[Urologic management of cystine lithiasis in the upper urinary tract. Modalities and indications].

Cystine urinary stones is a relatively rare hereditary disorder of dibasic amino acid transport characterized by frequent recurrences. The management of these stones remains problematical despite the remarkable progress in the urological treatment of upper urinary tract stones. Cystine stones are particularly refractory to extracorporeal shock waves and relatively inaccessible to dye pulsed laser (504 nm). Apart from this exception, endourological techniques often represent the most appropriate therapeutic solution, but they are associated with significant morbidity. The physicochemical characteristics of these stones also allow dissolution by urinary alkalinization or the formation of disulfide compounds. In parallel with oral treatments, which constitute the basis of prevention of recurrence, dissolution can be obtained by direct perfusion of the urinary tract. This approach often requires irrigation for several weeks with a risk of the specific complications of catheterization, especially percutaneous catheterization. Prophylaxis, essentially consisting of dilution and dissolution of urinary cystine, raises the problem of the potential adverse effects of drug treatment. Cystinuria is easily detectable and can be investigated either systematically or only in the families concerned. However, the incidence as well as the frequently benign nature of cystinuria tend to limit its value and its indications.