Efficiency Of Lithotripsy Research Articles

Laser Lithotripsy Fundamentals: From the Physics to Optimal Fragmentation

Purpose: Laser Lithotripsy has remained the cornerstone for the management of urolithiasis for more than thirty years. Miniaturization of endoscopic equipment, digital vision, improvement of laser lithotripters, laser fibers has made endourology a field of growing interest, immersed in a technologic revolution. The aim of this article is to do an extense review on laser lithotripsy starting from the physics of the lasers, to translational science apply to lithotripsy fundamentals in order to make lithotripsy safer and more efficient. Methods: We performed a review of the literature in four different databases (PubMed, Embase, Ovid®, and Scopus®,) on any information concerning laser lithotripsy in February 2020 independently by three authors, a total of 186 articles were reviewed and 38 of the most influential articles were selected and a detailed reviewed on this topic is presented. Results: We aim to make a reference paper for all urologists and health personal involved in laser lithotripsy, starting from the physics to answer practical questions as how to set the parameters in my laser system, how to improve lithotripsy efficiency, should we dust or bust? and finally discussing new technologies such as the Holmium: Ytrium-aluminium-garnet (Ho:YAG) Moses technology, the revolutionary thulium laser fiber (TLF) and discussing the future of laser lithotripsy. Conclusions: Laser lithotripsy must offer higher ablative efficiency, wider range of laser parameters and comprehensive combinations, reduce retropulsion and fiber burn-back, scope miniaturization capabilities, smaller fiber sizes, increased safety, lower environmental impact, reduced maintenance costs Ho: YAG has remained the unquestioned gold standard for laser lithotripsy, but the recently launched Thulium fiber laser has all the above mentioned features and outruns without no doubt the current gold standard and is set to gradually replace.

Особенности и эффективность экстракорпоральной ударно-волновой литотрипсии у детей с использованием сонографического наведения

The aim of the study was to retrospectively evaluate the efficiency of extracorporeal shock wave lithotripsy (ESWL) with ultrasound guidance and the results of treatment of children with urolithiasis, of different age groups depending on the stone location and size. A total of 135 children and adolescents, aged from 1 to 18 years treated by ESWL at IZMIRLIAN Medical Center from 2005 to 2016 were enrolled in this study. Number, size and location of stones were evaluated. A total of 153 ESWL sessions were performed, including two sessions in 9 cases, three sessions in 1 case, and four sessions in 2 cases. Intra- and posttreatment stone fragmentation rate, number of ESWL sessions, shock-wave pulses per session, stone-free rate, and number of ancillary procedures depending on the stone location and size as well as radiation exposure were evaluated. Follow-up observation was performed after 14, 30 and 90 days. In most cases, there was a good stone fragmentation after ESWL. From 200 to 3000 low-energy pulses with a frequency 1-2 Hz and power of 30-50 units on Modulith SLK scale were delivered. Number of shock-wave pulses up to 1000, 2000 and 3000 was sufficient in 18.3%, 51.9% and 26.8% cases, respectively. SFR in children aged 1-5 years was 95.2%, compared to 100%, 100% and 83.7% in patients in the 6-10, 11-15 and 16-18 year age groups, respectively. Complete stone clearance was achieved in patients of 1-5 and 6-10 years after two weeks. In only one patient in the 11- to 15-year age group, all fragments passed after two weeks, while in 4 adolescents in the 16- 18-year age group SFR was achieved after more than 3 months. In addition, in other 3 patients in this age group ESWL was unsuccessful. Our results suggest high efficiency of ESWL under ultrasound guidance in children and adolescents. Absence of X-ray exposure, minimal complication rate, non-invasiveness and high efficiency allow to consider ESWL as a method of choice for the treatment of urolithiasis in children and adolescents.

Surfactant Enhanced Laser-Induced Vapor Bubbles for Potential use in Thulium Fiber Laser Lithotripsy.

