DISCUSSION
Transcatheter closure of PIVSR may provide an attractive and less
invasive for residual defects after surgical repair (6). This
catheter-based procedure can be accomplished using different devices,
some of them not specifically designed for this purpose. To date, the
majority of studies of transcatheter closure of post-infarction VSR have
reported on the use of Amplatzer muscular VSD occluder and recently on
the Amplatzer postinfarction muscular VSD device (PIMVSD) (Abbott
Vascular, Santa Clara, CA, USA) (7-12). The Amplatzer PIMVSD device is a
nitinol construct available in larger sizes than the Amplatzer muscular
VSD device (maximum waist diameter, 24 mm versus 18 mm, respectively)
with a longer connecting waist (10 mm versus 7 mm) and therefore more
suited to larger and complex VSRs. Nevertheless, sometimes there’s the
need to implant additional devices with a substantial increase in
procedural risks.
A primary transcatheter closure of an acute anterior post-infarction VSD
closure has been performed few years ago in an 85-year old female using
for the first time the custom-made Occlutech® PIVSD occluder with a
successful outcome [13].
The Occlutech® PIVSD occluder is a newly designed
device with several advanced features compared to previously existing
technology: unique braiding technology, no distal hub, soft and
atraumatic flexible oval-shaped discs, special surface treatment
reducing the risk of thrombosis. The main advantages of this innovative
device in comparison with the Amplatzer post MI occluder are (Suppl
Video): first, a wider range of waist sizes (from 16 mm to 36 mm) with
bigger left-sided oval disc and a much greater overlap to be able to
catch more substantial healthy myocardium and allow a larger surface
area between the ventricular septum and the left-sided disc of the
device; second, the 10-mm slit-like elliptical connecting waist has no
radial strength to prevent tearing the borders of the patch dehiscence;
third, due to its conformability, a waist size of the occluder 8 mm or
even 10 mm larger than the rupture size may be used without undermining
the margins of the repaired area.
Polyester fabric sutured into both discs and into the inside of the
waist requires time to thrombose and endothelialize before being
efficient in preventing shunt across the high transventricular pressure
gradient. Further minor device modifications such as a denser fabric and
covering on the distal left ventricle disc to completely seal off the
shunt (“closure at implant”) may be hopefully awaited as well as a
dedicated braided and less deformable delivery sheath in order to avoid
its kinking.