Platt J F, Ellis J H, Rubin J M
Department of Radiology, University of Michigan Hospitals, Ann Arbor 48109-0030.
AJR Am J Roentgenol. 1993 Jul;161(1):87-90. doi: 10.2214/ajr.161.1.8517329.
The purpose of this study was to evaluate duplex Doppler sonography in the assessment of internal ureteral stent patency.
Thirty-three kidneys with pyelocaliectasis and an internal stent were studied with Doppler sonography and conventional sonography. Stent patency was proved by subsequent contrast-enhanced studies, direct inspection of the stent after removal, or clinical follow-up.
The 11 kidneys with stent dysfunction had a significantly higher mean resistive index (0.78 +/- 0.08) than the 22 kidneys with patent stents (resistive index = 0.62 +/- 0.05) (p < .001). Eighty-two percent (9/11) of kidneys with occluded stents had elevated resistive indexes. The two occluded stents with normal resistive indexes were found in kidneys without significant obstruction before stent placement. Ninety-one percent (20/22) of patent stents were associated with a resistive index of less than 0.70. In the two cases of falsely elevated Doppler studies, the resistive index was obtained only 24-36 hr after placement of the stent; however, the resistive index was at least 10% less than that before stent placement. No significant correlation existed between degree of pyelocaliectasis shown on real-time sonography and stent status.
In the presence of pyelocaliectasis after placement of an internal ureteral stent, intrarenal Doppler sonography can be used to accurately distinguish between patency and obstruction. Real-time sonographic findings (degree of pyelocaliectasis) are not useful in this clinical situation.
本研究旨在评估双功多普勒超声在评估输尿管内支架通畅性方面的作用。
对33例肾盂扩张且置入输尿管内支架的患者进行了多普勒超声和传统超声检查。通过后续的增强造影检查、取出支架后直接观察或临床随访来证实支架的通畅情况。
11例支架功能异常的肾脏平均阻力指数（0.78±0.08）显著高于22例支架通畅的肾脏（阻力指数=0.62±0.05）（p<0.001）。82%（9/11）的支架堵塞肾脏阻力指数升高。两个阻力指数正常的堵塞支架见于置入支架前无明显梗阻的肾脏。91%（20/22）的通畅支架阻力指数小于0.70。在两例多普勒检查结果假性升高的病例中，阻力指数是在支架置入后仅24 - 36小时测得的；然而，该阻力指数至少比支架置入前低10%。实时超声显示的肾盂扩张程度与支架状态之间无显著相关性。
在置入输尿管内支架后出现肾盂扩张的情况下，肾内多普勒超声可用于准确区分支架通畅与梗阻情况。在这种临床情况下，实时超声检查结果（肾盂扩张程度）并无帮助。