The Thulium fiber laser (TFL) is being explored as a potential alternative to the gold standard Holmium:YAG laser for infrared laser ablation of kidney stones. Laser-induced vapor bubbles contribute to both the ablation mechanism and stone retropulsion. In this preliminary study, a biocompatible surfactant with concentrations of 1-5% was used to enhance the vapor bubble dimensions during the laser pulse. Bubble dimensions using surfactant increased on average by 25% compared with water only (control). With further development, introduction of the surfactant into the saline irrigation flow typically delivered through the working channel of the ureteroscope during laser lithotripsy, may contribute to more efficient stone ablation.Clinical Relevance-This preliminary study demonstrates that the dimensions of laser-induced vapor bubbles created during infrared laser lithotripsy can be enhanced by up to 25%, for potential clinical translation into more efficient lithotripsy and use in the "popcorn" ablation method.

Initial Experiences Using Super Pulse Thulium Fiber Laser: Multipurpose Applications and the Assessment of Urologists' First Impression

Abstract Introduction: The super pulse thulium fiber (SPTF) laser has recently been acclaimed by more efficient lithotripsy activities, shorter laser, and treatment times demonstrated in preclinica...

MP04-02 THE ROLE OF PULSE DURATION AND PULSE ENERGY ON FIBER TIP DEGRADATION DURING HIGH-POWER HOLMIUM LASER LITHOTRIPSY

INTRODUCTION AND OBJECTIVE: High-power holmium lasers are becoming increasingly popular for ureteroscopic laser lithotripsy and dusting technique. Because settings and power selection may impact fiber-tip degradation and lithotripsy efficiency, we investigated the effect of pulse duration and pulse energy on fiber-tip degradation when using high-power settings for popcorn laser lithotripsy. METHODS: BegoStones were fragmented in an 11 mm bulb to simulate renal calyx, using a 120W Ho:YAG laser (Lumenis, CA). A 242 μm fiber (Boston Scientific, MA) was introduced through a ureteroscope mounted to a 3D positioner with its tip positioned at 2 mm distance from the stones (popcorn model). To assess the effect of pulse duration on tip degradation, settings with variable power of 1.0Jx20Hz (20W), 0.5Jx70Hz (35W), and 1.0Jx40Hz (40W) were tested on long pulse (LP) and short pulse (SP) modes. To assess the effect of pulse energy on tip degradation, high-power settings with equal power of 40W were tested (0.5Jx80Hz, 0.8Jx50Hz, and 1.0Jx40Hz) using SP. Experiments were conducted for a total duration of 4 minutes and outcome was fiber-tip length measured before and after each experiment using a digital caliper. Pulse duration and peak power were measured using a photodetector (DTE05D2, Thorlabs, NJ). RESULTS: Fiber-tip degradation was greatest when using SP compared to LP for all settings tested (P<0.01), with the highest degradation occurring at 1.0Jx40Hz using SP (Figure 1A). For 40W settings tested, tip degradation was significantly lower when using a pulse energy of 0.5J compared to 0.8J or 1.0J (P < 0.004; Figure 1B). Pulse energy of 0.5J at SP and LP had low peak power of 2.4 and 2.0 kW, respectively (Table 1). CONCLUSIONS: Using LP mode results in less fiber burnback for all power settings tested. High-power 40W settings can be utilized with minimal fiber burnback if low pulse energy settings are used. Understanding these parameters can help clinicians improve the longevity of the laser fiber and improve procedural efficiency.Source of Funding: Research grant form Boston Scientific

Optimal settings for the Holmium: YAG laser in pediatric endourology: Tips and tricks

To the best of our knowledge, no pediatric paper has been published regarding specifically how to set the Holmium:YAG laser for multiple urologic applications. To provide insight into the laser parameters for pediatric applications. We describe the principle and the settings of the laser. The Holmium:YAG laser can produce four different biological effects: (1) fragmentation of stones in small fragments that can be retrieved with grasping instruments, thereby increasing the immediate stone-free outcome. For fragmentation lithotripsy, the laser has to be set with a high energy, low frequency and short pulse duration; (2) dusting which produces fine dust that can spontaneously evacuate, avoiding the use of basket retrieval. The dusting setting requires low energy, high frequency and long pulse duration; (3) incision of posterior urethral valves or ureterocele when all settings are maximized: high energy, high frequency and long pulse duration; (4) coagulation of urothelial tumors using high frequency, long pulse duration and slightly lower energy than required for incision. Both dusting by painting and fragmentation with retrieval for ureteroscopic laser lithotripsy are effective. Although dusting tends to be associated with shorter operative times and a lower risk of ureteral trauma, this approach has a potential risk of recurrent stone formation from dust failing to pass. In contrast, fragmentation with extraction may provide for a more immediate postoperative stone-free result. Altering the pulse energy, frequency, width and modulation can help to optimize lithotripsy efficiency. Lower pulse energy settings result in smaller fragments, less retropulsion and reduce fiber tip degradation. A shallow depth of penetration in water and tissue allows precise energy application and provides a margin of safety. An understanding of Ho-YAG laser settings will permit the pediatric surgeon to make a better use of the device for different urological applications.

