A clinical trial is underway at Emory University to study the safety and effectiveness of an endovascular medical device used to treat life-threatening thoracic aortic aneurysms (TAA). Emory vascular surgeon Ross Milner, MD, is one of 35 principal investigators in North America to participate in the trial and is the lead investigator for the Emory site. To date, the vascular surgery group at Emory has treated five patients.
The clinical trial, called STARZ-TX2 (Study of Thoracic Aortic Aneurysm Repair with the Zenith TX2(TM) Thoracic TAA Endovascular Graft), is open to patients diagnosed with a descending thoracic aortic aneurysm. The STARZ-TX2 trial will compare the outcomes of patients treated with open surgery to patients treated with the Zenith TX2 Thoracic TAA Endovascular Graft, manufactured by Cook Incorporated. The Zenith TX2 Thoracic TAA Endovascular Graft is an investigational device, limited by federal (U.S.) law to investigational use.
Specifically, the trial will assess device performance, as well as patient survival and aneurysm rupture rates between the surgical and endovascular treatment groups, over a 12-month period. The trial will enroll 275 patients at up to 35 medical institutions in the United States and Canada. Additional trial sites in Japan, Australia, and Europe also will participate.
"Aneurysms in the descending thoracic aorta are a time-sensitive condition that increases patient risks for life-threatening rupture," says Dr. Milner, assistant professor of vascular surgery, Emory University School of Medicine. "The non-surgical approach that is used in the STARZ-TX2 trial could benefit thousands of lives because it's a less invasive and lower risk procedure compared to the open-chest operation."
Since it is less invasive, the recovery time is also shorter for endovascular procedures. For an open repair, Dr. Milner says, the hospital stay lasts between seven to ten days. Patients who participate in the trial, as do all patients who have an endovascular repair, must come in for follow-up exams (including chest x-rays and CT scan) at intervals of one month, 6 months, and 12 months after the procedure, then yearly.
Elliot Chaikof, MD, is the director of the Emory University School of Medicine's Division of Vascular Surgery.
"Under the leadership of Dr. Milner and fellow vascular surgeon Dr. Karthik Kasirajan, Emory has become one of the preeminent centers for the minimally invasive treatment of thoracic aneurysms and dissections in the country," he says.
Each year, more than 20,000 people in the United States are diagnosed with TAAs. Aortic aneurysms -- including thoracic and abdominal aortic aneurysms -- remain the 13th major cause of death in this country, accounting for nearly 15,000 deaths annually.
TAAs occur when a section of the aorta -- the body's largest artery that carries blood out of the heart and into the organs of the body -- weakens and bulges outward like a balloon in the section of the artery that runs down the chest.
Currently, surgical repair is the standard of care for the treatment of TAAs. Surgical repair requires a surgeon to open the chest cavity, clamp off the aorta and sew a surgical graft in place to prevent an aneurysm from rupturing. Open surgical repairs carry high health risks for many older patients, who may also suffer from other significant medical conditions such as heart disease, lung disease, diabetes, or hypertension.
The Zenith TX2 system requires an incision to insert the graft's hydrophilic, kink-resistant delivery system into the femoral artery in the leg. Once the system is guided into position through the patient's arteries under fluoroscopy, a one- or two-piece, fabric-covered, self-expanding stent graft is placed inside the weakened section of the thoracic aorta to relieve pressure on the aneurysm, helping to reduce the risk of rupture.