COOK Medical Zenith Flex, Инструкция по эксплуатации

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Table 12.1.1 Recommended Imaging Schedule for Endograft Patients
Angiogram
CT
(Contrast and non-contrast)
Abdominal
Radiographs
Pre-procedure X
1
X
1
Procedural X
Pre-discharge (within 7 days) X 2,3,4 X
1 month X 2,3,4 X
3 month X 2,4,5
6 month X
2,4
X
12 month (annually thereafter) X 2,4 X
1 Imaging should be performed within 6 months before the procedure.
2 Duplex ultrasound may be used for those patients experiencing renal failure or who are otherwise unable to undergo contrast enhanced CT scan. With
ultrasound, non-contrast CT is still recommended.
3
Either pre-discharge or 1 month CT recommended.
4 If Type I or III endoleak, prompt intervention and additional follow-up post-intervention recommended. See Section 12.6, Additional Surveillance and
Treatment.
5 Recommended if endoleak reported at pre-discharge or 1 month.
12.2 Contrast and Non-Contrast CT Recommendations
• Film 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 images/film sets, as it prevents precise anatomical and device comparisons over time.
• All images should include a scale for each film/image. Images should be arranged no smaller than 20:1 images on 14 inch x 17 inch sheets if film is used.
• Both non-contrast and contrast runs are required, with matching or corresponding table positions.
• Pre-contrast and contrast run slice thickness and interval must match.
• DO NOT change patient orientation or re-landmark patient between non-contrast and contrast runs.
Non-contrast and contrast enhanced baseline and follow-up imaging are important for optimal patient surveillance. It is important to follow acceptable imaging
protocols during the CT exam. Table 12.2.1 lists examples of acceptable imaging protocols.
Table 12.2.1 Acceptable Imaging Protocols
Non-Contrast Contrast
IV contrast No Yes
Acceptable machines Spiral CT or high performance
MDCT capable of >40 seconds
Spiral CT or high performance MDCT
capable of >40 seconds
Injection volume n/a Per institutional protocol
Injection rate n/a >2.5 cc/sec
Injection mode n/a Power
Bolus timing n/a Test bolus: SmartPrep, C.A.R.E. or equivalent
Coverage - start Diaphragm 1 cm superior to celiac axis
Coverage - finish Proximal femur Profunda femoris origin
Collimation <3 mm <3 mm
Reconstruction 2.5 mm throughout – soft algorithm 2.5 mm throughout – soft algorithm
Axial DFOV 32 cm 32 cm
Post-injection runs None None
12.3 Abdominal Radiographs
The following views are required:
• Four films: supine-frontal (AP), cross-table lateral, 30 degree LPO and 30
degree RPO views centered on umbilicus.
• 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.
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.
12.4 Ultrasound
Ultrasound imaging may be performed in place of contrast CT when patient
factors preclude the use of image contrast media. Ultrasound may be
paired with non-contrast CT. A complete aortic duplex is to be videotaped
for maximum aneurysm diameter, endoleaks, stent patency and stenosis.
Included on the videotape should be the following information as outlined
below:
• Transverse and longitudinal imaging should be obtained from the level of
the proximal aorta demonstrating mesenteric and renal arteries to the iliac
bifurcations to determine if endoleaks are present utilizing color flow and
color power angiography (if accessible).
• Spectral analysis confirmation should be performed for any suspected
endoleaks.
• Transverse and longitudinal imaging of the maximum aneurysm should be
obtained.
12.5 MRI Information
Non-clinical testing has demonstrated that the Zenith AAA Endovascular
Graft is MR Conditional. A patient with this endovascular graft can be scanned
safely immediately after placement under the following conditions:
Static Magnetic Field
• Static magnetic field of 3.0 Tesla or less.
• Highest spatial magnetic gradient field of 720 Gauss/cm
Non-clinical evaluation was conducted in a 3 Tesla MR system (General
Electric Excite) with a maximum spatial magnetic gradient field of 720 Gauss/
cm as measured with a gaussmeter in the position of the static magnetic
field pertinent to the patient (i.e., outside of scanner covering, accessible to a
patient or individual).
MRI-Related Heating
1.5 Tesla Systems:
• Static magnetic field of 1.5 Tesla
• Maximum whole-body-averaged specific absorption rate (SAR) of 2 W/kg
for 15 minutes of scanning ( i.e., per scanning sequence)
In non-clinical testing, the Zenith AAA Endovascular Graft produced a
temperature rise of less than or equal to 1.4 °C at a MR system reported
whole-body-averaged specific absorption rate (SAR) of 2.8 W/kg, for
15 minutes of MR scanning in a 1.5 Tesla Magnetom, Siemens Medical
Magnetom, Numaris/4 Software, Version Syngo MR 2002B DHHS MR Scanner.
