441Incidence and Risk Factors for Development of Liver Abscesses in Liver Transplant Recipients with Intra Abdominal Infections - a 10 year retrospective review

• Introduction: Although intra-abdominal infection (IAI) is a frequent complication after liver transplantation (LT), liver abscesses (LA) appear to be uncommon. There is scarce data regarding LA among liver transplant recipients (LTR). We report on the clinical epidemiology, risk factors, and outcomes of LA in LTR at our institution. • Methods: A retrospective cohort study was performed of all LTs done at Henry Ford Hospital, Detroit Michigan from January 2003 till December 2012. LA was defined as a parenchymal lesion consistent with an abscess as seen on imaging, together with compatible clinical features. Frequency analysis was performed of all variables using a chi-square test for dichotomous variables and a students’t test for continuous variables. A logistic regression for risk factors that could contribute to development of a LA in patients with IAI post-LT was performed. Patients who developed other intra-abdominal infections (OIAI) after transplant (intra-abdominal abscesses or peritonitis) were used as a comparative group. • Results: Of all 986 LTs done from 2003 to 2012 the incidence of IAI was 15.3 per 100 LTRs. The incidence of LA alone was 2.4 per 100 LTRs. The median time from LT to diagnosis of LA was 120 days (IQR: 59-1163). Most (46%) of LAs were polymicrobial infections. Pathogens isolated included: aerobic gram-positive cocci (47.5%); gram-negative (30%); Candida spp. (17.5%); and anaerobes (5%). Among LTRs with LA as compared to LTRs with OIAIs, mortality related to infection was 17% vs. 5% (P value 0.03) and liver failure requiring re-transplantation was 13% vs. 3% (P value 0.045). Overall 33% of LA patients died due to infection, developed liver failure requiring re-transplantation or had other serious complications compared to 9% for patients who had OIAI (P value 0.008). Logistic regression analysis identified doppler evidence of hepatic artery abnormality (thrombosis, stenosis or rupture) (odds ratio [OR], 10.51; 95% confidence interval [CI], 3.27-33.71) and liver failure due to NASH, Primary sclerosing cholangitis (PSC) or Primary biliary cirrhosis (PBC) (OR, 3.58; 95% CI, 1.27-10.10) as predictors for developing LA compared to OIAI. • Conclusions: In LTRs with IAIs, hepatic artery abnormality and liver failure due to NASH, PSC or PBC are significant risk factors for LA. The development of LA is associated with increased risk of death and re-transplantation.