Small Stone Fragments Research Articles

Electrohydraulic Shock‐wave Lithotripsy in Experimental Canine Struvite Bladder Stone Disease

Electrohydraulic shock‐wave lithotripsy (EHL), the fragmentation of urinary stones with hydraulic shock waves, was performed through a cystoscope in two female dogs with surgically implanted struvite bladder stones. Stone fragmentation was achieved after about an hour, but complete removal of fragments by irrigation through the cystoscope sheath was not successful. After the procedure, small stone fragments and pieces of the shock‐wave electrode remained in the bladders of both dogs. All stone fragments and electrode pieces were spontaneously voided by one dog; further cystoscopy was required in the other dog to remove three larger stone fragments with a stone basket, and pieces of the electode with grasping forceps. Bladder‐stone removal in the female dog by EHL, irrigation, and using a stone basket is technically feasible, but requires expensive equipment.

Transurethral Removal of Large Ureteral and Renal Pelvic Calculi Using Ureteroscopic Ultrasonic Lithotripsy

Transurethral ultrasonic fragmentation of stones allows successful endoscopic removal of upper urinary calculi that otherwise would be considered too large to extract. We successfully extracted endoscopically 2 large renal pelvic and 5 large urreteral stones using transurethral ureteropyeloscopy and ultrasonic lithotripsy. The stone is visualized first with the ureternpyeloscope, and then engaged in a basket and either fragmented or disintegrated with the ultrasonic transducer. Any remaining small stone fragments can be retrieved with a stone basket forceps. There has been little morbidity with this procedure and patients can return to normal activity after discharge from the hospital.

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.

Nephroscopy in stone surgery.

We present the results of our experience with the use of the nephroscope in 130 open procedures for removal of renal stones. The Storz rigid instrument was used and permitted visualisation of approximately 60% of calices and frequent identification of small stone fragments which would not otherwise have been seen. In 32 patients biopsies were taken on papillary epithelium. In 8, plaques of subepithelial calcification were identified. These were macroscopically obvious and widely distributed over the caliceal epithelium. A high proportion of the biopsies (66%) showed a chronic inflammatory cellular infiltrate which was not necessarily related to urinary infection. Such generalised changes again indicate the futility of partial resection in the management of renal stone disease.