The aorta, the largest artery in the body, which delivers oxygenated blood from the heart to the body, is a complex circulatory system. For this reason, open heart surgery to address heart diseases in this area often involves complex valve reconstruction. In the past, these valves were replaced. Now, the approach is all about repair.
Here at the Libin Cardiovasclar Institute of Alberta, cardiovascular surgeon Dr. Jehangir Appoo is the director of the Thoracic Aortic Surgery Program. In 2006, he implanted the first left ventricular assist device (VAD) in Southern Alberta.
Appoo is currently preforming a new type of surgery to better tackle life-threatening Type A aortic dissections—tears in the aorta wall. The procedure, hybrid aortic arch reconstruction surgery, doesn’t require circulatory arrest (cooling the patient down to 18 degrees and stopping blood flow for up to 90 minutes) and more importantly, addresses multiple areas in a single operation.
“Some patients have complex pathologies that involve the ascending, the arch and the descending [aorta] and it usually involves two or three different operations to try and fix,” he says. Using a special “Bavaria” graft to replace the ascending aorta, this process allows him to connect to the heart’s head vessels and place an endovascular stent graft—all at the same time.
“We’ve been able to do things in one operation rather than two or three and we’ve
found that at three years, these grafts look stable in the aorta and haven’t had any complications,” says Appoo. “This allows for more complete aortic repair.”
Appoo says that the current understanding of when a dissection is going to occur or when an aorta is going to rupture is still very rudimentary. It’s essentially based on size but researchers think there’s more to it than that.
“We’re trying to use engineering principles to determine things like wall stress and strain in the aorta,” he explains. He is collaborating more closely with the biomedical engineering group at the University of Calgary, specifically with Dr. Elena Di Martino, to further explore aortic mechanics.