A New Service for Pacemaker Patients|
Laser Technology Now Lets Specialists Replace Worn-Out Wires More Effectively
File this one under "good problems to have."
The thousands of Americans with surgically implanted electronic pacemakers and defibrillators are now surviving much longer than they did a few decades ago. As they do, the electronic "leads"—the special wires that connect the devices to the heart muscle—eventually wear out or burn out, and new ones need to be installed.
In the past, for the few patients who lived long enough to need replacements, the old wires were often left in place, because it wasn't worth major open surgery to take them out. But now, with laser technology, removing these used-up wires is a much simpler matter—and Westchester Medical Center is alone in the area in providing this service.
Expanding use of pacemakers
Pacemakers, which keep the heart from beating too slowly or erratically, and defibrillators, which shock the heart out of a too-fast rhythm, work in similar ways, explains Martin Cohen, M.D., an interventional cardiologist and electrophysiologist at Westchester. They consist of a battery, a computerized generator and wires. The generator sends electrical pulses that set or correct the heart rhythm, and the wires, which are implanted directly into the heart muscle, carry pulses to and from various chambers of the heart.
Once pacemakers were installed exclusively as a secondary treatment after a patient had suffered an arrythmia event, such as a fainting episode or a dangerously accelerated heartbeat. Today, many devices are used as a primary prophylactic treatment. "That means we are putting more devices into younger and otherwise healthier people," says Dr. Cohen.
Increasing need to remove leads
Removing the leads is especially desirable when a patient needs to change from one device to another (each needs its own wires) or if an infection sets in around the lead, the doctor explains. "You can't clear an infection completely without removing the lead," he says.
Until recently, however, techniques to remove the leads were primitive. "In the 1950s, you'd take the lead off the device and tie a weight to it," Dr. Cohen says. "It would hang outside the body and the weight would gradually pull the lead out. It sounds crazy now, doesn't it?"
Not surprisingly, the success rate was less than 50 percent and complications such as infection were common—one reason why, if no infection was yet present, the leads were often simply left in place.
In and out in one night
Nowadays, the laser procedure is done in the hospital's cardiac catheterization lab. The patient is put under heavy sedation, but not full anesthesia. Dr. Cohen cuts a small opening in the chest up near the shoulder, where the device's power pack is located. He cuts the connection between the pack and the wire, then slides a sheath over the wire and guides it down to where it connects to the heart. The laser is located at the last millimeter of the sheath.
Using X-ray fluoroscopy to see what he's doing in real time, Dr. Cohen then uses the laser to cut the adhesions and scar tissue that hold the lead in place. He then pulls the lead up through the sheath, removes it and attaches a new lead from the device to the heart muscle.
The entire procedure takes about an hour and a half, says Dr. Cohen, and requires a one-night stay in the hospital. There are some risks—the laser could possibly cut a hole in neighboring tissue or cause excessive bleeding—but he has never had any such problems, he says. And a heart surgeon is always standing by, just in case.
This procedure has been available at Westchester for about two years. "Before that," says the doctor, "you had to travel out of the area."