Pacemaker and Defibrillator Excimer Laser Assisted Lead Extraction at the University of Toledo Health Sciences Center

In this article, the authors provide an updated overview on successful lead extraction methods for pacemaker and defibrillator cases. Permanent pacemakers and automatic internal cardioverter defibrillators (AICDs) have been improving and saving lives for over 50 years.1 Unfortunately, in rare cases these devices can pose potential harm to a patient, thus indicating removal. Removal or replacement of the generator only does not pose as much risk as lead extraction. Abandoning or disabling malfunctioning leads will suffice in the majority of patients who no longer have an indication or desire for continued therapy. However, lead extraction is indicated when malfunction results in potential harm, when there is difficulty clearing a blood stream infection, when venous stenosis has ensued, or when procedures, normally contraindicated with implanted devices, are necessary.2 The risk of lead extraction increases with duration of implant. After a few weeks, endothelialization causes lead adherence to the endocardium, vessel walls, and other leads. The thinner pacemaker leads and bulkier defibrillator leads should be referred to a specialized extraction center after 1 and 2 years post implant, respectively. In the past, open-heart surgical extraction or direct traction was required to remove these leads, both of which carry significant risk to the patient. Locking stylets and telescoping sheaths have also been used with success. Other factors associated with the difficulty of extraction include the type of insulation, structural integrity, associated thrombus or vegetation, and position or number of these leads. At the University of Toledo Medical Center, we typically use an excimer laser sheath to assist with extraction of these endothelialized leads. The excimer laser is a rigid sheath that slides over the lead, disrupting a cylinder of fibrous tissue located extremely close to the lead’s insulation surface (Figures 1 and 2). This technique allows for safer stripping and shorter extraction time of the lead encompassed by endothelialization.3,4 Upsizing the sheath can also extract thrombus surrounding the lead, which may prevent thromboembolism downstream from the lead. An endovascular approach, with emergency surgical back-up, will usually present less risk to the patient for thrombi less than 3 centimeters.5 The experience of the operator and center typically plays a major role in success. The general consensus suggests at least 30 lead extractions performed per year to maintain proficiency.6 Pre-Procedural Checklist Once lead extraction is indicated, preparation begins with discontinuation of anti-coagulant and anti-platelet medications if possible. Bridging with similar medications with shorter half-lives may be required in patients with high embolic risk. Pre-medication for contrast or medication allergies may be needed pre-procedure. The implant procedure report is reviewed to determine location of lead implant, type of lead fixation, vessel used, lead model and manufacturer, duration of lead implant, insulation type and potential problems faced by the implanting clinician. Factors such as prior surgical procedures, patient co-morbidities, urgency of extraction, cardiac or vascular congenital anomalies, pacemaker dependence and need for re-implantation are all taken into consideration when planning the procedure. Transesophageal and transthoracic echocardiography, occasionally other cardiac imaging, EKG, chest x-ray, and device interrogation are typically performed. Blood work, including type and cross of packed red blood cells, chemistries, CBC and coagulation studies, are reviewed. In some cases, testing for pregnancy, cardiac enzymes, brain natriuretic peptide, microbiologic results, and anti-arrhythmic levels may be necessary. A thorough discussion with the family and patient addresses the risks and benefits as a potentially life-threatening procedure before obtaining consent. Major complications of lead extraction include death, cardiac avulsion, vascular injury, pulmonary embolism, respiratory arrest, stroke, or pacing system infection. Minor complications include pericardial effusion, hemothorax, hematoma, arm swelling, need for vascular repair, hemodynamically significant air embolism, migrating lead fragments, blood loss requiring transfusion, pneumothorax, or pulmonary embolism not requiring surgery.6 Major complications range between 0.4–1.9%.3,4,7 Large-bore IV access and prophylactic antibiotics are started in the holding area. Electrophysiology lab personnel present during the case can include nurses, radiology technicians, electrophysiology and general cardiology fellows, an experienced electrophysiologist, and device and laser company representatives. A cardiothoracic surgeon as well as operating room back-up is made available. The patient is connected to external defibrillator pads, telemetry monitoring, electrocautery grounding pads, pulse oximetry monitoring, supplemental oxygen and an external blood pressure cuff. In addition, arterial access is obtained to monitor for rapid or small fluctuations in blood pressure. Pericardiocentesis, thoracotomy and intubation kits are immediately available in the same room. In some