Laser Fiber Displacement Velocity during Tm-Fiber and Ho:YAG Laser Lithotripsy: Introducing the Concept of Optimal Displacement Velocity

Background: Endocorporeal laser lithotripsy (EL) during flexible ureteroscopy (URS-f) often uses “dusting” settings with “painting” technique. The displacement velocity of the laser fiber (LF) at the stone surface remains unknown and could improve EL’s ablation rates. This in vitro study aimed to define the optimal displacement velocity (ODV) for both holmium:yttrium-aluminium-garnet (Ho:YAG) and thulium fiber laser (Tm-Fiber). Methods: A 50W-TFL (IRE Polus®, Russia) and a 30W-MH1-Ho:YAG laser (Rocamed®), were used with 272µm-Core-Diameter LF (Sureflex, Boston Scientific©), comparing three TFL modes, “fine dusting” (FD:0.05–0.15 J/100–600 Hz); “dusting” (D:0.5 J/30–60 Hz); “fragmentation” (Fr:1 J/15–30 Hz) and two Ho:YAG modes (D:0.5 J/20 Hz, Fr:1 J/15 Hz). An experimental setup consisting of immerged cubes of calcium oxalate monohydrate (COM) stone phantoms (Begostone Plus, Begoã) was used with a 2 seconds’ laser operation time. LF were in contact with the stones, static or with a displacement of 5, 10 or 20 mm. Experiments were repeated four times. Stones were dried and µ-scanned. Ablation volumes (mm3) were measured by 3D-segmentation. Results: ODV was higher in dusting compared to fragmentation mode during Ho:YAG lithotripsy (10 mm/sec vs. 5 mm/sec, respectively). With Tm-Fiber, dusting and fragmentation OVDs were similar (5 mm/sec). Tm-Fiber ODV was lower than Ho:YAGs in dusting settings (5 mm/s vs. 10 mm/sec, respectively). Without LF displacement, ablation volumes were at least two-fold higher with Tm-Fiber compared to Ho:YAG. Despite the LF-DV, we report a 1.5 to 5-fold higher ablation volume with Tm-Fiber compared to Ho:YAG. Conclusions: In dusting mode, the ODVTm-Fiber is lower compared to ODVHo:YAG, translating to a potential easier Tm-Fiber utilization for “painting” dusting technique. The ODV determinants remain unknown. Dynamic ablation volumes are higher to static ones, regardless of the laser source, settings or LF displacement velocity.

Case – Renal artery pseudoaneurysm: A life-threatening occurrence following thulium laser lithotripsy

Introduction Renal artery pseudoaneurysm post-laser lithotripsy is a rare and potentially life-threatening complication. Traditionally, the most common modalities used for treatment of urinary tract stones were holmium laser lithotripsy and extracorporeal shockwave lithotripsy. However, thulium laser has recently gained momentum in the treatment of urinary tract stones with increasing use and availability in healthcare systems. We report a case of renal artery pseudoaneurysm post-thulium laser lithotripsy who presented in hemorrhagic shock after ureteral stent removal and was subsequently stabilized by endovascular embolization.

METAPHYLAXIS OF UROLITHIASIS BY VEGETABLE MEDICINES

Мочекаменная болезнь является одной из главных проблем современной урологии как наиболее часто встречающаяся патология органов мочевой системы и составляющая 30 - 50% всех больных урологических стационаров. Целью настоящего исследования явилось изучение эффективности применения препарата «Фитолизин» у больных мочекаменной болезнью. В основу исследования положены результаты лечения 160 (85 женщин и 75 мужчин) пациентов, находившихся на стационарном лечение, средний возраст больных составил 42,2±12,4 года, длительность заболевания от 1-3 до 72 часов, размер конкрементов, в том числе и дезинтегрированных фрагментов после дистанционной ударно-волновой литотрипсии и контактно-лазерная литотрипсия варьировал от 0,4 до 0,8 см. Все больные были разделены на две группы. В основную группу вошли 70 больных, получавших помимо традиционной симптоматической терапии (спазмолитики и водная нагрузка) «Фитолизин» по 43 мл 3 раза в день. В контрольной группе (90 больных) проводилась только традиционная терапия. При включение в терапию препарата «Фитолизин» самостоятельное отхождение отмечено у 64(91,4%) больных, частота возникновения почечной колики имело место у 7(10%), лейкоцитурия - у 14(20%), бактериурия - у 10(15%). Применение фитопрепарата «Фитолизин» в составе комплексной терапии, является эффективным методом консервативного лечения больных мочекаменной болезнью и после после дистанционной ударно-волновой литотрипсии и контактно-лазерная литотрипсия в 90,9% случаев в отношении самостоятельного отхождения конкрементов. Urolithiasis is one of the main problems of modern urology as the most common pathology of the urinary system and makes up 30 - 50% of all patients in urological hospitals. The purpose of this study was to study the effectiveness of the use of the drug "Phytolysin" in patients with urolithiasis. The study is based on the treatment results of 160 (85 women and 75 men) patients who were hospitalized, the average age of the patients was 42.2 ± 12.4 years, the duration of the disease from 1-3 to 72 hours, the size of the stones and disintegrated fragments after remote shock wave lithotripsy and contact laser lithotripsy ranged from 0.4 to 0.8 cm. All patients were divided into two groups. The main group included 70 patients who received in addition to the traditional symptomatic therapy (antispasmodics and water load) "Phytolysin" 43 ml 3 times a day. In the control group (90 patients), only traditional therapy was performed. When "Phytolysin" was included in the therapy, independent discharge was observed in 64 (91.4%) patients, the incidence of renal colic occurred in 7 (10%), leukocyturia in 14 (20%), bacteriuria in 10 (15%). The use of the phytopreparation "Phytolysin" as a part of complex therapy is an effective method of conservative treatment of patients with urolithiasis and after remote shock-wave lithotripsy and contact laser lithotripsy in 90.9% of cases with regard to self-discharge of calculi.

