The stone usually is reduced to granules that can be passed in the patient's urine. Large struvite stones, because of their jagged shape, sometimes become lodged in positions or locations that make them difficult to treat effectively with shock waves. The surgeon or urologist makes a 1- centimeter incision under local anesthesia through which a nephroscope is passed directly into the kidney and, if necessary, the ureter. Smaller stones may be manually extracted and large ones may be broken up with ultrasonic, electrohydraulic, or laser-tipped probes and extracted. A tube may be inserted into the kidney for drainage and this procedure usually requires hospitalization for several days.
Most patients can resume normal activity within two weeks.
Uric acid stones can be dissolved with a solution of sodium bicarbonate in saline. Cystine stones may be treated with a combination of acetylcysteine and sodium bicarbonate in saline. Struvite and carbon apatite stones can be treated with an acidic solution of hemiacidrin. The procedure involves infusing the chemical solution into the affected area through a ureteral catheter in a series of treatments, until the stone is dissolved. The patient's urine is cultured regularly during treatment to monitor for urinary infection and to prevent the build up of excessive chemical levels, which can cause other health problems.