Lead Removal and Extraction

Introduction

Lead extraction or removal is increasingly required given the increased numbers of cardiovascular implantable electronic devices (CIED). The number of extractions or lead removals has increased due to increasing infection rates, expanded indications such as the need to upgrade to newer technology in the setting of occluded veins or lead/device safety alerts, and improved access to extraction providers. Leads implanted for a short duration are usually easily removable with simple traction and are associated with much less risk than when leads require additional tools for removal. Thus the CIED community has divided lead removal into transvenous “lead explantation” versus transvenous “lead extraction.” Transvenous lead extraction is defined as “a procedure when at least one of the transvenous leads has been implanted for 365 days or when more than a standard stylet is required for removal of the lead.” This distinction allows for better alignment of resources and training requirements and also better measurement of outcomes and quality.

Leads that have been implanted for a short period of time are usually removed with simple traction without the need for specialized tools. However, with the progression of time, inflammation, clots, and scar develop into dense fibrotic attachments between leads and vascular or cardiac tissue. Freeing of leads from encapsulating fibrous tissue can result in vascular and cardiac damage and perforation. Infection remains the most common indication and carries the strongest mandate for lead removal as substantial mortality risk accompanies CIED infection. Other indications with varying strength of recommendation will be covered later in the chapter and include removal/extraction of redundant leads, and extraction for access.

In this chapter we will discuss the indications, techniques, and devices for lead extraction in detail. Throughout the chapter we will be using definitions and cite information from the recent Heart Rhythm Society expert consensus on facilities, training, indications and patient management published in May 2009.

Lead-Related Fibrosis

With prolonged duration of implantation, segments of chronically implanted leads are encased in encapsulating fibrous tissue and bound to the vein and/or heart wall, bound to another lead, or both. With time, the tensile strength of the encapsulating fibrous tissue increases. In a recent histologic analysis Rennert et al studied 28 leads having attached tissue. They found that there was predominance of type I collagen consistent with scar but that there was persistence of type III collagen suggestive of ongoing active fibrosis and inflammation even after chronic implantation. The cellular makeup was predominantly myofibroblasts. These changes are consistent with ongoing chronic foreign body reaction. Removal of chronically implanted leads from these binding sites becomes very difficult and potentially hazardous with traction alone given the imperfect separation of the fibrotic attachments from the venous and cardiac tissue. Given that the tensile strength of encapsulating fibrous tissue is often greater than that of the surrounding tissue, leads cannot easily be removed without risking a tear or avulsion of the vein or heart wall ( Figs. 35-1 to 35-3 ).

Pathology of Leads

The tensile strength of an implanted lead is degraded with longer duration of implantation resulting in more fragility and less transmissibility of forces throughout the length of the lead's body. This is due to wear and tear and to exposure to the blood pool, inflammation and antecedent fibrosis, and calcification that form around the lead. Some leads, due to their design and anatomy, have inherently weak tensile strength and unravel quickly during extraction. Leads with asymmetrical noncoaxial leads are particularly susceptible to unraveling and fracturing during extraction. Also “stretchy leads” such as the Fine Line PM leads tend to unravel more easily, especially if not appropriately prepared. During extraction utmost care should be taken in proper preparation of the lead and avoidance of lead fracture leaving remnants that will then require different approaches for extraction, most notably a femoral approach or a nonentry vein approach as discussed later in the chapter.

Theory of Extraction

In theory extraction is needed for removal of a lead when simple traction will not work. With simple traction lead removal fails for the following reasons:

• 1.

  With traction there is lead disruption with elongation due to conductor and insulation fractures when subjected to continuous pulling without counter measures, because the tensile strength of the binding sites are stronger than the lead.

• 2.

  Tissue disruption may occur because the tensile strength of the binding sites is stronger than the vascular or cardiac tissue.

When the likelihood of either of these conditions is recognized, escalation to proper extraction techniques is required to safely remove the lead from the body. For extraction to work safely two conditions must be achieved: control over all components of the lead and countermeasures to decrease the risk of perforation and avulsion of the tissue.

Control of the Lead Body and Its Components

Lead preparation will be discussed in detail later in the chapter. These components include the insulation material, pacing and sensing conductors, and in the case of defibrillator leads, the shocking coils. If these materials are not all bound together as one unit the chances of losing lead integrity, snow plowing the insulation, and lead fracture increase ( Fig. 35-4 ).

