COOK Medical FORMULA 418 Gebrauchsanweisung Seite 8

guiding catheter/sheath. A slight contact of the stent with the guiding catheter/sheath may be felt, but there
must be no resistance.
b. If using a Tuohy-Borst "Y" adapter, advance the pre-mounted Formula 418 Vascular Balloon-Expandable
Stent System over the wire and into the fully opened large-bore Tuohy-Borst "Y" adapter. Gently advance
the Formula 418 Vascular Balloon-Expandable Stent System completely through the Tuohy-Borst "Y" adapter,
taking care to maintain wire guide position. Then advance the Formula 418 Vascular Balloon-Expandable Stent
System into the guiding catheter/sheath. A slight contact of the stent with the guiding catheter/sheath may
be felt, but there must be no resistance.
WARNING: If resistance is encountered, do not force passage. Resistance may indicate damage to stent.
Positioning the Stent
1. Ensure guiding catheter/sheath stability before advancing the stent delivery balloon into the vascular artery.
WARNING: If initial guiding catheter/sheath position is lost, avoid pulling or pushing the guiding catheter/
sheath over the stent. If this is done, the distal end of the guiding catheter/sheath may damage the stent.
2. Position the Formula Vascular Stent across the lesion, using both the distal and proximal balloon markers as
reference points. Optimal placement requires the ends of the stent to extend beyond the margin of the lesion to
be stented.
WARNING: If the Formula 418 Vascular Balloon-Expandable Stent System does not readily advance
through the vessel, do not force. If the stent will not advance in spite of good guiding catheter/sheath
support, consider dilating proximal obstructing plaque, or changing the wire guide or the guiding
catheter/sheath. (Refer to instructions for Removal of Unexpanded Stent.)
NOTE: When stenting long lesions, be sure to cover the distal portion of the lesion first. It is very important not
to leave distal lesions uncovered. Frequent injections of contrast around the uninflated Formula 418 Vascular
Balloon-Expandable Stent System will allow visualization of the extent of the lesion and facilitate accurate
placement of the stent.
Balloon Expansion/Stent Deployment
Prior to stent expansion, utilize high-resolution fluoroscopy to verify that the stent has not been dislodged during
positioning.
1. To expand the stent, inflate the balloon with a 1:1 contrast-saline mixture to the recommended expansion
pressure indicated on product label. Do not move stent system during deployment.
2. Complete expansion and apposition of the stent against the vessel wall is necessary for clinical success. Do not
exceed rated burst pressure of the balloon as indicated on the product label.
3. Once the stent has been deployed, post-deployment inflation is at the discretion of the operator to achieve
optimum angiographic appearance. The stent may be post-dilated up to 1 mm beyond nominal labeled stent
diameter.
Balloon Deflation and Removal
1. Completely deflate the balloon, by pulling negative pressure with the inflation device or a 20 ml syringe. This
usually requires 10 seconds or less.
WARNING: Allow enough time for the balloon to fully deflate prior to removal.
2. Slowly withdraw the balloon catheter from the stent while maintaining negative pressure on the balloon.
Maintain position of the guiding catheter/sheath to prevent it from being drawn into the vessel. Observe under
fluoroscopy to ensure that the balloon disengages from the stent.
Removal of Unexpanded Stent
Do not attempt to pull an unexpanded stent back into the guiding catheter/sheath. The Formula 418 Vascular
Balloon-Expandable Stent System should be withdrawn until the proximal end of the stent is aligned with the distal
tip of the guiding catheter/sheath. Withdraw the guiding catheter/sheath and stent delivery system as a single unit,
leaving the wire guide in place.
WARNING: If stent is removed, do not attempt to reuse the device. Damage to the stent may occur upon
removal.
Stent-Assisted, High-Pressure Balloon Angioplasty
A deployed Formula 418 Vascular Balloon-Expandable Stent may be further expanded using a low-profile, high-
pressure balloon catheter. The stent should have been well embedded into the vessel wall by the deployment
balloon before the lesion is recrossed. If recrossing is necessary, the position of the stent should be monitored and
care should be taken to avoid displacing the stent with subsequent manipulation of wire guides and balloons. An
appropriate balloon catheter should be used with a very flexible wire guide.
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