Central Venous Recanalization and Right Atrial Thrombectomy Using IVUS

Central venous occlusions (CVOs) of the systemic circulation are highly morbid, causing significant symptoms from venous congestion, venous thromboembolism (VTE) and impaired vascular access. Endovascular recanalization (EVR) has emerged as the treatment of choice for medically refractory nonthrombotic and thrombotic CVOs with Intravascular Ultrasound (IVUS) playing a pivotal role. Radial and side-firing IVUS catheters are used during central venous recanalization in the chest, abdomen and pelvis. The intraluminal ultrasonic view of a CVO shows dynamic details of pathology not obtained with conventional venography or cone-beam CT, allowing for a more accurate evaluation of clot burden, wall integrity, tumor invasion, occlusion length and luminal caliber. IVUS is also superb for guiding treatment of CVOs involving blunt and sharp recanalization, stenting, and mechanical thromboembolectomy (MTE) of VTE, especially high-risk free-floating thrombi (FFT) and clot in-transit (CIT) in the right atrium (RA). It most accurately assesses procedural endpoints, including successful intravascular traversal across an occlusion, adequate luminal gain after venoplasty and stenting, and complete clot extraction during thrombectomy. Moreover, this is all done without added contrast or radiation, which is paramount to reduce exposure during a challenging recanalization, especially in the aging hemodialysis population. Long-term data is now available that shows IVUS can enhance technical and clinical success and reduce complications during EVR. To achieve these benefits with IVUS interventionalists must be familiar with the available catheters and how to optimize and interpret the intraluminal images obtained. This paper will review the patient evaluation, indications, equipment, steps, challenges, complications, and outcomes for central venous recanalization (CVR) and RA thrombectomy with IVUS.