Definitions

Implant lead removal technically means removal of a CIED lead using any technique. However, leads with short implantation duration can usually be removed with simple traction, and this is defined as a “lead removal procedure.”

However, with prolongation of the duration of implantation, segments of chronically implanted leads are encased in encapsulating fibrous tissue and may be bound to the vein and/or heart wall, bound to another lead, or both (Figs. 26-1 to 26-4). Removal of chronically implanted leads from these binding sites becomes very difficult and potentially hazardous with traction alone. The tensile strength of encapsulating fibrous tissue is greater than that of the surrounding tissue, and thus leads cannot easily be removed without risking a tear or avulsion of the vein or heart wall. In such cases the removal, separation, and freeing of leads from encapsulating fibrous tissue are defined as lead extraction. As a rule, if one or more of the leads implanted in the patient that require removal are more than 1 year old or require extraction tools for removal, the procedure is labeled as a “lead extraction procedure,” and if not, then a “lead removal without extraction.”

Figure 26-1 Canine model of fibrosis with lead extraction.

A, Acute thrombus formation 1 week after lead implantation in a dog. Thrombus has formed at each site where the lead touches the wall and in some regions of stasis or eddying blood flow. Most of this early thrombus lyses. It persists and organizes at sites of continued pressure on the wall and in areas with stagnant blood flow. Inset, Close-up of thrombus. B, Organized fibrous tissue encapsulating the lead forms chronically at sites of pressure. It progresses from fibrous tissue to cartilaginous tissue and finally to bone. C, Magnified view of chronic encapsulation shows the magnitude of the fibrous tissue to be ablated in extracting the lead.

Figure 26-2 Encapsulation in leads implanted 12 weeks.

A, Polyurethane lead has minimal encapsulation. B, Silicone rubber lead is completely encapsulated. Surface thrombogenicity phenomenon is not related to the mechanical properties of the silicone lead. The magnitude of the surface encapsulation contributes to the greater difficulty extracting silicone leads 2 to 3 years after implantation, compared with polyurethane leads.

Figure 26-3 Fibrosis.

Encapsulating fibrous tissue on extracted lead.

Figure 26-4 Fibrosis.

Fibrous tissue peeled from encapsulated lead.

Extraction techniques include traction, countertraction, counterpressure, and tissue disruption, cutting locally with an instrument, laser, or electrosurgery unit. Lead extraction techniques are designed to free the lead from the encapsulating fibrous tissue (countertraction) or to free the encapsulating fibrous tissue (counterpressure) from the vein or heart wall.^2–4 Telescoping sheaths are used remotely to apply countertraction and counterpressure at the selected binding sites. Lead extraction procedures are those approaches used to apply the sheaths and remove the lead in a safe and efficacious manner.

 Indications for Extraction

Considerable divergence of opinion surrounds the indications for lead extraction. However, the 2009 HRS consensus document has unified opinions to a large extent.¹ Indications are divided into three major categories: infection, venous access, and broken or nonfunctional leads. Also, emerging indications include implant patients who require magnetic resonance imaging (MRI) scanning for diagnosis (Box 26-2).

Noninfected Systems

When functional or nonfunctional leads pose immediate risk, such as in a patient with life-threatening arrhythmias from a retained lead or fragment, or when the lead design poses a risk of perforation (e.g., Accufix with protrusion of J stylet outside lead), the decision to extract is straightforward (Fig. 26-5). Extraction of functional or nonfunctional leads becomes controversial when there is no immediate threat to the patient, because it is possible to abandon a failed or a nonrequired lead and implant ipsilaterally if the vein is patent, or contralaterally or even transiliac if the ipsilateral vein is occluded. The controversy persists because it is difficult to calculate the risk/benefit ratio of lead extraction versus abandoning such leads. Thus, when considering extraction of noninfected leads, it is important to balance the risk of extraction with the patient’s situation and to factor in the operator’s experience and not just literature data. Some operators may choose to extract only when there is infection; others who are more experienced may elect to extract all leads that are not required, whether functional or not, when the opportunity arises.

Figure 26-5 Extracted lead.

A, Chest radiograph of Accufix lead. Note below the lead the J wire is outside the main lead body, exposing the patient to risk of perforation. B, Extracted Accufix lead outside of the body. Note the broken J wire exposed and outside the insulation.

Regarding the patient’s situation, two examples help clarify the approach. A 60-year-old patient with a pacemaker implanted for compete heart block and a failing 20-year-old right ventricular (RV) lead may have either (1) extraction of the RV lead and reimplantation of a new lead or (2) abandonment of the failing RV lead and addition of a new RV lead using the ipsilateral patent vein. The decision on which approach to adopt will depend on the operator’s skill and comfort. On the other hand, with a 95-year-old patient in the same situation, only the second approach seems reasonable, because the abandoned lead will likely never become a clinical issue. The following sections address extraction indications for noninfected leads.

