This study aims to evaluate the effectiveness of interventional treatment guided by Intravascular Ultrasound (IVUS) compared to Digital Subtraction Angiography (DSA) in patients with Budd-Chiari Syndrome (BCS). Using a prospective, randomized controlled trial design, patients who meet the diagnostic criteria for BCS and are suitable for interventional treatment are randomly divided into the IVUS group and the DSA group. The IVUS group will undergo detailed assessment of vascular structure before interventional treatment to select the appropriate balloon for dilation, whereas the control group will make decisions based on DSA results. The primary endpoint of the study is the postoperative restenosis rate, while secondary endpoints include complications of interventional treatment, liver function, and patient survival rate. Successful implementation of this study will provide new technical means to optimize interventional treatment strategies for BCS, and help improve treatment outcomes and long-term prognosis for patients.

This study aims to establish a precise interventional diagnostic and therapeutic system for Budd-Chiari Syndrome (BCS) based on IVUS assistance by comparing it with conventional DSA-guided diagnosis and intervention. The goal is to improve diagnostic accuracy and treatment outcomes for complex and difficult BCS patients using IVUS technology, reduce the incidence of postoperative restenosis, and enhance long-term patient prognosis. Specific objectives include:

1. Enhance the diagnostic accuracy for BCS patients, particularly in determining the nature of vascular obstruction and assessing hemodynamic status.
2. Optimize the interventional treatment strategy for BCS, including the selection and implantation of balloons and stents, and reduce surgical complications.
3. Increase the patency rate of vessels after interventional treatment and lower the incidence of restenosis.
4. Establish a set of IVUS-based precise diagnosis and treatment processes for BCS, promoting the application and dissemination of IVUS technology in BCS diagnosis and treatment.

Inclusion Criteria:

• Age between 18 and 75 years.
• Primary Budd-Chiari Syndrome (narrowing or occlusion of the inferior vena cava near the hepatic veins or hepatic vein openings).
• Presence of membrane or short segment stenosis or occlusion suitable for balloon dilation (≤ 5 cm).
• Child-Pugh score less than 13.
• The patient or their authorized family member signs an informed consent form, voluntarily participating in the study and agreeing to follow-up.

Exclusion Criteria:

• Prior interventional treatment.
• Unfit for balloon dilation or stent placement (e.g., diffuse obstruction of the hepatic veins recommended for TIPS treatment, end-stage liver disease recommended for liver transplantation, etc.).
• Coexisting severe heart disease (such as heart failure, severe arrhythmias), liver or kidney failure, severe infections, iodinated contrast agent allergy.
• Coexisting hepatocellular carcinoma or other malignant tumors.
• Pregnant or breastfeeding women.
• Patients with a life expectancy of less than 1 year.
• Patients unable to complete follow-up or cooperate with the study.