In the relatively short time since its approval, transcatheter aortic valve replacement (TAVR) has been a life-changing procedure for many people, relieving their aortic stenosis without open-heart surgery. However, the traditional access for TAVR — the femoral artery — is not appropriate for every patient.
“Patients who have aortic stenosis and coronary disease may also have peripheral vascular disease and narrowing of the femoral and iliac arteries,” said Michael Salinger, MD, medical director of structural heart disease and Medical College of Wisconsin faculty member. “Their leg arteries may be too small to introduce the relatively larger catheter necessary to deliver the transcatheter valve.”
The goal of ensuring TAVR availability to all who need it has led to the development of alternative approaches for reaching the aortic valve. The Froedtert & MCW team offers patients and their physicians extensive experience in a range of alternate access procedures:
• Transapical (TA) TAVR — The first alternative approved, transapical TAVR requires a 3”-5” incision in the chest by the left nipple. Surgeons then make a small incision in the apex of the beating heart, which provides direct access to the aortic valve through the left ventricle. TA is the only retrograde TAVR approach. Going through the apex of the heart presents liabilities, however. “Bleeding and transient compromise of left ventricular function can occur,” Dr. Salinger said. “This has been confirmed over the years with studies where transapical outcomes were less favorable.”
• Transvaal (TCv) approach — This novel percutaneous alternative circumvents artery disease by using the femoral vein. “Veins don’t get atherosclerosis or narrowing as a rule,” Dr. Salinger said. Surgeons make a wire and electrical cautery passage from the inferior vena cava to the abdominal aorta, then go up to perform TAVR. After the valve is placed, a small plug is delivered to seal the passage that was created.
• Transaortic (TAo) access — “Historically, the alternate artery to the femoral is the ascending aorta,” Dr. Salinger said. Surgeons make a small incision near the sternum and directly access the aorta to place the valve. “Our surgeons are very familiar with this approach, however, it still often involves resection of the sternum or rib to gain access,” he said.
• Trans-subclavian (TS) approach — “The second alternate artery used, and perhaps favored, is called the axillary subclavian artery,” Dr. Salinger said. A small incision near the clavicle exposes the subclavian artery, and surgeons direct a catheter through it into the aorta and across the narrowed aortic valve. “The advantage is there’s no bone cutting involved, however, there can be challenges and it may not be available to all patients,” he said.
• Transcarotid (TC) approach — A newer alternative for patients ineligible for femoral access, the transcarotid approach, is growing in use. Dr. Salinger said the approach is well-developed but requires expertise with carotid access. “We’re very fortunate at Froedtert & MCW Froedtert Hospital to have Lucian Durham, MD, a mechanical circulatory support surgeon who has extensive experience placing mechanical support catheters through the carotid approach,” Dr. Salinger said. “The carotid artery must be unobstructed, however. Every patient is screened with a CT scan to make sure the carotid is both straight and healthy.” As a result of Dr. Durham’s expertise, our health network introduced carotid TAVR access for select patients earlier this year.
An Approach for Every Patient
Indeed, thorough and detailed planning is critical with all forms of TAVR. “Quality CT scanning and talented radiologists are key,” Dr. Salinger said. “Having the full spectrum of cardiovascular specialists — both surgical and transcatheter — that you are likely to find only at an academic center allows us to offer these procedures safely and effectively for our patients.”
The vast experience of Froedtert & MCW cardiovascular specialists, combined with their ability to offer alternatives through investigational trials, facilitates the best match of patient and procedure. “We would prefer the transfemoral approach when we can use it and do the majority of our cases this way,” Dr. Salinger said. “The literature clearly shows it to be the safest and in the best interest of the patient.
“When that will not work, we can go to transapical, transcaval, transaortic, transaxillary, and transcarotid approaches. And, we’re now back to transfemoral with new techniques such as shock wave peripheral balloon lithotripsy to displace calcium deposits and make unusable femoral access usable again.”
TAVR via femoral access was the first minimally invasive procedure for replacing the aortic valve without open-heart surgery, but it is no longer the only option. “To treat everyone, you have to have the full complement of approaches, and at Froedtert Hospital, we absolutely have the full complement of all available alternative access procedures,” Dr. Salinger said.
For Our Referring Physicians:
Academic Advantage of Cardiovascular Specialists
The Froedtert & MCW health network gives patients and their referring physicians a distinct advantage.
Contact our physician liaison team for more information about our TAVR alternatives or if you would be interested in meeting with any of the cardiology team members.