Thrombosis or Venous Stenosis

Lead extraction is indicated for patients with clinically significant thromboembolic events with evidence of clot on the lead, as well as in patients with superior vena cava (SVC) or subclavian vein stenosis or occlusion with symptoms. Lead extraction is also recommended in cases of bilateral occlusion for the creation of a conduit or for planned stent deployment (Fig. 26-6). When there is a contraindication to implantation on the contralateral side (e.g., arteriovenous fistula), extraction for creation of a conduit is recommended; otherwise, extraction is considered reasonable.

Figure 26-6 Bilateral occlusion.

Lead extraction is recommended.

Creation of a Conduit

The rationale for creating a conduit is applicable to component failures. Consider a patient with a dual-chamber pacemaker and an atrial lead conductor coil fracture. This patient has a normal ventricular lead, an occlusion of the brachiocephalic vein, and the need to implant a new atrial lead. Although venoplasty through the total occlusion is possible, a more reasonable approach to maintaining access through the same vein entry site is to extract the failed atrial lead and to insert the new lead through the extraction conduit, or to remove both existing leads and start over with new leads. This same logic would apply to other situations, such as an upgrade requiring the addition of a new lead. For example, a patient with a dual-chamber ICD requires a cardiac vein implant for biventricular pacing. The alternatives are doing nothing, implanting the new lead through a contralateral vein or a transfemoral vein, or using a cardiac surgical approach. Venoplasty is also reasonable if the existing leads are all functional.

Sometimes, when there is severe stenosis with or without symptoms from the obstruction of flow, physicians have initiated balloon venoplasty and stenting without extraction of the leads. This is particularly difficult if either infection or reocclusion occurs, because extraction now becomes impossible without extensive open-heart surgery (Fig. 26-7). A more appropriate approach includes extraction, venoplasty, stenting, and reimplantation through the stent, as reported by Chan et al.⁷ in a subclavian occlusion that progressed to an SVC occlusion.

Figure 26-7 Severe stenosis.

Leads are stented to the superior vena cava (SVC), making extraction in case of infection impossible. The patient required surgery and an SVC graft.

Implantation through a contralateral vein seems logical, especially if it is the implanter’s only skill-level option. The simplest alternative is to abandon the two original leads on the ipsilateral side and implant the new leads on the contralateral side. In the example of a conductor coil fracture, the patient has the risk of having two functioning and two nonactive leads in the heart and the risk of instrumentation of the superior veins on the opposite side. In the example of adding a left ventricular lead for biventricular stimulation, the patient has the risk of having three functioning leads and two nonactive leads in the heart and the risk of instrumentation of the superior veins on the opposite side. These risks are weighed against the risk of extracting the one atrial lead. The resultant risk of having a complication is the sum of the individual risk factors.

For these two examples, another approach would be to implant the new atrial lead or biventricular lead on the contralateral side and tunnel it across to the pulse generator and ventricular lead. In addition to the risk of instrumentation of the superior veins and tunneling, the patient with conductor coil fracture will have two functioning leads and one nonactive lead in the heart, and the patient with the biventricular lead will have three functioning leads in the heart.

Total bilateral occlusion of the superior veins further complicates the problem. The transfemoral approach is then the only approach available to the nonsurgeon implanter. The surgical implanter has the options of a transatrial or epicardial approach. The risks associated with these choices make the decision to extract the atrial lead easier. However, without extraction skills, the medical and surgical implanter may choose these alternatives.

The risk/benefit ratio is crucial to the rationale for extracting these leads. For example, the life-threatening risk associated with infection in effect forces an implanter to extract the lead and abandon the pocket. The risk of not creating a conduit to insert new leads is a potential risk for a future complication related to bilateral implants, nonactive leads, multiple implanted leads, and tunneling. This risk is obviously less than the life-threatening risk of infection. In the situation of lead failure, the alternatives presented provide an acceptable short-term solution and can be performed by implanters without lead extraction skills. Potential risks are not as compelling a reason for action as the immediate risks associated with lead extraction. However, physicians with experience in lead extraction may not be comfortable with abandoning two leads, creating two inactive leads, and leaving a total of four or five leads implanted. Tunneling of a lead from the opposite side, crossing over the sternum, is a potential source of infection and increased risk of lead fracture. Again, the risk of not extracting must be compared with the risk of extracting to help resolve these issues. To limit the risk of subclavian vein or SVC occlusion, it is considered reasonable to extract nonfunctional leads if a planned CIED implantation would require more than four leads on one side or more than five leads through the SVC.

