Techniques and Devices for Lead Extraction

26 Techniques and Devices for Lead Extraction



Lead extraction is increasingly required and is directly related to the increased numbers of cardiac implantable electronic devices (CIEDs). The number of extractions has increased because of expanded indications, such as the need to upgrade to newer technology in patients with occluded veins or lead-device safety alerts, and improved access to extraction providers. The components of the CIED, the leads and pulse generators, have a limited functional life. As the population and the devices age, components of the system require removal for a variety of reasons, including infection, lead malfunction, venous stenosis/occlusion, and safety alerts.


This chapter discusses the indications, techniques, and devices for lead extraction in detail, using definitions and information from the 2009 Heart Rhythm Society (HRS) Expert Consensus on Facilities, Training, Indications, and Patient Management for transvenous lead extraction.1



image 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.”






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.24 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.



Goals and Outcomes


The clinical outcomes targeted with lead extraction are elimination of infection, elimination of risk associated with a lead (e.g., perforation, arrhythmia), and creation of venous access. Other clinical outcomes include removal of all functional leads and attempting to resolve pocket-related symptoms such as pain.


Outcome definitions depend on the indication of the procedure. If the indication is systemic infection, complete removal of all targeted leads and material without any complication, defined as “complete procedural success,” is required to achieve clinical success. However, in non-infection-related cases, “partial procedural success,” with only a small part or the tip of the lead retained, may be associated with clinical success and the desired clinical outcome, such as resolution of a pocket infection or creation of a conduit. In case of partial procedural success, clinical success is conditional and based on achievement of clinical goals and the absence of untoward effects such as perforation, embolism, or persistent infection caused by the retained part of the lead.


The HRS consensus document, in an effort to unify nomenclature, suggested the following definitions1:




Although there are no published benchmarks, operators should strive for clinical success in 100% of patients with the least possible number of complications. Table 26-1 summarizes current rates of success and complications based on collective studies.



Intraprocedural complications are any complication that occurs during the procedure, as recorded from the time the patient enters the operating or procedure room to the time the patient leaves. This includes all preparation, from administering anesthesia to groin access to closing the incision and reversal of anesthesia. Postprocedural complications are any events that become evident within 30 days after the intraprocedural period. Major complications are any life-threatening complications, those that result in death, or any complication that results in persistent or significant disability or significant surgical intervention. A minor complication is any undesired event related to the procedure that requires medical intervention or “minor procedural intervention” and does not limit, persistently or significantly, the patient’s function or threaten life or cause death (Box 26-1).




image 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).



Box 26-2


Indications for Transvenous Lead Extraction*






Leads Affecting Patient: Functional or Nonfunctional Leads









Infection


Infection remains the most common indication for extraction. Complete extraction is indicated in cases of definite CIED infection when there is erosion, pocket infection, lead vegetations, or sepsis (see Chapter 25). Extraction is also recommended in patients with a device and endocarditis or occult gram-positive bacteremia. Extraction is also reasonable in patients with a device and persistent occult gram-negative bacteremia. Antibiotic therapy should be considered adjunctive therapy, and pocket debridement with local relocation is only palliative.


To prevent further serious and potentially lethal complications, all device components, including leads, must be removed to cure the infection. Also, the morbidity associated with a local pocket infection, the lethal sequelae of septicemia, and the potential risk of infected thrombus formation in the heart are well known. Because leaving an infected lead in the body is potentially lethal, the risk of the procedure is clearly less than the risk of lead extraction; that is, the risk of not extracting far exceeds the risk of extracting. The risk of Staphylococcus aureus device infection without extraction was supported by a series of 33 patients from the Duke Medical Center; 10 of 21 patients (47.6%) died without lead extraction, and 2 of 12 (16.7%) died despite lead extraction, and none from lead extraction.5 The safety and efficacy of complete lead extraction, with debridement and delayed reimplantation at a remote anatomic site, were demonstrated in 123 patients at the Cleveland Clinic with device infection. Despite infections with a wide range of bacterial organisms, mostly coagulase-negative staphylococci and S. aureus, extraction was associated with no major complications. Infection recurred only in those four patients who had incomplete extraction or reimplantation concurrent with the extraction.6


Chronic pain at the site of the device or lead insertion should be considered as a subclinical infection, and extraction in such patients is indicated. After extraction, the patient should be treated as having a pocket infection, with adjunctive antibiotics and reimplantation on the contralateral side.



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.



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.




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.



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.





image 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.



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 1999.911 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.



image 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.



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.




Anesthesia


The types of anesthesia available include local anesthesia, conscious sedation, managed anesthesia care (MAC), laryngeal mask anesthesia (LMA), and general endotracheal anesthesia. The rationale for using a specific form of anesthesia is based on type of procedure, physician comfort level with general anesthesia, perceived risk of a given type of anesthesia, and availability of general anesthesia.


