Foshager M C, Ferral H, Nazarian G K, Castañeda-Zúñiga W R, Letourneau J G
Department of Radiology, University of Minnesota, Minneapolis 55455, USA.
AJR Am J Roentgenol. 1995 Jul;165(1):1-7. doi: 10.2214/ajr.165.1.7785564.
Portal hemodynamics are altered by placement of a transjugular intrahepatic portosystemic shunt (TIPS). Normal duplex sonographic findings after TIPS placement and hemodynamic alterations indicating shunt failure have not yet been well described. The purposes of this study were to determine normal hemodynamic changes on duplex sonography after TIPS placement and to assess the efficacy of duplex sonography in detecting shunt dysfunction.
Forty patients underwent TIPS placement and were entered into a study that included routine sonographic evaluation and portal venography at regular intervals. Portal venography was also performed if shunt velocities on duplex sonography changed from the baseline, which raised the question of shunt stenosis or occlusion. The pre-TIPS duplex sonographic study included determination of patency, velocity, and flow direction in the main, right, and left portal veins and in the hepatic artery. Follow-up sonography included the pre-TIPS examination in addition to velocity determinations in three segments of the shunt. Correlation was made between 82 concurrent sonographic and portal venographic studies.
High-velocity blood flow (mean peak velocity, 135-200 cm/sec) was consistently seen within patent, well-functioning shunts. Hepatic artery peak systolic velocities increased from 79 cm/sec before TIPS placement to 131 cm/sec after TIPS placement (p < .001). Main portal vein velocities increased from 21.8 cm/sec before TIPS placement to 41.5 cm/sec after TIPS placement (p < .001). When compared with portal venography, duplex sonography was 98% sensitive and 100% specific in predicting the presence of blood flow within the stent. Sonography was highly sensitive and specific for detecting stent stenosis. Final sonographic criteria for shunt stenosis in angiographically documented cases were low-velocity shunt flow (< or = 60 cm/sec) in the entire stent, or low-velocity shunt flow with an associated focal velocity elevation.
Consistent changes in portal venous and hepatic arterial hemodynamics are normally seen on duplex sonography after placement of a TIPS. Duplex sonography accurately predicts shunt patency and dysfunction when compared with portal venography. Duplex sonography is an effective, noninvasive method of evaluating shunt function and should be considered for use as the primary imaging technique in routine follow-up after TIPS placement.
经颈静脉肝内门体分流术（TIPS）可改变门静脉血流动力学。TIPS术后正常的双功超声检查结果以及提示分流失败的血流动力学改变尚未得到充分描述。本研究的目的是确定TIPS术后双功超声检查的正常血流动力学变化，并评估双功超声检查在检测分流功能障碍方面的有效性。
40例患者接受了TIPS手术，并纳入一项定期进行常规超声检查和门静脉造影的研究。如果双功超声检查显示的分流速度与基线相比发生变化，提示存在分流狭窄或闭塞时，也需进行门静脉造影。TIPS术前的双功超声检查包括确定门静脉主干、右支和左支以及肝动脉的通畅情况、血流速度和血流方向。随访超声检查除了进行TIPS术前检查外，还需测定分流三个节段的血流速度。对82项同时进行的超声检查和门静脉造影研究进行了相关性分析。
在通畅且功能良好的分流通道内始终可见高速血流（平均峰值速度为135 - 200 cm/秒）。肝动脉峰值收缩速度从TIPS术前的79 cm/秒增加到TIPS术后的131 cm/秒（p < 0.001）。门静脉主干血流速度从TIPS术前的21.8 cm/秒增加到TIPS术后的41.5 cm/秒（p < 0.001）。与门静脉造影相比，双功超声检查在预测支架内血流情况时的敏感性为98%，特异性为100%。超声检查在检测支架狭窄方面具有高度敏感性和特异性。血管造影记录病例中分流狭窄的最终超声检查标准为整个支架内分流血流速度低（≤60 cm/秒），或分流血流速度低且伴有局部速度升高。
TIPS术后双功超声检查通常可观察到门静脉和肝动脉血流动力学的一致性变化。与门静脉造影相比，双功超声检查能准确预测分流的通畅情况和功能障碍。双功超声检查是评估分流功能的一种有效、无创方法，应考虑作为TIPS术后常规随访的主要影像学技术。