The maximum whole-body-averaged specific absorption rate (SAR) was 2.8
W/kg, which corresponds to a calorimetry measured value of 1.5 W/kg.
3.0 Tesla Systems:
• Static magnetic field of 3.0 Tesla
• Maximum whole-body-averaged specific absorption rate (SAR) of 2 W/kg
for 15 minutes of scanning ( i.e., per scanning sequence)
In non-clinical testing, the Zenith AAA Endovascular Graft produced a
temperature rise of less than or equal to 1.9 °C at a MR system reported
whole-body-averaged specific absorption rate (SAR) of 3.0 W/kg, for 15
minutes of MR scanning in a 3.0 Tesla Excite, GE Electric Healthcare, G3.0-
052B Software, MR Scanner. The maximum whole-body-averaged specific
absorption rate (SAR) was 3.0 W/kg, which corresponds to a calorimetry
measured value of 2.8 W/kg.
Image Artifact
The image artifact extends throughout the anatomical region containing the
device, obscuring the view of immediately adjacent anatomical structures
within approximately 20 cm of the device, as well as the entire device and its
lumen, when scanned in non-clinical testing using the sequence: Fast spin
echo, in a 3.0 Tesla, Excite, GE Electric Healthcare, with G3.0-052B Software,
MR system with body radiofrequency coil.
For all scanners, the image artifact dissipates as the distance from the device
to the area of interest increases. MR scans of the head and neck and lower
extremities may be obtained without image artifact. Image artifact may be
present in scans of the abdominal region and upper extremities, depending
on distance from the device to the area of interest.
Final Angiogram
1. Position angiographic catheter just above the level of the renal arteries.
Perform angiography to verify that the renal arteries are patent and that
there are no endoleaks. Verify patency of internal iliac arteries.
2. Confirm there are no endoleaks or kinks and verify position of proximal
gold radiopaque markers. Remove the sheaths, wires and catheters.
NOTE: If endoleaks or other problems are observed, refer to the Suggested
Instructions for Use for the Zenith AAA Endovascular Graft Ancillary
Components.
3. Repair vessels and close in standard surgical fashion.
12 IMAGING GUIDELINES AND POSTOPERATIVE FOLLOW-UP
12.1 General
• The long-term performance of endovascular grafts has not yet been
established. All patients should be advised that endovascular
treatment requires lifelong, regular follow-up to assess their health
and performance of their endovascular graft. Patients with specific
clinical findings (e.g., endoleaks, enlarging aneurysms or changes in the
structure or position of the endovascular graft) should receive additional
follow-up. Patients should be counseled on the importance of adhering to
the follow-up schedule, both during the first year and at yearly intervals
thereafter. Patients should be told that regular and consistent follow-up is a
critical part of ensuring the ongoing safety and effectiveness of
endovascular treatment of AAAs.
• Physicians should evaluate patients on an individual basis and prescribe
their follow-up relative to the needs and circumstances of each individual
patient. The recommended imaging schedule is presented in Table 12.1.1.
This schedule was used in the pivotal trial, and is recommended even in the
absence of clinical symptoms (e.g., pain, numbness, weakness). Patients
with specific clinical findings (e.g., endoleaks, enlarging aneurysms or
changes in the structure or position of the stent graft) should receive
follow-up at more frequent intervals.
• Annual imaging follow-up should include abdominal radiographs and both
contrast and non-contrast CT examinations. If renal complications or other
factors preclude the use of image contrast media, abdominal radiographs,
non-contrast CT and duplex ultrasound may be used.
• The combination of contrast and non-contrast CT imaging provides
information on aneurysm diameter change, endoleak, patency, tortuosity,
progressive disease, fixation length and other morphological changes.
• The abdominal radiographs provide information on device integrity
(separation between components, stent fracture and barb separation).
• Duplex ultrasound imaging may provide information on aneurysm
diameter change, endoleak, patency, tortuosity and progressive disease. In
this circumstance, a non-contrast CT should be performed to use in
conjunction with the ultrasound. Ultrasound may be a less reliable and
sensitive diagnostic method compared to CT.
Table 12.1.1 lists the minimum imaging follow-up for patients with the
Zenith Flex AAA Endovascular Graft. Patients requiring enhanced follow-up
should have interim evaluations.