What is the optimum lithotripsy method for high density stones during mini-PNL? Laser, ballistic or combination of both.

Percutaneous nephrolithotomy (PNL) is the primary treatment option for renal stones > 20mm in diameter. Mini-PNL gained popularity with its minimally invasive nature. The aim of this study was to compare the efficiency of ballistic and laser lithotripsy with the combined use of both techniques. Data of 312 patients underwent mini-PNL for renal stones with Hounsfield Unit > 1000 was investigated retrospectively. We identified 104 patients underwent combined ballistic and laser lithotripsy. Propensity score technique was used to create the laser and ballistic lithotripsy groups. Groups were matched on stone size, stone density, and Guy's stone score. Primary end point of the study was to compare the stone free rate (SFR), complication rates, and duration of surgery. Mean age of the population was 49.4 ± 6.1, stone size was 24.6 ± 6.3mm, and stone density was 1215 ± 89 HU. The groups were similar for age, stone size, stone density, and Guy's stone score. The SFR and the complication rates of the 3 groups were similar (p = 0.67). The duration of the surgery was shorter in the combined group (46.1 ± 6.3min) compared to the laser lithotripsy (54.5 ± 6.6min) and ballistic lithotripsy (57.2 ± 6.9min) groups. Both laser and ballistic lithotripsy are effective methods for stone fragmentation during mini-PNL. Combined use of both methods has the potential to improve the fragmentation rates and diminish the operative times in case of high density stones.

Eficacia del manejo de la litiasis renal con litotricia extracorpórea por ondas de choque (LEOCh) en la población pediátrica de un hospital de tercer nivel en México

Introducción: La incidencia de litiasis urinaria en niños es baja (~3%). La litotricia extracorpórea por ondas de choque (leoch) es una alternativa terapéutica de primera línea para cálculos renales menores a 20mm. Sin embargo, posee algunas desventajas: la tasa de éxito es variable (después de la primera sesión oscila entre 60 - 90%), directamente asociado al tamaño, densidad y composición del lito. Los factores predictores del éxito del procedimiento son la carga litiásica, la longitud infundibular y el ángulo infundibulopélvico (&gt; 45o).&#x0D; Objetivo: Establecer la eficacia global de la leoch en litiasis renal en la población pediátrica del Hospital General de México.&#x0D; Material y métodos: Estudio retrospectivo, transversal, analítico; incluyó 45 expedientes de pacientes pediátricos sometidos a leoch como manejo para litiasis renal. Criterios de inclusión: Edad: 1-18 años; lito &lt;/= 20mm, localización renal. Criterios de exclusión. Pacientes &gt; 18 años, lito &gt; 20mm, localización extrarrenal, presencia de obstrucción, embarazo y discrasia sanguínea. Criterios de eliminación: Paciente sin seguimiento (1 mes) radiológico.&#x0D; Resultados: 28 pacientes alcanzaron la resolución de su estado de litiasis, tasa de éxito del 62.2% (ic 95% de 47.5 a 77.0). Los factores asociados a la falla terapéutica fueron el tamaño del lito (p=0.03) y su localización en la unidad renal (p= 0.03).&#x0D; Conclusiones: Los resultados obtenidos en nuestro estudio para el manejo de la litiasis renal en la población pediátrica son similares a lo reportado en la literatura en cuanto a seguridad, eficacia y estado libre de litiasis.

