The practical use of ultrasound as an adjunct to renal calculous surgery.

Removal of small stones and stone fragments from the kidney is difficult and can be an extremely frustrating experience for the surgeon. The major difficulty is the precise localization of the stone within the pelvicalyceal system. Conventional probing of individual calyces is unreliable, even with optimal exposure and direct visualization of the infundibula, using the extended pyelotomy technique. Intraoperative radiographic techniques can be use reliably to detect small stones and fragments. However, such two-dimensional localization limits their effectiveness. Radiographic methods are also cumbersome and require 10 to 15 minutes for each film. Ultrasonography is repeatable and noninvasive. It is a complementary study that offers precise, three-dimensional localization.