The balloon at the end of the catheter is filled with saltwater to expand the stent’s metal frame until it fits snugly against the old valve, which is pressed against the walls at the base of the aorta. As the balloon is deflated, the leaflets of the artificial valve begin to open and close with the blood flow.
A new biological valve should last 10 to 15 years, Dr. Webb said. “When they wear out, though, we can put another inside the first one.”
TAVI has other uses as well. Cardiologists are following similar steps to replace pulmonary valves and artificial aortic valves that have failed after open-heart surgery. Recently, Dr. Webb replaced the valve of a man who’d had aortic valve surgery four times, thus preventing a fifth open-heart surgery. “That’s kind of a big deal because the risk gets very high every time you redo heart surgery,” Dr. Webb said.
Another patient, Jeremy Wilkins, had undergone a quintuple heart bypass a decade earlier when his aortic valve began to fail. Mr. Wilkins, who is 61 and HIV-positive, said his surgeon was concerned he might disturb two of the bypasses he had put in place years before.
Mr. Wilkins’s case drew the attention of Dr. Webb, who replaced his aortic valve using TAVI in June, 2011, without interrupting the cocktail of medications Mr. Wilkins takes for HIV.
The psychological impact of TAVI was much less than that of open-heart surgery, said Mr. Wilkins, who went hiking in the Fraser Valley near Vancouver five days after his valve was replaced. “It feels kind of like science fiction has come to life.”
So far in Canada, however, the procedure is available only to patients who are not good candidates for surgery.
TAVI may not be cost-effective for lower-risk patients, who tend to spend less time in the hospital, Dr. Webb explained. A standard surgical valve costs $5,000, compared with $22,000 for a trans-catheter valve. After factoring in recovery times and the cost of the device, he said, “I think [TAVI] is cheaper in high-risk patients but more expensive in lower-risk patients.”
Health-care decisions will determine whether Canada goes the route of Germany, where a quarter of all aortic valves are replaced using the less invasive procedure, he said.
Nevertheless, Dr. Webb predicts that TAVI may become the gold-standard procedure for aortic valve replacement down the road.
“This is just better than surgery for many patients – not just the people who can’t have surgery.”
