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Figure 1: Timeline of Advances in Lead Extraction thereby locking the insulation and conductor to the extender. The
advent of locking stylets permitted safer and more successful
transvenous lead extraction via the implant vein, stimulating the
development of new techniques and technologies.
‘Powered’ sheaths employ a source of energy to make the dissection
Snare Forceps Limited Excimer
of encapsulating fibrous tissue easier and more efficient, thus enabling
extraction extraction atriotomy laser Evolution
the advancement of the sheath along the lead with reduced traction
and counterpressure forces.
One such powered sheath, the Excimer
1960 1970 1980 1990 2000 2010
Laser System (Spectranetics), a ‘cool’ pulsed ultraviolet laser at a
wavelength of 308nm, was developed between 1993 and 1999.
laser sheath applies circumferential pulses of energy at its distal
Simple/weighted traction Countertraction sheaths
end, dissolving tissue in contact with the tip of the sheath by
photochemical destruction of molecular bonds and photothermal
ablation that vaporizes water and ruptures cells with resultant
fibrous tissue, the myocardium falls away from the sheath, reducing photomechanical creation of kinetic energy.
The sheath is advanced
the risk for myocardial invagination and injury.
over the lead body utilising the standard techniques of counterpressure
and countertraction, and laser energy is delivered when encapsulating
Telescoping sheaths are ‘non-powered’ sheaths made of different fibrous tissue arrests sheath advancement. Tissue in direct contact with
materials with varying properties, including stainless steel, Teflon
, the sheath tip is ablated to a depth of 50µ until the distal electrode is
and polypropylene. Teflon is soft and flexible but is unable to cut reached; countertraction is still necessary to dislocate the lead tip. In
through dense scar tissue, while polypropylene is stiffer and better at comparison with mechanical telescoping sheaths, laser-assisted
disrupting encapsulating scar but must be used with caution to avoid extraction resulted in more frequent complete lead removal and
vascular injury. Stainless steel sheaths are employed only for shortened extraction times without an increase in procedural risk.
disrupting dense and calcified fibrosis as the central venous The introduction of laser extraction changed the landscape of
circulation is entered.
The inner and outer sheath pair is advanced transvenous extraction, providing a highly effective and low-morbidity
along the lead with alternating counterclockwise and clockwise technique with broad applications.
motions with moderate pressure.
The soft inner sheath is used as a
guide; the more rigid outer sheath serves to disrupt and dilate the Shortly after the development of the Excimer Laser System, the
encapsulating fibrous tissue. Sufficient traction is essential to ensure Perfecta
Electrosurgical Dissection Sheath (EDS; Cook Medical)
that the sheaths track the path of the lead and remain within the followed. The EDS consists of an inner polytetrafluoroethylene sheath
confines of the vasculature. Transvenous lead extraction success rates with bipolar tungsten electrodes exposed at the distal tip and an outer
via a superior (i.e. implant vein) approach improved to 71–97% with the sheath for counterpressure and countertraction. Radiofrequency energy
addition of this new extraction technique.
is delivered between the bipoles to dissect through fibrous binding
sites, much like a surgical cautery tool, although the lead tip must be
Locking Stylets liberated with countertraction.
In contrast to the Excimer Laser
The ability to successfully extract a lead with traction is directly Sheath, the EDS permits a localized application of radiofrequency
dependent on the lead construction and its tensile strength.
Locking energy with linear rather than circumferential dissection of the
stylets were developed in 1990 to reinforce the lead, transmit the encapsulating fibrous tissue. The focused and steerable dissection plane
extraction force to the tip of the lead, reduce the risk for lead offers the potential advantages of improved precision and diminished
disruption, and increase the likelihood of complete lead removal.
risk. The introduction of the EDS offered a cost-effective alternative to
Since 1990, a number of types of locking stylet have been designed. the Excimer Laser System without compromising safety or efficacy.
While the original locking stylets had to be sized to the lead lumen, the
most commonly utilized locking stylets today are designed to Despite the improved success of lead extraction with powered sheath
accommodate a range of lead lumen diameters. The Liberator
(Cook technologies, disruption of calcified binding sites remained difficult with
Medical) and Lead Locking Device (LLD
) EZ (Spectranetics) stylets offer both systems. The most recent addition to the armamentarium of lead
similar support but differ in their locking mechanism design. The extraction tools provides a solution. The Evolution
locking mechanism of the Liberator is at the distal tip of the stylet, Shortie Mechanical Dilator Sheaths (Cook Medical) are ‘hand-powered’
providing focal traction at the tip of the lead, whereas the LLD EZ stylet mechanical sheaths that consist of a flexible, braided stainless steel
grabs the lead in multiple areas and exerts force along the length of the sheath with a stainless steel spiral-cut dissection tip. The sheath is
Applying sufficient traction to leads that could not receive a attached to a trigger activation handle that rotates the sheath and
locking stylet, due to either extensive damage or a solid core design, allows the threaded metal end to bore through calcified and dense
had proved challenging until the introduction of the Bulldog™ Lead adhesions.
This technology has provided an effective alternative for
Extender (Cook Medical) in 1997. The device consists of a wire with a dealing with the challenges of densely scarred venous entry sites and
threadable handle through which the lead is passed and secured, heavily calcified adhesions.
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