Purpose: Certain congenital causes of end stage kidney disease (ESKD) such as obstructive uropathy and hypodysplasia are associated with severe urinary concentrating defects and polyuria. Per a recent survey we sent to the PedNeph listserve, the community was divided 50:50 as to whether a) this polyuria attenuates on its own once a working renal allograft is in place, and with calcineurin inhibitor immunosuppression reducing native kidney polyuria;  versus b) the need for native nephrectomies around the transplant procedure. 
Methods: At our center, we have recently taken care of several teenagers with ESKD and severe polyuria from the above conditions who received a renal allograft. We tracked the 24-hour urine output pre- and post-transplant and the need for intravenous fluid infusions or nephrectomy, plus biopsy results and last estimated glomerular filtration rate (eGFR). Based on the responses in the first 7 subjects, we changed our strategy for subject 8.
Results: For the first 7 teenagers (6 boys, mean age 16.8 years), we did not perform any pre- or peri-transplant native nephrectomy. Primary diagnoses included obstructive uropathy, hypodysplasia, reflux nephropathy, neonatal acute kidney injury and unknown. Urine output pre-transplant was median /range 1160-6780 ml/day. 5/7 got readmitted within 30 days post-transplant for dehydration from continuing polyuria. We observed clinical acute kidney injury or obstructive hydronephrosis in 5/7, and 5/7 (not the same 5) had native nephrectomies at 41-189 days post-transplant. 2/7 showed infarcts on biopsy or nuclear medicine imaging. Last eGFR in these 6 subjects is median 56 ml/min/1.73m2 (range 46-90) at 223-1035 days post-transplant (mean eGFR at 12-24 months post-transplant is 70-73 per last NAPRTCS Transplant report). In response, for subject 8, a 15 year old boy with obstructive uropathy and pre-transplant urine output 6825 ml/day, we performed pre-emptive unilateral left native nephrectomy pre-transplant and early right native nephrectomy post-transplant, yet last eGFR is 52 at 116 days post-transplant. But trying to perform bilateral native nephrectomies pre-transplant has brought up several practical and logistic challenges for our patient families that either live far away from a dialysis unit, or are not on any maintenance dialysis, or on peritoneal dialysis only.  
Conclusions:  In our teenage cohort, the lifelong polyuria did not drop post-kidney transplant and many needed IV fluids or early nephrectomies, with suboptimal latest eGFR. Management changes in subject 8 did not lead to a better eGFR yet. Our results do not support the belief that native kidney polyuria remits on its own post-transplant, in this age group. Teenagers may behave differently than toddlers with a lesser length of lifelong polyuria. Given the logistic challenges, these teenagers need newer strategies.