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 Peter Mason, MD, MPH, interventional cardiologist and Medical College of Wisconsin faculty member. “Given this narrowing, their leg arteries may be too small to introduce the catheter necessary to deliver the transcatheter valve.”
Medical technology is helping more arteries become accessible for catheter-based treatment. The Froedtert & MCW health network was the first in Wisconsin to use intravascular lithotripsy balloon angioplasty (IVL) to help expand calcified iliac and femoral arteries to allow for the safe insertion of catheters to perform transfemoral TAVR.
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. Studies have show that going through the apex of the heart presents liabilities, however, including bleeding and transient compromise of left ventricular function.
- Transvaal (TCv) approach — This novel percutaneous alternative circumvents artery disease by using the femoral vein. 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. Mason said. Surgeons make a small incision near the sternum and directly access the aorta to place the valve. The team of surgeons at Froedtert Hospital is very familiar with this approach, however, it still often involves resection of the sternum or rib to gain access to the heart.
- Transcarotid (TC) approach — A newer alternative, the transcarotid approach, has become one of the favored options when patients are not eligible for transfemoral access. We’re very fortunate at Froedtert & MCW Froedtert Hospital to have surgeons, including Lucian Durham, MD, and Stefano Schena, MD, who have extensive experience transcarotid access.
- Trans-subclavian (TS) approach — “The second alternate artery used, and perhaps favored, is called the axillary subclavian artery,” Dr. Mason 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.
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 to recommending the best approach for patients,” Dr. Mason said. “With 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. Mason said. “The literature clearly shows it to be the safest and in the best interest of the patient.
“Transfemoral access is available more often due to new techniques such as shock wave peripheral balloon lithotripsy, Dr. Mason said. "However, when this access point will not work, we have a host of alternative approaches for our patients."
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. Mason said.
