Femoral Lead Extraction: An Underappreciated and Underutilized Approach to Lead Removal

DOI: 10.19102/icrm.2012.030304

¹AVI FISCHER, MD, ²VICTOR PRETORIUS, MBchB and ²ULRIKA BIRGERSDOTTER-GREEN, MD

¹Mount Sinai School of Medicine, New York, NY
²University of California San Diego, San Diego, CA

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KEYWORDS. cardiac implantable electronic devices, femoral extraction, fluoroscopy.

The authors report no conflicts of interest for the published content.
Manuscript received January 12, 2012, final version accepted January 23, 2012.
Address correspondence to: Avi Fischer, MD, Mount Sinai Medical Center, One Gustave L. Levy Place, Box 1054, New York, NY 10029. E-mail: avi.fischer@mssm.edu

Introduction

Transvenous lead extraction is a critical component in the care of patients with cardiac implantable electronic devices (CIEDs). As a result of the alarming increase in cardiac rhythm device infection and greater recognition of lead failures, particularly of defibrillator leads, the need to extract chronically implanted endocardial leads has grown. The role of transvenous lead extraction techniques in managing all lead-related problems, along with the number of physicians interested in performing extraction procedures, has grown substantially. Paramount in the management of patients requiring lead extraction is an understanding of the pathophysiologic mechanisms of lead binding within the cardiovascular system. The safety and efficacy of transvenous lead extraction, the techniques employed for lead extraction, and the experience of the extracting physician vary widely.¹ This review will discuss the role of femoral lead extraction focusing on a “hands-on” approach describing fundamental concepts related to femoral extraction techniques and tools.

Historical perspective

Many of the tools and techniques utilized in femoral extraction have evolved from procedures employed to retrieve wires, catheters, and other foreign bodies from the central circulation. Femoral lead extraction is arguably the most versatile approach for lead removal allowing for the use of numerous techniques and tools, often simultaneously. However, it is now generally considered a secondary approach for lead removal most often used only after a failure of the primary approach via the implant vein. It remains the procedure of choice for removal of cut leads or lead fragments with free ends free-floating in the venous system, heart, or pulmonary arteries. Today, a number of tools and techniques have been developed for extracting leads via the femoral vein. As lead extraction continues to take a more central role in the management of cardiac rhythm device patients, the interest in femoral extraction techniques and the utility of this approach have been renewed. Although data suggest that the safety and efficacy of femoral extraction are equivalent to other approaches, the femoral approach often results in more fluoroscopy time and longer procedures.²

Basic considerations

The necessity to approach leads via the femoral vein is most often to remove leads that have been purposefully cut or lead fragments that have been abandoned during a previous attempt at removal. Regardless of the reason, virtually all femoral extractions use some form of snaring technique and all femoral extractions employ one of two fundamental snaring techniques. The first involves tools that are used to snare “free ends” of a lead or free-floating lead fragments that contain a free end in the cardiovascular system and that is not reachable through the access site. The second involves creating a loop around a lead when there is no “free end” available and then mobilizing the lead for extraction. Following these snaring techniques, the lead can then be removed using a variety of tools. Actual lead removal via the femoral approach therefore takes place as a two-step process. In the two-step process, a free end is made available for snaring by first pulling either the proximal or distal end of the lead into the inferior vena cava. In the second step, the free end is then used to place traction on the lead for its ultimate removal.

As the indications for cardiac rhythm device therapy expand, more patients are undergoing device revision and upgrade. As a result, more venous occlusions are being recognized, and lead extraction, including the use of femoral techniques, is now recognized as a safe and effective method to maintain venous access.^3,4

Venous occlusion can be addressed by performing extraction of a lead while maintaining access using the extraction sheath. During such an extraction attempt, the lead might actually come free from its location and pull out of the occluded vein before the sheath can be advanced into the patent central venous system. Either prophylactically or once it is recognized that the lead has coming loose, femoral snaring of the lead can be used as support while the extraction sheath is maneuvered through the occlusion into the patent central venous system (Figure 1).

Differences in lead preparation

As opposed to extraction via the superior approach where the proximal portion of the lead is available for the helix to be retracted and for the lead to be prepared with locking stylets, often with femoral lead extraction, there is no proximal portion of the lead to prepare. An important preparatory step for cut leads is to free any lead portion attached via anchoring sleeves or suture material inside the device pocket. Additionally, cut leads may be dissected free from surrounding fibrous tissue in the pocket to facilitate removal via traction from the femoral approach. When utilized as a secondary approach once extraction via the implant vein has failed, a locking stylet is already present and may help “stiffen” the lead for subsequent removal.

Tools utilized for femoral extraction

Similar to other extraction procedures, femoral extractions are performed under general anesthesia, with the chest and abdomen prepared for emergency sternotomy or laparotomy and femoral arterial and venous access obtained for hemodynamic monitoring and access to the central circulation. An invaluable device employed for femoral extraction is the Byrd Femoral Work Station (Cook Vascular Inc., (Vandergrift, PA)) (Figure 2), which is the most commonly used tool for extraction using the femoral approach. The work station sheath is inserted almost exclusively via the right femoral vein. The sheath acts as a countertraction device and provides a conduit for delivering additional extraction tools. The work station consists of a set of instruments including an 18-gauge needle, a guidewire, a 16-French sheath work station, an 11-French tapered dilator, an 11-French telescoping sheath and either a deflecting wire/Dotter basket or a Needle-eye snare The sheath is advanced to the lower right atrium or inferior vena cava and then additional tools and techniques can be used through the work station. A side-port is present on the 16-French work station and can be used to provide continuous irrigation to prevent thrombus formation.

