DISCUSSION
The significant 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 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 was 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 the extraction of
chronically implanted leads with fibrotic adhesions to the vascular and
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 reimbursement 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 using
TightRailTM mechanical dilator sheath; complete
success rate was 91%, and the major complication rate was 2%12. In our study, the complete procedural and clinical
success rates were 86.9% and 90.5% using the
TightRailTM system without rescue methods. Complete
clinical success was increased to 98.2% with the use of a rescue
snaring system. Major and minor complication rates were 1.2% and 8.2%,
respectively, per 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 the
used technique, extraction tool, patient, and lead characteristics7,9,13. In our study, the need for rescue tools was
observed in 11.2% of the Evolution® group and 8.2%
of the TightRailTM group (p>0.05). Higher
lead dwell time, and the lead burden was associated with an increased
need for rescue tools and major complication rates 14.
Involved leads in the lead fracture or infection categories were also
more prevalent than other categories of TLE indications in patients with
lead breakage, incomplete lead extraction, and need for rescue snaring
tools 9. As in line with previous studies, the lead
dwell time, lead burden, leads with passive fixation, and infection
parameters were significantly higher in patients with procedural failure
who required a rescue snaring tool in our study.
In our study, major complications were 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 in the
TightRailTM group, major vascular lacerations in 3
patients by 0.99% in the 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 and
vascular laceration were followed by 0.06% and 0.4-0.9%, respectively,
and our data was similar to this registry 8. Patients
with cardiac tamponade had both atrial and ventricular PM electrodes
with a passive fixation mechanism in which lead dwell time was ten
years. We thought that the lead dwell time of ten years was likely the
relevant clinical factor for such a critical life-threatening
complication. The myocardial avulsion was thought to be during the
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 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. However, most of these cases were
pocket hematoma requiring no drainage which did not cause any clinical
problems.
There was no difference between TightRailTM and
Evolution® groups regarding the all-cause mortality
rate at long-term follow-up in our study. If the
TightRailTM group was followed for the same duration
as the Evolution® group, it is likely higher all-cause
mortality would be seen in the TightRailTM population.
Moreover, there was a significant separation of the survival curves of
both groups with the log-rank test, which was thought to be due to a
sicker population with more hypertension, diabetes mellitus, CAD, HFrEF,
NYHA class II-IV, and lower LVEF of TightRailTM group
compared to Evolution® group. To the best of our
knowledge, our study is unique, with its largest sample size of the
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 was 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 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 were collected
retrospectively in this cohort study. Second, the impact of the learning
curve on the outcomes of the Evolution® group, which
was available at first, could not be ignored. Third, data for procedure
and fluoroscopy time as markers of the case complexity were not
available for all participants. Fourth, second-generation
EvolutionR/L mechanical dilator sheath could not be
used during the study period. At last, the availability of TLE devices
mainly depends on the reimbursement policy of our National Social
Security System, which limits the randomization. Thus, the study
compared two non-contemporaneous periods where the different devices
were available rather than a direct comparison. 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 the TLE tool should be based on the operator
preference/experience, availability, and reimbursement of the devices.
Continued investigation is required to compare safety, success, and
complication rates with other techniques.