General endotracheal anesthesia is the only type of anesthesia that is suitable for all procedures, and essential for some. General anesthesia consists of an “anesthesia package:” anesthesiologist, compliance with preoperative anesthesia protocols, anesthesia and monitoring machines, and general anesthetic agents and gases. It requires procedure room space, scheduling, and an anesthesia recovery room. In addition, the electrophysiologist and anesthesiologist must work as a team to manage the patient. The merits of placing a patient at any desired level of anesthesia and providing a satisfactory environment to perform any type of surgical procedure are universally accepted when presented in this abstract fashion. However, the practical demands of the anesthesia package and the fundamental questions relating to the safety of general anesthesia limit its use.


Many of the maneuvers performed during a lead extraction can reduce filling pressure. Traction on an atrial lead may block the SVC and reduce blood flow to the heart. Traction on a ventricular lead reduces the compliance of the chamber wall during diastole or, if strong enough, can pull the wall to the tricuspid valve, reducing blood flow. Immediate injections of a short-term α-adrenergic stimulant such as phenylephrine (Neo-Synephrine) or norepinephrine (Levophed) constrict the cardiovascular system, causing an increase in both filling pressure and systemic blood pressure. This may frequently be required throughout the case to compensate for these transient iatrogenic insults. Use of these agents does not reflect on the safety and efficacy of general anesthesia.


In conclusion, the risk of anesthesia is mostly related to the procedure and not the general anesthesia.



Procedure Room


Electrophysiology (EP) procedures are currently performed in general OR suites, device implantation procedure rooms, EP procedure rooms, catheterization laboratories, and fully equipped cardiovascular ORs. The room must be large enough to support the procedure. Small procedure rooms are sufficient for a device implantation but not large enough for a complicated lead extraction procedure. There should also be space to accommodate emergency procedures and/or a more extensive surgical EP procedure. Procedures should not be performed in smaller rooms without a contingency plan for an emergency.


The ideal procedure room should meet most of the requirements for an OR, especially those related to room cleaning, patient draping, gown and gloving, and instrument sterility. It should have the full “anesthesia package” including continuous monitoring of ECG, arterial pressures, and oxygen saturation. Essential specialty equipment includes high-quality fluoroscopy, echocardiography, pacemaker system analyzer (PSA), and other external EP devices to ensure pacing and defibrillation, as well as an excimer laser or dedicated electrosurgical unit for lead extraction. In addition, for minimally invasive cardiac procedures, lighted retractors, access to thoracoscopy equipment, and an emergency tray to open the chest should be available. Additional safety devices to help protect physicians and nurses include lead drapes for radiation protection, smoke evacuators, and chairs for sitting when appropriate during the procedure.



Pocket Management


Tissue debridement is the surgical removal of all inflammatory and damaged native tissues, leaving only normal native tissue behind. The need for tissue debridement in normal pockets seen on routine reimplantation is minimal. On opening an old pocket, the debridement goal is to remove any exuberant inflammatory tissue (fibrous tissue), leaving only thin, healthy fibrous tissue (biophysical interface) or normal native tissue behind. The fibrous tissue present is involved in the chronic remodeling inflammatory reaction; rarely is an acute inflammatory reaction present. This is important, because exuberant fibrous tissue masses, which are the result of an inflammatory reaction, can injure adjacent tissue, continuing the inflammatory reaction (recursive reaction). Also, if this tissue is contaminated by bacteria, it becomes a nidus for infection; bacteria adhere to the smooth surface of the exuberant encapsulating tissue, and the body’s immunodefense mechanisms cannot reach the bacteria. Leads entrapped in the encapsulating fibrous tissue may be under undue stress if the pulse generator is not placed back in the same position. Tissue debridement and freeing of the leads rectify this situation. Tissue debridement is best performed with an electrosurgical cautery tool.


Tissue debridement, even in infected cases, is rarely extensive and can be treated as described earlier. Occasionally, however, the pocket must be extensively debrided and then abandoned; this situation usually involves infection. If an acute inflammatory reaction is extensive, debridement is tedious because of the presence of acute and chronic inflammatory material and proximity of large blood vessels and important nerves. Knowledge of local anatomy is mandatory in this situation. In some cases, the inflammatory tissue can be more than 2.5 cm thick, extending above and below the pectoralis major muscle with fingers to the clavicle, and damaging a large amount of skin. In these cases, skin loss is significant, and reapproximation of skin edges is challenging. Once the debridement is complete, hemostasis is difficult to achieve, especially on the muscles. Wherever possible, muscle fascia should be reapproximated.


Jun 4, 2016 | Posted by in CARDIAC SURGERY | Comments Off on Techniques and Devices for Lead Extraction

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