Ball Tip Fiber Research Articles

Thulium fiber laser-induced vapor bubble dynamics using bare, tapered, ball, hollow steel, and muzzle brake fiber optic tips

This study characterizes laser-induced vapor bubble dynamics for five different distal fiber optic tip configurations, to provide insight into stone retropulsion commonly experienced during laser ablation of kidney stones. A thulium fiber laser with 1908-nm wavelength delivered 34-mJ energy per pulse at 500-μs pulse duration through five different fibers such as 100-μm-core / 170-μm-OD bare fiber tip, 150- to 300-μm-core tapered fiber tip, 100-μm-core / 300-μm-OD ball tip fiber, 100-μm-core / 340-μm-OD hollow steel tip fiber, and 100-μm-core / 560-μm-OD muzzle brake fiber tip. A high-speed camera with 10-μm-spatial and 9.5-μs-temporal resolution was used to image the vapor bubble dynamics. A needle hydrophone measured pressure transients in the forward (0 deg) and side (90 deg) directions while placed at a 6.8 ± 0.4 mm distance from the distal fiber tip. Maximum bubble dimensions (width/length) averaged 0.7/1.5, 1.0/1.6, 0.5/1.1, 0.8/1.9, and 0.7 / 1.5 mm, for bare, tapered, ball, hollow steel, and muzzle brake fiber tips, respectively (n = 5). The hollow steel tip exhibited the most elongated vapor bubble shape, translating into increased forward pressure in this study and consistent with higher stone retropulsion in previous reports. Relative pressures (a.u.) in (forward/side) directions averaged 1.7/1.6, 2.0/2.0, 1.4/1.2, 6.8/1.1, and 0.3/1.2, for each fiber tip (n = 5). For the hollow steel tip, forward pressure was 4 × higher than for the bare fiber. For the muzzle brake fiber tip, forward pressure was 5 × lower than the bare fiber. Bubble dimensions and pressure measurements demonstrated that the muzzle brake fiber tip reduced forward pressure by partially venting vapors through the portholes, which is consistent with the observation of lower stone retropulsion in previous reports.

Miniature ball-tip optical fibers for use in thulium fiber laser ablation of kidney stones.

Optical fibers, consisting of 240-μm-core trunk fibers with rounded, 450-μm-diameter ball tips, are currently used during Holmium:YAG laser lithotripsy to reduce mechanical damage to the inner lining of the ureteroscope working channel during fiber insertion and prolong ureteroscope lifetime. Similarly, this study tests a smaller, 100-μm-core fiber with 300-μm-diameter ball tip during thulium fiber laser (TFL) lithotripsy. TFL was operated at a wavelength of 1908 nm, with 35-mJ pulse energy, 500-μs pulse duration, and 300-Hz pulse rate. Calcium oxalate/phosphate stone samples were weighed, laser procedure times were measured, and ablation rates were calculated for ball tip fibers, with comparison to bare tip fibers. Photographs of ball tips were taken before and after each procedure to track ball tip degradation and determine number of procedures completed before need for replacement. A high speed camera also recorded the cavitation bubble dynamics during TFL lithotripsy. Additionally, saline irrigation rates and ureteroscope deflection were measured with and without the presence of TFL fiber. There was no statistical difference (P>0.05) between stone ablation rates for single-use ball tip fiber (1.3±0.4 mg/s) (n=10), multiple-use ball tip fiber (1.3±0.5 mg/s) (n=44), and conventional single-use bare tip fibers (1.3±0.2 mg/s) (n=10). Ball tip durability varied widely, but fibers averaged greater than four stone procedures before failure, defined by rapid decline in stone ablation rates. Mechanical damage at the front surface of the ball tip was the limiting factor in fiber lifetime. The small fiber diameter did not significantly impact ureteroscope deflection or saline flow rates. The miniature ball tip fiber may provide a cost-effective design for safe fiber insertion through the ureteroscope working channel and into the ureter without risk of instrument damage or tissue perforation, and without compromising stone ablation efficiency during TFL lithotripsy.

