Williams James C, Borofsky Michael S, Bledsoe Sharon B, Evan Andrew P, Coe Fredric L, Worcester Elaine M, Lingeman James E
Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.
Department of Urology, University of Minnesota, Minneapolis, Minnesota.
J Urol. 2018 Jan;199(1):186-192. doi: 10.1016/j.juro.2017.08.063. Epub 2017 Aug 16.
Mechanisms of early stone retention in the kidney are under studied and poorly understood. To date attachment via Randall's plaque is the only widely accepted theory in this regard, which is best described in idiopathic calcium oxalate stone formers. Brushite stone formers are known to have distinct papillary morphology relative to calcium oxalate stone formers. As such we sought to determine whether stone attachment mechanisms in such patients may be similarly unique.
Patients undergoing percutaneous and or ureteroscopic procedures for stone removal consented to endoscopic renal papillary examination and individual stone collection. Each removed stone was processed using micro computerized tomography to assess the 3-dimensional microstructure and the minerals contained, and search for common structural features indicative of novel mechanisms of early growth and attachment to renal tissue.
A total of 25 intact brushite stones were removed from 8 patients and analyzed. Video confirmed attachment of 13 of the 25 stones with the remainder believed to have been accidently dislodged during the procedure. Microscopic examination by light and computerized tomography failed to show evidence of Randall's plaque associated with any stone containing brushite. Conversely each brushite stone demonstrated microstructural evidence of having grown attached to a ductal plug formed of apatite.
Three-dimensional analysis of small brushite stones suggests overgrowth on ductal apatite plugs as a mechanism of early stone growth and retention. Such findings represent what is to our knowledge the initial supporting evidence for a novel mechanism of stone formation which has previously been hypothesized but never verified.
肾脏早期结石滞留的机制研究不足且了解甚少。迄今为止，通过兰德尔斑附着是这方面唯一被广泛接受的理论，这在特发性草酸钙结石形成者中描述得最为清楚。已知透钙磷石结石形成者相对于草酸钙结石形成者具有独特的乳头形态。因此，我们试图确定这类患者的结石附着机制是否同样独特。
接受经皮和/或输尿管镜取石手术的患者同意进行内镜下肾乳头检查并单独收集结石。每颗取出的结石都通过微型计算机断层扫描进行处理，以评估其三维微观结构和所含矿物质，并寻找表明早期生长和附着于肾组织的新机制的共同结构特征。
共从8例患者中取出25颗完整的透钙磷石结石并进行分析。视频证实25颗结石中有13颗附着，其余结石据信在手术过程中意外脱落。光镜和计算机断层扫描的显微镜检查均未发现与任何含透钙磷石的结石相关的兰德尔斑证据。相反，每颗透钙磷石结石都显示出在由磷灰石形成的导管栓上生长附着的微观结构证据。
对小透钙磷石结石的三维分析表明，导管磷灰石栓上的过度生长是早期结石生长和滞留的一种机制。据我们所知，这些发现代表了一种先前已被假设但从未得到证实的结石形成新机制的初步支持证据。
