Use Of Laser Lithotripsy Research Articles

Realizing enhanced lithotripsy efficiency using 700 W peak power thulium-doped fiber laser

Despite its widespread use in laser lithotripsy, the Ho:YAG solid-state laser suffers from limited parameter combinations, poor beam quality, and low photoelectric conversion efficiency. The development of 2.0 μm fiber laser technology has positioned the thulium-doped fiber laser (TFL) as a superior alternative to the Ho:YAG laser in lithotripsy. The TFL excels because of its high-water absorption coefficient, all-fiber structure and pump modulation flexibility. However, the peak power reported for TFL in lithotripsy remains at most 500 W. This study presented a quasi-continuous wave (QCW) TFL featuring a wide tunable range of pulse width and pulse repetition rates, and a peak power of 700 W to realize enhanced ablation efficiency. A high-speed camera was used to acquire the laser-induced cavitation bubble images for the analysis of the interaction mechanism of a high peak power QCW TFL pulse with water and stones. While the synergistic action of photothermal and photomechanical effects constituted the mechanism of TFL lithotripsy, the laser-induced bubble channel was a prerequisite for TFL noncontact effective lithotripsy, with bubble length and width markedly influencing stone ablation rates. Ablation experiments on uric acid and calcium oxalate monohydrate stones conducted with various parameter combinations at a peak power of 700 W yielded rates of 8.9 mg/s for uric acid stones and 7.5 mg/s for calcium oxalate monohydrate stones. A comparison with prior findings confirmed that a high peak power TFL could notably improve stone ablation rates.

Comparison of long-term results following ureteroscopic stone fragmentation with removal versus stone dusting without removal

Purpose: To compare long-term results following ureteroscopic stone fragmentation and removal versus stone dusting. Methods: We conducted a retrospective analysis of patients who underwent ureteroscopy for renal calculi at two high-volume tertiary centres between 2012 and 2013, therefore allowing long-term follow-up. The surgeons differed in their technique, some performing dusting for the most part and the others fragmentation. Inclusion criteria were stone free at the first follow-up and the sole use of laser lithotripsy is either by dusting or by fragmentation. Operative and post-operative data as well as re-treatment rates were compared between the groups. Stone-free rates and long-term stone recurrence rates were analysed by a single radiologist blinded to the treatment technique. Results: Between 2012 and 2013, 669 ureteroscopies were performed at both centres. The study group included 100 patients, which met the inclusion criteria, equally distributed between dusting and fragmentation. The cumulative stone diameter in patients treated with dusting was significantly larger (12.7 mm versus 17 mm, p = 0.006). Operative time was shorter in patients treated with dusting (56 minutes versus 47.2 minutes, p = 0.6). The mean follow-up was 58.9 (standard deviation (SD) 17.2) and 69.4 (SD 13.8) months for the fragmentation and dusting-treated patients, respectively( p = 0.06). The long-term recurrence rate in the fragmentation group was 22% compared to 38% in the dusting group ( p = 0 .08). Most of the patients in the dusting group required a repeat ureteroscopy during their follow-up (28% versus 6%, p = 0.003). A multivariable logistic regression analysis revealed that the fragmentation was not associated with a lower stone recurrence rate when compared to dusting (OR 0.6, 95% CI 0.199-1.810, p = 0.3). Conclusions: The recurrence rate of renal stones was not significantly influenced by the choice of surgical techniques. However, dusting was associated with a greater need for repeat ureteroscopy than fragmentation with removal. Level of evidence: Not applicable

Neural Networks Modeling for Prediction of Required Resources for Personalized Endourologic Treatment of Urolithiasis.

When scheduling surgeries for urolithiasis, the lack of information about the complexity of procedures and required instruments can lead to mismanagement, cancellations of elective surgeries and financial risk for the hospital. The aim of this study was to develop, train, and test prediction models for ureterorenoscopy. Routinely acquired Computer Tomography (CT) imaging data and patient data were used as data sources. Machine learning models were trained and tested to predict the need for laser lithotripsy and to forecast the expected duration of ureterorenoscopy on the bases of 474 patients over a period from May 2016 to December 2019. Negative predictive value for use of laser lithotripsy was 92%, and positive predictive value 91% before application of the reject option, increasing to 97% and 94% after application of the reject option. Similar results were found for duration of surgery at ≤30 min. This combined prediction is possible for 54% of patients. Factors influencing prediction of laser application and duration ≤30 min are age, sex, height, weight, Body Mass Index (BMI), stone size, stone volume, stone density, and presence of a ureteral stent. Neuronal networks for prediction help to identify patients with an operative time ≤30 min who did not require laser lithotripsy. Thus, surgical planning and resource allocation can be optimised to increase efficiency in the Operating Room (OR).

