Comparison of Intravascular Ultrasound With Venography in the Diagnosis and Treatment of Iliac Vein Compression Syndrome

Primary outcomes

• Percentage diameter reduction [1 month]: Compare the percentage diameter reduction measured by intravascular ultrasound (IVUS) and venography
• Percentage area reduction [1 month]: Compare the percentage area reduction measured by IVUS and the calculated percentage area reduction measured by venography

Secondary outcomes

• CEAP score [18 months]: Improvement in Clinical, Etiology, Anatomy, Pathophysiology (CEAP) score
• Primary patency [18 months]: Primary patency can be defined as without additional revascularization of the target lesions, the target vessels are still patent which measured by ultrasound or magentic resonance venography (MRV) and the diameter reduction is <50% during follow-up period.
• Secondary patency [18 months]: Secondary patency can be defined as: with additional revascularization of the target lesions after the first surgery in our department, the target vessels are still patent which measured by ultrasound or magentic resonance venography (MRV) and the diameter reduction is <50% during follow-up period.

Sex: All, ages: 18 Years to 90 Years

Inclusion Criteria:

* Age: 18 to 90 years
* Willing to participate in and sign the informed consent
* Patients with suspicious iliac vein stenosis or compression presented by preoperative magnetic resonance venography (MRV)
* Patent common femoral vein and/or femoral vein of the study leg
* Undergoing iliofemoral venography with the intend to treat potential iliac vein compression syndrome

Exclusion Criteria:

* Not providing informed consent
* Venous compression caused by pelvic tumors or fibroid uterus
* Previous stent implantation or venovenous bypass surgery of the study leg
* Known metal allergy precluding the possibility of stent implantation
* Known iodine allergy or severe renal insufficient function which are unsuitable for venography
* Pregnant or planning to be pregnant recently
* Acute deep vein thrombosis or tumor thrombus involving the study leg
* Know history of thrombophilia (e.g. protein C or S deficiency, anti-thrombin III deficiency, etc )
* Any concurrent disease, for example, heart failure, might make the patients unsuitable for surgery