A strategy of cystine stone management

Simple mechanical disintegration of cystine calculi by extracorporeal shock wave lithotripsy and/or percutaneous nephrolithotomy is being performed widely around the world. However, it cannot be denied that the cystine calculus is one of the most difficult stones for mechanical disintegration. We previously reported the oral medical chemolysis of cystine calculi in 1982 and a third of the patients became stone-free. In another third of the patients the cystine component was replaced by apatite during the medical treatment and apatite stones formed in this manner are easily disintegrated. In view of the complications of mechanical disintegration, oral medical treatment for chemolysis should be recommended before simple destruction of cystine calculi.