Countermeasures

Counterpressure

When withdrawal tension is placed on the lead by the operator and advancement force to the extraction sheath, counterpressure is applied to binding sites at the tip of the extraction sheath along the trajectory of the lead in order to free it from the encapsulating noncompliant fibrotic tissue ( Fig. 35-5 ). The encapsulating fibrous tissue is often attached to the vascular structures (vein, tricuspid valve, or heart wall) or other leads ( Video 35-1 ). The sheath counters the withdrawal (traction) force applied to the tissue mass by converting these forces into a point of opposing dynamic forces concentrated locally between the tip of the extraction sheath and the fibrosis and vein wall (counterpressure sheath). This focused opposing local action peels the sometimes calcified mass off the vein or heart wall. This can be expedited by using powered sheaths such as laser, radiofrequency, or mechanical rotation (power-assisted counterpressure). The force applied is limited by the tensile strength of the lead and/or the wall. Power assistance may result in less net force to achieve the same goal given that now there is a cutting edge to the sheath. Because the magnitude of the counterpressure force actually focused on the wall is unknown, application of force is subjective. Counterpressure is potentially dangerous and should be approached with caution. As long as the tensile properties of the lead prevent elongation or fracture of the lead body, the inability to safely pass a binding site using counterpressure, power assisted or not, is the primary reason for abandoning this approach and changing to a transfemoral or transatrial approach. These approaches allow the lead to be pulled out of the superior veins from below, through the binding site. Often friction, which dissipates the advancement force before it reaches the tip of the sheath, is confused with counterpressure. Friction can occur between the outside surface of the sheath to the vessel/fibrosis, between the outer sheath and inner sheath, between the inner sheath and the fibrosis on the lead and is increased by the curvature of the vasculature. In addition, obstacles to advancement can be mechanical (including a size mismatch between the sheath and the lead), “snowplowed” insulation, and nonisodiametric features of the lead such as at transitions to the shocking coils. Both the diameter of the sheath and its stiffness, as well as the maintenance of the lead body rail to keep the geometry conducive to sheath advancement, are important. Rotation of the sheath and sliding the sheath back and then readvancing can help overcome the initial friction and facilitate advancement.

Countertraction

Direct traction is the term used when withdrawal force is applied by pulling directly on the lead manually, with a suture or locking stylet or both. This is in contrast to indirect traction, which refers to grasping the lead with a snare and applying traction by the snare. Some leads are easily removed by direct traction.

Countertraction ( Fig. 35-6 ) is usually the last step in a normal lead extraction procedure, using any type of sheath. Extraction sheaths free leads from binding sites along the lead body, proximal to the distal lead tip with counterpressure as described above. Once the sheath is passed over the lead and down to just a few millimeters from the myocardial interface, traction on the lead pulls the lead tip and the myocardium to the tip of the extraction sheath. The traction force is countered by the circumference of the sheath. The countertraction sheath focuses the traction force at the tip of the sheath, limiting the excursion of the heart wall. This prevents compliance changes and blockage of the tricuspid valve with possible perforation, tearing, and avulsion of the heart wall. The countertraction forces are limited by the tensile strength of the lead. At some point, the electrode is freed from the encapsulating fibrous tissue, allowing the heart wall to fall away and the electrode to be pulled out through the sheath.

The way countertraction actually frees the lead is postulated but not known. It is imagined that the traction force wedges the lead against the countertraction sheath. The pulling force on the electrode tries to pull the encapsulating fibrous tissue on the electrode into the sheath but cannot due to the size mismatch. The electrode is then imagined to be freed either by a plastic deformation of the tissue that allows it to slide out of the encapsulating tissue as the countertraction sheath peels the tissue off the electrode or by an actual disruption or bursting of the encapsulating tissue that frees the electrode, or both. For a passive electrode, the tines are removed intact with the electrode; for an active fixation electrode, the fixation mechanism is ideally retracted or unscrewed before countertraction is applied. In some cases, continued “unscrewing” of an active fixation lead results in complete lead removal without the need for countertraction because of the absence of significant binding at other sites along the lead. If the helix will not retract, the electrode and fixation mechanism are removed together. The same scenario is envisioned for removal of electrodes from the atrial wall. Countertraction can be performed with either the inner or the outer extraction sheath.

Lysis of Fibrotic Attachments

As described above, the binding attachments are mostly made of fibrotic tissue that over a long implantation time may also become calcified, increasing its density and strength as time goes by. Simple mechanical sheaths can disrupt these binding sites, but the forces needed are usually high, which can increase the risk of perforation and avulsion. Therefore powered sheaths were developed to increase the ability to disrupt the fibrosis with decreased traction and advancement forces. The powered cutting tips are positioned at the leading edge of the telescoping sheaths. These powered sheaths were designed to lyse or cut the fibrotic attachments. Lysis or cutting can be achieved using laser-powered sheath or a radiofrequency electrosurgical dissection sheath. Newer mechanically rotating tips were also introduced. These mechanically cut the fibrotic attachments from the leads.

The ability to free the leads by cutting tissue significantly decreases the required counterpressure force to disrupt the attachments. Reduction in the applied force has made lead breakage and separation of the lead body from the distal electrode rare events. Before the advent of powered sheaths, a lead breakage rate of 15% to 20% was common for leads with satisfactory tensile strengths.

In the event that a lead breaks with resultant loss of control of the lead from the vein entry site or in the instances when there are retained lead materials, other distant sites are utilized. The most common is through a femoral work station or through the right internal jugular through which snares and sheaths are deployed to grasp the remaining lead material and complete the extraction using the same concepts of counterpressure and countertraction described above.

