Morbid obesity and functional status as predictors of surgical complication after renal transplantation

Background This study evaluated the impact of body mass index (BMI) and patient functional status on the risk for surgical complications after kidney transplant. Methods This retrospective cohort study of adult kidney transplant recipients grouped patients by baseline Karnofsky status (low function ≤ 70%) and further stratified by morbid obesity (BMI ≥ 35 kg/m2) to assess surgical complication risk. Results 736 patients were included with surgical complications occurring in 25%. Logistic regression analysis with interaction terms demonstrated that morbid obesity and low functional status conditionally impact risk with an OR of 2.8 [95% CI (1.1–7.3)]. Within the functional status cohort, BMI ≥35 kg/m2 was associated with increased risk of surgical complication, superficial wound infection, and DGF. Independent predictors for surgical complications included diabetes and morbid obesity with low functional status. There was no significant difference in graft loss or death across the cohorts. Conclusions While neither morbid obesity nor poor functional status alone predicts increased complications, the combined presence is associated with significant increase in risk for surgical complications after renal transplantation.