LAUSR

Background. Patients undergoing simultaneous liver-kidney transplantation (SLK) have impaired native kidney function. The relative contribution of allograft versus native function after SLK is unknown. We sought to characterize the return of native kidney function following SLK. Methods. Following SLK, patients underwent technetium-99 m-mercaptoacetyltriglycine renal scintigraphy following serum creatinine nadir. Kidney contributions to estimated glomerular filtration rate (eGFR) were determined. Patients with native kidney function at serum creatinine nadir contributing eGFR ≥30 versus <30 mL/min/1.73 m2 were compared, and multiple linear regression analysis for native eGFR improvement was performed. Results. Thirty-one patients were included in this analysis. Average native kidney contribution to overall kidney function following SLK was 51.1% corresponding to native kidney eGFR of 44.5 mL/min/1.73 m2 and native kidney function eGFR improvement of 30.3 mL/min/1.73 m2 (P < 0.001). Twenty-six of 31 patients had native kidney contribution of eGFR ≥30 mL/min/1.73 m2. Hepatorenal syndrome as the sole primary etiology of kidney dysfunction was 100% specific for native kidney eGFR >30 mL/min/1.73 m2 and predicted native eGFR improvement (P = 0.03). Conclusions. Substantial improvement in native kidney function follows SLK, and hepatorenal syndrome as the sole primary etiology of kidney dysfunction is predictive of improvement. Whether such patients are suitable for liver transplant followed by surveillance with option for subsequent kidney transplants requires investigation.