A comparative in vitro research of the efficiency of nanosecond electropulse (Urolit-105M) and Holmium laser (Auriga) lithotripters is presented in this work. Four sizes of BegoStone cement stones of various densities were fabricated for these tests. A comparison of the efficiency of the lithotripters was performed in the experiments on pairs of probes corresponding to a predetermined stone size. The probes and stones sizes that were used simulate an actual clinical situation to some extent. During the execution of the tests, stones of the specified size were placed on a stainless steel grid with the 2×2 mm cells, immersed in a liquid. The distal part of each probe type was placed in contact perpendicularly with regard to the horizontal surface of a stone. The experiment was discontinued when the destroyed particles did not remain on the grid's surface (i.e., when the sample had been shattered into fragments of less than 2 mm). It was ascertained that, for all of the stone samples used in the given experiments the nanosecond electropulse lithotripter demands significantly less cumulative energy and less time for destruction of the stones than the laser lithotripter, that is, according to physical parameters, it is more effective. With that, various dependences from pulse energy and from stones properties at their disintegration for two examined methods of contact lithotripsy are confirmed experimentally. Operation of the compared lithotripters differs according to the mechanism by which the stones are destroyed, accounting for the variable influence of sample density on the received results.

PurposeThe 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.MethodsThe 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.ResultsNanosecond 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.ConclusionsNEPL 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.

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