彩色多普勒超声在移植肾动脉狭窄中的临床应用

 目的 探讨彩色多普勒超声诊断移植肾动脉狭窄（transplant renal artery stenosis，TRAS）、判断狭窄程度及评估血管介入治疗疗效的临床应用价值。方法 回顾性分析2013年2月至2020年5月复旦大学附属中山医院收治的肾移植术后患者资料，其中经数字减影血管造影（digital substraction angiography，DSA）或磁共振血管造影（magnetic resonance angiography，MRA）确诊为TRAS的患者27例，作为狭窄组（中度狭窄6例，重度狭窄21例），随机选取同期移植肾功能稳定的48例患者作为对照组。所有患者均行常规彩色多普勒超声检查，测量并记录主肾动脉、段间动脉、叶间动脉的收缩期峰值流速（peak systolic velocity，PSV）以及阻力指数（resistance index，RI）。比较狭窄组与对照组、中度狭窄组与重度狭窄组的彩色多普勒超声血流动力学参数，计算以常用的彩色多普勒超声血流动力学标准评估TRAS的诊断效能，并比较狭窄组患者治疗前后的彩色多普勒超声血流动力学参数。结果 狭窄组患者主肾动脉PSV［（3.42±1.31）m/s vs.（1.26±0.48）m/s，P<0.001］及峰值流速后比［14.75±7.30 vs.3.91±1.77，P<0.001］均高于对照组，段间动脉PSV［（0.43±0.19）m/s vs.（0.53±0.16）m/s，P=0.021］和RI（0.52±0.11vs.0.63±0.08，P<0.001）、叶间动脉PSV［（0.26±0.11）m/s vs.（0.34±0.10）m/s，P=0.002］和RI（0.49±0.10 vs.0.61±0.09，P<0.001）及主肾动脉RI （0.60±0.12 vs.0.71±0.09，P<0.001）均低于对照组。主肾动脉PSV≥2.5 m/s、峰值流速后比≥10.0以及叶间动脉RI<0.55诊断TRAS的灵敏度分别为77.8%、77.8%和70.4%，特异度分别为50.0%、75.0%和50.0%，准确率分别为74.2%、77.4%和67.7%。重度狭窄组峰值流速后比大于中度狭窄组（16.41±7.00 vs.8.96±5.41，P=0.024）；狭窄组患者行介入治疗后，各参数均发生显著改变，主肾动脉PSV［（1.48±0.43）m/s vs.（3.50±1.35）m/s，P<0.001］及峰值流速后比（4.20±1.90 vs.16.78±9.35，P<0.001）较治疗前下降，段间动脉PSV［（0.52±0.19）m/s vs.（0.40±0.14）m/s，P=0.008］和RI（0.64±0.07 vs.0.52±0.17，P<0.001）、叶间动脉PSV［（0.39±0.11）m/s vs.（0.25±0.11）m/s，P<0.001］和RI（0.62±0.11 vs.0.50±0.18，P=0.001）、主肾动脉RI（0.67±0.09 vs.0.62±0.15，P=0.035）均较治疗前上升。结论 彩色多普勒超声操作简便、无创、准确度高，可作为肾移植术后监测移植肾动脉狭窄、评估狭窄程度及评价TRAS患者血管介入治疗效果的首选方法。

Clinical application of color Doppler ultrasound in evaluation of transplant renal artery stenosis

Objective To explore the clinical value of color Doppler ultrasound in the diagnosis of transplant renal artery stenosis(TRAS),the assessment of stenosis degree and the efficacy evaluation of interventional therapy. Methods The data of patients with kidney transplantation admitted to Zhongshan Hospital,Fudan University from Feb 2013 to May 2020 were analyzed retrospectively. Twenty-seven patients diagnosed with TRAS by digital substraction angiography (DSA) or magnetic resonance angiography (MRA) were enrolled as the stenosis group (6 patients were moderate stenosis and 21 patients were severe stenosis). Fourty-eight patients with stable kidney function during the same period were randomly selected as the control group. All the patients underwent color Doppler ultrasound. Peak systolic velocity(PSV)and resistance index(RI)from the main renal artery,segmental renal artery and interlobular artery of the transplanted kidney were recorded,respectively. The parameters derived from color Doppler ultrasound between the stenosis group and the control group as well as between the moderate stenosis group and the severe stenosis group were compared,and the diagnostic efficacy of commonly used parameters was calculated. Furtheremore,changes of color Doppler hemodynamic parameters before and after treatment were analyzed in the stenosis group. Results Compared with the control group,PSV from main renal artery[(3.42±1.31)m/s vs.(1.26±0.48)m/s,P<0.001]and the ratio of PSV between main renal artery and interlobar artery(14.75±7.30 vs. 3.91±1.77,P<0.001)were significantly higher in the stenosis group. While PSV of segmental renal artery[(0.43±0.19)m/s vs.(0.53±0.16)m/s,P=0.021],RI of segmental renal artery(0.52±0.11 vs. 0.63±0.08,P<0.001),PSV of interlobular artery[(0.26±0.11)m/s vs.(0.34±0.10)m/s,P=0.002],RI of interlobular artery(0.49±0.10 vs. 0.61±0.09, P<0.001)and RI of main renal artery(0.60±0.12 vs. 0.71±0.09,P<0.001)were much lower than those in the control group. With PSV of main renal artery ≥ 2.50 m/s,ratio of PSV between main renal artery and interlobar artery ≥ 10,and RI of interlobular artery<0.55 as the cut-off value for TRAS diagnosis,the sensitivity were 77.8%,77.8% and 70.4%,the specificity were 50.0%,75.0% and 50.0%,and the accuracy were 70.4%,50.0% and 67.7%,respectively. Ratio of PSV between main renal artery and interlobar artery of severe stenosis group was higher than that of moderate stenosis group(16.41±7.00 vs. 8.96±5.41,P=0.024).For those with TRAS treated with interventional therapy,great changes occurred in all color Doppler ultrasound related parameters. After treatment,PSV from main renal artery[(1.48±0.43)m/s vs.(3.50±1.35)m/s,P<0.001)]and ratio of PSV between main renal artery and interlobar artery(4.20±1.90 vs. 16.78±9.35,P<0.001)significantly decreased,while PSV of segmental renal artery[(0.52±0.19)m/s vs.(0.40±0.14)m/s,P=0.008],RI of segmental renal artery(0.64±0.07 vs. 0.52±0.17,P<0.001),PSV of interlobular artery[(0.39±0.11)m/s vs.(0.25±0.11)m/s,P<0.001],RI of interlobular artery (0.62±0.11 vs. 0.50±0.18,P=0.001) and RI of main renal artery (0.67±0.09 vs. 0.62±0.15,P=0.035)increased. Conclusion Color Doppler ultrasound is an simple,noninvasive,and highly accurate technique that can be used as the preferred method for screening TRAS,assessing the degree of stenosis and evaluating the treatment efficacy of interventional therapy.