Comparison of sun's tip-flexible ureterorenoscopy and minimally invasive percutaneous nephrolithotomy in the treatment for senile upper ureteral incarcerated calculi

Objective To compare the efficacy of Sun's tip-flexible ureterorenoscopy and minimally invasive percutaneous nephroscopy in the treatment of incarcerated upper ureteral calculi in elderly patients. Methods From July 2016 to December 2017, 60 elderly patients with upper ureteral incarcerated calculi were selected from the department of urology of the Huaian hospital affiliated to Xuzhou medical university. According to the order of hospitalization, it was divided into the Sun's tip-flexible ureterorenoscopy (30 cases) and the minimally invasive percutaneous nephroscope (30 cases), respectively, with Sun's tip-flexible ureterorenoscopy and minimally invasive percutaneous nephrolithotomy. The one-time success rate, stone clearance rate, intraoperative bleeding volume, postoperative hospital stay, postoperative complications, postoperative comfort, pain and trauma index (TNF-a, IL-6 and CRP) were compared between the two groups. Results The two groups were successful in the first stage operation, and there was no significant difference between the two groups after 1 month of operation (P>0.05). The intraoperative bleeding volume, postoperative hospitalization time and incidence of postoperative complications in the Sun's tip-flexible ureterorenoscopy group were significantly lower than those in the minimally invasive percutaneous nephrolithotomy group (P<0.05), and the pain scores in the Sun's tip-flexible ureterorenoscopy group were significantly lower than those in the minimally invasive percutaneous nephrolithotomy group (P<0.05), while the comfort scores were significantly higher than those in the minimally invasive percutaneous nephrolithotomy group (P<0.05). The levels of serum TNF-α, IL-6 and CRP in both groups increased 24 hours after operation, but decreased 72 hours later. The levels of TNF-α, IL-6 and CRP in percutaneous nephroscopy group were significantly higher than those in Sun's tip-flexible ureterorenoscopy group at different time points (P<0.05). Conclusions Sun's tip-flexible ureterorenoscopy and minimally invasive percutaneous nephroscope both have high lithotripsy efficiency in the treatment of incarcerated upper ureteral calculi in the elderly, but Sun's tip-flexible ureterorenoscopy has the advantages of small trauma, low complications and high comfort, which is worthy of wide clinical application. Key words: Ureteral Calculi; Ureteroscopy; Nephrostomy, Percutaneous

Are We Cutting Ourselves Short? Laser Lithotripsy Performance Based on Differences in Fiber-tip Preparation

ObjectiveTo better understand the impact of laser fiber-tip configuration on lithotripsy performance, we undertook an in vitro study comparing 3 fiber-tip configurations: (1) new (single-use), (2) cleaved (reusable), and (3) coated (cut with scissors). MethodsLithotripsy was performed using a Ho:YAG laser utilizing fragmentation (1 J × 10 Hz) and dusting (0.5 J × 20 Hz) settings. BegoStones were fragmented with a laser fiber advancing at a speed of 1 mm/s (220 seconds of activation). Three fiber-tip configurations were tested: new single-use standard (242 μm core) and cleaved (272 μm core), compared to the same fiber-tip coated/cut flush with scissors, respectively. Study outcome was difference in stone mass before and after each experiment. Power output was measured using a power meter. ResultsFragmentation for new or cleaved fibers was greater than the coated/cut flush fiber-tip (P <.05). For 1 J × 10 Hz and 0.5 J × 20 Hz settings, fragmentation was 59% and 75% higher with new fiber-tip compared to the coated/cut flush fiber-tip, respectively. For 1J × 10 Hz and 0.5 J × 20 Hz settings, fragmentation was 51% and 45% higher with cleaved fiber-tip compared to the coated/cut flush fiber-tip, respectively. Power output at the end of laser activation was higher for new and cleaved fiber-tips. ConclusionNew and cleaved laser fibers demonstrated superior lithotripsy performance compared to fibers that were coated/cut flush with scissors. Cutting single-use laser fibers risks damaging the fiber-tip which can disperse the energy and reduce lithotripsy efficiency.

