Colombato L A, Spahr L, Martinet J P, Dufresne M P, Lafortune M, Fenyves D, Pomier-Layrargues G
Radiology Department, André-Viallet Clinical Research Center, Hôpital Saint-Luc, University of Montreal, Québec, Canada.
Gut. 1996 Oct;39(4):600-4. doi: 10.1136/gut.39.4.600.
In portal hypertensive patients, transjugular intrahepatic portosystemic shunt (TIPS) acutely increases cardiac output and exaggerates peripheral vasodilatation. It has been suggested that the worsened hyperdynamic state may progress to high output heart failure. The aim was to evaluate the acute and short-term haemodynamic adaptation to this procedure.
Systemic, splanchnic, and pulmonary haemodynamics were studied in 15 cirrhotic patients under stable haemodynamic conditions before placement of TIPS, then 15-30 minutes after and two months later. For inclusion in the final analysis, an uneventful post-TIPS at two months follow up and a stable portacaval gradient were required. The following variables were measured or calculated: portacaval gradient; cardiac index (thermodilution); systolic and diastolic mean arterial, atrial, pulmonary arterial, and wedged pulmonary capillary pressures; heart rate; and total peripheral and pulmonary vascular resistances. Blood flow in the shunt was measured using duplex Doppler ultrasound.
The portacaval gradient decreased by 56% and remained stable thereafter. Shunt blood flow was unchanged when measured immediately after TIPS and two months later. Immediately after TIPS there was a pronounced increase in cardiac index (+32%; p < 0.05) in association with a decrease in peripheral and pulmonary vascular resistance (-21%; p < 0.05 and -14%; NS). Two months later, whereas the initial rise in cardiac index was attenuated, peripheral vascular resistances remained similar and pulmonary vascular resistances decreased further (-33%; p < 0.05) compared with immediate post-TIPS values.
Hyperdynamic circulation worsened immediately after TIPS, with a progressive adaptation during follow up. The mechanisms of post-TIPS induced haemodynamic changes include an abrupt volume load resulting from splanchnic decompression and an increased delivery of gut derived vasodilators to the systemic circulation. The persistence of decreased peripheral and pulmonary vascular resistances despite the reduction in high cardiac output two months after TIPS suggests that vasodilatation is not solely a compensatory response to a TIPS induced increased preload. Vasodilatory substances shunted away from the liver probably play an important part in this phenomenon.
在门静脉高压患者中,经颈静脉肝内门体分流术(TIPS)可急性增加心输出量并加剧外周血管扩张。有人提出,这种恶化的高动力状态可能会发展为高输出量心力衰竭。本研究旨在评估该手术的急性和短期血流动力学适应性。
对15例肝硬化患者在TIPS置入前血流动力学稳定状态下、术后15 - 30分钟及两个月后进行全身、内脏和肺血流动力学研究。纳入最终分析的患者需在术后两个月随访时情况平稳且门静脉-腔静脉压力梯度稳定。测量或计算以下变量:门静脉-腔静脉压力梯度;心脏指数(热稀释法);收缩压和舒张压、平均动脉压、心房压、肺动脉压和肺楔压;心率;以及总外周血管阻力和肺血管阻力。使用双功多普勒超声测量分流中的血流量。
门静脉-腔静脉压力梯度下降了56%,此后保持稳定。TIPS术后即刻及两个月后测量时,分流血流量无变化。TIPS术后即刻,心脏指数显著增加(+32%;p < 0.05),同时外周血管阻力和肺血管阻力下降(分别为-21%;p < 0.05和-14%;无统计学意义)。两个月后,尽管心脏指数最初的升高有所减弱,但外周血管阻力保持相似,与TIPS术后即刻值相比,肺血管阻力进一步下降(-33%;p < 0.05)。
TIPS术后即刻高动力循环恶化,随访期间逐渐适应。TIPS术后血流动力学变化的机制包括内脏减压导致的突然容量负荷增加以及肠道源性血管扩张剂向体循环的输送增加。尽管TIPS术后两个月高心输出量有所下降,但外周血管阻力和肺血管阻力持续降低,这表明血管扩张并非仅仅是对TIPS诱导的前负荷增加的代偿反应。从肝脏分流的血管扩张物质可能在这一现象中起重要作用。