Questions And Answers - Stryker Neuroform Atlas Mode D'emploi

note: After tightening the RHV firmly, the introducer sheath tip should not
move when pulled gently. Failure to secure the introducer sheath may
result in premature deployment of the stent within the microcatheter hub or
difficulty in transferring the stent.
note: The introducer sheath tip must be fully inserted into the microcatheter
hub to enable the stent to move into the microcatheter. Over-tightening the
RHV may crush the introducer sheath, while under-tightening the RHV may
result in premature deployment of the stent.
14. Advance the stent delivery wire to transfer the stent from the introducer
sheath into the microcatheter.
note: Ensure that the introducer sheath does not move while advancing
the stent delivery wire. Movement of the introducer sheath during stent
advancement may result in premature deployment of the stent within the
microcatheter hub.
15. Continue advancing the stent delivery wire into the microcatheter until the
distal edge of the fluoro saver mark enters the introducer sheath. The fluoro
saver mark is 135 cm from the stent delivery wire distal tip. When the fluoro
saver mark enters the introducer sheath, the stent is approximately
90 cm inside the microcatheter.
16. Loosen the RHV on the stent delivery microcatheter, remove the introducer
sheath from the proximal end of the stent delivery wire while holding the stent
delivery wire fixed in place, and set the introducer sheath aside.
note: At this point, fluoroscopy may be used at the physician's discretion.
17. If desired, place torque device on proximal end of wire (at least 5 cm from
proximal end of fluoro saver marker).
note: The torque device may be attached to the proximal end of the stent
delivery wire to facilitate handling and stabilization. Be sure to tighten the
torque device to secure the stent delivery wire. Do not use the torque device
to torque the stent delivery wire as it is not designed to be torqued.
18. Slowly advance the delivery wire and stent until the distal edge of the stent
delivery wire fluoro saver mark reaches the stent delivery microcatheter's RHV.
note: If resistance is encountered at any point during stent manipulation, do
not apply undue force. Withdraw the microcatheter, stent, and stent delivery
wire as a unit and repeat the procedure with new devices.
stent positioning and Deployment
19. Under fluoroscopy, advance the stent delivery wire until the stent's distal
radiopaque markers are 1 – 2 mm proximal of the distal tip marker of the stent
delivery microcatheter.
note: Maintain adequate stent length (approximately 4 mm) on each side of
the aneurysm neck to ensure appropriate neck coverage.
20. Withdraw the microcatheter slightly to remove any slack from the stent
system and position the stent for deployment by aligning the stent radiopaque
markers across the target aneurysm.
21. If stent delivery microcatheter positioning is satisfactory, carefully retract the
stent delivery microcatheter in a continuous movement while maintaining the
position of the stent delivery wire. This will allow the stent to deploy across
the neck of aneurysm. The stent's distal radiopaque markers will expand as
the stent exits the stent delivery microcatheter.
note: Do not use the stent delivery wire to push the stent out of the
microcatheter while deploying.
note: Do not deploy the stent if it is not properly positioned in the vessel.
22. Confirm deployed stent position using fluoroscopy.
23. If stent did not adequately cover aneurysm, withdraw the stent delivery wire
from the stent delivery microcatheter in preparation for placing additional
stents. Place additional Neuroform Atlas™ Stents as needed.
24. Once the aneurysm is adequately covered, remove stent delivery wire and
stent delivery microcatheter from patient.
25. Perform coiling procedure per appropriate coiling device DFU and establish
hemostasis.
26. Discard used devices.

QUestIons anD answers

Q: What is the optimal position of the stent with respect to the aneurysm?
A: Generally, try to position the stent so that each end of the stent is secured in
relatively straight areas of the parent vessel. The stent will be more stable
if each end of the stent is anchored in at least 4 mm of normal vessel. For
example, if an aneurysm is located in the supraclinoid carotid, it may be
better to secure the stent by deploying the distal end in the M1 (middle
cerebral artery, first segment) than trying to deploy it in the few millimeters
between the aneurysm and the ICA (internal carotid artery) bifurcation. When
deploying the stent, care should be taken to use a view that best shows the
parent vessel distal to the aneurysm; this enables the distal end of the stent
to be accurately deployed with respect to the aneurysm. This view may be
different from the view used to advance the Neuroform Atlas Stent System, or
the view used as a working position for aneurysm embolization.
Q: Which stent size should I choose if I intend to place the stent in a vessel that
has a different diameter between the proximal and distal ends of the stent?
Example: A vessel increases from a 2.5 mm PCA (posterior communicating
artery) to a 3.5 mm basilar artery.
A: Choose the stent sized for the larger vessel. In this example, choose the
4.0 mm stent. This stent can be deployed safely in the smaller PCA and will be
well anchored in the basilar artery.
Q: Is there any problem with deploying the stent across a branch vessel? Can
the stent be safely deployed across the anterior choroidal artery? What about
lenticulostriate arteries or perforators arising from the basilar?
A: No adverse events resulting from branch vessel occlusion or emboli have
been observed in the limited clinical study conducted on this stent (26 patients
followed through 6 months). Stents have been placed extending from the
M1 (middle cerebral artery, first segment) to the ICA (internal carotid artery)
without problems.
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Black (K) ∆E ≤5.0