Contemporary management of cystinuria.

Abstract

Cystinuria is an autosomal recessive disorder characterized by a defect in intestinal and renal tubular transport of dibasic amino acids which results in excessive urinary excretion of cystine. Because of the relative insolubility of cystine in urine, patients with this condition are prone to recurrent stone formation. Medical therapy aims both to decrease the urinary concentration of cystine and to increase its solubility. Standard prevention and treatment regimens include hydration, moderate salt and protein restriction, oral alkalinization, and thiol derivatives. Despite aggressive medical management, however, cystinuric patients are likely to suffer frequent recurrent episodes of stones necessitating urologic intervention. Fortunately, the application of safe and efficacious minimally invasive modalities, including advancements in shockwave lithotripsy, ureteroscopic lithotripsy, and percutaneous nephrolithotomy, have obviated open operative intervention in nearly all cases.