Techniques for dealing with failed pacing leads have evolved over time. Initially, non-functioning pacing leads were abandoned and left in the pacemaker pocket and a lead cap was applied to the lead tip if it was not critical to remove the pacing lead. If necessary but not critical to remove the pacing lead, weights were applied to the end of the lead to apply constant outward traction to facilitate lead removal (Figure 2).
This technique frequently resulted in a part of the heart muscle wall being avulsed (torn away) and removed with the lead. Tearing of the heart muscle wall may lead to fluid collection around the heart (pericardial effusion). When absolutely necessary to remove non-functioning pacing leads, open heart surgery was resorted to.
In the 1990’s, tools were developed to facilitate the mechanical extraction of pacing leads. The tools included counter-traction with mechanical sheaths (plastic tubes) to avoid the problem of ripping the heart muscle wall, telescoping mechanical sheaths, and locking stylets (Figures 3 , 4 and 5).
While very effective in removing pacing leads, these tools were difficult to use and made the procedure very time consuming. In the late 1990’s, sheaths were developed that had laser fibers at the tip to allow local delivery of laser energy at the site of scar tissue binding the pacing lead in place (Figure 6).
At sites of lead binding a pulse of laser energy is applied that results in freeing of the lead – dissolution of the scar tissue holding the lead in place, facilitating advancement of the sheath. The sheath is gradually advanced to the lead tip (Figure 7).
Using counter-traction techniques, the lead tip is eventually freed and the lead can be removed through the sheath.
The laser sheath is connected to an Excimer laser system that uses xenon chloride gas, and emits a pulse of light energy at a wavelength of 308 nm (in the ultraviolet spectrum), with a depth of penetration of only 50 microns (Figure 8).
The laser energy “ablates” the scar tissue through 3 mechanisms of action: 1) photochemical – dissolution of chemical bonds, 2) photothermal – heating created through photo heating process of intracellular water, and 3) photomechanical – creating kinetic energy (Figures 9), (10 and 11).
The doctor first makes a 5-centimeter incision on the side of the chest where your child's pacemaker or ICD incision was made. Through this incision, the doctor removes the battery from your child's pacemaker or ICD and disconnects it from the pacing lead. Scar tissue holding the pacemaker and leads in place is dissected to free them up from inside the pacemaker pocket. Then, the doctor places the laser sheath over the lead that needs to be removed and directs the sheath inside the vein. The laser sheath is guided down to the tip of the lead, where it attaches to the heart. The sheath helps stabilize the heart muscle while the lead is removed. The sheath is attached to a laser. The laser delivers energy to remove the scar tissue holding the lead in place – either in the vein or around the tip of the lead (Figure 12).
This detaches the lead from the inside of the vein and at the tip of the lead. The doctor then removes the lead from the sheath, and may implant a new lead right away, or wait to a later date if your child has an infection of the pacing system.