Lafortune M, Martinet J P, Denys A, Patriquin H, Dauzat M, Dufresne M P, Colombato L, Pomier-Layrargues G
Department of Radiology, Hôpital Saint-Luc, Montreal, Quebec, Canada.
AJR Am J Roentgenol. 1995 Apr;164(4):997-1002. doi: 10.2214/ajr.164.4.7726065.
The purposes of this study were to evaluate the effect of a well-functioning transjugular intrahepatic portosystemic shunt (TIPS) on the splanchnic and intrahepatic circulation, to determine if sonographic measurements can predict shunt dysfunction before clinical manifestations of portal hypertension occur, and to compare Doppler sonographic findings with portocaval gradient measurements before and after shunt revision.
Forty-four patients with cirrhosis (n = 43) and myelofibrosis (n = 1) who underwent successful TIPS insertion were included in this prospective study. Indications for TIPS placement were: refractory ascites (24 patients), bleeding esophageal varices (17 patients), portal hypertensive gastropathy (two patients), and bleeding colonic varices (one patient). The portal vein and the inferior vena cava were catheterized; and the portocaval gradient was recorded before TIPS placement, at 2 and 12 months after TIPS placement, and when clinical or Doppler findings suggested shunt dysfunction. Doppler studies were done within 1 week before TIPS placement, within 2 days after TIPS placement, every 2-3 months thereafter, and before and after a TIPS revision. The Doppler studies included flow volume measurements in the portal vein and in the stent, as well as determination of the direction of flow in the segmental branches of the portal vein, in the splanchnic veins, and in portosystemic collaterals. Changes in Doppler findings and in catheter pressure measurements were compared using Spearman's rank correlation test. Significance was set at the .05 level.
A marked decrease (-51%) in portocaval gradient was observed after TIPS placement. At Doppler sonography, portal vein velocity and diameter were both higher after TIPS placement, resulting in a marked increase in portal venous flow (170%). Mean flow velocity in the shunt was 55.8 +/- 3.6 cm/sec, and flow volumes in the shunt and in the main portal vein were 1596 ml/min and 1731 ml/min, respectively (p = nonsignificant). Dysfunction of the stent occurred in 27% of the patients. Changes in stent blood flow volume were closely related to changes in the portocaval gradient (r = -0.67, p < .001). Reduction of blood flow volume in the stent or change of direction of flow in intrahepatic portal veins or in collateral veins signaled shunt dysfunction (84% sensitivity, 89% specificity).
Marked hemodynamic changes in the portal venous system occur soon after a TIPS procedure. Monitoring of shunt function with periodic Doppler sonography, including calculation of shunt blood flow, is useful in detecting shunt dysfunction before clinical signs occur.
本研究旨在评估功能良好的经颈静脉肝内门体分流术（TIPS）对内脏和肝内循环的影响，确定超声测量能否在门静脉高压临床表现出现之前预测分流功能障碍，并比较分流术修订前后多普勒超声检查结果与门腔静脉梯度测量结果。
本前瞻性研究纳入了44例成功进行TIPS置入术的肝硬化患者（n = 43）和骨髓纤维化患者（n = 1）。TIPS置入的指征为：难治性腹水（24例）、食管静脉曲张出血（17例）、门静脉高压性胃病（2例）和结肠静脉曲张出血（1例）。对门静脉和下腔静脉进行插管；在TIPS置入前、置入后2个月和12个月以及临床或多普勒检查结果提示分流功能障碍时记录门腔静脉梯度。在TIPS置入前1周内、置入后2天内、此后每2 - 3个月以及TIPS修订前后进行多普勒检查。多普勒检查包括门静脉和支架内的血流量测量，以及门静脉分支、内脏静脉和门体侧支循环内血流方向的测定。使用Spearman等级相关检验比较多普勒检查结果和导管压力测量的变化。显著性设定为0.05水平。
TIPS置入后门腔静脉梯度显著降低（-51%）。在多普勒超声检查中，TIPS置入后门静脉速度和直径均较高，导致门静脉血流量显著增加（170%）。分流器内平均流速为55.8±3.6 cm/秒，分流器和门静脉主干内的血流量分别为1596 ml/分钟和1731 ml/分钟（p = 无显著性差异）。27%的患者出现支架功能障碍。支架内血流量的变化与门腔静脉梯度的变化密切相关（r = -0.67，p < 0.001）。支架内血流量减少或肝内门静脉或侧支静脉内血流方向改变提示分流功能障碍（敏感性84%，特异性89%）。
TIPS手术后门静脉系统很快会出现明显的血流动力学变化。定期进行多普勒超声检查监测分流功能，包括计算分流血流量，有助于在临床症状出现之前检测分流功能障碍。