Support Vector Machine-Based Analysis of Holmium Laser Lithotripsy in Treatment of Urinary Calculus from Ultrasound Images

This study was to investigate the application value of ultrasound images optimized by support vector machine (SVM) algorithm in the efficacy analysis of holmium laser lithotripsy in the treatment of urinary calculi. 92 patients for treatment of UC were selected as research subjects, with 46 cases in each group. The control group received pneumatic lithotripsy for diagnosis and treatment. The observation group received holmium laser lithotripsy for calculus treatment. The perimeter and area of the defect and the length and width of the external distance of the most effective area of the defect were used as classification features, and a classifier based on SVM was constructed and applied to it. After treatment, the success rate, operation duration, stone clearance time, and hospital stay of the two groups were comprehensively evaluated. The results showed that the success rate of the observation group adopting holmium laser lithotripsy was 100%. The duration of operation in the observation group was (29.7 ± 7.65) min, and the time to clear calculus was (6.99 ± 5.29) days. The length of hospital stay was (3.67 ± 2.9) days. The probability of complications in the observation group was 3.11%. The observation group was superior to the control group in all surgical indicators (95%, 40.7 ± 8.36 minutes, 14.1 ± 7.21 days, and 5.12 ± 3.72 days), with considerable differences between groups ( P < 0.05 ). The strong support structure similarity information improved the detection and diagnostic analysis ability of ultrasonic images. In conclusion, after ultrasound image evaluation based on SVM algorithm, the adoption of holmium laser lithotripsy can effectively improve the success rate of patients with urinary system disease, which was worthy of clinical adoption and promotion.

Cost-effectiveness of using stone cone, balloon dilator, stone basket, and entrapment device in ureteroscopic laser lithotripsy for ureteric stones

Objective To evaluate the costs and stone-free rates of ureteroscopic laser lithotripsy (ULL) performed with and without auxiliary equipment and to compare first-time ULL with total treatment. Methods One hundred patients who underwent first-time ULL without the use of auxiliary equipment because its unavailability comprised the no-device ULL (ndULL) group. Additionally, 100 patients who underwent first-time ULL with the use of auxiliary equipment when necessary comprised the device ULL (dULL) group. Results In the ndULL and dULL groups, the stone-free rates after first-time ULL were 72% and 94% and the mean cost was US $1037 ± 15.10 and US $1452 ± 19.80 per case, respectively, with a statistically significant difference. The stone-free rates at the end of treatment were 98% and 99%, respectively, without a statistically significant difference. When secondary treatment costs were added to the first ULL costs after failed treatment, the mean total cost was US $1625 ± 12.60 in the ndULL group and US $1566 ± 11.01 in the dULL group without a statistically significant difference. Conclusions The stone-free rates and costs after first-time ULL were significantly different between the groups. However, after total treatment, there was no statistically significant difference between the two groups.

Laser lithotripsy using dusting technique (low energy, high frequency) for symptomatic upper urinary tract stones

Background A prospective study to assess the feasibility of stone dusting technique (low energy and high frequency) during laser lithotripsy in symptomatic upper urinary tract |(UUT) stones. Methods Sixty patients with symptomatic single or multiple UUT stones less than 3 cm in diameter were included. Patients with coagulation disorders and active UTIs were excluded. All patients were clinically evaluated and underwent non-contrast spiral CT (NCSCT) to detect stone site, size, number, Hounsfield unit. A rigid or flexible ureteroscope was used with stone dusting using the Ho: YAG laser at low-energy and high-frequency (0.5 J & 20 Hz) set. Operative and fluoroscopy time, total energy delivered, type of stent, hospitalization time, complications and its grade, and stone-free rate using NCSCT after 4 weeks were recorded. Results The mean stone size ± SD (range) was 1.55 ± 0.55 (0.5–3) cm; out of sixty patients (50 with single stone and 10 with multiple stones), fifty-five patients were stone-free at 4 weeks. Complications had occurred in 11 patients (eight with grade I, one with grade II, and two with grade IIIa) according to Clavien–Dindo grading of surgical complications. Stone size was the only parameter which correlated significantly with stone-free rate. No significant correlation was found between incidence of complications and other parameters (stone size, site, BMI, age and operative time). Conclusions Stone dusting technique is feasible, safe and effective in management of UUT stones.