Vanbiervliet Geoffroy, Pomier-Layrargues Gilles, Huet Pierre-Michel
Fédération des maladies de l'appareil digestif, Hôpital de l'Archet 2, Centre Hospitalier Universitaire de Nice.
Gastroenterol Clin Biol. 2005 Oct;29(10):988-96. doi: 10.1016/s0399-8320(05)88171-0.
Portal hypertension is defined by an increased pressure gradient between the portal vein and the inferior vena cava (N < 5 mmHg). The most commonly used technique to assess the severity of portal hypertension is the catheterization of one hepatic vein with measurement of pressures in a free position and in a wedged position using preferably a balloon catheter. The hepatic venous pressure gradient is calculated by the difference between both pressures. In most cirrhotic processes, venous pressure gradient gives a good evaluation of portal hypertension however, portal vein pressure can be higher than wedged hepatic venous pressure, particularly in presence of an increased pre-sinusoidal resistance. In such cases, a direct access to portal vein might be needed to assess the severity of portal hypertension. For an accurate interpretation of the hepatic venous pressure gradient, several strict criteria must be followed; otherwise the validity of measurements might be seriously questioned. Hepatic venous pressure gradient has been used as a prognostic marker of portal hypertension, particularly for the occurrence of bleeding from gastrophageal varices which almost never occur below a threshold value of 12 mmHg. However, the prognostic value of the hepatic venous pressure gradient for survival is still a controversial matter On the other hand, the use of hepatic venous pressure gradient has been proposed to monitor the pharmacological treatment of portal hypertension and it is generally accepted that reaching a same threshold value of 12 mmHg should almost completely abolish the risk of first or recurrent variceal bleeding. A large number of studies have also reported that a 20% hepatic venous pressure gradient decrease should be considered as a significant response to therapy, the risk of the first or recurrent bleeding being significantly reduced in responders. But again there are conflicting results.
门静脉高压定义为门静脉与下腔静脉之间的压力梯度增加（N<5mmHg）。评估门静脉高压严重程度最常用的技术是通过使用球囊导管，经一根肝静脉插管，测量自由位置和楔嵌位置的压力。肝静脉压力梯度通过两者压力之差计算得出。在大多数肝硬化过程中，静脉压力梯度能很好地评估门静脉高压，然而，门静脉压力可能高于楔嵌肝静脉压力，特别是在窦性前阻力增加的情况下。在这种情况下，可能需要直接进入门静脉来评估门静脉高压的严重程度。为了准确解释肝静脉压力梯度，必须遵循几个严格的标准；否则，测量的有效性可能会受到严重质疑。肝静脉压力梯度已被用作门静脉高压的预后指标，特别是对于胃静脉曲张出血的发生，低于12mmHg的阈值几乎不会发生。然而，肝静脉压力梯度对生存的预后价值仍然存在争议。另一方面，有人提议使用肝静脉压力梯度来监测门静脉高压的药物治疗，并且普遍认为达到相同的12mmHg阈值几乎可以完全消除首次或复发性静脉曲张出血的风险。大量研究还报告说，肝静脉压力梯度降低20%应被视为对治疗的显著反应，反应者首次或复发性出血的风险会显著降低。但同样存在相互矛盾的结果。
