seminars in Vascular Surgery 2011

6 Definitive Graft Infection Treatment Excision Without Revascularization Entire graft removal is conventional approach; revascularization not always required If graft thrombosed, then removal alone is OK May also work when indication was claudication or proximal anastomosis was E-S Aortic aneurysms unlikely to tolerate graft removal alone 15/101 patients in one series not revascularized

7 Graft Excision with Extra-anatomic Revascularization 1st described by Blaisdell in 1961 Early results resulted in 40% mortality and 25% amputation Gold standard for aortic infection Recent results with improved anesthesia and sequencing of procedures have 25% mortality Graft Thrombosis: 10-20% at 5 yr Reinfection: 5-20% at 5 years Aortic stump disruption: <5% at 5 yr

8 Prosthetic Insitu Replacement Not appropriate when suture line is involved with bleeding Major risk is recurrent infection Debridement of infected aortic wall is critical Most appropriate for patients with normal defenses and no extensive purulence Best prosthesis is antibiotic bonded Dacron, using Rifampin with a gelatin bond

9 In Situ Replacement with Femoral Veins (NAIS) Popularized by Claggett and colleagues at Southwestern Neoaortoiliac system (NAIS)

10 NAIS Results Study Patients (n) Follow-Up (Months) 30-day Mortality Major Amputation Clagett (1993) % 10% Ehsan (2009) % 0% Ali (2009) % 7%

11 Insitu Revascularization with Allograft Patients Indication for allograft use: Primary graft infection (70%) Secondary aorto-enteric fistula (30%) 62% of patients underwent 3 ± 2 repeat operations before allograft Fresh allograft: 111 Patients Cryopreserved allograft: 68 Patients Late mortality = 25.9% All 3 patient deaths were due to allograft rupture at 9, 10, and 27 months. 2 patients received fresh allograft (66%)

12 Cyropreserved Allograft Previous aneurysm concerns have been addressed with changes in preservation Options include Cryovein and Cryoartery Expensive- are Cryoartery costs justified by better outcomes?

13 Technique Need proximal/distal control above and below infection Often requires supra-celiac clamping Opening the retroperitoneum may still result in significant bleeding Necrotic tissue requires debridement Sew up to the orifices of the renal arteries Occasionally need transplant of renal arteries

14 The Use of Cryopreserved Aortoiliac Allograft for Aortic Reconstruction in the United States On behalf of the Investigators

15 Results 220 Patients at 14 institutions (M:F = 1.6/1, Mean age = 65±12 yrs) Type of Initial Aortic Procedure n (%) Open reconstruction 209 (95%) Endovascular 11 (5%) Indication for Use of CAA n (%) Prosthetic graft infection 134 (61%) Primary abdominal aortic infection 35 (16%) Graft enteric fistula/erosion 33 (15%) Infection pseudoaneurysm 9 (4%) Other, including high risk of graft infection 9 (4%)

16 Early and Late Complications Complication (n = 55) n (%) Persistent sepsis 17 (8%) 92% 86% 80% 71% CAA thrombosis/occlusion 9 (4%) CAA rupture 8 (4%) Recurrent CAA infection 8 (4%) CAA pseudoaneurysm 6 (3%) Fistula recurrence 4 (2%) Lower extremity compartment syndrome 1 (<1%) Mean follow-up = 30 ± 3 months Range = 1 to 160 months Colonic perforation 1 (<1%) Lower limb ischemia 1 (<1%)

17 Factors Associated with Graft Related Complications 31 Patients (15%) had CAA related complications Factor Hazard Ratio 95% Confidence Interval p-value Age > Peripheral arterial disease Virulent Organism Prosthetic graft excision: Partial Emergent Surgery Indications for CAA: Prosthetic graft infection Enteric fistula/erosion Primary aortic infection

18 Patient Survival, Graft Patency, and Limb Loss 98% 98% 97% 97% 97% 93% 94% 91% 75% Cumulative Survival Primary Graft Patency 54% 51% 43% Freedom from Limb Loss 71% Mean follow-up = 30 months; Range = 1 to 160 months

19 Treatment and Outcomes of Aortic Endograft Infection On behalf of the Vascular Low-Frequency Disease Consortium: Audra A. Duncan, MD, Matthew R. Smeds, MD, Michael P. Harlander- Locke, MPH, Peter F. Lawrence, MD, Sean P. Lyden, MD, Javairiah Fatima, MD, Kristofer M. Charlton-Ouw, MD, Mark Morasch, MD, Raghu L. Motaganahalli, MD, Peter Nelson, MD, Sherene Shalhub, MD, Paul G. Bove, MD, J. Gregory Modrall, MD, Victor J. Davila, MD, Nasim Hedayati, MD, Ahmed Abou-Zamzam, MD, Christopher J. Abularrage, MD, Catherine M. Wittgen, MD

20 Participants

21 Demographic and Comorbidities (206 Aortic Endograft Infections) Patient Demographics and Risk Factors N (Total = 206) % of Total Sex Male % Female 45 22% Age at diagnosis (years) 68 ± 9 Comorbidities Hypertension % Smoking % Renal Insufficiency 62 30% Diabetes Mellitus 54 26% Congestive Heart Failure 45 22% Peripheral Arterial Disease 33 16% Chronic Infection 31 15%

22 Time to Infection Type of infection Mean time from endograft to infection diagnosis (months) 95% CI range (months) Gram (-) Gram (+) Culture negative Polymicrobial Fungal

23 Complete Explantation

24 Operative Details Blood Loss Operative Time P <.001

25 Patient Survival

26 Medically Managed Patients Mean length of follow-up = 2 months Patients = 9 (4%) TEVAR = 5 pts EVAR = 4 pts Mortality (TEVAR) 4 pts (80%) after mean of 56 days post endograft infection diagnosis all grafts remained infected Mortality (EVAR) 2 pts (50%) hemorrhage from AE fistula (1wk) graft infected, cardiac arrest (10yrs)

27 Remaining Questions Should thoracic graft infections be managed differently than AA graft infections? What is the role of endografts to control aortoenteric/bronchial fistula bleeding? How long should antibiotics be continued in aortic graft infections? Should be type of bacteria determine the treatment? Stay Tuned: Treatment and Outcomes of Aortic Graft Infection On behalf of the Investigators

28 Conclusions Patients with chronic infections or contaminated procedures are the one preventable cause of aortic graft infections NAIS or cryopreserved, then antibiotic soaked prosthetic grafts, should be considered for reconstruction after complete infected graft explantation Medical management is associated with a high mortality Endografts are increasingly responsible for aortic graft infection and more difficult to diagnose The best procedure, duration of antibiotics, and role of endografts to temporize acute complications and bleeding is still undetermined

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