Discussion and Conclusion
Both the transcatheter or surgical approach are reasonable for Secundum
ASD repair but surgical closure is preferred if defect size is large,
there is significant proximity to adjacent structures, history of failed
percutaneous closure, inadequate atria to device size, or an associated
pathology requiring cardiac surgery. Surgically there are many
approaches including sternotomy, thoracotomy, video-assisted-assisted
thoracoscopic surgery, and robotics. Median sternotomy is thought to be
the gold standard approach and, in this procedure, the sternum is
usually divided in its entirety and cannulation is via the ascending
aorta and both cava. After the surgery, complications are seldom but
arrhythmia, cardiac tamponade, or an infection can develop.
To our knowledge, we describe the first case in the published literature
of secundum ASD closure with the bovine patch that degraded within 2
months with the redevelopment of the bidirectional shunt. In the
literature, data on bioprosthetic patch degeneration are scarce;
however, degradation or failure of the aortic bioprosthetic valve is
well established. One of the most common causes of bioprosthetic valve
degeneration is calcification. Other potential culprits include suture
dehiscence, collagen fiber disruption, tissue disruption due to
mechanical stress and shear forces, and inflammatory or immune response.
Given the acute failure of the patch in our case, we suspect either
dehiscence or host immune response caused degeneration of the ASD repair
patch.
Restoration of cardiac septation in the vast majority of cases requires
a patch material for reconstruction.1 CardioCel patch
is one such bovine scaffold of great interest due to greater mechanical
stability and decreased cost. For instance, in one comparative study,
all the bioscaffolds commonly used in cardiac surgery were compared
including bovine pericardial scaffolds, cross-linked with 0.6%
glutaraldehyde such as XenoLogiX™, PeriGuard®, dye-mediated
photo-oxidized PhotoFix™ and a non-crosslinked porcine scaffold
CorMatrix®, and CardioCel® (decellularized, cross-linked with 0.05%
monomeric glutaraldehyde, detoxified). CardioCel demonstrated greater
cross-linked stability and comparable tensile strength at 12 weeks
follow-up.
Previous data on CardioCel patch use in adults are sparse. In one study
by Tomisic et al., they looked at 30 patients with a median age of 57
years who underwent mitral valve leaflet repair with a CardioCel patch.
At a mean follow-up of 1.7 years, there were 3 deaths and 2 of them had
infective endocarditis as a complication. In the pediatric population,
the Cardiocel patch has been well studied. A study by Bell et al looked
at 501 CardioCel implanted patches with a median follow up of 31 months
which showed that a total of 14 implants require intervention and
freedom from reintervention was close to 96% at 3 and 5 years. Multiple
other studies looked at Cardiocel use in congenital heart disease with
short term to long term follow-ups all found positive results with
Cardiocel and no cases on patch degradation or reabsorption ever noted.
Studies on the CardioCel patch have not shown any cases of early
degeneration. We can infer the etiology of degeneration from studies on
bioprosthetic aortic valve degeneration. Currently known common culprits
in bioprosthetic material degeneration are calcification, dehiscence,
microstructure alteration, and host inflammatory or immune response. The
dearth of published cases of degradation of patch closure may be
indicative of the rarity of this complication and its need for further
study.
List of abbreviations
ASD = atrial septal defect
RA = right atrium
RV – right ventricle
TTE = transthoracic echocardiography
LVEF = left ventricle ejection fraction
LHC = left heart catheterization
RHC = right heart catheterization
TEE = transesopahgeal echocardiography
CONFLICT OF INTERESTS
The authors declare that there is no conflict of interest.
ETHICS STATEMENT
All research meets the ethical guidelines, including adherence to the
legal requirements of the United States.
References