Tools

Locking Stylets

The first-generation locking stylet came in various sizes to fit a variety of conductor coil diameters. The conductor coil had to be measured before selecting the locking stylet. Current models of locking stylets no longer require sizing of the conductor coil. The locking stylet binds to the inner conductor coil, ideally at the distal electrode, and prevents stretching of the lead with traction forces. The locking stylet also functions as a lead extender so that the lead can be grasped after feeding it through the extraction sheath. The locking stylet is the mainstay of maintaining lead integrity, preventing the lead from elongating or breaking with traction, and facilitates the development of a rail in the lumen of the vessel over which the extraction sheaths are advanced.

The two currently marketed models of locking stylets include the Spectranetics LLD Lead Locking Device (LLD) models E, EZ, #1, #2 and #3 (Spectranetics, Colorado Springs, CO), which use a long cylindrical wire mesh over a wire and the Cook Liberator Beacon Tip Locking Stylet (Cook Medical, Bloomington, IN), which uses a fine wire coil braised to the tip of the stylet and coiled for several centimeters around the stylet, which is compressed and expanded by advancing a thin metal cylinder, which binds the stylet against the inside of the conductor coil. Both work well and usually are effective with all lead conductors, but differences in stiffness, diameter, and roughness of the wire mesh can make one more effective than the other in individual cases. The major difference is that the Cook locking stylet will expand to fit in any conductor coil lumen but locks only at the tip. The Spectranetics LLD-EZ locking stylet may be too small for some rare but very large lumens and locks along the entire length of the conductor. Spectranetics also makes longer (LLD-E) and larger-diameter locking stylets (LLD #2, LLD #3) that are rarely required.

As mentioned earlier, the goals for inserting the locking stylet are to provide a lead extender and to distribute the traction force along the length of the lead, maintaining lead integrity ( Fig. 35-7 ). Although these goals are met, the insulation still has to be secured with a suture. Without withdrawal traction on the insulation, the friction between the inside of the extraction sheath can push on the insulation, “snow-plow,” and tear it more easily, impeding passage of the extraction sheaths and, in some cases, preventing their advancement. Therefore the development of a rail to advance the sheaths over the lead is most effective when traction is applied to all the conductors (cables to shocking coils, electrodes), suture (insulation), and the locking stylet (inner conductor coil).

A more recently introduced tool, the Bulldog Lead Extender ( Fig. 35-8 ), designed for leads that have no conductor coil or when the conductor coil has been damaged, mechanically locks onto the cables to the shocking and pacing electrodes and produces an excellent mechanism for improving the tensile properties of the lead. The Bulldog can also be used to lock on to the cables of the shocking coils in leads with a conductor coil whereby a locking stylet is used in the conductor coil.

A valuable tool, particularly for leads with more poor intrinsic tensile properties of the conductors and insulation, is the One-Tie compression coil ( Fig. 35-9A and B ). This tool is designed to bind together by crimping all the proximal components of the lead to a locking stylet. This is especially helpful when extracting defibrillator leads by keeping the components of the lead (cables, insulation, conductors) from slipping in relationship to each other. It is still useful to be able to tie a suture to the insulation even if the individual cables are not tied back to the locking stylet to prevent too much force focused on the locking stylet. It is possible to exceed the tensile properties of the locking stylet, but it is less likely to break if the force is distributed between the suture and the locking stylet.

Mechanical Sheaths and Basic Extraction Principles

Mechanical Sheaths

The physical principles and manipulation employed with mechanical sheaths are fundamental to all extraction sheaths, including laser and rotational sheaths. Mechanical sheaths consist of telescoping (inner and outer) sheaths made of Teflon, polypropylene, or stainless steel ( Fig. 35-10 ).

These telescoping sheaths are designed to pass over the lead, which acts as a rail, guiding the sheaths through the veins and down to the heart wall. Counterpressure is applied as the sheaths move down the lead from one binding site to another until countertraction is applied at the myocardial electrode interface. The outer sheath also acts as a workstation. As a workstation, it facilitates the free movement of the inner sheath and lead by eliminating binding, and it protects the surrounding vascular structures. The leading edge of the sheaths is beveled. The rotation of the beveled tips facilitates maneuvering past obstructions and through the narrow channels along the tortuous paths surrounding the lead body. This is especially true in the superior veins. For the sheaths to pass down the lead in a true fashion, the lead must be stiff enough to act as a guiderail. The slack is removed from the lead positioning it in the vessel, by pulling on the locking stylet, but also taking care to not transmit more than mild tension to the cardiac muscle. The lead must be stiff enough to resist bending or kinking as the sheaths are passed over it (lead stiffness > sheath stiffness). The telescoping action of the sheaths allows the more supple inner sheath to track over the lead. The larger and stiffer outer sheath is then advanced using the combination of taut lead and inner sheath as the guide rail. The positioning of the lead and the tension on the lead through the locking stylet must be constantly fluoroscopically monitored and adjusted during sheath advancement. This is due to the dynamic advancement force applied to the inner and outer sheaths. In addition, the impact on arterial blood pressure, the movement (dislodgement) of the other leads, the heart rhythm, the temporary pacemaker stability, the cardiac silhouette, and the lung fields need to watched. If there is ever a moment when everything is not under control, the operator must stop, assess, and consider adjustment of the technique.

