Freiha G S, Glickman R D, Teichman J M
Division of Urology, The University of Texas Health Science Center, San Antonio 78284-7845, USA.
J Endourol. 1997 Oct;11(5):331-6. doi: 10.1089/end.1997.11.331.
The holmium:YAG laser fragments stones of all compositions effectively. However, damage to ureteral guidewires by the laser has been described, including in one of our own patients, in whom such damage resulted in morbidity. The purpose of this study was to characterize the interaction of Ho:YAG energy with guidewires in vitro. Seven ureteral guidewires were tested in a waterbath. The 365-microm Ho:YAG laser fiber was placed at defined distances (0, 1, 2, 4, and 5 mm) from the guidewire. All guidewires were tested at angles of 0 degrees, 45 degrees, and 70 degrees from normal incidence. The minimum energy setting that resulted in structural damage to the guidewires was detected by endoscopic video monitoring. All guidewires were susceptible to Ho:YAG laser damage at modest energy settings. The energy required to produce visual damage varied inversely with the square of the distance of the laser fiber from the guidewire. At a distance of 5 mm, none of the guidewires was damaged, even at energy settings of 2.8 J (the maximum output from the laser). The energy required to induce guidewire damage varied with the inverse of the cosine of the incident angle. The results demonstrate that no guidewire is immune from Ho:YAG laser damage when the fiber and guidewire are in contact. Caution must be exercised when operating the Ho:YAG laser near a guidewire, and guidewire integrity should be assured by the surgeon. Generally, the energy required to induce guidewire damage exceeded lithotripsy levels at distances >1 mm and with higher incident angles, implying a reasonable margin of safety during ureteroscopy. The pattern of energy thresholds required to induce damage with respect to distance and incident angle suggests that the mechanism of Ho:YAG lithotripsy is thermal.
钬激光能有效击碎各种成分的结石。然而，已有关于激光对输尿管导丝造成损伤的报道，包括我们自己的一名患者，这种损伤导致了发病。本研究的目的是在体外描述钬激光能量与导丝的相互作用。在水浴中测试了7根输尿管导丝。将365微米的钬激光光纤放置在距导丝特定距离（0、1、2、4和5毫米）处。所有导丝均在与法线入射角为0度、45度和70度的角度下进行测试。通过内镜视频监测检测导致导丝结构损伤的最小能量设置。所有导丝在适度的能量设置下都易受钬激光损伤。产生可见损伤所需的能量与激光光纤距导丝距离的平方成反比。在5毫米的距离处，即使在2.8焦耳（激光的最大输出能量）的能量设置下，也没有导丝受损。导致导丝损伤所需的能量随入射角余弦值的倒数而变化。结果表明，当光纤与导丝接触时，没有导丝能免受钬激光损伤。在导丝附近操作钬激光时必须谨慎，外科医生应确保导丝的完整性。一般来说，在距离大于1毫米且入射角较大时，导致导丝损伤所需的能量超过了碎石水平，这意味着在输尿管镜检查期间有合理的安全 margin。关于距离和入射角导致损伤所需的能量阈值模式表明，钬激光碎石的机制是热机制。