Evaluation of Novel Ball-Tip Holmium Laser Fiber: Impact on Ureteroscope Performance and Fragmentation Efficiency

A novel ball tip (BT) holmium laser fiber has recently been developed, which features a modified rounded tip. The modification is purported to aid in insertion and minimize damage to the ureteroscope working channel. We evaluated this laser fiber with regard to stone comminution, tip degradation, insertional force into the ureteroscope, and impact on ureteroscope deflection. A 242 μm BT fiber and a standard flat tip (SF) fiber were compared. Four kilojoules was delivered to a BegoStone over a constant surface area using settings of 0.2/50, 0.6/6, 0.8/8, and 1 J/10 Hz. Fiber tip degradation was measured at 1 and 4 kJ. Ureteroscope deflection was measured with the Olympus URF-P5, URF-P6, and URF-V. Insertion force into a 270° angled ureteroscope sheath model was measured. A sample size of five fibers was used for each comminution energy setting. Comminution increased with pulse energy without significant difference between fibers. No significant differences in tip degradation were observed. Both fibers reduced deflection (10°-30°) in all ureteroscopes without significant differences between fibers. Four new fibers paired with new sheath models were used to test insertion force. The BT insertion forces were approximately one-third of the SF. One SF fiber caused significant damage to the sheath and could not be advanced completely. The BT fiber has comparable comminution, tip degradation, and ureteroscope deflection performance compared with the SF fiber while exhibiting reduced insertion force within an aggressively deflected working sheath. The new tip design is likely protective of the working channel without loss of performance.

PD42-06 BALL TIPPED HOLMIUM:YAG OPTICAL FIBERS FOR FLEXIBLE URETEROSCOPY: IS THERE A DIFFERENCE?

INTRODUCTION AND OBJECTIVES: Ball tipped laser fibers have been introduced for laser lithotripsy with the intent to allow passage of the fiber through a deflected ureteroscope, without causing trauma to the working channel. We objectively compare a series of commercially available and prototype ball tipped fibers in order to characterize differences in performance characteristics and to compare them to a non-ball tipped variant (Flexiva 200, Boston Scientific). METHODS: A series of experiments were performed to evaluate (i) the insertion force needed to pass the fiber through a ureteroscope deflected to 240 degrees, (ii) the true diameter, (iii) the flexibility (max deflection in Stryker U-500), (iv) energy transmission pre and post testing, and (iv) the resistance to fracture with energy transmission during deflection. RESULTS: Results are summarized in Table 1. CONCLUSIONS: The Med Fibers Dome Tip had the lowest energy transmission. The Flexiva and Flexiva TracTip were the most resistant to fracture with energy transmission during deflection. Three of the four ball-tipped laser fibers required less force than the non-ball tipped fiber for insertion through a maximally deflected ureteroscope (p < 0.05). The Flexiva TracTip allows more facile insertion compared to other ball tipped fibers (p < 0.05) and performs on par or better than the Flexiva 200.

1072 In vivo and ex vivo comparison of optics and performance of a novel dual channel fiberoptic ureteroscope

INTRODUCTION AND OBJECTIVES: Flexible ureteroscopy has become a standard for the treatment of small renal calculi. Ureteroscopic equipment has a well-documented limited lifespan prior to need for maintenance. The most common location and etiology of scope damage is due to passing or misfiring a laser fiber in the working channel of a flexible ureteroscope. Conventional laser fibers utilize a blunt tip that can be difficult to pass through a deflected scope, and can potentially result in damage. A new laser fiber has become commercially available with a ball-shaped output tip. This is proposed to pass more easily through a fully deflected ureteroscope in an atraumatic manner. Our objective was to evaluate the use of this ball-tipped fiber and its effect on the incidence and cost of ureteroscope repairs. METHODS: Our institution began using the single-use ball-tipped fibers in January 2013. We retrospectively reviewed the charts of the first 80 patients undergoing ureteroscopy with laser lithotripsy utilizing the ball-tipped laser fiber, and compared them to the 80 patients immediately prior to the switch, where a reusable blunt tip fiber was utilized. We collected basic patient demographics, as well as stone location, stone size, type of ureteroscope used, use of a ureteral access sheath, total operative time, and energy used for lithotripsy. Repair data of the flexible ureteroscopes, including cost and type of damage was obtained. Pertinent repair costs included those related to damaged working channels. A cost analysis was performed to see if decrease ureteroscope repair cost justified the increase cost of the single use ball-tip fiber. RESULTS: During the review period, 58 patients underwent flexible ureteroscopy with the traditional blunt tip laser fiber and 60 patients with the ball tip fiber. There was no significant difference in patient age, stone burden, or operative time between the two groups. During use of the blunt tip fiber there were 5 repairs to working channels, incurring a cost of $28,018, while 2 working channel repairs, costing $12,408 were attributed to use of the ball-tipped fiber. Accounting for the increased cost of the ball tipped fiber of $195 per use, it was associated with a net savings of $81.27 per case. CONCLUSIONS: The use of a ball tipped laser fiber during flexible ureteroscopy with laser lithotripsy may be associated less frequent working channel repairs, and a modest cost savings.

