Papillary necrosis causing hydronephrosis in renal allograft treated by percutaneous retrieval of sloughed papilla.

Obstructive uropathy is the second most common urological complication in a transplanted kidney. The usual causes of obstruction are ureteral stenosis and calculi. Papillary necrosis as a cause of obstruction in a transplant kidney is extremely rare with only one prior report published. Moreover, percutaneous removal of sloughed papilla in a transplant kidney has not previously been reported. We report an unusual case of a sloughed papilla causing hydronephrosis of a transplant kidney and its successful percutaneous removal. The recognition of renal papillary necrosis is important, not only because it can be a sign of acute rejection but also it because it can lead to obstruction, infection and potentially the loss of the transplant as exemplified by our case. Rapid diagnosis and meticulous retrieval technique are the crucial factors in minimizing the complications due to obstruction of a transplanted kidney by sloughed papilla.