Additional Surveillance And Treatment - Medtronic Valiant Navion Gebrauchsanweisung

■
Precontrast and contrast run slice thicknesses and intervals must match.
■
Do not change patient orientation or relandmark the patient between noncontrast and contrast runs.
Noncontrast and contrast-enhanced baseline and follow-up imaging are important for optimal patient surveillance. Table 11 lists
examples of accepted imaging protocols.
Injection volume (cc or mL)
Injection rate (cc/sec or mL/sec)
Bolus timing
Scan range
Scan diameter (FOV)
DFOV (cm)
Scan type
Rotation speed (sec)
Slice thickness (mm)
Scan mode
Table speed (mm/rot)
Interval (mm)
kVp
mA
Reconstruction (mm)
11.4. X-ray
Chest X-rays may be used to assess device integrity such as stent graft fracture or separation between components.
Posterior/Anterior (PA) and lateral images are recommended for visualizing the stent graft. Ensure the entire device is captured
on images for device assessment.
11.5. MRI safety information
Nonclinical testing has demonstrated that the Valiant Navion thoracic stent graft is MR Conditional. A patient with this device
can be safely scanned in an MR system meeting the following conditions:
■ Static magnetic field of 1.5 and 3.0 tesla only
■
Maximum spatial gradient magnetic field of 2,000 gauss/cm (20 T/m) or less
■
Maximum MR System reported, whole-body-averaged specific absorption rate (SAR) of 4 W/kg (First Level Controlled
Mode)
Under the scan conditions defined above, the Valiant Navion thoracic stent graft is expected to produce a maximum
temperature rise of 2.8°C after 15 minutes of continuous scanning.
In nonclinical testing, the image artifact caused by the device extends approximately 6 mm from the Valiant Navion thoracic
stent graft when imaged with a gradient echo pulse sequence and a 3.0 Tesla MRI system. The artifact does not obscure the
device lumen.
11.6. Supplemental imaging
Note: Additional radiological imaging may be necessary to further evaluate the stent graft in situ based on findings revealed by
previous imaging assessments. The following recommendations may be considered.
■
If there is evidence of poor or irregular position of the stent graft, severe angulation, kinking, or migration of the stent graft
on chest X-rays, a spiral CT should be performed to assess lesion size and the presence or absence of an endoleak.
■ If a new endoleak or increase in lesion size is observed by spiral CT, adjunctive studies such as 3D reconstruction or
angiographic assessment of the stent graft and native vasculature may be helpful in further evaluating any changes of the
stent graft or lesion.
■
Spiral CT without contrast, MRI, or MRA may be considered in select patients who cannot tolerate contrast media or who
have renal function impairment. For centers with appropriate expertise, gadolinium or CO
for patients with renal function impairment requiring angiographic assessment.

12. Additional surveillance and treatment

Additional endovascular repair or open surgical aneurysm repair should be considered for patients with evidence of enlarged
aneurysm (>5 mm), endoleak, migration, inadequate seal zone, false lumen enlargement, or fracture. Consideration for
reintervention or conversion to open repair should include the attending physician's assessment of an individual patient's
Table 11. CTA imaging guidelines
100–150
3–4 via 20G IV or larger (4–5 for obese pts >220 lbs (99.8 kg))
SmartPrep, carebolus, or equivalent
Thoracic inlet to aortic bifurcation
Large
24–30
Helical
0.8
≤2.5
HS
15
1
120
120 for Noncontrast/200 for contrast portion of study
1 (Normal body habitus) to 2 (>220 lbs (99.8 kg))
angiography may be considered
2
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