Mues Adam C, Teichman Joel M H, Knudsen Bodo E
Department of Urology, The Ohio State University Medical Center, Columbus, Ohio, USA.
J Endourol. 2009 Sep;23(9):1425-8. doi: 10.1089/end.2009.0384.
Optical laser fibers are utilized to transmit energy to the surface of a stone during holmium:yttrium aluminum garnet (Ho:YAG) laser lithotripsy. During lithotripsy, fiber tip degradation (burn back) can occur. Fiber burn back may diminish fragmentation efficiency, increase operative time, and increase cost because of fiber replacement. We hypothesize that fiber tip degradation (burn back) varies among different commercially available Ho:YAG laser fibers.
Fibers of varying core diameter sizes for Ho:YAG lithotripsy were evaluated from different manufacturers. Fibers were cleaved, stripped, polished, and inspected for tip uniformity. Fibers were initially tested without contact followed by contact testing using artificial Bego stones. Pre- and postcontact energy outputs were measured by energy detector. Distal tip degradation (burn back) was measured by digital micrometer. Testing was performed on two Ho:YAG lasers (Lumenis VersaPulse 100W and Dornier Medilas H20). All fibers were tested while submerged in water.
No burn back was observed in any fiber tested in still water (without contact). Before and after lithotripsy, a trend existed with fibers demonstrating high burn back and high preablation energy outputs. The majority of these fibers were <300 microm diameter. Conversely, fibers with low burn back showed low preablation energy outputs and were >300 microm diameter.
Fiber burn back and energy transmission varied among the fibers tested. Burn back only occurred during lithotripsy. Burn back may be reduced by fiber selection or using low pulse energy. Fiber burn back may affect the efficiency of fragmentation and contribute to decreased longevity of the fiber.
在钬：钇铝石榴石（Ho:YAG）激光碎石术中，光学激光纤维用于将能量传输到结石表面。在碎石过程中，纤维尖端可能会出现降解（烧蚀回缩）。纤维烧蚀回缩可能会降低破碎效率、增加手术时间并因纤维更换而增加成本。我们假设不同市售的Ho:YAG激光纤维的纤维尖端降解（烧蚀回缩）情况各不相同。
对不同制造商生产的用于Ho:YAG碎石术的不同芯径尺寸的纤维进行了评估。将纤维切割、剥皮、抛光并检查尖端均匀性。纤维首先在无接触情况下进行测试，然后使用人工Bego结石进行接触测试。通过能量探测器测量接触前后的能量输出。用数字千分尺测量远端尖端降解（烧蚀回缩）。测试在两台Ho:YAG激光（Lumenis VersaPulse 100W和Dornier Medilas H20）上进行。所有纤维均在水中浸没时进行测试。
在静水中测试的任何纤维（无接触）均未观察到烧蚀回缩。在碎石术前和术后，呈现出一种趋势，即烧蚀回缩高且消融前能量输出高的纤维。这些纤维大多数直径小于300微米。相反，烧蚀回缩低的纤维显示出低消融前能量输出且直径大于300微米。
在所测试的纤维中，纤维烧蚀回缩和能量传输各不相同。烧蚀回缩仅在碎石术中发生。可通过纤维选择或使用低脉冲能量来减少烧蚀回缩。纤维烧蚀回缩可能会影响破碎效率并导致纤维寿命缩短。
