Transvenous Lead Extraction

The implantation rate of devices such as pacemakers (PMs) and implantable cardioverter–defibrillators (ICDs), with or without cardiac resynchronization therapy (CRT) options, has significantly increased over the last few decades,1-3 leading to a rising number of failed leads, device-related infections, and lead or device recalls. Consequently, the need for PM and/or ICD lead extractions is increasing.4 Recently introduced PM leads can typically be removed by direct traction. However, chronically implanted leads become encapsulated by fibrotic attachments.5-8 Adhesions not only occur Received: September 25, 2017 Accepted: September 29, 2017 Correspondence: Boyoung Joung, MD, PhD Professor of Medicine, Yonsei Cardiovascular Hospital, Yonsei University College of Medicine 50 Yonseino, Seodaemun-gu, Seoul, 03722, Republic of Korea Tel: +82-2-2228-8460 Fax: +82-2-2227-7732 E-mail: cby6908@yuhs.ac


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Transvenous Lead Extraction at the lead tip but also are commonly found along any length of lead where a contact between the lead and vein, valve, or endocardial structures such as the superior vena cava exists. [5][6][7][8][9][10] Over the last 20 years, specific tools and techniques for transvenous lead extraction have been developed to assist in freeing the lead body from the adhesions as well as the lead tip from the myocardium, to prevent laceration of the myocardium and to provide enough room for the lead to be withdrawn while preventing its disintegration. Specialized tools include locking stylets, telescoping sheaths with or without additional cutting capability (e.g., metal composition, excimer laser, and radiofrequency current), snares, grasping devices, or other devices used to engage or entrap and remove lead fragments. The current review aims to provide an overview of lead extraction, including the success and complication rates of different extraction methods currently available.

Definition of lead and system extraction
Within the general category of "lead removal, " distinctions must be made between simple procedures that can be performed via the implant vein without specialized tools ("lead explant") and removal of leads involving more complex procedures ("lead extraction"). 11 The definitions are as follows: Lead removal: Removal of a pacing or defibrillator lead using any technique Lead explant: Lead removal using simple traction techniques (no locking stylet, telescoping sheaths, or femoral extraction tools) Lead extraction: Removal of a lead that has been implanted for more than 1 year, removal of a lead, regardless of the duration of implant, that requires the assistance of specialized equipment that is not included as part of the typical implant package, and/or removal of a lead through a route other than via the implant vein ICD leads may require specialized extraction equipment even when the duration of implantation is less than 1 year.  Figure 1. 12

Simple traction
The first attempt to extract a transvenous PM or ICD lead usually involves simple traction. Simple traction has been performed for almost 40 years and is the most basic technique for lead removal. It can be combined with graded traction and/or rotational forces. This technique of applying traction to the lead in combination with the use of tools typically supplied for lead implantation (non-locking stylets, fixation screw retraction clips) is particularly successful in leads with recently implanted leads. 13 The success rate of TLE by simple traction was observed in

Non-powered traction tools
Over time, leads become adherent to either the myocardium or vascular walls in varying degrees owing to encapsulating fibrotic tissue at the contact sites. Thus, during application of traction to chronically implanted leads, force is distributed over all fibrotic binding sites and weakened at the distal end of the lead. Non-powered tools are developed to direct the force of traction to the length or at the distal end of the lead (locking stylets) or to disrupt and dilate the encapsulating fibrotic tissue (mechanical dilator sheaths).

Locking stylets
This technique uses a special traction device to minimize lead disintegration. A locking stylet is introduced into the central lumen of the lead where it can be locked into the coil close to the  Table 1. Indications for lead extraction Class I 1. Sepsis (including endocarditis) as a result of documented infection of any intravascular part of the pacing system or of a pacemaker pocket infection when the intravascular portion of the lead system cannot be aseptically separated from the pocket.
2. Life-threatening arrhythmias secondary to a retained lead fragment.
3. Retained lead, lead fragment, or extraction hardware that poses an immediate or imminent physical threat to the patient. 4. Clinically significant thromboembolic event caused by a retained lead or lead fragment.

5.
Obliteration of occlusion of all useable veins, with the need to implant a new transvenous pacing system. 6. Lead interferes with the operation of another implanted device (e.g., pacemaker or defibrillator).