Cholangioscopy: Has It Changed Management?

AbstractThe single operator per oral cholangioscope is a catheter-based system that allows for direct visualization of the bile duct and pancreatic duct. The instrument with its improved imaging technique and larger accessory channel allows for high-quality image acquisition and performance of therapeutic and diagnostic procedures within the bile duct and pancreatic duct. There has been an increase in the range of indications for the use of the cholangioscope. The current indications include management of difficult biliary stones, pancreatic calculi, assessment of indeterminate biliary stricture, pancreatic stricture, intra-ductal papillary mucinous neoplasms, and extractions of proximally migrated stents. The use of laser lithotripsy and electro-hydraulic lithotripsy has improved the management of difficult bile duct stones. Direct visualization of biliary and pancreatic duct strictures is helpful in the diagnosis of indeterminate strictures. In this review, we explore how cholangioscopy has changed management.

Уретероскопия в лечении камней мочеточника: необходимость в лазерной литотрипсии и дополнительном оборудовании

Over the past several decades, there has been a significant increase in the prevalence of nephrolithiasis in the general population. Ureteroscopy has become the treatment of choice for a growing number of urologic conditions; ureteroscopy is still relatively new procedure and continue to undergo significant advancement. The recent technical development of small caliber semi rigid and flexible deflectable ureteroscopes and the development of diminutive intra-corporeal lithotripsy probes have made the retrograde access to urinary calculi throughout the entire ureter a more feasible and low-risk technique. The study aims to identify the need for use of laser lithotripsy and/or other ureteroscopic ancillary equipment (ureteric stent, ureteric catheter, forceps and dormia basket) in patient undergoing ureteroscopy for ureteric stone management. A prospective observational study from 2013 to 2015. The study conducted in urosurgical theater in Al-Jumhoori Teaching Hospital. 200 patient with ureteric stone in the study treated by ureteroscopy. The mean age of the patient is 36 years. Ureteroscopy had done in the right side in 98 patients, left side in 83 patients, and bilateral ureteroscopy in 19 patients. Ureteric stones found in upper ureter in 86 patients, middle ureteric stone seen in 40 patients, and lower ureteric stone founded in 108 patients, whereas 16 patients had stones at more than one location. Ureteric catheter used in 33 patients, and had been removed after 48-72 hours, while Double J stent had been used in 175 patients and had been removed after 2 to 8 weeks.

Consultation on kidney stones, Copenhagen 2019: lithotripsy in percutaneous nephrolithotomy

PurposeTo evaluate the balance between existing evidence and expert opinions on the safety and efficacy of new technological improvements in lithotripsy techniques for percutaneous nephrolithotomy (PCNL).MethodsA scoping review approach was applied to search literature in Pubmed, Embase, and Web of Science. Consensus by key opinion leaders was reached at a 2-day meeting entitled “Consultation on Kidney Stones: Aspects of Intracorporeal Lithotripsy” held in Copenhagen, Denmark, in September 2019.ResultsNew-generation dual-mode single-probe lithotripsy devices have shown favourable results compared with use of ballistic or ultrasonic lithotripters only. However, ballistic and ultrasonic lithotripters are also highly effective and safe and have been the backbone of PCNL for many years. Compared with standard PCNL, it seems that mini PCNL is associated with fewer bleeding complications and shorter hospital admissions, but also with longer operating room (OR) time and higher intrarenal pressure. Use of laser lithotripsy combined with suction in mini PCNL is a promising alternative that may improve such PCNL by shortening OR times. Furthermore, supine PCNL is a good alternative, especially in cases with complex renal stones and large proximal ureteric stones; in addition, it facilitates endoscopic combined intrarenal surgery (ECIRS).ConclusionRecent technological improvements in PCNL techniques are promising, but there is a lack of high-level evidence on safety and efficacy. Different techniques suit different types of stones and patients. The evolution of diverse methods has given urologists the possibility of a personalized stone approach, in other words, the right approach for the right patient.

Polymer-Mineral Composites Mimic Human Kidney Stones in Laser Lithotripsy Experiments.