Does Aging Affect the Efficiency of Extracorporeal Shock Wave Lithotripsy (ESWL) on Ureter Stones?

Does Aging Affect the Efficiency of Extracorporeal Shock Wave Lithotripsy (ESWL) on Ureter Stones?

The clinical role of X-ray computed tomography to predict the clinical efficiency of extracorporeal shock wave lithotripsy

To evaluate the clinical efficiency of computed tomography for diagnostics of patients with urolithiasis and the choice of treatment strategy. The study was carried out at the Urological Clinic of I.M. Sechenov First Moscow State Medical University and included 1044 patients with urinary stones. The ultimate goal of this study was to predict the clinical efficiency of extracorporeal shock wave lithotripsy using a combination of computed tomography and densitometry. Extracorporeal shock wave lithotripsy was performed on "Siemens Lithostar Plus," "Siemens Modularis Uro," and "Dornier Gemini" lithotripters. Statistical analysis of clinical data included evaluation of individual sampling groups and calculation of weighted arithmetic mean ( M). The efficiency of extracorporeal shock wave lithotripsy has been determined primarily using X-ray analysis of the concrement outlines and the structure (homogeneous or heterogeneous) of its central zone. However, in terms of efficiency and repetition rate (the number of fragmentation procedures required for complete clearance) of extracorporeal shock wave lithotripsy, the mean density of the concrement along the whole length of its three-dimensional structure (expressed in Hounsfield units) appeared to be the most reliable and informative predictive index in this study. The combination of computed tomography with densitometry in the treatment of patients with urolithiasis allows one (1) to determine the exact localization, size, X-ray structure, and structural density of urinary stones and (2) to predict, on the basis of densitometric data histograms, the clinical efficiency and repetition rate of extracorporeal shock wave lithotripsy with due regard to the X-ray structure of peripheral and central zones, and mean density (in Hounsfield units) of urinary concrements.

ENDOSCOPIC TRANSPAPILLARY TREATMENT OF CHOLEDOCHOLITHIASIS

Aim. To evaluate the results of endoscopic treatment of choledocholithiasis in clinically difficult cases. Material and Methods. We have analyzed treatment of 322 patients with choledocholithiasis. EPT, mechanical lithotripsy, nasobiliary drainage and transpapillary stenting were applied to restore biliary flow-out and sanitation of bile duct. Effectiveness of endoscopic stone removal was compared in 2 groups of patients: group 1 – patients with large stones and normal anatomy of periampullary zone and group 2 – patients with choledocholithiasis and periampullary diverticula, strictures and stenoses of bile ducts. Results. Endoscopic sphincterotomy was performed in 301 (97.4%) patients. In 88 (29.2%) patients with periampullary diverticula stones were removed using standard extractors, in other 213 (70.8%) cases attempts of mechanical lithotripsy were made. The stones were successfully destroyed in 196 (92%) patients. Lithotripsy was not successful in 14 patients of group 1 and 3 patients of group 2. Herewith lithotripsy efficiency was not significantly different in both groups. Complications of endoscopic interventions were observed in 30 (9.9%) patients including 8 cases of bleeding after endoscopic sphincterotomy, 8 – acute pancreatitis, 12 – adverse course of cholangitis and in 2 cases – impaction of lithotripter basket with a captured stone. Incidence of complications in group 1 was 13.5%, in group 2 – 6.1%. There is no mortality in our study. Conclusion. Bile ducts sanitation was successful in 88% of patients. Endoscopic treatment was equally effective in both groups of patients.

PT066 - The clinical role of X-ray computed tomography to predict the clinical efficiency of extracorporeal shock wave lithotripsy

PT066 - The clinical role of X-ray computed tomography to predict the clinical efficiency of extracorporeal shock wave lithotripsy

Moses technology in a stone simulator.

