Palatresi S, Longari V, Airoldi F, Benti R, Nador B, Bencini C, Lovaria A, Del Vecchio C, Nicolini A, Voltini F, Gerundini P, Morganti A
Istituto di Clinica Medica Generale e Terapia Medica, Università di Milano, Italy.
J Hypertens. 2001 Aug;19(8):1489-96. doi: 10.1097/00004872-200108000-00018.
Distal echo-Doppler velocimetric indices are widely used for revealing the presence of a renal artery stenosis but there is scarce information as to whether they reflect the renal hemodynamics in stenotic and nonstenotic kidneys.
We evaluated the pulsatility and resistive indices (PI and RI), acceleration (A) and acceleration time (At) and correlated their values with those of effective renal plasma flow (ERPF), glomerular filtration rate (GFR), renal vascular resistance (RVR) and filtration fraction (FF) estimated by single kidney scintigraphy in 24 kidneys with 70-95% renal artery stenosis (atherosclerotic n = 17, fibromuscular n = 7) and in 27 non-stenotic kidneys (11 contralateral to renal artery stenosis and 16 of patients with essential hypertension). In patients with stenotic kidneys, these measurements were repeated within 7 days after a successful percutaneous transluminal renal angioplasty (PTRA) (in 11 arteries performed in combination with stent implantation).
Prior to dilation we found that the stenotic kidneys had significantly lower values of ERPF, GFR and higher RVR than the non-stenotic kidneys and that these hemodynamic alterations were associated with those, also statistically significant, of the four velocimetric indices. In non-stenotic kidneys, there were highly significant relationships between PI and ERPF, and RVR (r = -0.68 and 0.81 respectively P < 0.01); similar relationships were found for RI (r = -0.67 and 0.78 P < 0.01) whereas no such correlations were found between these two velocimetric indices and GFR and FF; also no correlations were found between A and Atand ERPF, GFR, RVR and FF. In stenotic kidneys no significant correlations were found between any of the velocimetric and the hemodynamic indices. Renal artery dilation induced clear cut increments in ERPF, GFR and reduction in RVR in post-stenotic kidneys, which were associated with normalization of all four velocimetric indices. No relationships were observed between the renal hemodynamic and the velocimetric changes induced by dilation; however in post-stenotic kidneys the relationships between PI and RI, ERPF and RVR were restored as in nonstenotic kidneys.
These data indicate that PI and RI can be used to assess ERPF and RVR both in non-stenotic and post-stenotic kidneys; however, none of the velocimetric indices examined in this study can provide valid informations on the renal hemodynamics of stenotic kidneys and on their changes induced by PTRA.
远端回声多普勒测速指标广泛用于揭示肾动脉狭窄的存在，但关于它们是否反映狭窄和非狭窄肾脏的肾血流动力学的信息却很少。
我们评估了搏动指数和阻力指数（PI和RI）、加速度（A）和加速时间（At），并将它们的值与通过单肾闪烁扫描估计的有效肾血浆流量（ERPF）、肾小球滤过率（GFR）、肾血管阻力（RVR）和滤过分数（FF）的值进行了关联，这些测量对象包括24个肾动脉狭窄70 - 95%的肾脏（动脉粥样硬化性狭窄n = 17，纤维肌性狭窄n = 7）以及27个非狭窄肾脏（11个与肾动脉狭窄对侧，16个来自原发性高血压患者）。对于有狭窄肾脏的患者，在成功进行经皮腔内肾血管成形术（PTRA）（11例动脉成形术联合支架植入）后7天内重复进行这些测量。
在扩张前，我们发现狭窄肾脏的ERPF、GFR值显著低于非狭窄肾脏，RVR则更高，并且这些血流动力学改变与四个测速指标的改变相关，且差异也具有统计学意义。在非狭窄肾脏中，PI与ERPF和RVR之间存在高度显著的关系（r分别为 - 0.68和0.81，P < 0.01）；RI也有类似关系（r = - 0.67和0.78，P < 0.01），而这两个测速指标与GFR和FF之间未发现此类相关性；A和At与ERPF、GFR、RVR和FF之间也未发现相关性。在狭窄肾脏中，任何测速指标与血流动力学指标之间均未发现显著相关性。肾动脉扩张使狭窄后肾脏的ERPF、GFR明显增加，RVR降低，这与所有四个测速指标的正常化相关。未观察到扩张引起的肾血流动力学变化与测速变化之间的关系；然而，在狭窄后肾脏中，PI与RI、ERPF与RVR之间的关系恢复到了与非狭窄肾脏相同的状态。
这些数据表明，PI和RI可用于评估非狭窄和狭窄后肾脏的ERPF和RVR；然而，本研究中检查的任何测速指标均不能提供关于狭窄肾脏的肾血流动力学及其由PTRA引起的变化的有效信息。
