We’ve talked in this blog about putting pacemakers and defibrillators in, but what about when they need to be taken out? Lead extraction involves the removal of pacemaker or implantable cardioverter-defibrillator (ICD) leads from within the heart. Leads are thin, flexible wires that deliver energy to the heart muscle from a pacemaker or defibrillator to regulate the heart’s rhythm or deliver a shock if the patient is in a lethal heart rhythm.
Sometimes, the leads stop working properly or become obsolete and need to be taken out, usually to make way for new leads. They can be difficult to extract because, over time, scar tissues grows over them. During lead extraction, a sheath, or tube, is inserted threaded over the existing lead and inserted through a vein in the chest wall and into the heart. The sheath helps free the lead from any scar tissue that may have developed around it, helping the doctor to gently pull the lead from the heart muscle. Sometimes a laser is required to remove excess scar tissue that has grown around the lead.
Removing these adhered leads poses a risk of damaging the heart, which is why it used to be standard practice to do this complicated extraction procedure in the operating room (OR). Nowadays, though, most high-volume Electrophysiology (EP) centers (TCAI included) do lead extractions in the EP Lab itself, with an OR and a cardio-thoracic surgeon (and his or her surgical team) on-call in case of emergencies. A study published in the July 2011 issue Heart Rhythm, the journal of the Heart Rhythm Society (see full citation below), validated the safety of this approach. The first of its kind, the study compared the safety and effectiveness of extracting leads in the OR versus the EP lab and found them to be essentially equal if a rapid-response surgical team is on-call to assist with any emergencies that might require surgery.
The study found that the most common complication associated with lead extraction was damage to blood vessels or chambers in the heart, which if it is serious enough, sometimes needs to be corrected with open heart surgery. The major predictor of these complications during a lead extraction, according to the study, is age of the lead being extracted. Older leads, have had more time to become adhered to other structures in the heart and are usually more difficult to extract. Whether the extraction was done in the EP Lab by an electrophysiologist or in the OR by a Cardio-Thoracic Surgeon did not significantly impact the rate of complications, as long as there was a surgical team standing by to intervene in the EP lab in the event of complications. We look forward to further study on this important matter—as the population of folks with cardiac devices ages, so will their leads.
REFERENCE: Francheschi, Frederic, MD, Dubuc, Marc MD, FHRS, Dharo, Jean-Claude, MD et al. “Extraction of Transvenous Leads in the Operating Room Versus Electrophysiology Laboratory: A Comparative Study.” Heart Rhythm, vol. 8, issue 11. July 2011.