Discussion
Our study demonstrates the feasibility, efficacy, and safety of CHG
scrubbing of the generator pocket while avoiding complete capsulectomy
in the management of CIED infections. The main findings of our study
are:
- Total capsulectomy is associated with a significant (13%) risk of
hematoma formation.
- No significant adverse reactions were observed associated with CHG
scrubbing.
- Avoiding capsulectomy when performing CHG irrigation is not associated
with a higher risk of reinfection, even in patients undergoing early
device implant (i.e., within the first week of extracting the infected
CIED) or in patients undergoing extraction for pocket infection.
- Capsulectomy is associated with significantly longer procedural times
than a more straightforward strategy involving CHG scrubbing.
Current rates of CIED infection have risen over the last several decades
despite improved procedural techniques and prophylactic antibiotics,
probably owing to a higher proportion of critically-ill patients being
treated with implantable devices (particularly implantable cardiac
defibrillators and resynchronization therapy devices). Several
mechanisms have been proposed to explain device-related infections,
including contamination during implantation, lead seeding during
bacteremia episodes associated with distant infections, and skin erosion
(which can be the cause or the consequence of a subclinical pocket
infection). The risk of infection appears to be higher in patients
undergoing generator replacement, lead or pocket revisions, device
upgrades, and resynchronization device implantation. Given that 9% of
patients presenting with a pocket infection have had a device-related
infection in the past(18) and that a prior infection increases the risk
of a future infection by 65%,(19) strategies to reduce the risk of
infection recurrence are of paramount importance. Complete hardware
removal undoubtedly plays a significant role in reducing this risk of
reinfection and is recommended in current guidelines to achieve
infection control.
Nevertheless, the appropriate management strategy for the generator
pocket and the wound has yet to be established based on solid
evidence.(5) This knowledge gap has led to many protocols, including the
use of costly therapies with unproven clinical benefits.(20,21)
Total capsulectomy has been proposed to achieve resolution of the
infection and is currently used by approximately 58-76% of centers,
with no distinction made in current guidelines regarding the type of
infection (i.e., pocket infection vs. bacteremia/endocarditis).(7,8)
Furthermore, there is insufficient evidence to support its routine use,
and capsulectomy is an arduous procedure associated with a significant
risk of hematoma formation and the occasional need for pocket revision
to control the bleeding.(6) The presence of post-procedural hematoma is
associated with a substantial increase in the risk of infection (22) and
could result in prolonged hospitalization and increased healthcare
costs. Moreover, large hematomas frequently require OAC interruption,
which is associated with significant stroke risks in patients with
atrial fibrillation, the most frequent indication for OAC use. The
hematoma formation rate in the present study is higher than that
described in the MAKE IT CLEAN trial, which found hematoma formation in
6.1% of patients undergoing capsulectomy.(6) Interestingly, 6 out of
the 7 hematomas were found in patients with a pocket infection, with
only 1 in patients with infective endocarditis/bacteremia. As such,
operators may perform more aggressive tissue debridement when managing
pocket infections, thus explaining the higher rate of hematoma compared
to the MAKE IT CLEAN trial.
Given the low cost, widespread availability, and low risk of adverse
reactions associated with CHG, our current protocol is valuable by
reporting the reduced risk of hematoma formation without increasing the
risk of reinfection. To avoid adverse reactions associated with
chlorhexidine, thorough washing of the pocket cavity is important, being
careful not to exert excessive pressure during saline irrigation since
high pressure can be associated with soft tissue damage. Moreover,
allergic reactions to chlorhexidine are infrequent, with only 124 cases
reported in the literature in over 40 years of use.(23)
As expected, the most frequently identified infectious organisms in our
study were gram-positive bacteria (including MSSA, MRSA, and CoNS).
Their presence explains this as normal skin flora in some patients and
their ability to adhere to non-biological surfaces, creating biofilms.
Biofilm mitigates antimicrobial effect, thus explaining the poor
response to antibiotics to treat CIED infections if complete hardware
removal is not performed. Notably, chlorhexidine can eradicate bacteria
present in biofilm (and, possibly, on capsules),(9) which could explain
our positive results.
Other protocols have been described to reduce the risk of recurrent
infection in patients with CIED infection. Buckarma et al. described a
protocol including surgical debridement, total capsulectomy, negative
pressure, and surgical reevaluation 48 hours after the initial
treatment.(24) Even though this protocol was associated with a reduction
in the length of hospital stay, it failed to decrease the reinfection
rates. Therefore, it is possible that many of the interventions applied
in this protocol (including capsulectomy and negative pressure) are
unnecessary and only increase procedural times and costs. Our
reinfection rate is lower than previously published by Sohail et al.,
who described a 5% risk of recurrent/persistent infection.(25) These
positive results are compelling, considering the high percentage of
patients with pocket infection (50%) in our series, given that a more
“aggressive” approach (i.e., complete capsulectomy) would be preferred
by most physicians in cases of pocket infection/device extrusion.
Thereupon, contrary to what would be expected, the use of a “less
aggressive” (i.e., CHG irrigation) approach in patients with pocket or
device-related infections had similar outcomes to a “more aggressive”
approach. Likewise, although 54.9% of patients received a new device,
with patients in the CHG having a numerically shorter time to reimplant
than patients in the capsulectomy group (albeit statistically
non-significant), there were no significant differences in the rate of
reinfection. Finally, CHG scrubbing was associated with a substantial
reduction in procedural times, an important finding considering the
rising importance of increasing lab efficiency. Although variations in
individual procedural times may exist between different hospitals (as it
is highly related to operator experience), a more straightforward
procedure (i.e., CHG irrigation) is expected to be associated with
reduced procedural times, particularly since during capsulectomy
operators must constantly address and undertake different actions to
control bleeding (e.g. identifying the site of bleeding and the use of
cautery, manual pressure, or artery ligation).