 Risks and Outcomes

The risks associated with lead extraction are tamponade caused by intrapericardial vascular disruption of the SVC or heart; hemothorax from extrapericardial vascular tear outside the pericardial sac and into the thorax; arteriovenous fistula or dissecting hematoma (e.g., aortic arch); and failure to complete the lead extraction (Fig. 26-8). The latter is usually not considered a risk; however, a failed lead extraction may lead to additional procedures or may be a precursor for dangerous situations in the future.

Figure 26-8 Potentially lethal complications from vascular tissue disruption during lead extraction.

Disruptions are caused by tears, cutting, perforations, or avulsions of a vascular wall. Tearing or cutting of the superior vena cava (SVC) or atrial wall (A) is the most common complication resulting in cardiac tamponade. Leads that are contiguous with or embedded in the subclavian artery, innominate artery, or aorta can tear these vessels during lead extraction (B). Acutely, a dissecting hematoma develops, with potential rupture into the thorax or, chronically, development of an arteriovenous fistula. Disruption of the right brachiocephalic vein into the right thoracic cavity (C) is insidious; tearing occurs during a difficult lead extraction when the vein and pleura are adherent or when a dissecting hematoma ruptures the pleura.

There are two situations in which the risk of tearing the SVC and heart is reduced but other risks could be increased. The first situation involves patients who have undergone an open-heart procedure; the pericardial space has been obliterated, and fibrous tissue reinforces the SVC and heart wall. In this situation, if an intrathoracic bleed occurs, quick surgical chest entry is difficult. The second situation involves an implant of short duration: less than 2 years for pacemaker leads and less than 1 year for ICD leads. The forces involved in freeing these leads usually are not sufficient to tear the SVC or heart.

Extraction centers from the continental United States and Hawaii voluntarily submitted data for a national registry between December 1988 and December 1999.^9–11 The most recent published report, from 1996, included data from 226 centers, 2338 patients, and 3540 leads and demonstrated major complications in 1.4% of the cases (<1% for centers with >300 extraction procedures).^10,11 The total U.S. data included 7823 extraction procedures and 12,833 leads (presented in 2000). Multivariate analysis of the data from 1994 through 1999 demonstrated four predictors of major complications (1.6%): (1) implant duration of oldest lead, (2) female gender, (3) ICD lead removal, and (4) use of laser extraction technique. Major complications were (1) death, 0.3%; (2) nonfatal hemopericardium or tamponade, 0.7%; (3) nonfatal hemothorax, 0.2%; (4) transfusion for bleeding/hypotension, 0.1%; (5) pneumothorax requiring a chest tube, 0.1%; and (6) other nonfatal events, 0.2% (including 4 arteriovenous fistulae, 2 pulmonary embolisms, 2 thoracotomies for defibrillator leads trapped in sheaths, 2 respiratory arrests, 2 strokes, 2 cases of renal failure, 1 anoxic encephalopathy, and 1 open-heart retrieval of a device fragment). In the more recent LExICon study of data from 13 centers in the United States and Canada, procedural success was 96.5%, with 97.7% clinical success.¹² In LExICon, 1449 patients underwent laser-assisted lead extraction of 2405 leads. Failure to achieve clinical success was associated with body mass index (BMI) of 25 kg/m² or less and low-extraction-volume centers. Procedural failure was higher in leads implanted for more than 10 years and when performed in low-volume centers. Major adverse events in 20 patients were directly related to the procedure (1.4%), including four deaths (0.28%). Major adverse effects were associated with patients with BMI less than 25 kg/m². Overall, all-cause in-hospital mortality was 1.86%.

Risk of lead extraction depends on the extractor’s experience, duration of implant, and the patient’s age and condition. There is no ongoing national database or registry, and the risks depend on the individual, the assembled team, and the institution. The most reliable indicator of risk is the individual extractor’s personal statistics. It is important that each institution and individual keep track of complications and effectiveness.

Risks are caused by maturation of the encapsulating fibrous tissue, which is related to the duration of the implant and the patient’s age. With time, the tensile strength of the encapsulating fibrous tissue increases; it may calcify in 3 to 4 years in children and in 8 to 10 years in older adults. Sedentary patients increase their tensile strength more slowly, and the tissue takes longer to mineralize. In sedentary elderly patients, the tensile strength seems to decrease with time. The influences of duration and age are apparent in the extremes. Also, patients with calcium metabolism abnormalities can calcify at any age in a short duration. Although the properties of encapsulated fibrous tissue are known, it is difficult to apply general principles to a specific patient and assign a risk.

