Maria Grazia Bongiorni, Ezio Soldati, Giuseppe Arena, Gherardo Gherarducci, Massimo Ratti, Mario Mariani.
Interventional Arrhythmology Unit, Cardiothoracic Department, Cisanello Hospital, Pisa, Italy
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Many different factors and conditions play an important role in
transvenous removal procedures. Some of them can be predicted and evaluated before the procedure, while
others can be exclusively observed during the removal procedures.
All these factors may affect: 1) the feasibility of the removal; 2) the complexity and duration of the procedure; 3)
the outcome of the attempt; 4) the incidence of complications.
The factors making a lead extraction procedure difficult can be distinguished in technical factors and clinical
factors.
The technical factors are related both to the physical characteristics of pacing and defibrillating leads and to
particular conditions due to the damage of the lead during its life.
Fixation mechanism
The pacing leads provided with an active fixation mechanism are reported to be extracted with a higher success
rate than other fixation mechanism9. This condition can be explained by the different adhaerence of the tip to
the myocardial wall, allowing an easier detachment once the screw has been retracted or unscrewed. On the
other hand, the removal of a unscrewed lead has a higher risk of complications than that of a tined lead.
Lead polarity
Bipolar leads usually require more complex and time-consuming procedures. The complexity of a bipolar lead
results in an increased fragility of the lead; the traction can result in the detachment of the inner coil and
insulation from the outer coil, thus leading to a partial removal of the lead.
Lead insulation
In comparison to silicon insulation, the polyuretane, both if it is used as outer insulation of the lead, and if it is
used as insulation between inner and outer coils, shows a higher fragility. As a consequence, the removal of a
polyuretane lead requires more attention and it is longer time consuming. In addition, polyuretane shows a
higher incidence of time-dependent degradation and insulation failure than silicon.
Lead shape and diameter
An isodiametric cylindrical shape of the lead allows an easier retraction of the lead once the tip is detached.
Moreover, the dilation of the adhaerences is facilitated by a uniform diameter. Very thin leads usually require a
more difficult and careful dilation; this is due both to the difference between the lead shape and the size of the
dilator sheath, and to the softness of the lead body.
Defibrillating leads
All the above mentioned features must be considered in presence of ICD leads. In addition, these leads are
provided with large exposed defibrillating coil electrodes; their particular design can lead to very extensive and
tenacious adherences, requiring more complex removal procedures.
Free-floating leads
In presence of free-floating leads the removal procedure is always more complex than in presence of exposed
leads9-10. When no part of the lead can be approached outside the vessels, the first problem is where and how
to grasp the lead. This manoeuvre requires the use of transvenous tools, usually put into action in combination.
Furthermore, the lead must be accessible and one end of the lead must be free or made free. If the use of the
transvenous approach can expose the proximal end of the lead, a standard procedure can be performed.
Otherwise, traction, dilation and countertraction must be performed by the transvenous workstation11; in this
case, traction, dilation and countertraction are usually more difficult or impossible.
Fractured coil
The fracture of the coil can prevent the operator from advancing the locking stylet up to the tip of the lead,
making the internal traction impossible. Traction on the insulation sheath usually produces a fracture of the
insulation, leading to a completely intravascular coil. As abovementioned, the absence of a stylet makes the
lead softer, thus affecting dilation of the adhaerences.
Insulation failure
The damage of the insulation makes the removal procedure more difficult. The adhaerences to the venous wall
are tenacious and extensive and the infiltration of the coil lumen prevents the advancement of the stylet up to
the tip of the lead. Extensive deterioration of the lead insulation can result in a complete adherence of the lead
to the vessels, making both transvenous or surgical removal impossible.
J-retention wire fracture
This condition involve the Telectronics Accufix and Encor leads. The removal procedures of these leads must be
planned case by case depending on the fracture site, the partial migration of a part of wire, the presence of
multiple fractures. Usually these procedures are at high risk of complications because the fractured wire can
perforate the heart or migrate while attempting to remove the lead. In order to remove the J-wire fragment
before extracting the lead, a different approach must be usually performed. The use of intravascular tools, such
as Catchers and Lassos (Osypka GmbH), is usually required; these difficult and risky procedures must be strictly
performed with a cardiosurgical standby.
Lead damage because of previous unsuccessful removal attempts
Unsuccessful removal attempts usually lead to serious damage of the lead. The most frequent damage is the coil
straightening with a consequent irregular reduction of the coil lumen’s size, which makes the use of the stylet
impossible; other possible damages are coil fractures, insulation fracture. These conditions adversely affect the
easiness and safety of the removal procedure.
Not pervious coil lumen
In various conditions, the locking stylet cannot be inserted or advanced inside the lead, because the coil lumen is
not pervious. This fact is observed in presence of a narrow turn of the coil, in presence of various materials inside
the coil or infiltration following an insulation failure. This factor makes the traction by locking stylets impossible.
Dilation and, when necessary, countertraction can be performed using the lead without the stylet, but are more
difficult and less effective, particularly when dilation is required in presence of tenacious binding sites and
narrow bends of the lead’s body.
The clinical factors are related to both the history and the interaction between patients and leads.
Implant duration
One of the most important factors affecting the difficulty, complexity and outcome of the removal procedure is the
implant duration, which directly affects the presence and tightness of the scar tissue. Very often the removal
procedure is easily performed by manual traction of the lead, if the latter had been implanted for less than six
months; the complexity of the procedure usually increases along with the lead implantation time.
Number of leads
In presence of multiple leads, the procedures are more difficult and complex. Multiple leads are often fibrosed
all together. In addition, multiple leads and/or their crossing can lead to venous thrombosis or obstruction,
making dilation and the use of intravascular devices more difficult.
Atrial or ventricular leads
Ventricular leads are usually more difficult to extract than the atrial leads, because of their adherences to the
tricuspid valve and ventricular wall. The risk and the outcome of complications are higher in presence of
ventricular leads.
Calcified scar tissue
The presence of scar tissue is the primary reason for partial or failed removal of a lead; most complications are
related to the dilation of these adherences. Scar tissue is usually present in multiple locations12; the most
frequent sites are the venous entry/subclavian area (66%) and the ventricle (72%). Older leads tend to be more
severely scarred and often calcifications of the scar tissue are present. The presence of calcium around the lead,
often visible at fluoroscopy, makes the extraction procedure nearly impossible.
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