PD42-07 THE EFFECT OF CLEAVE TECHNIQUE AND LITHOTRIPSY DURATION ON LASER FIBER POWER OUTPUT

INTRODUCTION AND OBJECTIVES: Ball tipped laser fibers have been introduced for laser lithotripsy with the intent to allow passage of the fiber through a deflected ureteroscope, without causing trauma to the working channel. We objectively compare a series of commercially available and prototype ball tipped fibers in order to characterize differences in performance characteristics and to compare them to a non-ball tipped variant (Flexiva 200, Boston Scientific). METHODS: A series of experiments were performed to evaluate (i) the insertion force needed to pass the fiber through a ureteroscope deflected to 240 degrees, (ii) the true diameter, (iii) the flexibility (max deflection in Stryker U-500), (iv) energy transmission pre and post testing, and (iv) the resistance to fracture with energy transmission during deflection. RESULTS: Results are summarized in Table 1. CONCLUSIONS: The Med Fibers Dome Tip had the lowest energy transmission. The Flexiva and Flexiva TracTip were the most resistant to fracture with energy transmission during deflection. Three of the four ball-tipped laser fibers required less force than the non-ball tipped fiber for insertion through a maximally deflected ureteroscope (p < 0.05). The Flexiva TracTip allows more facile insertion compared to other ball tipped fibers (p < 0.05) and performs on par or better than the Flexiva 200.

PD37-06 THE IMPACT ON COST AND FREQUENCY OF URETEROSCOPE REPAIRS USING A BALL-TIPPED LASER FIBER FOR URETEROSCOPY

You have accessJournal of UrologyStone Disease: New Technology II1 Apr 2014PD37-06 THE IMPACT ON COST AND FREQUENCY OF URETEROSCOPE REPAIRS USING A BALL-TIPPED LASER FIBER FOR URETEROSCOPY Scott Johnson, Daniel Lew, Carley Davis, and Amy Guise Scott JohnsonScott Johnson More articles by this author , Daniel LewDaniel Lew More articles by this author , Carley DavisCarley Davis More articles by this author , and Amy GuiseAmy Guise More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.2024AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Flexible ureteroscopy has become a standard for the treatment of small renal calculi. Ureteroscopic equipment has a well-documented limited lifespan prior to need for maintenance. The most common location and etiology of scope damage is due to passing or misfiring a laser fiber in the working channel of a flexible ureteroscope. Conventional laser fibers utilize a blunt tip that can be difficult to pass through a deflected scope, and can potentially result in damage. A new laser fiber has become commercially available with a ball-shaped output tip. This is proposed to pass more easily through a fully deflected ureteroscope in an atraumatic manner. Our objective was to evaluate the use of this ball-tipped fiber and its effect on the incidence and cost of ureteroscope repairs. METHODS Our institution began using the single-use ball-tipped fibers in January 2013. We retrospectively reviewed the charts of the first 80 patients undergoing ureteroscopy with laser lithotripsy utilizing the ball-tipped laser fiber, and compared them to the 80 patients immediately prior to the switch, where a reusable blunt tip fiber was utilized. We collected basic patient demographics, as well as stone location, stone size, type of ureteroscope used, use of a ureteral access sheath, total operative time, and energy used for lithotripsy. Repair data of the flexible ureteroscopes, including cost and type of damage was obtained. Pertinent repair costs included those related to damaged working channels. A cost analysis was performed to see if decrease ureteroscope repair cost justified the increase cost of the single use ball-tip fiber. RESULTS During the review period, 58 patients underwent flexible ureteroscopy with the traditional blunt tip laser fiber and 60 patients with the ball tip fiber. There was no significant difference in patient age, stone burden, or operative time between the two groups. During use of the blunt tip fiber there were 5 repairs to working channels, incurring a cost of $28,018, while 2 working channel repairs, costing $12,408 were attributed to use of the ball-tipped fiber. Accounting for the increased cost of the ball tipped fiber of $195 per use, it was associated with a net savings of $81.27 per case. CONCLUSIONS The use of a ball tipped laser fiber during flexible ureteroscopy with laser lithotripsy may be associated less frequent working channel repairs, and a modest cost savings. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e948 Peer Review Report Advertisement Copyright & Permissions© 2014MetricsAuthor Information Scott Johnson More articles by this author Daniel Lew More articles by this author Carley Davis More articles by this author Amy Guise More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

