Descending Thoracic Aortic Disease Clinical Trial
Official title:
A Clinical Study Evaluating Use of the Thoracic EXCLUDER Endoprosthesis in the Treatment of Descending Thoracic Aortic Diseases
The purpose of this study is to evaluate the safety and efficacy of endovascular repair, using the Thoracic EXCLUDER Endoprosthesis, when used in the treatment of descending thoracic aortic disease as indicated by radiological testing at time of discharge, and 1, 6, 12 months and annually following implantation, and to determine the proportion of patients who experience adverse events during and after the implantation procedure, including disease-specific and overall mortality rates.
Thoracic aortic aneurysm, while relatively rare, is a potentially lethal disorder with a
poor long-term prognosis if not treated. As the aortic diameter increases, wall tension
becomes higher, leading to further expansion of the aneurysm. Consequently, this disease
process is a "progressive and self propagating" phenomena, and the natural history of the
disease is progressive expansion of the aneurysm with eventual rupture. Patients with
descending thoracic aortic aneurysms frequently have concomitant major medical conditions,
making them poor candidates for major surgical procedures. Concomitant conditions may
include: hypertension, chronic obstructive pulmonary disease, congestive heart failure, and
peripheral vascular disease, including abdominal aortic aneurysm, previous stroke and
peripheral arterial occlusive disease.
The accepted treatment for aneurysms deemed to warrant intervention is surgical resection
and repair. Operative and post operative complications contributing to early mortality after
surgical repair of descending thoracic aortic aneurysms include low cardiac output,
pulmonary insufficiency, myocardial infarction, postoperative hemorrhage, pulmonary embolism
and sepsis.
In addition to mortality, two of the gravest complications of this surgical procedure,
neurologic complications due to spinal cord ischemia, such as paraplegia and paraparesis,
and renal failure or dysfunction, remain common.
Dissections, another disease process of the descending thoracic aorta, are rare. Aortic
dissections are thought to start with a tear or disruption of the intimal lining of the
aorta, either due to medial degenerative diseases, trauma or rupture of an ulcerated intimal
plaque. Blood at systemic arterial pressures invades the underlying medial layer of the
aortic wall, dissecting the layers of the aortic wall, and forming a false lumen. The
dissection then propagates for varying distances and in varying directions along the length
of the aorta.
As the false lumen increases in size, arterial flow to the true aortic lumen and to arteries
arising from the aorta may be blocked or disrupted. Depending upon the location of the
primary intimal tear and the direction of dissection propagation, various vital organs may
loose arterial blood supply, and the aorta may rupture into the pericardial sac or pleural
space, leading to cardiac tamponade or free pleural rupture. Blood flow from the false lumen
may reenter the true lumen through another intimal tear, which may occur proximal or distal
to the first, depending on the direction of dissection propagation.
Medical therapy is the first line treatment for dissections of the descending thoracic
aorta, and is aimed at reducing the mean, peak and diastolic recoil arterial pressure and
the dP/dt while maintaining sufficient pressure to adequately perfuse all vital organs.
Surgical intervention is warranted for patients with progression of dissection, impending
rupture, refractory hypertension, a sizable localized false aneurysmal component, or
continued pain.
A device has been designed to treat disease processes of the descending thoracic aorta. The
Thoracic EXCLUDER Endoprosthesis is a device that allows for primary endovascular repair of
the descending thoracic aorta and is intended to be used as an intraluminal blood conduit.
The Thoracic EXCLUDER Endoprosthesis is a flexible, self-expanding endoprosthesis that is
constrained on the leading end of a delivery catheter. A separate balloon catheter, the
Thoracic EXCLUDER Balloon Catheter, is used to smooth the endoprosthesis following
implantation.
Subjects will undergo an evaluation of the endoprosthesis, and will also be evaluated for
device and procedure related adverse events that may have occurred during the follow-up
period. Follow-up will be completed at 1, 3, 6, 12, 24, 36, 48, and 60 months. Subject
evaluation at 1 and 3 months will include a complete Physical Examination and a CT with
contrast enhancement. Subject evaluation at 6, 12, 24, 36, 48, and 60 months will also
undergo a complete Physical Examination, a CT with contrast enhancement, and a Chest X-Ray
(AP, Lateral, and 2 obliques).
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Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment