The 2003 death of Three’s Company actor John Ritter created new public awareness of aortic dissection, a condition that affects tens of thousands of Americans each year. Aortic dissection occurs when the wall of the aorta, the body’s main blood vessel, splits. Blood flows into the aortic wall and travels down the aorta, where it can rupture the vessel or shut down other important blood vessels, obstructing blood flow to other parts of the body and endangering the limbs. Patients may experience a tearing pain in their back, or other pain symptoms that are similar to heart attack symptoms. Aortic dissection causes a variety of health problems, each requiring potentially different treatments.
An aortic dissection may be treated with open chest surgery for dissections near the heart. During the procedure, the patient’s chest is opened up and a graft is sewn in place to fix the tear. Because the aortic wall is thin and inflamed, the procedure can be likened to sewing wet pieces of tissue paper together. Although 80 percent of patients with complex type B aortic dissection are treated medically and tend to recover in time, 20 percent of patients develop complications such as a ruptured aorta, persistent back pain, and obstruction to the blood vessels supplied by the aorta. Survival rates for type B aortic dissection treated with surgery can be as low as 60 percent.
Cook Medical has developed the only minimally invasive endovascular device to treat aortic dissection in patients who require surgical intervention. The Zenith Dissection Endovascular System is a two-component system designed to repair and support the aortic wall in thoracic aortic dissections. The graft component seals the initial tear that caused the dissection, and the stent component supports the wall of the aorta to enhance blood flow to the other vessels in the body. Physicians install the device via the blood vessels in the leg by making a small incision in the hip. The Zenith system offers a variety of configurations to accommodate the different presentations of aortic dissection.
The system is currently undergoing a Phase I study, known as the STABLE trial. The primary endpoint of the multi-site study is survival at 30 days after surgery. Kevin Walls, a 45-year-old former NCAA basketball player, became the first patient treated at Cooper University Hospital in the STABLE trial. Following his diagnosis, Walls was originally told he might not survive the week. Dr. Joseph Lombardi, the global principal investigator in the STABLE trial, implanted an endograft. Walls was released from the hospital in one week. Within a month, he was jogging and playing basketball. Three months later, the scar from the incision had nearly disappeared.
Cook Medical is continuing enrollment in the STABLE trial at four sites around the U.S. Once the trial data has been accumulated, the company will begin planning a Phase II trial that will involve more investigation sites.