Dr HANNAH WALLACE1, Dr HILARY HISCOCK1, Professor FRANK IERINO1
1St Vincent’s Health , Melbourne , Australia
BACKGROUND:
Nephrolithiasis in the transplant recipient has an incidence of approximately 1%, however remains an uncommon but important cause of renal failure post transplantation.
CASE REPORT:
We report a case of oliguric renal failure secondary to nephrolithiasis without imaging evidence of hydronephrosis in 57-year-old female 7months post renal transplantation. Past history of renal failure was secondary to presumed reflux nephropathy and a previous episode of obstruction secondary to a renal calculus. Her sister also had reflux nephropathy.
She underwent deceased donor renal transplantation with stable baseline graft function (serum creatinine 104 umol/l, eGFR 52 ml/min/1.73m2) and 7months post-transplant presented with oliguric renal failure. Imaging demonstrated a large stag-horn calculus without features of hydronephrosis. Calcification of the ureter was first noted following stent removal 4months prior to admission and serial imaging showed increasing calcification. The patient was awaiting a urology opinion.
Renal biopsy excluded rejection and demonstrated acute tubular injury with calcium oxalate deposition without other features of oxalate nephropathy. Due to concern for obstruction a nephrostomy was placed with improvement in transplant function. Stone analysis demonstrated composition of calcium phosphate (80%) and magnesium ammonium phosphate struvite (20%), and she was found to have cornebacterium urealyticum infection contributing to stone formation. Percutaneous nephrolithotomy was unsuccessful. Novel treatment with a citric acid and micodacyn super oxidised solution was used to attempt stone dissolution with some improvement.
CONCLUSIONS:
This case highlights an unusual cause of acute renal failure in the early post-transplant period with a staghorn calculus. The role of the ureteric stent as a “nidus”, and exclusion of genetic and metabolic causes of stone formation is required. Timely urology opinion in cases of nephrolithiasis post-transplant is essential.
Biography:
Dr Hannah Wallace is in her final year of Renal Advanced Training at St Vincent’s Health Melbourne.