[Comparative study of the influense of stone size and volume on the duration of thulium laser percutaneous nephrolithotripsy].

OBJECTIVE: The aim of the investigation was to determine the influence of such parametric characteristics of the stone such as size and volume on the duration of tulium laser disintegration of the urinary stone and to determine which of these parameters is more effective to use like prognostic criterion for the duration of the planned surgical intervention in the percutaneous nephrolithotripsy. MATERIALS AND METHODS: Overall 52 patients (27 females and 25 males) with an average age of 56,9 (25-79) years participated in the present study. All patients underwent percutaneous nephrolithotripsy with disintegration of the kidney stone by thulium energy. Inclusion criteria were: stone size more or equal 2 cm, stone density >1100 HU. Exclusion criteria were: patients with a single kidney, urinary tract divertions, coagulopathy. The average operation time was 30 (15-100) minutes, with an average puncture time of 3.15 (1-10) minutes and lithotripsy time of 28 (14-98) minutes. To determine the volume we used the method of automatic lithometry according to CT data using the software: Vitrea ver. 4.1.52. The size of the stone was determined by the longest length in one of the plane. During the study it was found that the average size of the stone was 28.25 (20-58) mm and the average volume was 2579.4 (250-9990) mm3. To confirm our assumption, we decided to determine the dependence of the time of disintegration of the stone on the size and volume of the stone. For this purpose, we graphically presented the correlation of these parameters. RESULTS: We have drawn 2 graphs reflecting the dependence of lithotripsy time parameters on the size and volume characteristics of the stone. As a result of comparing these parameters we found that size is a prognostically less reliable predictor of lithotripsy time, and is not characterized by a linear distribution, in contrast to the stone volume. CONCLUSIONS: Thereby, the main stereoscopic characteristic of a stone is a volume, which should be the primary guide in selecting the preferred method of treatment as well as in predicting the operative time and associated risks.

[Decrease in time of transurethral laser litotripsy due to micro-drainage applications].

INTRODUCTION: The length of the operation to remove urinary concernments has a marked effect on the occurrence of postoperative complications in the time of the postoperative patients in the hospital. A significant factor contributing to the increase in time is the clouding of the fragmentation region, which increases the operation time and the number of complications. PURPOSE: to develop a method of reducing the time of additional costs in contact lithotripsy with a holmium laser in order to reduce the risk of postoperative complications. MATERIALS AND METHODS: The paper presents the own results of in vivo measurements of time intervals spent on fragmentation of stone. Fragmentation of stones in kidney was carried out by a holmium lithotripter of Triple type with the help of semirigid and flexible ureteroscopes. In the case of severe clouding of the fragmentation region, the author s technique of percutaneous micro-drainage of the kidney was used. The evaluation of the duration of the fragmentation procedure is based on statistical processing of the obtained measurement data using Excell Data Analysis tools. RESULTS: In the process of analysis of literary sources and results of own studies it was revealed that with increase in duration of contact laser lithotripsy the number of postoperative complications significantly increases. In order to reduce the time of transurethral contact holmium lithotripsy, the author s technique of percutaneous micro-drainage has been developed. By in vivo measurements and statistical processing of the data, it was found that by using the micro-drainage technique, the average additional washing time of the fragmentation region was reduced by an average of 4 times compared to the conventional technique. CONCLUSION: By further washing the fragmentation region, it is possible to reduce the time of additional crushing costs by at least 4 times and reduce the number of postoperative complications.