Thoracic Aortic Aneurysm
Because of recent advances in endovascular technology, the treatment of thoracic aortic aneurysms is currently undergoing a major evolutionary change. Stent graft treatment has become a minimally invasive and effective therapeutic modality which is associated with significantly less perioperative morbidity than that associated with conventional surgical methods of thoracic aortic repair. Endovascular methods are increasingly appropriate for patients with other aortic diseases such as dissections, traumatic disruptions, and ulcerations.
A discussion of aortic aneurysms is available on the Society of Thoracic Surgeons web site http://www.sts.org/sections/patientinformation/aneurysmsurgery/
Current indications for treatment of thoracic aortic pathologies include fusiform aneurysms greater than 5.0cm in diameter, saccular aneurysm, dissections, penetrating ulcers, aortic rupture, and aorto-pulmonary fistulae. Most thoracic aneurysms are asymptomatic and are therefore incidentally diagnosed. Untreated thoracic aneurysms have an unfavorable prognosis if not treated. Patients with a TAA of greater than 5cm diameter have a 2 year survival of less than 30%. Surgical repair must often be contemplated for elderly patients with multiple co-morbid illnesses which frequently make them poor surgical candidates. Significant complications may occur with open repair such as pulmonary insufficiency, paraplegia, renal failure, and cardiac failure.
European experience with thoracic aortic endografts has been quite extensive. However, no randomized, controlled trials comparing endovascular to open repair have been carried out. Nevertheless, several studies have shown a favorable comparison between the two techniques with a significantly reduced periprocedural morbidity and mortality.
The W.L. Gore Company has been the first to obtain FDA approval for the release of its TAG® (Thoracic Aortic Graft) device in this country. The release of other devices such as the Medtronic Talent® device and the Cook Zenith® endograft are anticipated soon.
Implant criteria and restrictions are largely parallel to those required for AAA stent grafts. However, the role of branching vessels, intercostals vessels, and hemodynamic stresses make these implants potentially more challenging and therefore require extensive preoperative preparation.
We look forward to offering thoracic aortic stent grafts for our treatment of patients with thoracic aortic pathologies. We are confident the use of these devices will significantly improve the outcome for these patients while greatly reducing the morbidity associated with these interventions.