Device Selection; Implant Procedure; Molding Balloon Use - Optional; Mri Safety Information - COOK Medical Zenith Alpha Mode D'emploi

• Clinical experience indicates that contrast-enhanced spiral computed
tomographic angiography (CTA) with 3D reconstruction is the strongly
recommended imaging modality to accurately assess patient anatomy prior
to treatment with the Zenith Alpha Thoracic Endovascular Graft. If contrast-
enhanced spiral CTA with 3D reconstruction is not available, the patient
should be referred to a facility with these capabilities.
• Clinicians recommend positioning the x-ray C-arm during procedural
angiography so that it is perpendicular to the aortic vessel neck proximal to
the thoracic aneurysm or ulcer, typically 45-75 degrees left anterior oblique
(LAO) for the arch.
• Diameter: A contrast-enhanced spiral CTA is strongly recommended for
measuring aortic diameter. Diameter measurements should be determined
from the outer-wall-to-outer-wall vessel diameter and not the lumen
diameter. The spiral CTA scan must include the great vessels through the
femoral heads at an axial slice thickness of 3 mm or less. CTA measurements
should be based on a CTA of a fully resuscitated patient.
• Clinical experience has shown that temporary changes in aortic diameter
during blood loss can lead to incorrect aortic measurement on preoperative
CTA, inadequate sizing, and increased risks of graft complications,
migration and endoleak. If preoperative CTA is done during hemodynamic
instability, repeat CTA when the patient is stable or use IVUS at the time
of the procedure to confirm diameter measurements. If there is significant
periaortic hematoma in the region of the subclavian artery the hematoma
should not be counted in the diameter measurement, as there is a risk of
oversizing the graft.
• Length: Clinical experience indicates that 3D CTA reconstruction is the
strongly recommended imaging modality to accurately assess proximal
and distal neck lengths for the Zenith Alpha Thoracic Endovascular Graft.
These reconstructions should be performed in sagittal, coronal, and
varying oblique views depending upon individual patient anatomy. If 3D
reconstruction is not available, the patient should be referred to a facility
with these capabilities. Length measurements should be taken along the
greater curvature of the aorta, including the aneurysm, if present.
NOTE: The greater curvature is the longest measurement following the curve
of the aneurysm and may be on the outer or inner curvature of the aorta
depending on the location of the aneurysm.
NOTE: Large aneurysms and difficult anatomy may require extra care in
planning.

4.4 Device Selection

• Strict adherence to the Zenith Alpha Thoracic Endovascular Graft IFU
sizing guide both in terms of component diameter (Tables 1 and 2 in
Section 9.5, Device Diameter Sizing Guidelines) as well as component
type/length (as stated below and in Section 9.6, Device Length Sizing
Guidelines) is strongly recommended in order to mitigate the risk for
events (e.g., migration, endoleak, aneurysm growth) that could result
from selecting inappropriate device sizes.
• Tables 1 and 2 incorporate appropriate device oversizing. Sizing outside
of the recommendations provided in Tables 1 and 2, including that which
could result from a difference in location of graft deployment relative to
the location used for graft sizing, can result in aneurysm growth, endoleak,
migration, fracture, device infolding, or compression.
• Graft length should be selected to cover the aneurysm or ulcer as measured
along the greater curve of the aneurysm, plus a minimum of 20 mm of seal
zone on the proximal and distal ends.
• To treat more focal aortic lesions, such as ulcers/saccular aneurysms, a
proximal component can be used alone.
• In aneurysms the graft may settle into the greater curve of the aneurysm
over time. Accordingly, extra graft length needs to be planned:
• A two-component repair (proximal and distal component) is
recommended, as it provides the ability to adapt to the length change
over time. A two-component repair (proximal and distal component) also
provides active fixation at both the proximal and distal seal sites.
• The minimum required amount of overlap between devices is three stents.
Less than a three-stent overlap may result in endoleak (with or without
component separation). However, no part of the distal component should
overlap the proximal sealing stent of the proximal component, and no
part of the proximal component should overlap the distal sealing stent of
the distal component, as doing so may cause malapposition to the vessel
wall. Device lengths should be selected accordingly.
• If an acceptable two-component (proximal and distal component)
treatment plan cannot be achieved (e.g., excessive aortic coverage, even
with maximal overlap of shortest components), the proximal component
must be selected with enough length to achieve and maintain the
minimum 20 mm sealing zones at both ends even when positioned in the
greater curve of the aneurysm. Failure to do so could result in migration,
endoleak, and aneurysm growth.

