DISCUSSION
The major findings of our single-center large-scale cohort study were as
follows; (1) the TLE using either Evolution® or
TightRailTM hand-powered rotational mechanical dilator
sheaths was associated with high efficacy and acceptable complication
rates. Both procedural/clinical success and major/minor complication
rates were also similar between Evolution® or
TightRailTM groups. Additionally, there was no
difference in all-cause mortality rates at long-term follow-up between
each group. The presence of heart failure, baseline coagulopathy and
impaired renal functions were associated with an increased risk of
all-cause mortality.
Among various available TLE tools, hand-powered rotating mechanical
dilator sheaths are preferred by many operators during extraction of
chronically implanted leads with fibrotic adhesions to the vascular
and/or endocardial surfaces 8,9. In our study, the TLE
has been performed in patients with median lead dwell time of five years
by using either first-generation Evolution® or
TightRailTM systems at different time intervals
because of the availability and governmental re-imbursement policy.
Evolution® system has been associated with excellent
clinical and procedural success with low complication rates in previous
studies 9-11. In our study, complete clinical success
and procedural successes were 99.2% and 94.0%, respectively, as in
other studies, complete clinical and procedural success rates have been
mostly >95% 8,11. The clinical and
procedural success rates were 88.0% and 84.2% without using rescue
methods in our study. In previous studies, complete success rate without
using rescue methods and tools was in the range of 69%-94.5%, and
these studies major and minor complication rate was reported as
0%-4.2% and 0%-12%, respectively 4,6,10. In our
Evolution® group, major and minor complication rates
were 3.8% and 10.5%, respectively, with compatible low complication
rates as studies in the literature. The data about the
TightRailTM system is limited in the literature. In a
small observational study, the complete procedural and clinical success
rates without rescue methods were 96% and 100%, respectively5. In a larger retrospective multi-center study,
chronically implanted 147 leads in 100 patients were extracted by using
TightRailTM mechanical dilator sheath; complete
success rate was 91%, and major complication rate was 2%12. In our study, the complete procedural and clinical
success rates were 86.9% and 90.5% using TightRailTMsystem without rescue methods. Complete clinical success was increased
to 98.2% with use of rescue snaring system. Major and minor
complication rates were 1.2% and 8.2%, respectively, in accordance
with studies in the literature.
In the literature, the need for rescue tools during TLE with mechanical
dilator sheaths was highly variable (range of 2.4-27.1%) due to used
technique, extraction tool, patient and lead characteristics7,9,13. In our study, the need for rescue tools was
observed in 11.2% of Evolution® group and 8.2% of
TightRailTM group (p>0.05). Higher lead
dwell time and lead burden were associated with an increased need for
rescue tools and major complication rates 14. TLE
indications of lead dysfunction and infection were also more prevalent
in patients with lead breakage, incomplete lead extraction, and need for
rescue snaring tools 9. In our study, the lead dwell
time, lead burden, leads with passive fixation, and infection parameters
were significantly higher in patients with procedural failure who
required rescue snaring tool.
In our study, major complications were totally observed in 7 patients
(2.3%). Additionally, procedure-related death was seen in 2 patients
(0.66%) which was due to intracranial hemorrhage (n=1) in the
TightRailTM group and haemothorax (n=1) in the
Evolution® group. Besides these deaths, major
complications included cardiac tamponade in one patient at the
TightRailTM group, major vascular lacerations in 3
patients by 0.99% at Evolution® group, a
cerebrovascular accident by 0.33% in Evolution®group. In the ELECTRa registry, procedure-related death was seen in the
range of 0.3-0.8% rates, and our study data is similar to this
registry. In the ELECTRa registry, the cerebrovascular accident was
followed by 0.06%, and vascular laceration was followed by 0.4-0.9%,
and our data was similar to this registry 8. Patients
with cardiac tamponade had both atrial and ventricular PM electrodes
with passive fixation mechanism in which lead dwell time was ten years.
The myocardial avulsion was thought to be during extraction of the
atrial electrode which was successfully repaired surgically. In previous
studies, massive pericardial effusion was reported by 0.25-0.59% which
was 0.33% in our study accordingly. In the ELECTRa registry analysis,
84.5% of major complications were cardiovascular avulsion, and cardiac
avulsion with tamponade is the most common major complication by 61.2%15. In our study, 71% of major complications were
cardiovascular complications, and cardiac avulsion was observed in two
patients by 28.5%. In the ELECTRa registry, the minor complication rate
was reported as 5% (range 4.3-5.7%) which was 9.2% in our study. The
majority of minor complications in our study was pocket hematoma by
60%, but the drainage was only required in 2 (0.6%) of the patients In
previous studies, the rate of hematoma requiring drainage was in the
range of 0.9-1.6% 16,17. In our study, the minor
complication rate was higher than the ELECTRa registry, and because of
mostly hematoma, which didn’t require drainage, this condition did not
cause any clinical problems.
There was no difference between TightRailTM and
Evolution® groups in regard to all-cause mortality at
long-term follow-up in our study. To the best of our knowledge, our
study is unique with its largest sample size of
TightRailTM group in the literature in addition to
long-term mortality outcomes of both device technology. Higher leukocyte
count, lead burden, and lead dwell time were associated with a higher
risk of procedural failure; and presence of heart failure, coagulopathy
and chronic renal disease were associated with a higher risk of
all-cause mortality in our study. In previous studies, it was observed
that the lead burden associated with a 3.5 fold increased risk of any
complication. Moreover, TLE for infection, and high CRP levels were
found to be associated with all-cause mortality 18,19.
In a large-scale study with extracted 5521 leads that evaluated risk
factors of procedural failure, major complications, and all-cause
mortality, low platelet counts and higher INR levels (>1.2)
were associated with major complications and 30-day death20. Furthermore, heart failure and renal dysfunction
increased the 30-day mortality by 1.3-8.5 and 4.8 fold, respectively21,22.
Our study results have important clinical implications. The TLE using
either TightRailTM or Evolution®mechanical dilator sheaths can be performed with an excellent
clinical/procedural success and acceptable complication rates. These
findings suggest that these extraction tools require a learning curve
and should be used by experienced operators with a cardiothoracic
surgery team on standby to cope with any complication.
Our study results should be interpreted with some limitations. First,
the study groups were non-randomized and the data was collected
retrospectively in this cohort study. Second, the impact of learning
curve on outcomes of Evolution® group which was
available at first could not be ignored. Third, data for procedure and
fluoroscopy time were not available for all participants. Fourth, second
generation EvolutionR/L mechanical dilator sheath
couldn’t be used during the study period. At last, the availability of
TLE devices mainly depends on the re-imbursement policy of our National
Social Security System which limits the randomization. Furthermore,
non-rotational dissection tools and laser sheath were not available in
our country.
In conclusion, our results showed that the TLE by using either
TightRailTM or Evolution®hand-powered rotational mechanical dilator sheath systems was highly
effective with acceptable safety results. However, rescue extraction
tools and backup cardiothoracic surgery support should be available on
site. The selection of TLE tool should be based on the operator
preferance/experience, availability and re-imbursement of the devices.
Continued investigation is required to compare safety, success, and
complication rates with other techniques.