The FLEXTEND helix is electrically conductive regardless of helix position. Thus, pacing and sensing thresholds can be
measured without extending the helix into the tissue. Mapping of the atrium or ventricle prior to helix extension and lead
fixation is recommended as it can reduce the potential need for repositioning.
Fixate the Lead Helix
With the lead in the correct position, fixate the lead in the following manner:
1. Attach the fixation tool to the terminal pin (Figure 1).
2. Apply adequate pressure to seat the distal electrode against the fixation site and slowly rotate the fixation tool
clockwise approximately 6 to 8 turns (1 second per rotation) to affix the distal electrode helix into the heart wall.
3. Do not release the fixation tool—hold it stationary.
4. Verify under fluoroscopy that the radiopaque markers are joined and the fixation helix is extended outside the
distal fluoroscopy marker (Figure 2).
Figure 2. Fluoroscopic markers illustrating appropriate retraction/extension
Markers not joined
Markers joined
Helix retracted
Helix extended
5. If the markers are not joined, 1 to 2 additional turns may be necessary.
CAUTION
: Minimize the number of turns. Excessive turns can cause damage to the lead, increased acute
thresholds, lead dislodgement and/or lead perforation.
6. Loosely hold the proximal end of the lead and release the fixation tool.
7. Remove the fixation tool by squeezing the handles of the tool together.
8. Carefully remove the stylet. Minimize manipulation of the lead to prevent dislodgement.
9. Ensure sufficient lead slack is present to prevent dislodgement.
If the helix mechanism fails to function properly during implant, the following caution must be observed to avoid
possible tissue snagging when removing the lead:
CAUTION:
Do not use the lead if the helix cannot be retracted during implant. Continuous
counterclockwise
rotation of the lead body during lead removal is necessary to avoid inadvertent tissue trauma.
Counterclockwise lead rotation helps to prevent accidental fixation and releases the electrode helix if tissue
snagging has occurred.
Check for Lead Stability
After fixation, partially withdraw the stylet 8 to 10 cm. Check the stability of the lead using fluoroscopy. Do not tug on the lead.
If possible, have the patient cough or take several deep breaths. When electrode position is satisfactory, completely withdraw
the stylet.
CAUTION:
Should dislodgement occur, immediate medical care is required to resolve the electrode position
and minimize endocardial trauma.
Reposition the Lead
If lead repositioning is necessary,
•
Verify the stylet is fully inserted into the lead
•
Reattach the fixation tool and rotate the tool counterclockwise 6 to 8 turns to retract the helix. Do not over-rotate the
helix.
•
The use of fluoroscopy may help to verify that the helix is retracted and disengaged completely from the heart wall.
•
Reaffix the electrode using the positioning, fixation and checking for lead stability procedures described previously.
December 13, 2007
©2007 Boston Scientific Corporation or its affiliates. All rights reserved.
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