to be useful in addition to lithotripsy. Lithotripsy Extracorporeal shock wave lithotripsy (ESWL) is a noninvasive technique for the removal of kidney stones. Most ESWL is carried out when the stone is present near the renal pelvis. ESWL involves the use of a lithotriptor machine to deliver externally applied, focused, high-intensity pulses of ultrasonic energy to cause fragmentation of a stone over a period of around 30–60 minutes. Following its introduction in the United States in February 1984, ESWL was rapidly and widely accepted as a treatment alternative for renal and ureteral stones. It is currently used in the treatment of uncomplicated stones located in the kidney and upper ureter, provided the aggregate stone burden (stone size and number) is less than and the anatomy of the involved kidney is normal. For a stone greater than , ESWL may not help break the stone in one treatment; instead, two or three treatments may be needed. Some 80-85% of simple renal calculi can be effectively treated with ESWL. A number of factors can influence its efficacy, including chemical composition of the stone, presence of anomalous renal anatomy and the specific location of the stone within the kidney, presence of hydronephrosis, body mass index, and distance of the stone from the surface of the skin. Common adverse effects of ESWL include acute trauma, such as bruising at the site of shock administration, and damage to blood vessels of the kidney. In fact, the vast majority of people who are treated with a typical dose of shock waves using currently accepted treatment settings are likely to experience some degree of acute kidney injury. ESWL-induced acute kidney injury is dose-dependent (increases with the total number of shock waves administered and with the power setting of the lithotriptor) and can be severe, including internal bleeding and subcapsular hematomas. On rare occasions, such cases may require blood transfusion and even lead to acute kidney failure. Hematoma rates may be related to the type of lithotriptor used; hematoma rates of less than 1% and up to 13% have been reported for different lithotriptor machines. Recent studies show reduced acute tissue injury when the treatment protocol includes a brief pause following the initiation of treatment, and both improved stone breakage and a reduction in injury when ESWL is carried out at slow shock wave rate. In addition to the aforementioned potential for acute kidney injury, animal studies suggest