肝段下腔静脉压力对兔肝脏弹性影响的实验研究

The effect of venous pressure of inferior vena cava on liver stiffness:a rabbit experimental study

目的探讨肝段下腔静脉压力对兔肝脏弹性的影响。方法 16只新西兰大白兔,开腹后于第二肝门上方结扎下腔静脉,通过静脉内滴注肝素生理盐水溶液使下腔静脉压力逐渐上升至25 cm H2O(1 cm H2O=0.098 kPa),然后解除结扎。分别于下腔静脉阻断前、下腔静脉阻断后压力为15、20和25 cm H2O时及下腔静脉再通5 min后采用剪切波弹性成像技术测定实验动物肝脏弹性值。结果下腔静脉阻断前实验动物肝脏弹性平均值为(7.57±0.99)kPa,下腔静脉阻断后压力为15、20和25 cm H2O时实验动物肝脏弹性平均值分别为(14.40±0.78)、(18.99±1.22)和(25.73±1.46)kPa,下腔静脉再通5 min后实验动物肝脏弹性平均值为(7.33±0.95)kPa。不同时间点之间肝脏弹性平均值差异有统计学意义(F=686.99,P<0.01)。每个时间点肝脏弹性值与后一时间点肝脏弹性值差异均有统计学意义(阻断前vs阻断后下腔静脉压力为15 cm H2O时,q=22.78,P<0.01;阻断后下腔静脉压力为15 cm H2O时vs阻断后下腔静脉压力为20 cm H2O时,q=15.30,P<0.01;阻断后下腔静脉压力为20 cm H2O时vs阻断后下腔静脉压力为25 cm H2O时,q=22.50,P<0.01;阻断后下腔静脉压力为25 cm H2O时vs再通后,q=61.38,P<0.01)。肝脏弹性平均值与下腔静脉压力之间呈显著正相关(r=0.943,P<0.01)。结论下腔静脉压力升高可提高肝脏弹性值,且与静脉压力呈显著相关。

Objective To discuss the effect of the pressure of inferior vena cava on the liver stiffness.Methods Sixteen New Zealand rabbits were used in this study,in which the inferior vena cava was ligated in the level superior to the secondary porta of liver.Heparinized normal solution was infused to increase the pressure of inferior vena cava to 25 cm H2O(1 cm H2O=0.098 kPa),and liver stiffness was measured before and after ligation and under venous pressure of 15 cm H2O,20 cm H2O and 25 cm H2O.Results Liver stiffness was(7.57±0.99) kPa before ligation,and was(14.40±0.78) kPa,(18.99±1.22) kPa and(25.73±1.46) kPa respectively when the venous pressure was 15 cm H2O,20 cm H2O and 25 cm H2O.Five minutes after recanalization the liver stiffness decreased to(7.33±0.95) kPa.There was a significant difference in liver stiffness among different time points(F=686.99,P<0.01).Multi-comparison was performed,and significant differences were observed on liver stiffness in each adjacent pair(pre-ligation vs 15 cm H2O,q=22.78,P<0.01;15 cm H2O vs 20 cm H2O,q=15.30,P<0.01;20 cm H2O vs 25 cm H2O,q=22.50,P<0.01;25 cm H2O vs recanalization,q=61.38,P<0.01).A significant correlation was observed between liver stiffness and venous pressure(r=0.943,P<0.01).Conclusion The value of liver stiffness was significantly affected by pressure of inferior vena cava and there is a significant correlation between the venous pressure and liver stiffness.