Contrast And Non-Contrast Ct Recommendations; Thoracic Device Radiographs; Mri Safety Information; Additional Surveillance And Treatment - COOK Medical Zenith Alpha Mode D'emploi

Table 3 – Recommended Imaging Schedule for Endograft Patients
Pre-procedure
Procedural
1 month
6 month
12 month (annually thereafter)
1 Imaging should be performed within 6 months before the procedure.
2 MR imaging may be used for those patients experiencing renal failure or who are otherwise unable to undergo contrast-enhanced CT, with transesophageal echocardiography being an
additional option in the event of suboptimal MR imaging. For Type I or III endoleak, prompt intervention and additional follow-up post-intervention is recommended. See Section 11.5,

Additional Surveillance and Treatment.

11.2 Contrast and Non-Contrast CT Recommendations

• Image sets should include all sequential images at lowest possible slice
thickness (≤ 3 mm). Do NOT perform large slice thickness (> 3 mm) and/or
omit consecutive CT image sets, as it prevents precise anatomical and device
comparisons over time.
• The same scan parameters (i.e., spacing, thickness, and FOV) should be used
Table 4 – Acceptable Imaging Protocols
IV contrast
Acceptable machines
Injection volume
Injection rate
Injection mode
Bolus timing
Coverage - start
Coverage - finish
Collimation
Recon struction
Axial DFOV
Post-injection runs

11.3 Thoracic Device Radiographs

The following films are required: supine-frontal (AP), cross-table lateral,
30 degree RPO, and 30 degree LPO.
Follow the following protocols during each examination:
• Record the table-to-film distance and use the same distance at each
subsequent examination.
• Ensure entire device is captured on each single image format lengthwise.
• The middle photocell, thoracic spine technique, or manual technique should
be used for all views to ensure adequate penetration of the mediastinum.
If there is any concern about the device integrity (e.g., kinking, stent
breaks, barb separation, relative component migration), it is recommended
to use magnified views. The attending physician should evaluate films for
device integrity (entire device length, including components) using 2-4X
magnification visual aid.

11.4 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 after placement under the
following conditions.
• Static magnetic field of 1.5 or 3.0 tesla
• Maximum spatial magnetic field of 1600 gauss/cm (16.0 T/m) or less
• Maximum MR system reported, whole-body-averaged specific absorption
rate (SAR) of ≤ 2 W/kg (normal operating mode) for 15 minutes of
continuous scanning
Under the scan conditions defined above, the Zenith Alpha Thoracic
Endovascular Graft is expected to produce a maximum temperature rise of less
than 2.1 °C after 15 minutes of continuous scanning.
In nonclinical testing, the image artifact caused by the device extends
approximately 5 mm from the Zenith Alpha Thoracic Endovascular Graft when
imaged with a gradient echo pulse sequence and a 3.0 T MR system. The image
artifact obscures a portion of the device lumen.
11.5 Additional Surveillance and Treatment
(Refer to Section 4, WARNINGS AND PRECAUTIONS)
Additional surveillance and possible treatment is recommended for:
• Type I endoleak
• Type III endoleak
• Aneurysm or ulcer enlargement, ≥ 5 mm of maximum aneurysm diameter or
ulcer depth (regardless of endoleak status)
• Migration
• Inadequate seal length
• Graft thrombosis or occlusion
• Loss of device integrity
• Barb separation
• Stent fracture
• Relative component migration
Consideration for reintervention or conversion to open repair should include
the attending physician's assessment of an individual patient's comorbidities,
life expectancy, and the patient's personal choices. Patients should be
counseled that subsequent reinterventions, including catheter based and open
surgical conversion, are possible following endograft placement.
Angiogram (contrast and non-contrast)
X
at each follow-up. Do not change the scan table x- or y- coordinates while
scanning.
• Sequences must have matching or corresponding table positions. It is
important to follow acceptable imaging protocols during the CT exam.
Table 4 lists examples of acceptable imaging protocols.
Non-contrast
No
Spiral CT or high performance MDCT
capable of > 40 seconds
n/a
n/a
n/a
n/a
Neck
Diaphragm
< 3 mm
2.5 mm throughout - soft algorithm
32 cm
None

12 RELEASE TROUBLESHOOTING

NOTE: Technical assistance from a Cook product specialist may be obtained by
contacting your local Cook representative.

12.1 Difficulty Removing Release Wires

Turning the blue rotation handle pulls the release wire back, releasing the stent
graft attachment to the introducer. If the stent graft is not completely released,
it is possible to disassemble the blue rotation handle by following the steps
below:
1. Use surgical forceps to pull the back-end clips out (Fig. 17 and 18) and
2. Stabilize the gray positioner and slide the blue rotation handle backward
3. If leakage through the valve occurs, remove the inner introduction system
4. Close the Captor Hemostatic Valve on the Flexor Introducer Sheath by
12.2 Distal Component – Bare Stent Deployment
If the bare stent cannot be fully deployed from the cap: (Fig. 23)
1. Advance the Flexor sheath to the distal edge of the stent graft.
2. Stabilize the Flexor sheath and pull back the blue rotation handle. (Fig. 26)
CT
X 1
X 2
X 2
X 2
Spiral CT or high performance MDCT
Test bolus: Smart Prep, C.A.R.E. or equivalent
2.5 mm throughout - soft algorithm
remove the back-end cap. (Fig. 19)
to pull the release wires until the graft is released. Do not pull the release
wires completely out of the blue rotation handle. (Fig. 20 and 21)
entirely, leaving the sheath and wire guide in place.
turning it to the closed position.
NOTE: If extreme force is needed, wind the release wires around the
surgical forceps. (Fig. 22)
(Fig. 24 and 25)
The bare stent will now be released from the cap but still be inside the
sheath. Withdraw the sheath slowly with a rotating movement (Fig. 27)
until the bare stent is outside the sheath.
Thoracic Device Radiographs
X
X
X
Contrast
Yes
capable of > 40 seconds
Per institutional protocol
> 2.5 mL/sec
Power
Subclavian aorta
Profunda femoris origin
< 3 mm
32 cm
None
25