Emerging Technology And Innovative Surgical Methods for Aortic Valve Replacement
We recently assisted medical device innovator, Direct Flow Medical, Inc., by creating a medical animation video to demonstrate its Direct Flow Medical® Transcatheter Aortic Valve System. The system represents a new approach to the repair of aortic st enosis. Of course, aortic stenosis involves declining heart function due to faulty aortic valves. Whether it stems from scarring and calcification associated with advanced age, a congenital defect, or post-infection tissue damage, the valve fails to open fully. This restricts blood flow from the heart to the body.
Older technologies, presently in use, involve replacing the diseased valve with tissue from a donor animal or a synthetic substitute, among other options. These procedures typically suffer from a relatively high risk of aortic regurgitation; the backwash of blood into the left ventricle of the heart. Of course, the function of valves in the cardiovascular system is to prevent any back flow of blood, to ensure proper hemodynamics and pumping efficiency. Repair of the aortic valve may involve relatively risky open heart surgery. Or, increasingly, transcatheter procedures are performed by threading instruments or devices into the heart through a major blood vessel.
The Direct Approach
The Direct Flow system features a collapsible, re-inflatable substitute valve that’s threaded into place through an appropriate artery. The groin provides a typical point of access. Access may also be gained through thoracic sites or even the neck. Hollow guide wires are used to position the
compact device within the left ventricle of the heart.
Once in place, the delivery sheath is removed and the device is remotely inflated. It quickly deploys, immediately assuming the shape and function of the aortic valve. With the assistance of radiopaque dye delivered through the system’s hollow guide wires, doctors are able to image the beating heart and carefully guide the positioning of the device. The surgeon carefully seats the device within the annulus of the valve, essentially pushing defective native valve tissue out of the way, and allowing the now-functional replacement valve to take over.
The procedure eliminates the time needed to remove defective tissue, and reduces the risk of aortic regurgitation. The Direct Flow device has a polymer frame with a polyester cuff, and incorporates bovine pericardial leaflets.
Precise positioning is achieved by deflating the aortic ring and valve body, as needed, and moving the device into optimal position using the still-attached guide wires. The ring is then re-inflated to secure its position within the native annulus. This ability for physicians to reposition the device to exacting specifications — assisted by real-time hemodynamic imaging — is one of the system’s great advantages. Once aortic regurgitation has been eliminated, an anchoring polymer solution is delivered to the device through the hollow guide wires. The wires are then removed and the patient is allowed to recover.
Visualize the Benefits
This ingenious system — which has not yet received FDA approval — promises to improve the outlook for growing numbers of aging Americans who may one day require this potentially life-saving, life-extending procedure. Although it is being used abroad in real-world applications, our client is eager to demonstrate the potential benefits of its innovative technology here at home.
Our insightful aortic valve replacement animation brings this remarkable new procedure to life, allowing potential stakeholders to visualize the possibilities. Early results from Europe, where the device is under investigation, are decidedly encouraging. A recent article in the Journal of Interventional Cardiology concluded the device is associated with “higher rates of success” and “a lower incidence of post-procedural [aortic regurgitation],” compared to older, first-generation transcatheter aortic valve replacement (TAVR) devices. Another recent study, conducted on high-risk patients, concluded the Direct Flow device met three-day safety end points significantly more often than competing devices.
The incidence of moderate-to-severe post-procedural aortic regurgitation (a common drawback among older procedures) was significantly reduced among patients who received the Direct Flow device. There was also a reduced rate of valve embolization, and there were fewer instances in which a second valve needed to be implanted. The new generation device overcomes some limitations of first-generation devices, investigators concluded.