Potentially lethal complications requiring extensive surgical procedures include tear of the vein and heart wall causing tamponade, arterial tears causing arteriovenous fistula or dissecting hematoma; and tears into the thoracic cavity causing a hemothorax (see Fig. 26-8). The procedure-related complications are discussed in detail later. Time and surgeon experience are the two factors related to survival. Low blood pressure and poor tissue perfusion are time-dependent events. Being prepared for a cardiovascular emergency is the only way to meet time constraints. This includes having a cardiovascular surgeon immediately available, along with the proper instrumentation and experienced support personnel. A cardiovascular surgeon has the technical skill to manage these complications but may need direction from the extractor on the proper approach. Once a complication resulting in poor or no perfusion is recognized, the repair should begin immediately. The concern of needlessly subjecting the patient to extensive surgery and morbidity pales in comparison to that of applying the therapy late because of confusion or procrastination. Failure to recognize the complication in a timely fashion or the lack of access to qualified personnel may cause a lethal outcome.

 Clinical Considerations

Patient Information and Preparation

All patients presenting for an extraction procedure must have a standard history and physical examination with a detailed description and understanding of the indication for extraction. The initial indication for implantation should be known. Comorbidities that can affect outcome, such as kidney failure, should be noted. The procedure notes should be carefully reviewed for any problems observed during the implantation, such as difficult access. Also, if infection is present, detailed information on the time line, organism, susceptibilities, and antibiotic therapy is needed. Basic laboratory work is usually indicated and includes white blood cell count, hematocrit, hemoglobin, platelet count, blood urea nitrogen, creatinine, potassium, sodium, liver profile, and prothrombin time.

The patient’s blood should be typed and crossmatched for a possible blood transfusion. A current chest radiograph and electrocardiogram (ECG) are mandatory (Fig. 26-9). An echocardiogram is mandatory for two groups of patients before the procedure, even if transesophageal echocardiography (TEE) is routinely available in the procedure room: those with infection, to rule out vegetation in the right atrium; and those with heart failure, to define cardiac function.

Figure 26-9 Transaortic ICD implant.

Extraction in the EP laboratory is contraindicated. The patient was referred for extraction in the OR for vascular access control.

A plan for antibiotics before and after the procedure should be formulated. Also, the need for temporary pacing while waiting for clearance to reimplant a new, permanent CIED should be established. The timing of reimplantation should also be determined before extraction. The operator must know all devices and leads present, including those abandoned. A preprocedural chest radiograph must be obtained and examined for any abandoned leads and unusual locations of lead placement. A lead thought to be in the left ventricle should be extracted in the operating room (OR) with surgical techniques. If there is any question as to the location of a lead, additional imaging using TEE or computed tomography (CT) may be required. It is imperative to know the initial implantation date because the age of the leads may dictate different preparations and approaches to extraction. The need for pacing during and after the procedure should be established. Dependent patients will need temporary pacing during the procedure using an electrophysiology catheter. After extraction is complete, a temporary active-fixation wire can be used until reimplantation of a CIED is possible.

The device to be extracted should be interrogated before the procedure and all parameters recorded, to serve as baseline characteristics of leads that will not be extracted. Therefore, these leads should be retested after extraction to ensure they have sustained no damage.

In noninfected patients, preprocedural antibiotics should be administered. Antibiotic therapy before the procedure can be given for infected patients when the infective organism and susceptibilities are established. The patient should be continuously monitored by ECG, arterial pressure line, oxygen saturation, and at times a Foley catheter. A reliable intravenous (IV) line should be placed. In addition, an arterial line should be used for patients needing continuous vasopressor support and for those sent to an intensive care unit. Patients are prepared from chin to midthigh for all transvenous and cardiac surgical approaches, including an emergency procedure, if needed. Transthoracic or TEE should be immediately available to assess for pericardial effusion or thrombus or vegetation dislocation. Because of the potential risks, extraction should be performed only in a facility with accredited cardiac surgery programs. A cardiothoracic surgeon must be physically present on site and be able to initiate emergency surgery. To facilitate the surgeon’s rescue efforts, the procedure room must be equipped with the necessary tools to perform cardiac surgery, such as thoracotomy or sternotomy instrument sets in addition to a sternal saw.

Informed Consent

Written informed consent should be discussed with the patient, preferably in the presence of a family member. The patient and family must be made aware that lead extraction is a potentially life-threatening procedure, and this must be placed into local context by informing the patient about the hospital’s extraction volume and outcomes as well as the operator’s personal level of experience and outcomes. It is particularly important to discuss all alternatives when considering extraction versus abandonment during an upgrade procedure.