Staghorn calculus in renal allograft presenting as acute renal failure

Therapy-Refractory Matrix Staghorn in a Kidney Transplant Recipient: Endoscopic Percutaneous Morcellation as a Novel Treatment Option

Background: Urolithiasis of transplant kidneys usually encompasses a challenging clinical situation due to specific anatomical conditions and the patients' immunological status. In this case report, we describe the treatment of a rare Proteus mirabilis matrix staghorn stone applying percutaneous nephrolithotomy in combination with matrix stone extraction by morcellation while utilizing endo-urological equipment designed for transurethral prostate surgery. Case Presentation: We present the case of a 44-year-old Caucasian woman who had undergone a post-mortal kidney transplant at age 37. After recurrent urinary tract infections, symptomatic obstructions of the transplant ureter, and multiple surgical interventions (73 Double-J stent and nephrostomy placements and three ureter re-implantations), permanent percutaneous nephrostomy drainage was established 6 years after her kidney transplantation. The patient was referred to our department due to recurrent dysfunction of the nephrostomy tube caused by blockage due to stone-matrix material and a staghorn calculus in the transplant kidney's collecting system. Microbiological examination of the stone material retrieved from the nephrostomy tube revealed massive P. mirabilis contamination. In this work, we present a novel percutaneous technique of matrix stone removal by relying on endoscopic equipment usually employed during prostate surgery by urologists. Conclusion: Percutaneous matrix stone morcellation is a technically challenging but feasible method that might be considered as a salvage treatment strategy in situations described earlier and in highly selective cases. However, for this extremely rare stone entity and individual clinical presentations, matrix stone morcellation seems to be a reasonable alternative before considering more radical interventions such as open nephrolithotomy. Selection criteria are a very soft stone, large-caliber percutaneous access to the collecting system, and enough space in the collecting system to execute morcellation.

Obstructive uropathy and acute renal failure due to ureteral calculus in renal graft: a case report

INTRODUCTION

Obstructive uropathy caused by kidney stones is quite rare in transplant kidneys.

CLINICAL CASE

The authors report the case of a patient, previously gastrectomized for gastric carcinoma. He underwent renal transplantation using uretero-ureterostomy, and presented an episode of acute renal failure 7 years after surgery. Ultrasound (US) examination showed no sign of rejection but allowed detection of moderate hydronephrosis in the transplant kidney. Subsequent computed tomography (CT) revealed a kidney stone in the middle ureter at the crossing of the iliac vessels. The patient therefore urgently underwent percutaneous nephrostomy of the graft and recovered diuresis and renal function. The patient was transferred to the Transplant Center where he underwent ureterotomy with removal of the stone and subsequent ureteropyelostomy. Also transureteral resection of the prostate (TURP) was performed due to urinary retention of prostatic origin. Histological examination showed prostate carcinoma, Gleason stage 3, which was treated conservatively using radiotherapy without suspension of the administered low dose of immunotherapy.

DISCUSSION

Calculosis is one of the least common causes of obstructive uropathy in transplant kidneys. In the described case, US examination performed after onset of renal insufficiency led to subsequent radiological investigation and resulting interventional procedures (nephrostomy and surgical removal of the stone) with complete recovery of pre-existing renal function.