Medication The stones are less than 0.6 cm in diameter, smooth and without obstruction in the urinary tract below the stones. Uric acid stones are treated with potassium bicarbonate and sodium bicarbonate to alkalinize the urine. Oral e purinol is given. Cystine stones require alkalinization of the urine. Captopril has the effect of preventing cystine stone formation. Infected stones should be controlled by infection. Oral ammonium chloride to acidify the urine. Chinese medicine for stone removal. Extracorporeal lithotripsy Renal stones less than 2 cm in diameter and upper ureteral stones with lower and middle ureteral segments have a lower success rate than ureteroscopic stone extraction. Percutaneous nephrolithotomy for stone extraction For all stones requiring open surgical intervention, including deerstalker stones, stones larger than 2 cm, stones in the calyces or diverticula, stones that are difficult or fail to be crushed by extracorporeal shock waves, and larger ureteral stones above L4. Ureteroscopic lithotripsy Lower and middle ureteral stones, non-visible stones, failed shock wave or stone street. Open surgery Endoscopic intermediate open surgery, no endoscopic condition.