As described earlier, experience and judgment are required to avoid tearing and avulsing vein and heart wall tissues. Also, if the traction force exceeds the lead's tensile strength, it can cause lead disruption and/or breakage. Insertion of a locking stylet adds some stiffness to the lead and focuses the traction force to a locking site near the electrode. Except for simple cases, in which leads have been implanted for a short duration, a locking stylet should be inserted. Despite these provisions, when there is poor tensile strength of the lead, it is more difficult and more time-consuming to free the lead from its binding site. The forces involved frequently exceed the tensile strength of the lead, unless the there is a good locking stylet and suture, resulting in lead disruption and breakage.

The Evolution Mechanical Dilator Sheath (Cook Vascular) ( Video 35-2 ) comes in three major varieties ( Fig. 35-11 ). The original Evolution Mechanical Dilator Sheath consists of a clockwise rotating inner sheath with a threaded-barrel metal tip designed to function as a dilating drill. This bores through the encapsulating fibrous tissue as it advances down the lead through the binding sites. The outer sheath is a conventional beveled Teflon sheath. The clockwise rotation of the inner sheath is powered by a pistol grip handle squeezed by the operator (mechanical power). The results with this Evolution tool are mixed. Although there is a high procedural and clinical success rate, there is a tendency for the continuous clockwise rotation to bind on the outer insulation of the lead and cause binding if inadequate clearance is provided by the chosen sheath diameter. In addition, it is common for the other leads to wrap around the sheath as the rotation occurs, sometimes causing damage to these leads. The Evolution tools are particularly useful as a rescue when heavy calcifications are encountered. To address the tendency to damage adjacent leads and potentially the venous wall when the tip grabs onto and wraps these structures around the targeted lead, the Evolution RL Controlled-Rotation Dilator Sheath was designed with a less aggressive decagon-shaped tip that dilates instead of screws into the fibrosis and alternates the rotation direction with every squeeze of the handle. This system is less aggressive than the initial Evolution but is still effective for fibrosis and calcified lesions. Shorter versions of both sheaths, called the Evolution Shortie Mechanical Dilator Sheath and Evolution Shortie RL Controlled-Rotation Dilator Sheath, are designed specifically for vessel entry in cases of heavy calcification, particularly under the clavicle.

The TightRail Rotating Dilator Sheath ( Fig. 35-12 ) is a relatively new tool that was introduced by Spectranetics. It consists of a bidirectional rotating cutting mechanism without rotation of the inner or outer sheath. The forward-facing blade remains shielded inside the tip of the sheath until activated by squeezing the handle, which rotates the blade first clockwise and then counterclockwise. There is no published literature on is use. However, preliminary experience suggests that it may be effective in situations with heavy calcification. Lead wrap or collateral lead damage has not been described with the TightRailRotating Dilator Sheath or with the shorter TightRail MiniRotating Dilator Sheath.

Powered Extraction Sheaths

Perfecta Electrosurgical Dissection Sheaths

The Cook Medical Perfecta Electrosurgical Dissection Sheaths (EDS) is a conventional Teflon mechanical sheath with two tungsten electrodes embedded in the polymer ( Fig. 35-13 ). The bipolar electrodes are exposed at the tip of the bevel. The sheath is connected to an interface plate inserted on a conventional electrosurgery unit (Valley Lab Force V; PEMED, Denver, CO), placed in a bipolar cutting configuration, and activated with a foot switch. The interface plate is attached to the front panel of the electrosurgery unit to ensure that the EDS is connected in a bipolar configuration. The interface also has an attachment to pulse the electrosurgery unit 80 times per minute. A plasma arc is generated between the electrodes. The plasma arc extends out from the electrodes and vaporizes the tissue to a depth of about 1 mm. On continuous discharge, desiccated tissue debris shunts the arc between the electrodes, preventing it from cutting. Also, on continuous discharge, if one of the electrodes touches a conductor coil, a parallel alternate current (AC) circuit is created consisting of the EDS electrode in contact with the conductor coil, the conductor coil down to an electrode in the heart, and back to the other EDS electrode. An AC current applied to the heart in a unipolar configuration can fibrillate the heart. To ensure cutting and avoid fibrillating the heart, the EDS is operated in a pulsed mode at 80 pulses/min. In the pulsed mode, if a conductor coil is touched, it paces the heart. Placement of the EDS electrodes in a bipolar configuration at the tip of the inner telescoping sheath endows the EDS sheath with properties of mechanical sheaths: it can maneuver through tortuous veins, and it can be used to apply countertraction and counterpressure. The electrodes and sheath are radiopaque, allowing visualization during fluoroscopy. The electrodes' positions are continuously adjusted by rotation of the sheath. For example, around a curve, the electrodes are placed on the inner curvature passing down the lead. Also, the electrodes are rotated away from skeletal muscle and nerves to avoid stimulation. Stimulation of skeletal muscle and/or the phrenic nerve does not harm the patient and is not an issue for patients under general anesthesia. However, skeletal muscle and diaphragmatic contractions can be discomforting and even frightening if the patient is awake. At present, this is the only clinical issue associated with the EDS. The same emergency precautions applicable to mechanical and laser sheaths also apply to the EDS.

