Determinants of the serial changes in measurements of renal allograft Doppler resistive index in the first postoperative month

Abstract Introduction: The role of single Doppler-derived renal resistive index (RI) in renal allograft management is still a controversial issue, however detection of changes in serial duplex scanning has been reported as more valuable. This study aimed to test the hypothesis that early change in RI following transplantation may be related to factors associated with delayed graft function (DGF). Material and methods: 113 patients were included, in whom two RI measurements were performed within 30 days post-transplant. According to an RI change (equal to or more than 10%) in the second measurement, patients were assigned to decrease (Group I), no change (Group II), or increase (Group III) group. Results: 30 subjects had a decrease, 55 had no change, and 28 had an increase in the second RI measurement. The donors were younger in Group III in comparison to Group II. In comparison to Group I, Group III had a higher frequency of deceased donor, DGF, and presence of tubular necrosis and tubular vacuolization in peri-implantation biopsies. Conclusion: the increase of RI during the first weeks of the postoperative period seems to be associated with DGF and with tubular necrosis / tubular vacuolization in peri-implantation biopsies, likely related to ischemia reperfusion injury.

研究背景与假说：单多普勒衍生肾阻力指数（renal resistive index, RI）在肾移植移植物管理中的作用仍存在争议，但已有研究证实，连续双功超声扫描（serial duplex scanning）的动态变化检测具有更高的临床价值。本研究旨在验证下述假说：移植术后早期肾阻力指数的变化，可能与移植肾功能延迟恢复（delayed graft function, DGF）相关的危险因素存在关联。
材料与方法：本研究纳入113例患者，所有受试者均在移植术后30天内完成两次肾阻力指数检测。依据第二次检测的肾阻力指数变化幅度（≥10%），将患者分为三组：肾阻力指数下降组（第I组）、无变化组（第II组）以及上升组（第III组）。
研究结果：第二次检测中，30例患者肾阻力指数下降，55例无明显变化，28例出现肾阻力指数升高。与第II组相比，第III组的供体年龄更轻。相较于第I组，第III组的尸体供肾比例、移植肾功能延迟恢复发生率，以及移植围手术期活检中肾小管坏死、肾小管空泡变性的检出率均显著更高。
研究结论：术后早期数周内肾阻力指数升高，似乎与移植肾功能延迟恢复及移植围手术期活检中检出的肾小管坏死、肾小管空泡变性存在关联，该现象大概率与缺血再灌注损伤相关。