The objective of this study was to compare fragmentation efficiency of the conventional regular mode of holmium laser to the Moses contact mode on a stone simulator. The Lumenis® PulseTM P120 H holmium laser system, together with Moses D/F/L fibers were used to compare regular mode with Moses contact mode in a stone simulator model using flexible ureteroscopy with artificial stones. Efficiency of laser lithotripsy was measured by procedural time. Degree of stone retropulsion was also compared between regular and Moses modes using a Likert scale from 0 (no retropulsion) to 3 (maximum retropulsion). Using the stone simulator model, a significant reduction in stone retropulsion was noticed when comparing regular mode to the Moses contact mode (mean Grade 2.5 vs. Grade 1; p<0.01). When compared with the regular mode, the Moses contact mode was associated with significantly shorter procedural time during fragmentation (13.9 vs. 9.1 minutes; p≤0.01) and dusting (9.3 vs. 7.1 minutes; p≤0.01). In addition, when compared with the regular mode, the laser pedal was pressed significantly less often with the Moses mode during fragmentation (86 vs. 43 times; p<0.01) and dusting (50 vs. 26 times; p<0.01). Moses contact mode was associated with significantly higher percentage of lasing vs. pausing when compared with the regular mode for both fragmentation (0.8 J/10 Hz) and pulverization (0.4 J/50 Hz) settings (both p<0.05). Using the stone simulator setup, Moses technology was associated with more efficient laser lithotripsy (shorter operative time) due to significantly reduced stone retropulsion.

Ranges of extracorporeal shock wave lithotripsy efficiency in the treatment of non-staghorn kidney stones depending on their size and density

Ranges of extracorporeal shock wave lithotripsy efficiency in the treatment of non-staghorn kidney stones depending on their size and density

23 - Efficiency of ureteroscopic lithotripsy in case of anomalies of kidneys and ureters

23 - Efficiency of ureteroscopic lithotripsy in case of anomalies of kidneys and ureters

PD30-11 USE OF MOSES PULSE MODULATION TECHNOLOGY TO IMPROVE HOLMIUM LASER LITHOTRIPSY OUTCOMES: A PRECLINICAL STUDY

You have accessJournal of UrologyStone Disease: Surgical Therapy III1 Apr 2017PD30-11 USE OF MOSES PULSE MODULATION TECHNOLOGY TO IMPROVE HOLMIUM LASER LITHOTRIPSY OUTCOMES: A PRECLINICAL STUDY Mostafa Elhilali, Shadie Badaan, Ahmed Ibrahim, and Sero Andonian Mostafa ElhilaliMostafa Elhilali More articles by this author , Shadie BadaanShadie Badaan More articles by this author , Ahmed IbrahimAhmed Ibrahim More articles by this author , and Sero AndonianSero Andonian More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1376AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Efficient Holmium laser lithotripsy is limited by two main factors: retropulsion and energy transmission in water, which depends on fiber-stone distance. Recently, Lumenis developed the Moses technology, including the Moses D/F/L fibers, using pulse modulation resulting in improved energy transmission through water and reduced retropulsion. The Moses technology modulates the energy pulse that enables emission of a controlled portion of energy to create a bubble, known as the ″Moses effect″, while leaving a portion that travels through the bubble to the stone. The aim was to conduct a preclinical study investigating the effect of the Moses technology on Holmium laser lithotripsy comparing the Moses mode to the Regular mode in terms of lithotripsy efficiency and laser-tissue interaction METHODS Several experiments were performed to explore the advantages of the Moses technology using the Lumenis P120H system and Moses D/F/L fibers. Experiments included: stone fragmentation efficiency at 1 mm distance; effect on retropulsion (reaction to a single pulse) measured by high-speed camera; efficiency of in vitro laser lithotripsy measured by procedural time, and lasing-pause ratios. In addition, a porcine ureteroscopy model was used to assess stone fragmentation and dusting as well as laser-tissue interaction when the laser fiber touched the ureteral wall. RESULTS Stone fragmentation tests showed that the Moses mode resulted in significantly higher ablation volume when compared with Regular mode (160% higher; p=0.001). Stone displacement experiments following a single pulse showed significant reduction in retropulsion when using the Moses mode. The stone movement was reduced by 50 times at 0.8J and 10Hz (p=0.01). The pronounced reduction of retropulsion in the Moses mode was clearly observed during in vitro fragmentation settings (higher energy) and during dusting for smaller stones (low energy, high Hz). There was also significant reduction in procedure time (average 35% reduction for fragmentation and 23% for dusting, p=0.01) and longer lasing duration with shorter pauses indicating reduced need to reposition the fiber due to lack of retropulsion. Histological analysis of the porcine ureter after direct lasing in the Moses mode showed less damage than in the Regular mode. CONCLUSIONS The Moses technology resulted in more efficient laser lithotripsy in addition to significantly reduced stone retropulsion resulting in significantly shorter procedural time and greater margin of safety. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e582 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Mostafa Elhilali More articles by this author Shadie Badaan More articles by this author Ahmed Ibrahim More articles by this author Sero Andonian More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