Class II
1. Localized pocket infection, erosion, or chronic draining sinus that does not involve the transvenous portion of the lead system, when the lead can be cut through a clear incision that is totally separate from the infected area.
2. Occult infection for which no source can be found and for which the pacing system is suspected.
3. Chronic pain at the pocket or lead insertion site that causes significant discomfort for the patient, is not manageable by medical or surgical technique without lead removal, and for which no acceptable alternative is available. 4. Lead that, due to its design or its failure, may pose a threat to the patient, although the threat is not immediate or imminent if the lead is left in place. 5. Lead that interferes with treatment of a malignancy. 6. Traumatic injury to the entry site of the lead for which the lead may interfere with reconstruction of the site.
7. Leads preventing access to the venous circulation for newly required implantable devices. 8. Nonfunctional leads in a young patient.

Mechanical dilator sheaths
A common third step in the stepwise approach of lead extraction is the use of a mechanical dilator sheath. A telescoping sheath, available in different materials (i.e., polypropylene, Teflon , or stainless steel), is advanced along the lead to disrupt and dilate the encapsulating fibrotic attachments. A locking stylet is still required to enable countertraction as the sheath is advanced.
On reaching the distal electrode, the larger bore outer sheath is positioned and held against the myocardium to prevent its inversion during traction on the locking stylet. The force is, therefore, applied at the adherent scar without gross displacement of the myocardium ( Figure 2B).

Femoral and transjugular extraction techniques
A transfemoral approach is helpful when access or extraction via the implanting vein is impossible or when the leads are fractured or cut. The Needle's Eye Snare is the most frequently used tool for lead extractions via the transfemoral approach. Usually, the use of femoral snare is the last step in TLE ( Figure 2D). Bracke et al. 17 reported the results of the transfemoral approach in a large cohort of patients, and the mean dwell time of the leads was 7.6 years.
After simple traction had failed, 98% of the remaining leads were successfully extracted using the Needle's Eye Snare. No procedurerelated deaths were observed, major complications were observed in 0.6% of the patients (two patients with cardiac avulsion requiring surgical intervention), and no minor complications occurred.
The transjugular approach enables the removal of previously cut leads that have retracted into the central venous circulation and/or have been damaged during an extraction performed via a superior approach. In a large single-center study by Bongiorni et al., 18 the TLE approach using simple traction, dilator sheaths, and/or a femoral snare was successful in 89% of the leads.
However, extraction of the remaining leads was attempted via a transjugular approach, resulting in a total success rate of 99%.
Consecutive steps of the internal transjugular approach are presented in Figure 3. 18

Powered traction tools
Non-po wered sheaths use blunt dissection, while powered extraction sheaths use an energy source to disrupt adhesions between the lead and the endothelial or endocardial wall.

Electrosurgical dissection sheath
The electrosurgical dissection sheath utilizes radiofrequency energy, similar to the cautery tool used in surgery, to cut through fibrous tissue. Two electrodes are exposed at the tip of the sheath, which allows linear dissection of adhesions comparable to a cautery tool. As opposed to the laser sheath, the electrosurgical dissection sheath permits localized application of energy instead Transvenous Lead Extraction

Rotating threaded tip sheaths
The most recent addition to the equipment for the lead extractionist is a "hand-powered" rotating threaded tip sheath.
This sheath is attached to a handle that controls the rotation of a threaded screw mechanism at the tip of the sheath, causing it to bore through adhesions around the lead. The Evolution and Spectranetics TightRail rotating dilator sheaths are currently the only rotating threaded tip sheaths available, and they have been advocated as especially advantageous in disrupting calcified fibrosis ( Figure 4B and 4C). 19 The Evolution tool showed an overall success rate of 88%, with an average lead age of 7.1 years.
Major complications occurred in 0.7-1.5% of the patients, with vascular tear requiring surgery. 20, 21

Extraction of ICD and coronary sinus leads
The literature evidence supporting safe and successful extraction of standard pacemaker leads is extensive. 10,22 However, the use of nonstandard leads such as ICD or coronary sinus (CS) leads can pose some challenges, although the same tools and techniques may be used.

ICD leads
The shock coils of high-voltage ICD leads allow fibrous ingrowth, resulting in dense vascular and myocardial adhesions. 23 Therefore

Coronary sinus lead extraction
Limited experience regarding CS lead extraction has been reported, but initial reports 24,25 suggest that the vast majority of these leads can be safely removed. Simple traction of the lead is often successful; however, concerns exist regarding the perforation of the tortuous and fragile CS and complications in the often frail CRT recipients.

Complications of lead extraction
Most complications can be defined and/or classified according to the level of their severity (Table 2)