Evan Andrew P, McAteer James A, Connors Bret A, Blomgren Philip M, Lingeman James E
Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
BJU Int. 2007 Sep;100(3):624-7; discussion 627-8. doi: 10.1111/j.1464-410X.2007.07007.x. Epub 2007 Jun 5.
To assess the tissue protection afforded by simply reducing the rate of shock wave (SW) delivery, compared with studies in the pig in which SW lithotripsy (SWL)-induced vascular damage was significantly reduced by initiating treatment using low-amplitude SWs.
Juvenile pigs (6-7 weeks old) were treated with an unmodified lithotripter (HM3, Dornier Medical Systems, Kennesaw, GA) at either 120 or 30 SW/min. Treatment was to one kidney per pig, with SWs (2000, 24 kV) directed to a lower-pole calyx. After treatment, parenchymal haemorrhage was determined morphometrically and expressed as percentage of functional renal volume (%FRV).
Kidneys treated at 120 SW/min had focal to extensive subcapsular haematomas. Parenchymal lesions were found only at the lower pole, but included regions within renal papillae and the cortex. Occasionally, damage extended across the full thickness of the kidney. The lesion in the pigs treated at 120 SW/min occupied a mean (sd) of 4.6 (1.7) %FRV. Kidneys of pigs treated at 30 SW/min showed no surface bleeding. Parenchymal haemorrhage was limited to papillae within the focal volume, and measured 0.08 (0.02) %FRV, a significant (P < 0.005) reduction in injury.
Slowing the rate of delivery to 30 SW/min has a dramatic protective effect on the integrity of the kidney vasculature. This finding in our established pig model suggests a potential strategy to improve the safety of lithotripsy. As it was shown that a reduced SW rate also improves the efficiency of stone fragmentation, a slow rate appears to be a means to improve both the safety and efficacy of SWL.
与猪的研究相比，评估单纯降低冲击波（SW）释放速率所提供的组织保护作用。在猪的研究中，通过使用低振幅SW开始治疗，显著降低了SW碎石术（SWL）引起的血管损伤。
用未改良的碎石机（HM3，多尼尔医疗系统公司，肯尼索，佐治亚州）以每分钟120次或30次SW的频率治疗幼年猪（6 - 7周龄）。每只猪对一侧肾脏进行治疗，将SW（2000，24 kV）导向下极肾盏。治疗后，通过形态计量学确定实质出血，并表示为功能性肾体积的百分比（%FRV）。
以每分钟120次SW治疗的肾脏有局灶性至广泛性的包膜下血肿。实质损伤仅在下极发现，但包括肾乳头和皮质内的区域。偶尔，损伤会延伸至肾脏全层。以每分钟120次SW治疗的猪的损伤平均（标准差）占功能性肾体积的4.6（1.7）%FRV。以每分钟30次SW治疗的猪的肾脏未出现表面出血。实质出血局限于局灶体积内的乳头，测量值为0.08（0.02）%FRV，损伤显著（P < 0.005）减少。
将释放速率减慢至每分钟30次SW对肾脏血管系统的完整性具有显著的保护作用。在我们已建立的猪模型中的这一发现提示了一种改善碎石术安全性的潜在策略。由于已表明降低SW速率也能提高结石破碎的效率，缓慢的速率似乎是一种提高SWL安全性和有效性的方法。
