Bhatta K M, Rosen D I, Flotte T J, Dretler S P, Nishioka N S
Department of Urology, Massachusetts General Hospital, Boston 02114.
J Urol. 1990 Apr;143(4):857-60. doi: 10.1016/s0022-5347(17)40117-0.
The pulsed dye laser and electrohydraulic lithotriptor (EHL) are both effective devices for fragmenting urinary and biliary calculi. Both fragment stones by producing a plasma-mediated shockwave. Recently, a plasma shield consisting of a hollow spring and a metal end cap has been described for use with the laser and EHL devices in an attempt to minimize tissue damage without adversely affecting stone fragmentation rates. The tissue effects produced by a pulsed dye laser and an EHL device with and without plasma shields were examined and compared using rabbit urinary bladders. If blood was present, the unshielded laser perforated the bladder wall in two pulses. However, in the absence of blood, over 100 pulses were needed for the laser to perforate the bladder. A mean of six pulses were required to perforate the bladder wall with a shielded laser. The unshielded EHL perforated the bladder wall in two pulses, whereas, the shielded EHL required a mean of 35 pulses. Microscopically, areas of exposure revealed hemorrhage and tissue ablation. We conclude that all devices examined can produce significant tissue damage when discharged directly onto bladder epithelium.
脉冲染料激光和液电碎石器（EHL）都是用于破碎泌尿系统和胆道结石的有效设备。两者都是通过产生等离子体介导的冲击波来破碎结石。最近，有人描述了一种由空心弹簧和金属端盖组成的等离子体防护罩，用于与激光和EHL设备配合使用，以尽量减少组织损伤，同时又不会对结石破碎率产生不利影响。使用兔膀胱对有和没有等离子体防护罩的脉冲染料激光和EHL设备所产生的组织效应进行了检查和比较。如果有血液存在，未加防护罩的激光在两个脉冲内就会穿透膀胱壁。然而，在没有血液的情况下，激光需要超过100个脉冲才能穿透膀胱。使用带防护罩的激光平均需要六个脉冲才能穿透膀胱壁。未加防护罩的EHL在两个脉冲内就会穿透膀胱壁，而带防护罩的EHL平均需要35个脉冲。在显微镜下，暴露区域显示有出血和组织消融。我们得出结论，当直接作用于膀胱上皮时，所有检查的设备都会产生明显的组织损伤。
