The ultimate purpose is to explore the potential techniques to exclude aneurysms and provide
an alternative conduit for arterial flow. The single center sponsorship is intended to
provide the investigators the potential to incorporate improvements in existing technology
during the course of the study thereby ultimately enhancing the potential for superior
medical care of patients suffering from these disease states. The sponsor/investigator
recognizes and accepts responsibility to notify and receive approval from the agency when
device modifications are made that may affect patient safety.
The Arizona Heart Institute is respectfully submitting this protocol for a feasibility study
utilizing the endoluminal grafts constructed of PTFE encapsulated nitinol stents. The study
is intended to evaluate the use of this unique device in the treatment of aortic aneurysmal
disease. The stent graft is made by laminating a PTFE "jacket" around nitinol stents which
act as structural and fixation supports. Both materials have an extensive history of use in
various types of implanted devices. CT scans and angiography or 3D computer imaging, and
possibly IVUS imaging will be used to choose the sites for placement of the devices and to
assure precise deployment.
In comparison to the conventional surgical approach, endoluminal stent-graft techniques for
repair of abdominal aortic aneurysms (AAAs) offer the advantages of a minimally invasive
procedure with lower morbidity and perhaps cost reduction. The Arizona Heart Institute has a
long history in the area of endoluminal grafting for treatment of aneurysms and occlusive
disease. Endoluminal sleeves principally using ePTFE and both stainless steel and nitinol
stent structures have been studied using commercially available materials customized for
particular pathologic situations. As the technology advances however, sophisticated
engineering beyond the capabilities of our institution was required.
The proposed project originates because of the potential to escalate the combination of
ePTFE and stents to a higher level of performance in aneurysm exclusion procedures. Current
data reflect several deficiencies in approved exclusion devices. Migration, types I, II and
III endoleaks and continual aneurysm expansion are clear predictors for potential ruptures.
Increased complications associated with the initial peri-procedural deployment as devices
are released on a broader scale have been observed. In order to address these problems, the
Arizona Heart Institute has engaged EndoMed engineering to design the endoluminal graft to
repair abdominal aortic aneurysms. We believe this will result in a positive step forward in
the technology to exclude aneurysmal disease less invasively.
The endoluminal stent-graft is composed of multiple nitinol stents which are encapsulated in
expanded Polytetrafluoroethylene (ePTFE). The stents are composed of a Z-shaped, performed
nitinol wire, which is crimped together with a stainless steel sleeve to form the circular
frame of the graft. This frame is then encapsulated between two thin sheets of laminated
PTFE. The proximal end of the endoluminal stent-graft is made in two configurations. One is
a completely encapsulated graft where the PTFE covers the entire device. The other has an
open stent segment (bare wire configuration) that allows the open stent region of the graft
to be placed across the orifice of the renal, mesenteric, or internal iliac arteries without
obstructing antegrade blood flow. The device will be available in a straight tube,
aortomonoiliac or bifurcated design.
Once the endoluminal stent graft is built, a 4 French guidewire dilator is placed through
the center of the graft and the assembly is compressed into a high density polyethylene
(HDPE) cartridge for ease of intraluminal delivery. The endoluminal stent-graft is then
placed in two Tyvek pouches and sterilized using Hydrogen Peroxide.
Subjects will undergo an evaluation of the PTFE encapsulation of Nitinol stents to provide
data on the device's feasibility for therapeutic clinical use. Follow-up will be completed
at 1, 6, 12, 24, 36, 48, and 60 months. Subject evaluation at 1 month will include a
Complete History and Physical, Bilateral ABIs, Abdominal Duplex Ultrasound, and a KUB X-ray
(4 views). Subject evaluation at 6 months will also include a Complete History and Physical,
Bilateral ABIs, Abdominal Duplex Ultrasound, KUB X-ray (4 views), and based on the duplex
ultrasound an Abdominal CT scan with and without IV contrast 2.5 mm and Labs
(BUN/Creatinine). Subject evaluation at 12, 24, 36, 48, and 60 months will include a
Complete History and Physical, Bilateral ABIs, Abdominal CT scan with and without IV
contrast 2.5 mm, Abdominal Duplex Ultrasound, KUB X-ray (4 views), and Labs
- Aneurysm diameter ≥ 4.0 cm; or aneurysm diameter ≤ 4.0 cm which has exhibited rapid
expansion; or aneurysms with saccular configuration where potential for rupture is
increased; or aneurysms which have exhibited dissection and there is potential for
rupture or compromised flow to vital structures; or symptomatic leaking or ruptured
- Vessels proximal and distal to the lesion must be capable of accommodating the
- The access artery diameter and profile of the artery must be capable of the device
- Patients must be ASA III or higher.
- Informed consent must be obtainable.
- Patients must be willing and able to comply with the follow-up regime.
- Patients with neck grades as follow:
- Grade I: Length of Proximal Neck ≥ 1.5 cm and Distal Neck ≥ 1.0 cm
- Grade II: Length of Proximal Neck ≥ 1.5 cm, but Distal Neck < 1.0 cm without obvious
iliac aneurysms, or aneurysm extends into or is associated with iliac aneurysms.
- Grade III: Length of Proximal Neck < 1.5 cm and Distal Neck ≥ 1.0 cm
- Grade IV: Length of Proximal Neck < 1.5 cm and Distal Neck < 1.0 cm or the
involvement as in Grade II.
- A proximal neck less than 0.5 cm in length.
- Arterial diameter larger than 40 mm at the proximal or distal landing zones.
- Iliac diameter less than 6 mm (following balloon angioplasty as needed).
- The inferior mesenteric artery is indispensable.
- Patients under the age of 18.
- Pregnant or lactating women.
- Patients with allergy to any of the device materials.
- Patients with uncorrectable coagulopathy or bleeding disorders.
- Patients for whom contrast medium or anticoagulation drugs are contraindicated.
- Patients with active systemic or localized groin infection.