Comparision of intracorporeal lithotripsy methods and forceps use for distal ureteral stones: seven years experience

Retrograde endoscopic lithotripsy using the innovative nanosecond electropulse method

PURPOSE

The purpose of this clinical study is to assess the safety and efficiency of a novel lithotripsy method for endoscopic treatment of urinary stones throughout the urinary tract via semi-rigid and flexible endoscopes. This new method is based on the transfer of nanosecond high voltage electric pulses to the stones through flexible probes of various sizes.

METHODS

The study involved 879 patients aged 19-88 with renal, ureter and bladder calculi. Gender distribution: 46.3% female and 53.7% male. The prospective single-arm study took place at three centers. The goal of the clinical study was to evaluate the safety and efficacy of a novel lithotripsy method. All treatments were performed retrograde transurethrally. A variety of probes were used for stone fragmentation at different locations. Auxiliary treatments and adverse events were recorded as per protocol. Statistical analysis was conducted using SPSS software.

RESULTS

Nanosecond electropulse lithotripsy (NEPL) was found to be technically feasible for all patients with stones located in the kidney, UPJ, ureter and bladder. It requires only a few dozen pulses to disintegrate stones while causing only minor stone migration. The overall stone-free rate in the study was 96%. The average time required for executing the entire procedure was 45±28 min. The overwhelming majority of intraoperative complications occurred due to endoscopic manipulation when using a rigid ureterorenoscope and not due to lithotripsy impact.

CONCLUSIONS

NEPL is a new, efficient and safe method for urinary stone disintegration that can be used throughout the urinary tract using rigid and flexible endoscopes. Intraoperative complications of the NEPL procedure do not exceed the percentage of adverse effects observed in other lithotripsy methods. The main advantages of relatively low-cost NEPL are fast stone fragmentation requiring only a few dozen pulses to disintegrate stones, tissue safety and availability of highly flexible probes for treating stones in the lower pole through a flexible ureterorenoscope.

Is Early Forceps Application Necessary in the Treatment of Distal Ureteral Stone with Dye-Laser and Pneumatic Lithotripsy?

We report the success and complication rates of pulsed dye-laser and pneumatic lithotripsy methods, as well as emphasizing the importance of early forceps application.

Materials and Methods

We retrospectively evaluated ureterorenoscopy performed in 900 patients, between April 1996 and May 2004, due to distal ureter stones. Following stone fragmentation, patients with stones ≤4 mm in diameter were accepted as stone-free and patients with stones >4 mm had them removed with forceps.

Results

In the laser treated group, the 1st stone-free rate in patients with a stone diameter ≤4 mm was 56.9%. In this group, when forceps were used in patients after fragmentation, the total stone-free rate increased to 96.8%. Likewise, while the 1st stone-free rate in the pneumatic group was 71.56%, the total stone-free rate increased to 96.73% after forceps application.

Conclusion

Both success and complication rates were found to be significantly higher in the pneumatic lithotriptor applied group.