High-Frequency Dusting Versus Conventional Holmium Laser Lithotripsy for Intrarenal and Ureteral Calculi.

The efficiency of holmium laser lithotripsy for urolithiasis depends upon several factors, including laser pulse energy and frequency and stone composition and retropulsion. This study investigates the complex interplay between these factors and quantifies lithotripsy efficiency using different laser settings in a benchtop kidney and ureter model. In vitro caliceal and ex vivo porcine ureteral models were constructed. Calcium oxalate monohydrate stones were fragmented using a 200-μm laser fiber. In the caliceal model, stone fragmentation and vaporization rates at settings of 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz were compared. In the ureteral model, fragmentation time, retropulsion rate, fragmentation rate, and fragmented stone weight were compared at settings of 0.6 J/5 Hz and 0.2 J/15 Hz. Retropulsive forces generated at 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz settings were compared. Analysis was performed using Student's t-test and one-way ANOVA. In the caliceal model, the 0.6 J/5 Hz setting fragmented and vaporized stones at a higher rate than the 0.2 J/15 Hz setting (0.072 vs. 0.049 mg/s; p < 0.001). However, when the 0.2 J energy setting was combined with the 50 Hz frequency, the fragmentation rate (0.069 mg/s) was similar to the fragmentation rate at 0.6 J/5 Hz (0.072 mg/s; p = 0.677). In the ureteral model, the 0.6 J/5 Hz setting produced higher fragmentation rates (0.089 vs. 0.049 mg/s; p < 0.001), but resulted in significantly lower fragmented stone weight overall (16.815 vs. 25.485 mg; p = 0.009) due to higher retropulsion rates (0.732 vs. 0.213 mm/s; p < 0.001). Retropulsive forces decreased significantly when pulse energy decreased from 0.6 to 0.2 J (0.907 vs. 0.223 N; p < 0.001). Frequency did not affect retropulsive force at 15 and 50 Hz settings (0.223 vs. 0.288 N; p = 0.509). Laser lithotripsy of calcium oxalate monohydrate stones in the ureter should be performed using the low-energy, moderate-frequency dusting setting to minimize retropulsion and maximize efficiency. In the renal calix, the low-energy high-frequency setting performed similarly to the high-energy low-frequency setting.

钬激光与超声联合碎石的现状及发展趋势

结石可造成管腔梗阻，影响受累器官或液体的排出，产生疼痛，出血或继发性感染等症状，如何在达到高效碎石目的的同时将术后患者身体损伤降至最小是一个亟待解决的问题。本文首先回顾了早期碎石技术。其次，由于科学技术，医学仪器的发展推动着医疗水平的不断进步，故分析了在钬激光器，超声换能器等方面，钬激光碎石，超声碎石各自的临床应用。最后，对于钬激光与超声联合碎石的关键技术，新的进展进行了比较详细的阐述并探讨在该领域下一步可能的研究方向。 Stones can cause luminal obstruction, affect the affected organs or liquid discharge, resulting in pain, bleeding or secondary infection and other symptoms. Therefore, how to achieve the purpose of efficient lithotripsy at the same time to minimize the physical damage of postoperative patients is an urgent problem to be solved. Firstly, the early lithotripsy technology was reviewed in this article. Secondly, as the development of science and technology, medical equipment promotes the continuous progress of medical level; their respective clinical applications of holmium laser lithotripsy and ultrasonic lithotripsy were analyzed on the terms of holmium laser, ultrasonic transducer. Finally, the key technologies and new development of holmium laser and ultrasonic combined lithotripsy were reviewed in detail; possible directions in future were discussed as well.