Native Kidney Embolization as Minimally Invasive Treatment for Post-Transplant Polyuria

Introduction: High native kidney urine output post-transplant can lead to dehydration, poor graft perfusion, and increased risk of acute kidney injuries. We describe native kidney embolization as an effective, less invasive, lower morbidity alternative to nephrectomy for patients with post-transplant polyuria. Case Description: Seven patients ages 4 to 19 with renal disease from Bardet-Biedl syndrome, Dent disease, primary hyperoxaluria type 1, renal cortical necrosis, and obstructive uropathy underwent post-transplant native kidney embolization for high urine output. Barriers to performing nephrectomy included horseshoe kidney, elevated BMI, surgical history, and behavioral concerns. Interventional Radiology performed all embolizations via a femoral approach. Angiogram was performed to assess anatomy, followed by ethanol and coil embolization, with repeat angiogram after to ensure success. All patients received a short steroid taper for prevention of post-embolization syndrome. Hospital length of stay was 4-8 days post-embolization. Three patients required ICU stay for sedation during lay flat time post-procedure. Pain was overall well-controlled. Six of seven had lower 24-hour fluid intake requirements post-embolization, with subjective reports of 50-75% decrease in urine output from one patient, and decrease in overnight diapers from another. Half had improvement in GFR post-procedure. Patients with prior hospitalizations for acute kidney injury from dehydration had a decrease in these episodes post-embolization. One patient with primary hyperoxaluria had continued decline in plasma oxalate levels post-embolization. Discussion: This case series demonstrates that native kidney embolization was successful and well tolerated. Pain was well-controlled, with no significant complications from the procedure. Half of the patients experienced improved GFR, and multiple patients reported subjective decrease in urine output after the procedure. Native kidney embolization can be considered an effective, less invasive and lower morbidity alternative to nephrectomy for patients with post-transplant polyuria.