Clinicians at UCSF, led by Linda Reilly, M.D. and Timothy Chuter, M.D., have recently completed a multiyear study demonstrating that multi-branched stent grafts for throacoabdominal aortic aneurysm are safe and versatile. The specialized stent grafts were designed, developed and tested at UCSF, which remains one of the very few places where they are used.
"For the most sophisticated forms of this technology, we are the only ones who are doing this," says Chuter.
Multi-branched aortic stent grafts are a technological solution to a serious problem. Aortic aneurysm can be easily treated with a simple stent graft only where there are no branching arteries. Fenestrated stent grafts, which have cutouts to allow blood flow into arterial branches, are useful only when the aneurysm is close to, but not involving, the branches.
Three places along the aorta have branches that have to be preserved. High in the chest, the aortic arch has branches to the arms and the brain; at the diaphragm, the thoracoabdominal aorta has branches to the abdominal organs; and at the rim of the pelvis, the aorta divides in two to supply the lower extremities.
Researchers at UCSF have developed branched stent grafts that can stent not only the aorta, but carry the stent out into the first portion of the arterial branches. Chuter is well-known for developing the first Y-shaped stent grafts for the most common type of aortic aneurysm, which involves the spot where the iliac arteries split. This type of stent graft is now routinely used around the world.
Branched stent grafts for the aortic arch and thoracoabdominal aorta are much more complicated, and so is the current conventional surgical method of repair. This part of the aorta is high in the abdomen, behind the liver and pancreas. Surgical repair of a thoracoabdominal aneurysm requires clamping the artery, which stresses the heart and interrupts blood flow to abdominal organs, the spine and lower extremities. Statewide results for California show an overall mortality of more than 30 percent, which provides the impetus behind efforts to develop less dangerous alternatives, such as the branched stent grafts used by the UCSF team.
Although UCSF researchers performed the first branched repair of a thoracoabdominal aneurysm seven years ago, progress has been slow. Only recently has the UCSF team been able to accumulate sufficient experience to say with confidence that branched stent grafts are useful in a wide variety of thoracoabdominal cases. The medium-term results are very promising.
"You can treat just about any anatomy," Chuter says. The question is no longer whether thoracoabdominal aortic stenting can be done, but under what conditions it should be done. The answer will depend largely on the long-term results.
To contact Dr. Timothy Chuter, call (415) 353-4366.
UCSF Medical Center Among Top 10 Best Hospitals in Nation
For the seventh consecutive year, UCSF Medical Center ranks among the nation's top 10 premier hospitals, according to the 2007 survey by U.S. News & World Report. This year the survey ranked the medical center No. 7.