Despite the widespread use of laser lithotripsy to fragment kidney stones in vivo, there is a lack of robust artificial stone models to replicate the behavior of human stones during lithotripsy procedures. This need for accurate stone models is particularly important as novel laser technologies are introduced in the field of lithotripsy. In this work, we present a method to prepare composite materials that replicate the properties of human kidney stones during laser lithotripsy. Their behavior is understood through the lens of near-IR spectroscopy and helps to elucidate the mechanism of laser lithotripsy in kidney stone materials.

Multidisciplinary approach and use of laser lithotripsy in management of recurrent complex intrahepatic stones (Tricks of the trade)

Background: Complex biliary stones are managed via endoscopic, radiological or surgical approach. Failure of clearance may lead to repeated attacks of cholangitis or even biliary cirrhosis that may lead to liver failure. The aim of this presentation is to show the impact and safety of utilization of laser lithotripsy in such complex scenarios in a multidisciplinary fashion. Case: We are presenting a 38-year-old gentleman known to have oriental cholangitis. He underwent multiple operations including drainage procedures (hepaticojejunostomy) and even revision of hepaticojejunostomy before presenting to our institution (Hamad Medical Corporation). We adopted a multidisciplinary staged approach utilizing laser lithotripsy to successfully clear his diseased biliary segments. The patient required multiple attempts to clear the volume of stone disease within his biliary system. Over a short-term follow-up period the patient remains sepsis free with clear biliary system within the treated biliary segments. Conclusion: Multidisciplinary HPB approach and utilization of laser lithotripsy in management of complex intrahepatic stones may spare patients repeated surgical drainage procedures; However, such patients may require multiple sessions to minimize the volume of stone disease within the diseased biliary segments.

Efficacy and safety of laser lithotripsy in fragmentation of urocystoliths and urethroliths for removal in dogs

To characterize the efficacy and safety of laser lithotripsy in the fragmentation of urocystoliths and urethroliths for removal in dogs. Prospective case series. 100 dogs with naturally occurring urocystoliths and urethroliths. Via cystoscopy, laser lithotripsy was performed to fragment uroliths. Basket retrieval and voiding urohydropropulsion were used to remove fragments. Postprocedural contrast cystography was performed to assess efficacy and safety. In 40 dogs, midstream urine samples were collected just prior to laser lithotripsy (day 0) and on days 1, 3, and 11 after laser lithotripsy to assess inflammation. Urolith removal was complete in 82% of dogs (52/66 with only urocystoliths, 17/17 with only urethroliths, and 13/17 with urocystoliths and urethroliths). Urolith removal was incomplete in 18 dogs; of these dogs, 9, 6, and 3 had urolith fragments >or= 3 mm, 1 to < 3 mm, and < 1 mm in diameter, respectively. Sex (female) was the most significant predictor for success. Median procedure time was 72 minutes. Two dogs developed urinary tract obstruction following laser lithotripsy. Hematuria was detected in 53% of dogs on day 0 and in 84%, 13%, and 3% of dogs on days 1, 3, and 11, respectively. Leukocyturia was detected in 13% of dogs on day 0 and in 47%, 0%, and 3% of dogs on days 1, 3, and 11, respectively. Results suggested that use of laser lithotripsy was a safe and effective alternative to surgical removal of urocystoliths and urethroliths in dogs.

Use of laser lithotripsy for fragmentation of uroliths in dogs: 73 cases (2005–2006)

To describe use of transurethral cystoscope-guided laser lithotripsy for fragmentation of cystic and urethral uroliths and determine procedure duration and short-term and long-term outcome in dogs. Retrospective case series. 73 dogs with naturally occurring uroliths in the urinary bladder, urethra, or both. Transurethral cystoscope-guided laser lithotripsy was performed in all dogs, and medical records were reviewed for short-term and long-term outcome and complications. Laser lithotripsy resulted in complete fragmentation of all uroliths in all 28 female dogs and a majority of male dogs (39/45 [86.7%]). Dogs with urethroliths had shorter median laser time than dogs with cystic uroliths. Basket extraction and voiding urohydro-propulsion were successful for removal of the urolith fragments following laser lithotripsy. Complications related to cystoscope-guided laser lithotripsy occurred in 5 of 28 (17.9%) female dogs and 6 of 45 (13.3%) male dogs. Transurethral cystoscope-guided laser lithotripsy was successful in female dogs and most male dogs for fragmentation of cystic and urethral uroliths. Short-term complications were most commonly related to urethral swelling and resolved with placement of an indwelling urinary catheter. There were no long-term complications.