Excimer Laser Sheath

The initial development and use of the excimer laser (SLS I) in 1994 was a milestone for lead extraction ( Fig. 35-14 ). The excimer laser generates a high-energy 308-nm laser beam known to disrupt tissue (both cells and hydrated proteins) by an explosive vaporization of intracellular water. The rapid vaporization helps to cool the site. Unfortunately, the laser does not ablate mineralized tissue. If the laser cannot be maneuvered through this tissue in grinding fashion, counterpressure techniques are used.

The frequency of the pulses delivered by the excimer laser is adjustable. Most recently, the upper frequency limit was increased from 40 Hz to 80 Hz with the transition from the SLS II to the GLIDELIGHT. The repetition rate of the pulses increases the cutting rate of the sheath, reducing the advancement and retraction forces required, and in theory improves the control of the operator during the lead extraction. The laser is controlled by a foot switch. By design, the laser is on for 10 seconds or as long as the foot switch is depressed, and off for 5 seconds. The sound caused by the rapid pulsing of the laser indicates that the laser is on. The laser beam is a light cone that ablates tissue up to a distance of 1 mm. The water vapor generates bubbles that are clearly visible on echocardiography. The cutting action of the laser can disrupt any biologic material such as the superior vena cava (SVC) or the atrial wall if the lead is embedded in the wall. Because there is no way to know when a lead is embedded in the wall, the same emergency precautions apply to the laser as to the mechanical sheaths. The laser sheaths are sized as 12 French (Fr), 14 Fr, and 16 Fr, and employ either Teflon or VISISHEATH outer telescoping sheaths ( Table 35-1 ). The stiffness of the sheaths increase with size, but it is often important to improve the clearance of the sheath over the fibrosis by oversizing the sheath in relationship to the diameter of the lead body.

TABLE 35-1

SLS II and GLIDELIGHT Sheath Sizes and Leads

Labeled Sheath Size in French	12 Fr	14 Fr	16 Fr
Max target lead diameter (Fr)	7.5	9.5	11.5
Inner sheath diameter (Fr)	8.3	10.2	12.5
External sheath diameter (Fr)	12.5	14.7	17.2

Snares

Snares are used to grasp leads and to remove tissue in the bloodstream from the vein or transatrial entry site ( Case Study 35-1 ). The vein entry sites commonly used are the subclavian, internal jugular, and femoral veins. Only a few snares are safe to maneuver in the cardiovascular system or have the tensile strength to support the forces involved in a lead extraction procedure. The Dotter Basket, Needle's Eye Snare (Cook Medical) ( Fig. 35-15 ), Amplatz GooseNeck Snare (ev3/Vasocare, Seoul, Korea) ( Fig. 35-16 ), and EN Snare Endovascular Snare (Merit Medical, Salt Lake City, UT) ( Fig. 35-17 ) are discussed as examples of the types of snares available. The Dotter Basket snare, together with a tip-deflecting guidewire, is prepackaged in the Byrd Workstation Femoral Intravascular Retrieval Set ( Fig. 35-18 ).

Case Study 35-1

Pocket Infection

A 78-year-old male with history of an ischemic cardiomyopathy (left ventricular ejection fraction 15%), complete heart block, and implantable cardioverter-defibrillator (ICD) implantation in August of 1999 had an upgrade of his system to a cardiac resynchronization device in 2007 (CRT-D). He returned in February of 2011 with erythema and swelling at the device site, which was treated with antibiotics. One month later he had a procedure where the pocket was “incised and washed out.” Pocket cultures grew coagulase-negative staphylococci, but blood cultures were negative. When evaluated by a consultant in infectious disease, a recommendation was made for complete device extraction, which was attempted in March of 2011.

The right atrial lead and the coronary sinus leads were removed but the right ventricular ICD lead could not be extracted despite extensive laser use, during which the lead fractured proximal to the superior vena cava (SVC) coil ( Fig. E35-1 ). A temporary pacemaker lead was implanted and the patient was transferred for further therapy.

Given that the cut lead was now intravascular and retracted distal to the first rib, a femoral approach to snaring the lead was employed. A Byrd femoral workstation provided access for a tip-deflecting guidewire to wrap around the lead. The tip was grasped by an Amplatz GooseNeck snare and pulled into the sheath ( Videos 35-6 to 35-10 ).

