Title: Making the Cut for Generator Replacements
Authors: Venkatesh Ravi, MD1; Jeremiah Wasserlauf, MD,
MS1;
1: Section of electrophysiology, Division of Cardiology, Department of
Medicine, Rush University Medical Center, Chicago, USA
Corresponding author:
Jeremiah Wasserlauf, MD, MS
Assistant Professor of Medicine,
Cardiac Electrophysiology, Department of Internal Medicine/Division of
Cardiology,
Rush University Medical Center.
1717 W. Congress Parkway, Suite 345, Chicago, IL 60612
Email: Jeremiah_wasserlauf@rush.edu
Funding: None
Disclosure: Dr. Jeremiah Wasserlauf has received consulting fees from
Stryker. No other conflicts of interest to disclose.
Editorial
Cardiac implantable electronic devices (CIED) have become a common
treatment modality for cardiac arrhythmia with over 300,000 new implants
every year in the United States. A growing number of patients will
require device replacement procedures throughout their
lifetime.1 In a registry of 1744 patients undergoing
CIED replacement procedures, lead damage or dislodgement requiring
revision was found to occur in 1% of patients without previously
planned addition of leads.2 The resulting lead
addition and extraction procedures give rise to added procedural time,
risk of complications, prolonged hospitalization, and increased health
care costs.2 Polyurethane and copolymer insulation
materials are more susceptible to thermal damage when compared to
silicone.3,4 Avoidance of lead damage during CIED
replacement procedures has been a topic of increasing investigation,
with studies evaluating differences between electrosurgical modes, power
settings, blade orientation, and equipment manufacturers. Operators have
the option to choose between standard electrocautery with non-insulated
blades, and cautery with insulated blades (PEAK PlasmaBlade, Medtronic
Inc., Minneapolis, MN, or Photonblade, Stryker, Kalamazoo, MI).
Electrocautery operates by generating a high current density which
results in resistive heating and thereby cuts or coagulates tissue.
PlasmaBlade uses a proprietary power output waveform to deliver energy
along the exposed edge of a thin, insulated electrode powered by a
proprietary electrosurgical generator. Photonblade is an alternative
insulated electrocautery blade that is compatible with a standard
electrosurgical generator. In a retrospective study by Kypta et al,
PlasmaBlade was associated with a lesser risk of lead damage and shorter
procedure duration and hospital stay when compared with electrocautery
and scissors.3 In an ex vivo animal tissue model using
Photonblade, coagulation mode during cautery was associated with more
damage than cut, and this effect was greatest when contact occurred
using the active edge as opposed to the insulated flat side of the
cautery blade, and when the lead insulation consisted of polyurethane or
copolymer. Visible lead damage was found to be more common with
PlasmaBlade when compared to Photonblade. 4
In this edition of the Journal of Cardiovascular
Electrophysiology , Ananwattanasuk et al performed a retrospective
analysis of traditional electrocautery vs PlasmaBlade on lead parameters
and complications following CIED generator replacement
procedures.5 The study included 410 consecutive
patients (840 leads) who underwent CIED replacement using conventional
electrocautery (EC group) and 410 patients (824 leads) who underwent
CIED replacement using PlasmaBlade (PK group). The power settings for
the PK group were 6 in CUT mode and 8 in COAG mode. In the EC group,
power output was set to 40 Watts for both CUT and COAG mode. CUT mode
was used for tissue dissection and COAG was only used for hemostasis.
The two groups had similar device systems and baseline characteristics.
In comparison to the PK group, the EC group had a slightly lower
proportion of silicone leads (78% vs 83%, p < 0.01) and a
slightly higher proportion of polyurethane leads (19% vs 13%, p
< 0.01). The study found no statistically significant
difference in lead damage requiring lead revision between the EC group
and PK group (0.6% vs 0.4%, p=0.5). There was no difference in
procedural complications between the two groups (2.2% vs 1.2%, p =
0.28). There was no difference in lead sensing. There was a higher
number of patients with a decrease in lead impedance in the PK group
compared to the EC group (61.5% vs 52.1%, p < 0.01), and
perhaps unexpectedly, more patients with an increase in lead impedance
in the EC group compared to the PK group (46.8% vs 34.2%,
p<0.01).
On average, the change in pacing impedance changed less than 10% in
both groups. A majority of leads in both groups were comprised of
silicone which may have been a primary contributor to the low rate of
lead damage observed. These findings contrast with the older
retrospective study that found a lower risk of lead damage with
PlasmaBlade compared to a historical control group where titanium
scissors were used with conventional electrocautery for hemostasis. The
difference observed in the prior study between groups, and the overall
higher rates of lead damage in that study may have been related to the
use of scissors or perhaps a greater proportion of leads with
non-silicone insulation (lead insulation material was not reported). The
present study by Ananwattanasuk et al contributes to the literature with
a larger cohort of patients and contemporary operative technique.
It is never too late to scrutinize the benefit of tools that have added
costs as our procedural techniques evolve. The authors should be
commended for rigorously collecting not only clinical outcomes but also
electrical device parameters to assess for subclinical lead damage.
Although generator replacements are short and less complex when compared
to other EP procedures, the total cost of generator replacement
procedures is estimated at several billion dollars yearly in the US
alone.6 Leadless pacemakers and the evolution of
modular systems are attractive and may solve some problems related to
lead damage during generator replacements, or perhaps one day eliminate
generator replacements altogether. However, with the current number of
CIEDs in operation and the aging population, a growing number of
patients will continue to require generator replacement procedures over
the next several decades. The overall safety of generator replacement
procedures has improved though advances such as avoidance of routine
capsulectomy, antibiotic-impregnated pouches for appropriate candidates,
and prolonged replacement intervals due to improved battery longevity.
Through an unremitting focus on safety and cost-effectiveness, we will
stay on the cutting edge of straightforward and complex procedures in
the EP lab.
References
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burden for pacemakers and implantable cardioverter-defibrillators in the
United States 1993 to 2008. J Am Coll Cardiol. 2011;58:1001-1006.
2. Poole JE, Gleva MJ, Mela T, et al. Complication rates associated with
pacemaker or implantable cardioverter-defibrillator generator
replacements and upgrade procedures: results from the REPLACE registry.Circulation. 2010;122:1553-1561.
3. Kypta A, Blessberger H, Saleh K, et al. An electrical plasma surgery
tool for device replacement–retrospective evaluation of complications
and economic evaluation of costs and resource use. Pacing Clin
Electrophysiol. 2015;38:28-34.
4. Wasserlauf J, Esheim T, Jarett NM, et al. Avoiding damage to
transvenous leads-A comparison of electrocautery techniques and two
insulated electrocautery blades. Pacing Clin Electrophysiol.2018;41:1593-1599.
5. Ananwattanasuk T, Jame S, Bogun F, et al. Journal of Cardiovascular
Electrophysiology. 2021.
6. Hauser RG. The growing mismatch between patient longevity and the
service life of implantable cardioverter-defibrillators. J Am Coll
Cardiol. 2005;45:2022-2025.