[Cystinuria and urolithiasis]

Cystinuria is a hereditary metabolic disorder which causes urinary lithiasis. Patients with cystinuria present at an earlier age (17 years), and with larger stones than patients with other types of urinary stones. As a result of frequent formation of new stones and multiple operations, many patients suffer from obstructive nephropathy and deterioration of kidney function. During the past decade we treated and followed 51 patients with cystine urolithiasis from 39 families. Screening disclosed another family member with cystinuria in 56% of the cases. The diagnosis of cystinuria was only made an average of 2 years after a patient first presented. In the group 12 kidneys had been removed due to various complications and in 7 kidneys there was significant deterioration of function. Each patient underwent a mean of 5.8 surgical interventions, including open operations, extra-corporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotripsy (PCNL) and urethroscopy, but most still had residual stone fragments. To prevent complications from cystine urolithiasis every effort should be made to detect the disease early, including screening of families of patients with cystinuria and close follow-up of all family members. Early detection of stones, before they become large makes noninvasive treatment with ESWL possible, whereas large stones require PCNL. Patients should be urged to maintain high urine outputs and to continue uninterrupted treatment with penicillamine or tiopronin, and urinary alkalinization.