PD37-04 BALL-TIP HOLMIUM LASER FIBER: IN VITRO STONE COMMINUTION AND FIBER TIP DEGRADATION

You have accessJournal of UrologyStone Disease: New Technology II1 Apr 2014PD37-04 BALL-TIP HOLMIUM LASER FIBER: IN VITRO STONE COMMINUTION AND FIBER TIP DEGRADATION Richard Shin, Jaclyn Lautz, Fernando Cabrera, Zachariah Goldsmith, Nicholas Kuntz, Ramy Youssef, Andreas Neisius, Charles Scales, Michael Ferrandino, Pei Zhong, Walter Simmons, Glenn Preminger, and Michael Lipkin Richard ShinRichard Shin More articles by this author , Jaclyn LautzJaclyn Lautz More articles by this author , Fernando CabreraFernando Cabrera More articles by this author , Zachariah GoldsmithZachariah Goldsmith More articles by this author , Nicholas KuntzNicholas Kuntz More articles by this author , Ramy YoussefRamy Youssef More articles by this author , Andreas NeisiusAndreas Neisius More articles by this author , Charles ScalesCharles Scales More articles by this author , Michael FerrandinoMichael Ferrandino More articles by this author , Pei ZhongPei Zhong More articles by this author , Walter SimmonsWalter Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.2022AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Advancing a standard laser fiber through a fully deflected ureteroscope can result in significant damage to the delicate working channel, resulting in significant repair costs. A new ball-tip holmium laser fiber (Flexiva TracTip - Boston Scientific) was designed to atraumatically pass through a deflected ureteroscope. We evaluated the stone comminution capabilities and tip degradation of this fiber in an in vitro model. METHODS A 200 μm ball-tip (BT) fiber and standard fiber (SF) (Flexiva - Boston Scientific) were compared by delivering energy to a Begostone over a constant surface area controlled by a stage controller and 3 dimensional positioning system. Laser settings were 0.2J/50Hz, 0.6J/6Hz, 0.8J/8Hz, and 1J/10Hz. Fiber tip degradation was measured at 1 kJ and 4 kJ of delivered energy. Fiber-stone contact was adjusted every 1 kJ to account for any loss in length. Comminution efficiency was determined by measuring stone weight loss following lithotripsy at each energy setting. ANOVA or Kruskal Wallace test was used for multiple groups, and post hoc tests with Bonferroni correction were then applied (t-test, Wilcoxon). RESULTS A total of 5 virgin fibers were used to test each condition. Tip degradation by 1 kJ with all energy settings and 4 kJ at 0.2J/50Hz was minimal for both fibers without significant differences. By 4 kJ, tip degradation was less overall for the BT and maximal for the SF at 1J/10Hz (Table). Comminution was found to increase with pulse energy for both BT and SF fibers up to the 0.8J/8Hz setting (p < 0.003). No significant differences were found between 0.8J/8Hz and 1J/10Hz or between BT and SF fibers at any energy setting (Figure). CONCLUSIONS The ball-tip fiber exhibits similar comminution efficiency to a standard holmium laser fiber with minimal tip degradation at clinically relevant laser settings in our in vitro model. The new tip design may provide an advantage in access maneuverability without loss of performance. Further in vivo studies are warranted to validate these objective findings. Standard fiber (SF) and ball-tip (BT) fiber tip degradation at 1 kJ and 4 kJ (Median with IQR) Setting Energy SF tip degradation (mm) BT tip degradation (mm) P value 0.2J/50Hz 1 kJ 0 (-0.1 - 0.03) -0.02 (-0.05 - 0.02) 1 4 kJ 0 (-0.12 - 0.06) 0.07 (0.01 - 0.1) 0.207 0.6J/6Hz 1 kJ 0 (-0.08 - 0.05) 0 (-0.05 - 0.1) 0.747 4 kJ 0.16 (0.1 - 0.2) 0.15 (0.02 - 0.56) 0.599 0.8J/8Hz 1 kJ 0.05 (0 - 0.08) 0.1 (0 - 0.1) 0.576 4 kJ 0.25 (0.23 - 0.28) 0.1 (0.03 - 0.23) 0.112 1J/10Hz 1 kJ 0 (-0.05 - 0) 0.05 (0.02 - 0.1) 0.084 4 kJ 0.3 (0.2 - 1.35) 0.08 (0 - 0.2) 0.036 © 2014FiguresReferencesRelatedDetailsCited byKronenberg P and Traxer O (2018) Lithotripsy Performance of Specially Designed Laser Fiber TipsJournal of Urology, VOL. 195, NO. 5, (1606-1612), Online publication date: 1-May-2016. Volume 191Issue 4SApril 2014Page: e947 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Richard Shin More articles by this author Jaclyn Lautz More articles by this author Fernando Cabrera More articles by this author Zachariah Goldsmith More articles by this author Nicholas Kuntz More articles by this author Ramy Youssef More articles by this author Andreas Neisius More articles by this author Charles Scales More articles by this author Michael Ferrandino More articles by this author Pei Zhong More articles by this author Walter Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Characterization of pulsed‐dye laser‐mediated vasodilatation in a rabbit femoral artery model of vasoconstriction

