Surgical site infection after liver transplantation: risk factors and association with graft loss or death.

Background: Risk factors for surgical site infection (SSI) after liver transplantation and outcomes associated with these infections have not been assessed using consensus surveillance and optimal analytic methods.

Methods: A cohort study was performed of patients undergoing first liver transplantation at Mayo Clinic, Jacksonville, Florida, in 2003 and 2004. SSIs were identified by definitions and methods of the National Nosocomial Infections Surveillance System. Measures of known or suspected risk factors for SSI, graft loss, or death were collected on all patients. Associations of SSI with these factors and also with the primary composite endpoint of graft loss or death within 1 year of liver transplantation were examined using Cox proportional hazards models; relative risks (RRs) were estimated along with 95% confidence intervals (CIs).

Results: Of 370 patients, 66 (18%) had SSI and 57 (15%) died or sustained graft loss within 1 year after liver transplantation. Donor liver mass-to-recipient body mass ratio of less than 0.01 (RR 2.56; 95% CI 1.17-5.62; P=0.019) and increased operative time (RR 1.19 [1-hr increase]; 95% CI 1.03-1.37; P=0.018) were associated with increased SSI risk. SSI was associated with increased risk of death or graft loss within the first year after liver transplantation (RR 3.06; 95% CI 1.66-5.64; P<0.001).

Conclusion: SSI is associated with increased risk of death or graft loss during the first year after liver transplantation. Increased operative time and decreased donor liver-to-recipient body mass ratio showed evidence of association with SSI.