Defective ICD leads: should they stay or go?
Date: June 13, 2011
A key decision when replacing the leads of an implantable cardioverter defibrillator or pacemaker is whether to leave the old, defective wires in place or remove them. Because taking out the old leads is a delicate and sometimes complex procedure, the issue requires careful consideration.
There are no definitive studies to settle the debate, says electrophysiologist Charles Henrikson. It’s an important question, however, faced by millions of people who depend on these leads as a lifeline between their device and their heart. About 5 to 10 percent of leads will break or fail to operate within 15 years, according to Henrikson.
“We consider how long the leads have been in place and also the age of the patient,” says Henrikson. “In elderly patients, we often implant the new wires alongside the older ones. However, if the patient is relatively young or if the vein is occluded, the wire should be removed.” He says that keeping in the inoperative wire can cause trouble down the road, such as blocking the blood vessel or interfering with the new leads.
If an infection has developed around or near the ICD or its wires, then the wires must come out with the device in order to clear the infection. The longer the leads have been in, the harder it is to take them out.
“When we take out leads that have been in place for more than one year,” Henrikson says, “we perform the procedure in the operating room using fluoroscopy. Also, we have a cardiac surgeon standing by as a precaution. Overall, there is a 1 to 2 percent risk of creating a hole in the vessel or the heart during the removal of the wire that would require emergency surgery.”
For most of the difficult extractions, Henrikson slides a sheath around the defective wire, starting just under the collarbone and continuing to the right ventricle. Using an excimer laser located at the tip of the sheath, he can melt away areas of fibrosis that would block removal of the old wire and make it hard to put in a new one.
“Once we create that channel around the wire, we gently pull the wire to remove it,” he says. The channel stays in place to install the new lead.
The procedure usually involves a small incision in the upper chest, and patients can go home the next day. Henrikson recalls the case of a 48-year-old Baltimore woman last summer, for whom removing a defective pacemaker lead required a unique approach.
The patient had a pacemaker in place for 18 years when, one day last June, she passed out because her pacemaker’s battery had worn down and one of the leads was defective. She was referred to Henrikson from another hospital, where cardiologists had tried to replace the lead, but the vein was blocked.
“We knew where the blockage was and had to slide the sheath beyond it to put in the new lead. However, her defective lead had broken off, preventing us from sliding the sheath any further.” So Henrikson took another approach. “We inserted a catheter in the femoral vein with a loop of wire to snare the dangling lead that was still in her heart. Also, by coming in from that direction, we were able to advance the laser sheath beyond the blockage to put in the new lead.”
The only other option would have been leaving the older wires in place and putting another pacemaker and two additional wires on the other side. Henrikson says that wouldn’t have been a wise choice if the patient needs new wires in the future.
The first human ICD implantation in the world was performed at Hopkins in 1980. Today, many ICDs and pacemakers have been in place for decades and, since the leads don’t last forever, Henrikson and his colleagues are seeing increasing numbers of patients who need leads removed and replaced. Ten years ago, Hopkins was performing about 15 removals a year. However, by 2010, that number had jumped to 70.