Vasoconstriction is a clinical problem associated with invasive vascular procedures, microvascular reconstruction and subarachnoid hemorrhage. We sought to characterize the ability of pulsed-dye laser irradiation to reverse and prevent vasoconstriction in an anesthetized rabbit model of surgically and pharmacologically induced vasoconstriction. Five groups of experiments were performed to study the effect of pulsed-dye laser irradiation delivered through a 320 microns core ball-tip fiber into the femoral artery. The studies demonstrated that pulsed-dye irradiation can reproducibly cause vascular dilatation. The zone of vasodilatation propagated equally proximal and distal to the site of irradiation within the vessel. When saline was infused into the vessel to replace flowing blood during delivery of laser irradiation, no significant vasodilatation occurred. After laser irradiation reversed surgical and pharmacologic vasoconstriction, the vessel was resistant to further pharmacologic vasoconstriction. This resistance to pharmacologic vasoconstriction did not occur if the vessel was pharmacologically predilated before delivery of laser irradiation. Pathologic analysis of the vessels revealed endothelial damage and mild to moderate medial necrosis, most significant at the site of energy delivery. These studies provide characterization of pulsed-dye laser-mediated vasodilatation in an in vivo model. Delivery of pulsed-dye laser energy has potential clinical application and warrants further investigation.

Ball-tipped fibers for laser angioplasty with the pulsed-dye laser

A method of introducing high-intensity laser radiation into arteries has been developed and tested in amputated human limbs. The device consists of a small-diameter, flexible, quartz optical fiber which tapers to a large-diameter, smooth, rounded-ball tip. The small-ball tip minimizes the chance of mechanical dissection or perforation of the vessel wall. The spot size can be varied over a large range by varying the fiber input coupling, taper length, and numerical aperture. With 480-nm radiation, which is preferentially absorbed by atherosclerotic plaque and thrombus, at 80 mu s pulse durations, the device effectively recanalized occluded human peripheral arteries creating a 2-3-mm diameter channel.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>