4.5 Implant Procedure

• Systemic anticoagulation should be used during the implantation
procedure based on hospital- and physician-preferred protocol. If heparin is
contraindicated, an alternative anticoagulant should be used.
• Appropriate procedural imaging is required to successfully position the
Zenith Alpha Thoracic Endovascular Graft and ensure accurate apposition
to the aortic wall.
• Fluoroscopy should be used during introduction and deployment to confirm
proper operation of the introduction system components, proper placement
of the graft, and desired procedural outcome.
• The use of the Zenith Alpha Thoracic Endovascular Graft requires
administration of intravascular contrast. Patients with pre-existing renal
insufficiency may have an increased risk of renal failure postoperatively.
Care should be taken to limit the amount of contrast media used during the
procedure, and to observe preventative methods of treatment to decrease
renal compromise (e.g., adequate hydration).
• Use caution during manipulation of catheters, wires, and sheaths within the
thoracic aneurysm or ulcer. Significant disturbances may dislodge fragments
of thrombus or plaque, which can cause distal or cerebral embolization, or
cause rupture of the thoracic aneurysm, ulcer or aorta.
• Minimize handling of the constrained endoprosthesis during preparation
and insertion to decrease the risk of endoprosthesis contamination and
infection.
• To activate the hydrophilic coating on the outside of the Flexor Introducer
Sheath, the surface must be wiped with sterile gauze pads soaked in saline
solution. Always keep the sheath hydrated for optimal performance.
• Maintain wire guide position during introduction system insertion.
• Do not bend or kink the introduction system. Doing so may cause damage
to the introduction system and the Zenith Alpha Thoracic Endovascular
Graft.
• To avoid twisting the endovascular graft, never rotate the introduction
system during the procedure. Allow the device to conform naturally to the
curves and tortuosity of the vessels.
• To avoid damage to the sheath, be careful to advance all components of the
system together (from outer sheath to inner cannula).
• Do not continue advancing the wire guide or any portion of the introduction
system if resistance is felt. Stop and assess the cause of resistance; vessel,
catheter, or graft damage may occur. Exercise particular care in areas of
stenosis, intravascular thrombosis, or calcified or tortuous vessels.
20
• As the sheath and/or wire guide is withdrawn, anatomy and graft position
may change. Constantly monitor graft position and perform angiography to
check the position as necessary.
• During sheath withdrawal, the uncovered proximal stent and covered
proximal stent with barbs are in contact with the vessel wall. At this stage
it may be possible to advance the device, but retraction may cause aortic
wall damage.
• Inaccurate placement and/or incomplete sealing of the Zenith Alpha
Thoracic Endovascular Graft within the vessel may result in increased risk
of endoleak, migration, or inadvertent occlusion of the left subclavian, left
common carotid, and/or celiac arteries.
• Inadequate fixation of the Zenith Alpha Thoracic Endovascular Graft may
result in increased risk of migration of the stent graft. Incorrect deployment
or migration of the stent graft may require surgical intervention.
• Inadvertent partial deployment or migration of the endoprosthesis may
require surgical removal.
• Land the proximal and the distal ends of the device in parallel aortic neck
segments without acute angulation (> 45 degrees) or circumferential
thrombus/calcification to ensure fixation and seal.
• Be sure to land the proximal and distal ends of the device in an aortic
neck segment with a diameter that matches the initial sizing of the device.
Landing in a segment that is different from the location used to size the
device may potentially result in inadequate (< 10%) or excessive (> 25%)
graft diameter oversizing and therefore migration, endoleak, thoracic
aneurysm or ulcer growth, or increased risk of thrombosis.
• The Zenith Alpha Thoracic Endovascular Graft incorporates an uncovered
proximal stent, a covered proximal stent (on the proximal component) with
fixation barbs, and an uncovered distal stent (on the distal component) with
fixation barbs. Exercise extreme caution when manipulating interventional
and angiographic devices in the region of the uncovered proximal stent and
uncovered distal stent.
• When using a distal component, take care to avoid landing the distal bare
stent in tortuous anatomy (i.e., localized angulation > 45 degrees).
• Unless medically indicated, do not deploy the Zenith Alpha Thoracic
Endovascular Graft in a location that will occlude arteries necessary to
supply blood flow to organs or extremities. Do not cover significant arch or
mesenteric arteries (an exception may be the left subclavian artery) with
the device. Vessel occlusion may occur. If a left subclavian artery is to be
covered with the device, the clinician should be aware of the possibility of
compromise to cerebral and upper limb circulation and collateral circulation
to the spinal cord.
• Take care not to advance the sheath while the stent graft is still within it.
Advancing the sheath at this stage may cause the barbs to perforate the
introducer sheath.
• Do not attempt to resheath the graft after partial or complete deployment.
• Repositioning the stent graft distally after partial deployment of the covered
proximal stent may result in damage to the stent graft and/or vessel injury.
• To avoid entangling any catheters left in situ, rotate the introduction system
during withdrawal.
• In the final angiogram confirm that there are no endoleaks or kinks, that
the proximal and distal gold radiopaque markers demonstrate that there
is adequate overlap between components, and that there is sufficient graft
length to maintain over time a minimum of 20 mm in proximal and distal
seal.
NOTE: If endoleaks or other problems are observed (e.g., inadequate seal
length or overlap length), refer to Section 10.2, Ancillary Devices: Distal
Extension.
• In the event that reinstrumentation (secondary intervention) of the graft is
necessary, avoid damaging the graft or disturbing the graft's position.
4.6 Molding Balloon Use – Optional
• Do not inflate the balloon in the aorta outside of the graft, as doing so may
cause damage to the aorta. Use the molding balloon in accordance with its
labeling.
• Use care when inflating the balloon within the graft in the presence of
calcification, as excessive inflation may cause damage to the aorta.
• Confirm complete deflation of the balloon prior to repositioning.
• For added hemostasis, the Captor Hemostatic Valve can be loosened or
tightened to accommodate the insertion and subsequent withdrawal of a
molding balloon.

