Hypocitraturia-related Ureteral Steinstrasse in a Renal Transplant Recipient

Urolithiasis is an uncommon complication in renal transplantation. We report a case of hypocitraturia-related ureteral steinstrasse which was spontaneously formed in a renal transplant recipient. The patient who underwent renal transplantation was admitted with acute pyelonephritis. Hydronephrosis in the transplanted kidney and multiple stones (steinstrasse) in the distal ureter were incidentally found on computed tomography scanning. After a failed attempt of ureteroscopic removal of stones, the patient underwent open ureterolithotomy and ureteroureterostomy. On stone analysis, carbonate apatite was confirmed. Urinary citric acid levels were decreased to 127.6 mg/ day. Potassium citrate was administered to prevent stone recurrence by increasing urinary citrate excretion. No recurrence of stones was shown six months later. Urolithiasis in renal transplant recipients requires a high index of suspicion. Hypocitraturia can increase the risk for urolithiasis. Rapid recognition by careful surveillance, prompt removal of stones, and precautionary efforts to prevent recurrence are needed.