PREDICTORS FOR FEMORAL BAILOUT
In line with previous reports, lead dwell time and number of leads
extracted 8 9 were found as
independent predictors for femoral bailout procedure in univariate
analysis. Femoral approach may be needed for leads with longer dwelling
time for the following reasons: Older leads tend to break during TLE
making extraction from a different site mandatory 11,
and in cases of leads with well-formed adhesions, mechanical support
from inferior approach may be helpful 8. Increased
lead number adds to lead-lead and lead-vascular adhesions and TLE
complexity, promoting the need for femoral support.
The decision whether to extract or abandon non-infected CIED leads
during system upgrade, lead failures or other reasons, remains an
operational decision based on case by case risk-benefit ratio10. Eventually the presence of abandoned leads, adds
to the number of leads in the vasculature and intuitively, abandoned
leads also have longer dwell time and increase crowding within the vein
that may result in occlusion. Increased use of femoral bailout for
abandoned lead extraction has been observed previously12. Recently, Segreti et al reported a high success
rate for abandoned lead extraction using mechanical tools with
relatively limited need to switch to femoral approach. However, the
median dwelling time of the oldest abandoned leads in their cohort was
shorter than ours[108 months(60–168) vs 132 months(84-196)]13, and could account for the difference observed in
our cohort.
Patients in the femoral bailout group were found to be younger. One
might argue that any TLE cohort study may suffer from younger age
selection bias, as a more aggressive approach with possibly complicated
course(often requiring femoral bailout) for non-mandatory TLE
indications is potentially carried out for younger patients10. However, this age-driven selection bias is less
straightforward for TLE performed due to infectious etiologies for which
the operator doesn’t have much leeway in the decision to abandon or
extract a given lead. In accordance, our data shows that a large
majority of our patients were elderly and extracted due to infectious
etiologies and when compared with younger patients who were extracted
due to similar indications the elderly group had less tendency for
femoral bailout.
A partial explanation for femoral switchover tendency of younger
patients, is that younger patients have longer lead dwell time in our
cohort. This can be rationalized as younger patients have increased
chance to have CIED implanted from a very young age due to diverse
etiologies such as idiopathic dilated cardiomyopathy (DCM),
channelopathies and hypertrophic cardiomyopathy (HCM)14. Our analysis reveals that younger age is an
independent risk factors predisposing for a femoral bailout. It is
possible that vascular calcifications and adhesions might be found in
the overall younger patients population, resulting in reduced efficiency
of mechanical and powered tools, eventually predisposing them for the
need of a femoral bailout 15.
Venous occlusion after CIED implantation is quite common with a
prevalence of up to 27% of all implantations 16, and
site of occlusion is the subclavian vein in 60%, for 33% it is the
brachiocephalic vein and for the remaining it is the SVC17 . Venous occlusion by itself is not an indication
for lead extraction, but rather a class 2a indication for patients with
ipsilateral venous occlusion preventing access to the venous circulation
for required placement of an additional lead 10.
Presence of superior venous occlusion has been found to be a risk factor
for major complications of TLE 6, although trials
examining the outcomes of femoral support or bailout in the presence of
superior occluded veins are lacking.
Sub analysis of the ELECTRa study found a correlation between the use of
power sheaths for TLE of leads in occluded veins and vascular tears6. The authors recommended that venography should be
considered preprocedurally for all patients undergoing extraction and
that special precaution should be taken when using powered sheaths in
the presence of occluded veins.
Recognition of the hazards of SVC tear during superior approach and the
link between venous occlusion and the need for femoral support has been
stressed by Isawa et al. 7, reporting a high
prevalence of venous occlusion after routinely performing venography,
and a low threshold for femoral support for patients with occluded
veins, in order to avoid SVC tears. It has been previously suggested
that when occluded veins are encountered during TLE, femoral support
should be considered to stabilize the extracted lead4.
Suspected mechanism linking power sheath use in the presence of vascular
occlusion and resulting vascular tears is not known. We can speculate
that when faced with vascular obstruction in the brachiocephalic-SVC
junction, difficulty might rise to keep the sheath co-axial with the
lead, forcing unwanted contact between the sheath head and the SVC wall
potentially causing vascular tears.
Despite of all mentioned above, Sohal et al. reported high success rates
using laser sheaths for TLE due to occluded veins. However, their site
of occlusion was mainly the subclavian vein, which is less likely to
injure during TLE, in contrast to the brachiocephalic-SVC–high RA area.
Furthermore, their use of intraprocedural venography as part of their
extraction protocol to confirm intravascular position of tools could
have potentially minimized vascular injuries 1819.
Our results add and show that venous occlusion is associated with a
higher complication rate of TLE in the superior approach group, however,
when a femoral bailout approach was used to extract leads from occluded
veins, radiological success was achieved in all cases.