[Urinary lithiasis after kidney transplantation. Experience at a pediatric center].

BACKGROUND

Urologic complications are still a frequent and significant problem in renal transplant recipients. The search for risk factors is therefore mandatory.

MATERIAL AND

METHODS

652 renal transplantations were performed in children and adolescents between January 1973 and December 1988. 33 patients (5%) developed urolithiasis; their files were retrospectively analysed at the same time as the files of 28 patients transplanted during the same period and having similar ages, reasons for transplantation and immunosuppressive therapy.

RESULTS

The stones contained calcium in 27 patients and uric acid in 6. The first symptoms were hematuria (27 times) with or without dysuria (9 cases), urine retention (2 cases) and anuria (2 cases). Repeated urine infections frequently led to the use of imaging techniques that permitted diagnosis. Urolithiasis was responsible for urinary obstruction in 13 cases; 9 of these required surgery. The course was always good without any modification of renal functions. The main risk factors were local: ureteral reimplantation on intestinal bladder, use of nonresorbable stitches and repeated urinary infections. Metabolic factors were less frequent and included hypercalciuria (18 cases) and hyperparathyroidism (2 cases).

CONCLUSIONS

Some of the risk factors such as urinary infections, changes in the metabolism of phosphorus and calcium or insufficient diuresis, can be prevented. Repeated imaging techniques during the follow-up are mandatory.