Part One: Direct intrahepatic portacaval shunt: the experimental studyPurpose: To determine the safety and feasibility of creating direct intrahepatic portacaval shunt (DIPS) in swine with puncture under transcutaneous ultrasound guidance.

• 第一部分: 直接性门腔分流的实验研究目的：探讨采用体表超声引导穿刺，在猪体内建立直接性门腔分流（DIPS）的安全性及可行性。