18 - Effect of pre and peri-transplant native nephrectomy on allograft function and need for post-transplant antihypertensive therapy: a retrospective study

Poster Number: 18
Publication Number: 18.1625

Background: Native nephrectomy (Nx) is done in renal transplant patients for multiple reasons including increasing intra-abdominal space, improving hypertension, decreasing risk of recurrent UTI in the native kidney, resolving proteinuria. Only a few studies evaluate the impact of native Nx on post-transplant hypertension and graft survival.

Objective: To determine effect of Nx on the allograft function and prevalence of being on antihypertensives in pediatric patients transplanted in our institution.

Design/Methods: Renal transplants done at our institution between 1/2004 and 12/2018 were reviewed. Patients who underwent either pre or peri transplant bilateral nephrectomy (BN), unilateral nephrectomy (UN) or no nephrectomy (NN) were compared for renal function over time using estimated GFR based on serum creatinine (Schwartz formula) and prevalence of being on antihypertensive medications.

Results: Of total 50 patients (52% male/48% female), the diagnostic subgroups were congenital anomalies of the kidney and urinary tract (CAKUT) (28), glomerular disease (12), AKI/tubular (4), cystic disease (3), and other/unknown (3). Age ranged from 5-21 years. Amongst the total 50 patients, 10 had BN, 13 had UN and 27 NN. BN were in CAKUT (2), Glomerular disease (3), Cystic disease (3) and other/unknown categories (2). UN distribution was – CAKUT (11), Glomerular disease (2). Indications for Nx were intra-abdominal space, heavy proteinuria and recurrent UTI. Kidney transplant patients with BN had significantly lower GFR at months 12 and 18 compared to those with UN (geometric mean ratio (GMR) and 95% CI at month 12: 0.72 (0.56, 0.94), P=0.014; month 18: 0.71 (0.56, 0.91), P=0.0064) and NN (GMR and 95% CI at month 12: 0.78 (0.62, 0.98), P=0.030; month 18: 0.76 (0.61, 0.94), P=0.012). CAKUT patients with BN had significantly lower GFR at months 12 (P=0.047), 18 (P=0.017), and 24 (P=0.033) compared to those with UN. Additionally, CAKUT patients with NN also had lower GFR at month 24 compared to those with UN, P=0.032. Performance of Nx was not significantly associated with whether patients were placed on antihypertensives for the period of the study (24 months).

Conclusion(s): Nx was associated with reduced post-transplant GFR and did not improve antihypertensive treatment status in the short term in the pediatric population studied. This may be due to the native kidneys contributing to the overall kidney function, even if minimal, which is lost totally with BN. These results indicate that the necessity of pre-transplant native Nx should be carefully considered and studies of long term GFR and hypertension status are needed