Transcatheter Heart Valve Replacement
What is TAVR?
Transcatheter Heart Valve Replacement (TAVR) is an innovative and minimally invasive procedure designed to address aortic valve stenosis, a condition characterized by the narrowing of the aortic valve, hindering efficient blood flow from the heart to the rest of the body. This revolutionary approach has transformed the treatment of aortic valve stenosis, particularly for patients deemed too high-risk for traditional open-heart surgery.
TAVR provides a less invasive alternative to open-heart surgery, resulting in reduced recovery time and potentially improved outcomes for eligible patients. Compared to conventional open-heart surgery, which typically involves a recovery period spanning days to weeks, TAVR allows for significantly shorter recovery times, ranging from a few hours to a few days. The procedure offers several advantages, including smaller incisions, less trauma to the body, and reduced hospitalization, making it a preferred option for many patients.
Figure A (Right): 4D batch of the aortic valve and ventricular outflow tract. The rendering switches between maximum intensity projection (MIP) minimum intensity projection (MinIP), ThickMPR/Average projection, and simple multi-planar reconstructions.
The Procedure
The TAVR procedure begins with a comprehensive pre-procedure evaluation to assess the severity of the aortic valve stenosis and determine the patient’s suitability for the intervention. This involves a thorough evaluation of medical history, physical examination, and various diagnostic tests, such as echocardiography, computed tomography (CT), or magnetic resonance imaging (MRI) scans.
During the TAVR procedure, the patient is placed under local or general anesthesia as preferred. The interventional cardiology team and cardiac surgeons collaborate to access the heart through various routes, with the transfemoral approach being most common. The replacement valve is mounted on a catheter and positioned within the diseased aortic valve, aided by advanced imaging from the 3DQ Lab. After precise placement, the valve is deployed using balloon inflation or a self-expanding heat-activated mechanism,and its function and seal assessed before the catheter is removed.
Figure B (Left): Heart valve sizing is performed by overlaying the valve onto the patient scan data.
4D Valve Movie: A 4D valve movie, created from cardiac-gated imaging offers dynamic visualizations of the aortic valve and its motion during the cardiac cycle. Cardiac-gating is crucial for planning TAVR as it helps with precise valve sizing, optimal positioning, access route evaluation, and risk assessment.
En Face Video: An en face video of the valve is a dynamic visual representation used in TAVR planning. It uses the same source data as the 4D valve movie but displays the dynamic CT data instead of a volumetric reconstruction. These videos help with valve sizing, orientation, pathology assessment, procedural visualization, and patient education.
Aortic Measurements: Aortic measurements help with valve sizing, access route evaluation, valve positioning, assessment of aortic pathology, and risk assessment.
Iliac Measurements: Iliac measurements are used in TAVR planning to assess the suitability of the patient’s iliofemoral arteries for the procedure. They help in selecting the access route, sizing the delivery system, and evaluating the feasibility of the TAVR intervention.
Coronary Artery CPRs: These views eliminate the need for patients to get a separate coronary angiogram prior to their TAVR, saving the patient radiation. Special care is taken to ensure the CPR is created through the flow lumen and not the calcifications.
Iliac VR Rotations: Iliac VR rotations are dynamic CT images used in TAVR planning. They aid in the assessment of iliofemoral arteries, identification of obstructions, and catheter sizing, enhancing TAVR success and safety.