There are numerous snares, guiding catheters, guidewires, and tools that can be placed individually or in tandem through the femoral work station Depending on the particular situation and clinical need, a particular approach may be preferentially used. Familiarity with a variety of snares, guidewires, and tools allows for more flexibility and options for the operator. Generally, when a free end of the lead is available (either the electrode tip or a proximal portion), a gooseneck snare (Figure 3) or other grasping tool can be used to grasp the free end of the lead. Often the addition of a guide catheter is used to improve the three-dimensional orientation of the lead tip when viewed fluoroscopically. When no free end is available, a Needle’s Eye Snare (Cook Vascular Inc, Vandergrift PA) (Figure 4), deflectable guidewire or even a deflectable catheter (such as an ablation catheter) can be used to make a free end of lead available for removal.

The role of any of the grasping tools used is to capture and stabilize the lead. If a deflecting wire is used, the wire should encircle the lead around its body and then entrap the lead either by using a basket, snare, or other device which can be closed over the guidewire.

When a Needle-eye snare is used, the larger, needle-eye portion of the device is used to capture the lead and the “tongue” or threader mechanism secures the snare around the lead body. Once secured, the inner 11-French telescoping sheath which has immobilized the lead is pulled into the outer 16-French introducer sheath either by withdrawing the inner sheath and/or advancing the outer sheath. A similar sequence of maneuvers can be used if a gooseneck snare, bioptome, or other device is employed through the inner 11-French telescoping sheath (Figure 5a,b).

Although laser extraction sheaths have become widely used tools for superior extractions, they have limited application in femoral extractions. This is largely because during femoral extractions there is most often no extravascular component of the lead available to pass a laser sheath over while maintaining countertraction with a locking stylet. Although reports of femoral extractions using laser sheaths have been made, there has not been a trial or approval for this use. An additional point to consider is that the standard length of the laser sheaths might be inadequate for lysis of intracardiac adhesions via a femoral extraction.

Extracting the lead through the transfemoral approach

Once the lead has been grasped and pulled into the inferior vena cava (IVC) (usually within the work station’s outer sheath), binding sites have usually freed from their interaction with the lead(s). When utilizing this approach, the lead(s) slide inside the binding sites allowing for the entire lead to then be removed using traction. It is rare for leads to be so adherent as to prohibit complete extraction from the superior veins using this approach. It is important to consider that when performing femoral lead extraction, locking stylets are not often used and thus lead “unraveling” may occur with placement of traction on the lead. Particular challenges occur when attempting to navigate a sheath or portion of the work station beyond the tricuspid valve. The sharp turn across the tricuspid valve along with the stiffness of the extraction sheath add to the challenge of removing leads using this approach (Figure 6).

Once a lead has been successfully removed from within the heart and vascular system it can then be externalized through the work station which then acts as the conduit should additional leads and/or fragments require removal.

Limitations of femoral extraction

There are important considerations with regards to the ability to perform lead extraction using the femoral approach. As lead removal using the femoral approach involves use of snares and tools manipulated in a three-dimensional space, the procedure may be highly challenging as well as time-consuming. There is often an increase in overall procedure time and in particular fluoroscopy time.² This translates into more radiation exposure not just for the patient, but for the operator as well. Appropriate protection against radiation exposure is mandatory for all staff involved in the procedure. Additional limitations include the inability to use locking stylets causing lead unraveling, the extreme angle required to manipulate a sheath across the tricuspid valve into the right ventricle from the inferior approach and the need for the use of traction alone in removal of the lead or lead fragments. An important consideration is that femoral extraction should not be attempted through an IVC filter as the limbs of the filter can perforate the wall of the IVC if traction is applied (Figure 7).

Conclusion

There has been significant growth in the number of cardiac rhythm devices and endocardial leads implanted worldwide. There has been an associated increase in the role of lead extraction with a recent resurgence of interest in femoral extraction techniques. While often challenging, femoral extraction techniques are safe and effective for retrieval and removal of leads and lead fragments. Knowledge and familiarity of femoral extraction tools and techniques should be considered mandatory for anyone formally extracting pacemaker and defibrillator leads.

References

1. Wilkoff BL. Transvenous Lead Extraction: Heart Rhythm Society Expert Consensus on Facilities, Training, Indications, and Patient Management. Heart Rhythm 2009; 6:1085–1104. [CrossRef] [PubMed]
2. Bordachar P. Extraction of old pacemaker or cardioverter-defibrillator leads by laser sheath versus femoral approach. Circ Arrhythmia Electrophysiol 2010; 3:319–323. [CrossRef] [PubMed]
3. Fischer A. Transfemoral snaring and stabilization of pacemaker and defibrillator leads to maintain vascular access during lead extraction. Pacing Clin Electrophysiol 2009; 32:336–9. [CrossRef] [PubMed]
4. Gula LJ. Central venous occlusion is not an obstacle to device upgrade with the assistance of laser extraction. Pacing Clin Electrophysiol 2005; 28:661–666. [CrossRef] [PubMed]