After 1 week of IV antibiotics, negative blood cultures, and no systemic signs of infection, a new ICD system was implanted from the right prepectoral fossa.

This case illustrates the need to have all required skills and tools for complete lead extraction. The use of a femoral workstation in conjunction with a deflectable wire and GooseNeck Snare is demonstrated.

Before the availability of powered sheaths, lead breakage was more common and the snaring techniques were more commonly used either as the initial approach or as a rescue after lead disruption. The only substitute for a snare after the lead breaks is a cardiac surgical procedure. Consequently, operator facility with snares is still a requisite skill. Also, there are still extractors who do not use powered sheaths, relying only on the mechanical sheath extraction, and snares are integral to these procedures.

Pocket Management

Tissue debridement is the surgical removal of all inflammatory and damaged native tissues, leaving only normal native tissue. 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 fibrous tissue, leaving only thin healthy fibrous tissue (biophysical interface) or normal native tissue behind.

For infected cases, tissue debridement is more extensive, requiring the removal of the entire capsule and any at-risk skin. If an acute inflammatory reaction is extensive, debridement is tedious because of the presence of acute and chronic inflammatory material and/or 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. Whenever possible, muscle fascia should be reapproximated. Dissection of the pocket with the device still in it seems to afford better tissue plane delineation and easier prying of the capsule from adherent tissue.

Tissue Closure

Healing by primary intention is the closing of an open wound by reapproximation of tissue (muscle, subcutaneous tissue, and skin) using suture material. The suture material holds the tissue in place until the tensile strength of the bonding fibrous tissue produced by the inflammatory reaction is sufficient to permanently keep the tissue together. All initial and reimplanted pockets are closed in a conventional fashion by reapproximation of the tissue with suture material and allowed to heal by primary intention. Chronic pockets are debrided of all exuberant inflammatory material before closure. These pockets are debrided and closed using a closed drainage system (Jackson-Pratt) placed in the debrided pocket if necessary, applying suction to prevent the development of effusions or clot, and keeping normal tissue contiguous with normal tissue. A large defect, resulting from loss of tissue during debridement, is sometimes a challenge to close. In extreme cases, a major defect requires an experienced surgeon or a plastic surgeon, especially if a flap is needed. Alternatively, the pocket may be allowed to heal by secondary intention.

Another philosophy is that pockets that have debridement defects or are infected should be left open. This rationale shortens the procedure and is an accepted method of healing. Infection is not an issue, and it avoids the need for acquiring surgical debridement and closure skills. Concerns such as morbidity, extensive healing time, long-term antibiotic therapy, the requirement for constant professional care of the wound, and the possible need for some form of surgical intervention, including skin grafting, are considered the natural cost of healing the wound. Negative pressure or vacuum dressing may aid and accelerate healing time.

Healing by primary intention, on the other hand, does not have these issues. Healing by secondary intention was used a long time ago as the only way to heal an open wound. The healing stages were well documented: suppuration, granulation, closure of defect, and finally, skin closure. This was the recommended method of treating contaminated wounds by surgeons up and until the 1980s. Since the 1970s, however, primary closure of debrided infected pockets has been successfully and almost exclusively used to manage device-related infections.

Once the pocket is debrided and the leads are freed up, lead preparation is next.

Lead Preparation

The strategic importance of lead preparation is substantial with the goal of (1) deactivating the active fixation mechanisms and (2) reinforcing the tensile properties of the lead. The success or failure of the extraction is often determined by the lead preparation. The leads are dissected down to the tie-down sleeves and released. If there is a helical screw active fixation, some operators prefer to use a standard stylet with the connector pin connected to facilitate the rotation of the conductor; however, we prefer to cut the connector off and carefully cut away the outer insulation and outer coils (coaxial, triaxial leads) and inner insulator so that the inner coil can be directly rotated with a small snap or mosquito. Care should be taken to protect the inner coil so that the locking stylet can later be introduced. A standard or clearing stylet should be advanced as far down the lead as possible before attempting counterclockwise rotation of the coil. Most lead conductors will not be damaged, but care should be taken observe for damage to the coil with over rotation. Damage occurs consistently with Fidelis lead conductors with more than 20 turns. To address this, after 20 turns withdraw the stylet and reinsert and try again, up to three times. Even with this lead, the built-up torque on the conductor usually releases the helical screw as the extraction sheaths are advanced over the lead. The locking stylet is then advanced as distally as possible and locked. A strong suture (0 or 1 diameter) is firmly tied to the insulation around the body of the lead and then to the locking stylet so that when retracting the locking stylet the entire lead body is retracted. In case of an implantable cardioverter-defibrillator (ICD) the shocking cables are also tied to the locking stylet, often after they have been tied together first. Some people prefer to keep the sutures to the insulation and cables untied to the locking stylet to be able to adjust their length individually, but we prefer to tie to the locking stylet because it simplifies the management of the lead components. The One-Tie Compression Coil (see Fig. 35-9B ) can be used instead of tying individual components by being placed around the insulation, cables, and locking stylet. In this configuration all the elements of the lead are crimped at the proximal end of the lead. With this it is still useful to tie to the insulation several centimeters more centrally to control for potential snowplowing of the insulation. This is particularly useful with easily deformed silicone insulation leads like the Riata leads. Use of the One-Tie Compression Coil and the suture as described can limit the amount of snowplowing on these leads and limit further damage to the externalized conductors.

