Vakil N, Everbach E C
Department of Medicine, University of Rochester Medical Center, NY 14642.
Ultrasound Med Biol. 1993;19(4):331-42. doi: 10.1016/0301-5629(93)90105-w.
The mechanism of gallstone fragmentation by shock waves in vivo is uncertain. We used scanning electron microscopy to study 9 partially fragmented stones obtained from 6 patients who underwent lithotripsy and subsequently had surgery because of incomplete fragmentation. Surface characteristics of the stone were studied using scanning electron microscopy and compared to gallstones fragmented in degassed water in vitro and to control stones obtained from patients with uncomplicated cholelithiasis. Characteristic damage caused by transient acoustic cavitation was visible in all stones fragmented in vivo and in vitro as pits 10-100 microns diameter. In these pits, cholesterol crystals were fractured, and the symmetry of crystal boundaries was damaged. In areas of more severe damage, individual pits coalesced to form craters on the stone surface. High magnification of the pit walls revealed cracks, which in some instances radiated out onto the unpitted surface of the stone. We conclude that transient acoustic cavitation plays a role in gallstone fragmentation in vivo through the mechanism of surface pitting and the formation of cracks that radiate outward from the surface pits. Measures to enhance cavitation may improve the results of gallstone lithotripsy.
体内冲击波碎石的机制尚不确定。我们使用扫描电子显微镜研究了9块部分破碎的结石，这些结石取自6名接受了碎石术但随后因碎石不完全而接受手术的患者。使用扫描电子显微镜研究结石的表面特征，并将其与体外在脱气水中破碎的胆结石以及从未合并胆石症患者获得的对照结石进行比较。在体内和体外破碎的所有结石中，由瞬态声空化引起的特征性损伤均可见，表现为直径10 - 100微米的凹坑。在这些凹坑中，胆固醇晶体断裂，晶体边界的对称性受损。在损伤更严重的区域，单个凹坑合并形成结石表面的坑洼。对坑壁的高倍放大显示有裂纹，在某些情况下，裂纹会延伸到结石未出现凹坑的表面。我们得出结论，瞬态声空化通过表面点蚀机制以及从表面凹坑向外辐射形成裂纹的方式，在体内胆结石破碎过程中发挥作用。增强空化的措施可能会改善胆结石碎石的效果。
