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.

引言：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，连续双功超声扫描的动态变化检测具有更高的临床价值。本研究旨在验证以下假说：肾移植术后早期RI的变化可能与移植物功能延迟恢复（delayed graft function, DGF）相关的影响因素存在关联。
材料与方法：本研究共纳入113例患者，所有患者均在肾移植术后30天内完成两次RI检测。根据第二次检测中RI的变化幅度（≥10%），将患者分为三组：RI下降组（组I）、RI无变化组（组II）及RI升高组（组III）。
结果：第二次RI检测结果显示，30例患者RI较前下降，55例无明显变化，28例出现RI升高。组III供者的平均年龄较组II更年轻。与组I相比，组III死者供肾比例、移植物功能延迟恢复（DGF）发生率更高，且移植围手术期活检标本中肾小管坏死与肾小管空泡变性的检出率也更高。
结论：肾移植术后早期（数周内）RI升高似乎与DGF及移植围手术期活检标本中的肾小管坏死/肾小管空泡变性相关，其潜在机制可能与缺血再灌注损伤有关。