Sometimes the conductor is deformed, broken, or clogged or the insulation is damaged. Sometimes the leads have good tensile properties (e.g., Fidelis) and sometimes poor tensile properties (e.g., Fineline). It is the purpose of the lead preparation to optimize the tensile properties to maximize the extraction opportunity. An easy extraction can be made difficult or dangerous with poor lead preparation and an otherwise difficult extraction can be made surprisingly easy with good lead preparation ( Case Study 35-2 ).

Case Study 35-2

Importance of Repository of Skills and Tools

A 67-year-old male without a history of myocardial infarction and a reduced ejection fraction of 35% and complete heart block, hypertension, and diabetes had a dual-chamber implantable cardioverter defibrillator (ICD) implanted for primary prevention in 2006. He is pacemaker-dependent, and there had been a failed attempt to implant a biventricular stimulation system. Prior to his ICD generator change in May of 2013, his Riata lead (Model 1591) was noted to have a large amount of externalized conductor prolapsing into the right ventricular outflow tract. He was scheduled to have the Riata lead and ICD extracted and replaced under general anesthesia. Review of Video 35-11 shows how the smaller of the two loops of externalized cable is pulled out of the lead closing the loop in the preparation of the lead. Full preparation and extraction tools included retraction of the helical screw, locking stylet in the inner coil, tying separate sutures to the cables and to the insulation, and use of a one-tie, 16-Fr SLS II Laser sheath and outer Teflon sheath. Videos 35-12 and 35-13 reveal a large loop of externalized coil. The lead was extracted with the aid of the laser sheath and the outer dilator sheath engulfed the cables and the shocking coil. In such cases, it is important to emphasize the need for proper preparation of the lead and pulling on the prepared lead to permit its use as a rail, providing for true tracking to the lead tip ( Fig. E35-2 ).

Extraction

The goal of lead extraction is more complex than removing the lead. Actually, the goal is NOT to remove the lead but to advance the sheath over the lead to the lead myocardial interface and then apply countertraction to remove the lead. Often the goal is also to maintain access, particularly if there is an occlusion of the proximal vessels (subclavian or SVC), so advancement of the sheaths past the occlusion is critical to achieving this goal. Obviously, the goal is also to avoid complications.

To achieve these goals, once the lead is prepared it is fed through the extraction sheath. The sheath is then “positioned” in the vascular space by gently retracting the lead and observing the impact on fluoroscopy. The point here is to position the lead as a rail for the sheath to be advanced over and to gently pull the lead away from the SVC lateral wall (particularly if the lead comes in from the left subclavian) and to decrease the transmission of this force to the cardiac structures. This positioning should be done just before each attempt to advance the sheath but released in between attempts. By positioning the lead in this way and maintaining this lead position during sheath advancement by further retracting the lead when the sheath pushes in the lead, only the appropriate amount of force is placed on the lead and the sheath is then guided over the lead. The extraction sheath is advanced while keeping enough traction on the lead to ensure that the sheath advances coaxially without kinking or buckling. Once a binding site is encountered, the cutting mechanism of the sheath (laser, EDS, or rotational) is activated while applying counterpressure as discussed earlier. The sheath is advanced in this fashion from one binding site to the other until, finally, the tip of the lead at the myocardial interface is reached. Once the lead tip-myocardium interface is reached, while still applying traction on the lead, the sheath is no longer advanced but held in place and countertraction against the myocardium is used until the tip of the lead is freed without invagination or perforation. Often the lead will retract and be removed before advancement to the heart because there is little fibrosis distally, but the goal should be to try to advance the sheath, not remove the lead. Never advance the sheath without seeing that the sheath is advancing over the lead. Pushing the lead in with the sheath is of no value and can cause damage. If there is venous occlusion and the lead lets go, the lead needs to be snared from the femoral vein (Amplatz GooseNeck snare or En Snare) to provide tension until the extraction sheath is advanced to the right atrium.

Special Consideration When Extracting Riata and Fidelis Leads

The Fidelis (Medtronic) and Riata and Riata ST leads (St. Jude Medical, St. Paul, MN) have been recalled for conductor failure and for cable externalization, respectively. The Fidelis lead malfunction may result in loss of pacing and failure of tachy-therapy. The Riata and Riata ST were recalled due to cable externalization through the silicone insulation. Radiographic screening has shown that the incidence can be up to 30%; however, most continue to function normally. This lead failure can cause loss of sensing or pacing and also failure of defibrillation.

It is beyond the scope of this chapter to discuss the pros and cons of abandonment versus extraction and replacement. However, once the decision has been made for extraction, special considerations must be taken into account especially when extracting the Riata leads.

