Endovascular Repair of Descending ThoracoAbdominal Aortic Pathologies Using Physician Modified Endovascular Prosthesis

This is an early feasibility study that investigates the outcome of selected patients with complex thoracoabdominal aortic lesions who are suitable for endovascular (within the vessel) repair with a physician-modified Medtronic Thoracic Valiant stent graft. The Medtronic Valiant System includes a Valiant Thoracic Stent Graft, a self-expanding, tubular end prosthesis which is modified/customized by the Investigators to fit the patient's anatomy. The device is constructed by making a taper in the larger proximal thoracic device and attaching it to a smaller distal thoracic device. The Viabahn branches for the visceral vessels are sutured to holes made in the tapered section. The modified Valiant stent graft is advanced to the lesion site endoluminally via the iliac/femoral artery. Access for delivery of extensions to the device will be delivered through the left subclavian artery. Upon deployment, the stent graft self-expands at the target location, where it is designed to exclude the lesion by restoring blood flow through the stent graft lumen.

The study will be conducted with non-surgical or very high-risk patients who are considered suitable candidates for endoluminal repair and who are diagnosed with a Type IV complex thoracoabdominal aortic lesion. The total number of enrolled subjects is planned to be 15. It is a prospective evaluation of patients receiving the device to determine the proportion in whom successful implantation is achieved, as indicated by exclusion of the thoracic lesion and graft patency at implant, time of discharge, and 1, 6, and 12 months following implantation, and to determine the proportion of patients who die or experience adverse events during and after the implantation. Furthermore, the percentage of patients in whom technical and clinical success is achieved, will be determined. Patients will be followed for 5 years after the surgery in which the stent graft is implanted.

Eligibility Criteria:
Inclusion Criteria:

* Patients must have a Type IV complex thoracoabdominal aortic lesion and be considered candidates for endovascular repair;
* Patients must have an ileofemoral access compatible with delivery of a 25 Fr MedtronicValiant thoracic endograft;
* Patients must have a left subclavian artery anatomy compatible with 8 mm Dacron conduit to provide safe, sequential antegrade deployments of branch extensions
* Patients must have a nonaneurysmal proximal aortic segment distal to the left subclavian artery with at least 2 cm length to assure secure proximal fixation with a

  * Minimum diameter of 28 mm
  * Maximum diameter of 42mm
  * Angle less than 60° relative to axis of the aneurysm
  * Angle less than 60° relative to axis of the thoracic aorta;
* Patients must have a distal fixation iliac artery diameter greater than 2 cm in length and 12-28 mm in diameter;
* Patients must be high-risk surgical candidates according to the following established criteria: ASA score of IV.

Exclusion Criteria:

* Pregnant or pediatric patients (younger than 21 years of age);
* Patients who have a condition that threatens to infect the stent graft/aortic valve prosthesis;
* Patients with allergies to the stent graft material;
* Patients who fail to sign informed consent;
* Patients with expected survival less than one year.