4.7 MRI Safety Information

Nonclinical testing has demonstrated that the Zenith Alpha Thoracic
Endovascular Graft is MR Conditional according to ASTM F2503. A patient with
this endovascular graft can be scanned safely in a 1.5 T or 3.0 T MR system
using the specific testing parameters described in Section 11.4, MRI Safety
Information.

5 POTENTIAL ADVERSE EVENTS

Adverse events associated with either the Zenith Alpha Thoracic Endovascular
Graft or the implantation procedure that may occur and/or require intervention
include, but are not limited to:
• Amputation
• Anesthetic complications and subsequent attendant problems (e.g.,
aspiration)
• Aneurysm enlargement
• Aneurysm rupture and death
• Aortic damage, including perforation, dissection, bleeding, rupture and
death
• Aortic valve damage
• Aorto-bronchial fistula
• Aorto-esophageal fistula
• Arterial or venous thrombosis and/or pseudoaneurysm
• Arteriovenous fistula
• Bleeding, hematoma, or coagulopathy
• Bowel complications (e.g., ileus, transient ischemia, infarction, necrosis)
• Cardiac complications and subsequent attendant problems (e.g., arrhythmia,
tamponade, myocardial infarction, congestive heart failure, hypotension,
hypertension)
• Claudication (e.g., buttock, lower limb)
• Death
• Edema
• Embolization (micro and macro) with transient or permanent ischemia or
infarction
• Endoleak
• Endovascular graft: improper component placement, incomplete
component deployment, component migration and/or separation, suture