[Comparative evaluation of efficacy of electropulse and laser lithotriptors in vitro]

The article presents a comparative study of the nanosecond electropulse and holmium laser lithotriptors in vitro. Two types of samples simulating the "hard" and "soft" urinary stones were used; for their preparation stomatological ultrastrength plaster BegoStone was used. For the tests, four sizes of samples of stones in the cuboid shape were made. The sizes of the probes and stones, to some extent, simulated real clinical situation. In the experiments for Ho:YAG laser lithotriptor (LL), three sizes of probes were used: 230, 365 and 600 microns; for electropulse lithotriptor (EPL) - 2.7, 3.6, 4.5, and 6 Fr probes. A comparison of the effectiveness of lithotriptors in the experiments was performed for pairs of probes, which corresponded to a specific size of the stones. Comparative studies were performed in water at room temperature. "Stones" with specified size for each type of probe of lithotriptors were placed on stainless steel mesh with a mesh size 2 x 2 mm, immersed in water. Distal part of the probe (tip) was placed at an angle of 900 to the horizontal surface of the "stone" and brought into contact with the sample. The experiment was stopped when the surface of the mesh was free of particles of "stone" destroyed. Each experiment with the type and size of the "stone" and the probe was repeated at least 5 times. The results showed that nanosecond EPL requires much lower energy and time costs than the LL, ie, its physical parameters are more effective for the destruction of all types of samples stones. For the destruction of the "soft" stones, EPL always required much less energy than for the he destruction of "hard" stones. At the same time, working with LL often required same energy, and sometimes even more than for the destruction of "hard" stone. For the two methods of contact lithotripsy, different depending on the pulse energy and the properties of the "stones" in their destruction is confirmed experimentally.