cases, a temporary transvenous pacemaker, transesophageal or intracardiac echocardiograph, or Swan-Ganz catheter is placed. Conscious sedation is performed typically with an opiate and benzodiazepine intravenously. Prophylactic antibiotics are started in order to be therapeutic at the time of initial skin incision. Lead Extraction Procedure The actual procedure begins with local lidocaine anesthesia, opening the previous pocket, and removal of the old generator. In the case of suspected infection, fluid samples and scar tissue are sent for microbiologic analysis. The leads are disconnected from the generator and freed from the underlying scar tissue and suture sleeves, usually requiring an electrocautery scalpel and blunt dissection. This is performed along the leads up to the point of its entry into the subclavian vein. We typically dissect to approximately a centimeter of tissue outside the entrance of the vessel. This extra tissue may minimize bleeding after removal of the lead and laser sheath. We initially attempt to remove not so older leads by unscrewing the helix of an active fixation lead and giving a gentle tug. This may be true, especially in the era of steroid-eluting leads; they sometimes surprisingly can be removed without sophisticated extraction equipment. Once it is determined that the laser sheath needs to be used for extraction, we start preparing the lead by cutting it a few centimeters from its entrance into the access vein and 2-3 cm of the insulation is stripped with a scalpel. A locking stylet is advanced through the inner coil of the lead and deployed at its tip. Current locking stylet tips are radio-opaque and can be easily seen crossing the electrode tips. This will lock the lead with the stylet. An Ethibond suture (Ethicon, Inc., a Johnson & Johnson company, Somerville, NJ) is tied one each to the inner coil, insulation and, in the case of defibrillator leads, the shocking coil. All the sutures are tied to the proximal end of locking stylet. The excimer laser is turned on and calibrated. We use both the inner sheath and telescope it through an outer beveled sheath and pass it over the locking stylet and the lead. From here onwards it is a procedure of traction and counter traction. We advance the laser sheath and start lasing, and at the same time give a traction on the lead. If there is difficulty in advancing the sheath while lasing, then the outer sheath is advanced over it with bevel positioned properly along the path of the lead and with special precautions taken at certain points. The areas of concern are the innominate - superior vena cava junction, lateral right atrium, tricuspid annulus, and at the lead tip to myocardium interface. (Figure 2) In case there is difficulty in removing a particular lead, it may not be a bad idea to switch and try to laser out the other lead, which may free the prior lead. This is also the time when chances of air embolism are high. At times, the leads insulation may break along with either stretching of the coil or even may break completely (Figures 3 and 4). The operator should be experienced in the use of femoral retrieval devices. The entire procedure time varies, typically taking between one and five hours, depending upon how much fibrosis is present, amount of calcification along the path of the lead and the number of leads to be removed. The timing of re-implantation is often a factor, as extraction and re-implantation of leads during the same procedure is often required. This especially occurs in the era of malfunctioning leads with the potential for harm to the patient, or patients who would require four or more leads within the same vessel. After lead removal, the laser sheath can be used to place the guidewire for new lead implant. Infected leads will require a time period of at minimum 3 to 14 days prior to re-implantation. In some cases, bridging with a wearable external defibrillator or temporary pacemaker may be necessary. Post-Procedural Management Patients are admitted and monitored on telemetry for at least 23 hours. Additional antibiotics, resumption of anticoagulation, and level of care are provided on a case-by-case basis. If a new lead has been placed, posteroanterior (PA) and lateral chest x-rays and device interrogation will be performed the next morning. If re-evaluation post observation is satisfactory, most patients can be discharged with wound care instructions and pain medications on the first post operative day. We generally like to see patients in follow-up within one to two weeks post procedure. Summary In general, lead extraction techniques have progressed over the years. Ongoing trials are demonstrating less complication rates than previously. Lead extraction center and operator volume are important determinants of outcome. Physicians are being trained in laser lead techniques with a minimum number of extractions under an experienced operator recommended before a physician can be considered a primary operator in an extraction. The excimer laser is a critical tool in the entire extraction process. Helpful tips for lead extraction: 1. Know your patient and the hardware to be extracted. 2. Stay prepared to troubleshoot any complication. 3. Know the areas of concern along the path of extraction. 4. Ultimately it is a balance between the amount of push and pull.