A report from a multicenter experience of extraction of the Sprint Fidelis lead demonstrated a high success rate with all leads being extracted. The average implant duration was 27.5 months. About 27% were extracted prophylactically. Around 50% were removed with simple traction; the other 50% had longer implant duration and needed powered sheaths, most commonly laser sheath extraction. No major complications related to the extraction procedure were reported. In this study the implant duration was relatively short. Because the Fidelis lead had early demonstrable failure and dramatic clinical presentation with recurrent inappropriate shocks, most extractions were performed after a short dwell time, which may explain the initially favorable outcomes.

The Canadian Heart Rhythm Society presented data on extraction of 248 Fidelis leads and reported two deaths. However, these deaths were not directly related to the extraction procedure. One patient developed pneumonia and another pocket infection and sepsis after reoperation for hematoma.

The Riata and Riata ST leads have a different natural history and approach to extraction. A report from the Cleveland Clinic that compared extraction of the Riata leads (121 leads), the Fidelis leads, (313) and nonrecalled leads (755) found that the removal of these recalled leads was associated with similar procedural and clinical success as procedures for nonrecalled leads. As in other studies, in this study the Riata leads had longer implant duration than the Fidelis leads.

The presence of externalized cables with the Riata leads did not have any effect on the safety or efficacy of extraction; however, the one SVC laceration occurred in a patient with externalized cables, but the laceration was attributed to the extraction of the atrial lead in the same patient. Another single-center experience from Vanderbilt reported on the comparative extraction experience of Fidelis and Riata. In that study larger laser sheath size was required for the Riata leads, but there was no difference in procedural time or success. There were no reported differences in complication rates. A two-center study from Emory and University of Pittsburgh included 360 Fidelis leads and 102 Riata leads. Although the Riata leads had a longer implantation time, the procedural success was similar with both leads: 99.4% versus 97.1%. The risk of major complications was low in both groups: 1.1% in the Fidelis group versus 2.0% in the Riata group.

The largest series from a multicenter experience reported on the extraction of 577 Riata/Riata ST leads. The median implant duration was 42 months. Simple traction removed 17% of the leads, and the use of powered sheaths was needed in 60% of cases. In this series two or more sheaths were needed in about 30% of the cases, the majority of which were for upsizing of sheaths. There were three cases of SVC laceration, one case of RV perforation, and one case of tamponade. Externalization of cables was noted in 35% of leads and was more frequent with longer implant duration. In this paper Maytin et al also discuss the fact that in an earlier experience with extraction of 557 Fidelis leads, there were no major complications. This was mostly related to the shorter implant duration of the Fidelis leads (27.5 months vs. 44.7 months). Other contributing factors may be related to the nonbackfilled coils and externalized cables.

A more recent analysis by Dr. Bongiorni's group studied 134 Riata leads and 61 Sprint fidelis leads extracted between 1997 and 2014 with mechanical tools. Although there was a high procedural success rate (97.8% Riata and 100% for Fidelis), the Riata leads required more effort for extraction, including more frequent need for mechanical dilation and larger sheaths. The Riata leads required longer extraction time, and these procedures were judged to be more complex. Of note, unlike other reports, in this report externalization was associated with a more complex procedure, with more difficult stylet insertion, larger sheaths, and also higher prevalence of adherence to the right atrium (RA) and tricuspid valve. Importantly, there was no difference in the dwell times of the lead types in this report so the difficulties associated with Riata extraction cannot be attributed to implant duration. It is postulated that cable externalization can cause more thrombosis and more intense fibrosis, given contact of the cables with tissue without the protective effects of silicone through which the cables eroded.

In summary, when faced with extraction of the Riata leads family, one has to take into consideration the longer implant time, nonbackfilled coils, and exposed externalized cables, all of which are associated with stronger, more intense adhesions. The exposed cables may further complicate extraction as these can fold on themselves or result in a “snow-plowing” effect of the proximal edge of the broken insulation, thereby increasing the effective diameter of the lead, hence the frequent need for upsizing or using the bigger outer sheath to engulf this section of the lead. Every effort should be made to straighten out the slack of the externalized cables, usually by pulling these and securing them to the rest of the lead proximally using lead extenders and tying with suture or the One-Tie Compression Coil locked to the rest of the lead body.

Extraction Procedure Approaches

Extraction procedure approaches involve transvenous and cardiac surgical extraction techniques. Transvenous approaches are usually performed through the lead implant/entry site, but any other vein suitable for the extraction instruments may be used. Suitable veins include the axillary-subclavian-brachiocephalic, external jugular, internal jugular, and femoral-iliac. Cardiac surgical approaches to intravascular leads are transatrial, right ventriculotomy, and open heart surgery. All epicardial lead extractions are cardiac surgical procedures.

The approach selected depends on the experience, extraction skills, and extraction instruments available to the physician; the reason for the lead extraction; and situations that arise during lead extraction.