DISCUSSION
The incidence of residual defect after surgical repair of closure of
residual leak after surgery post-MI VSR is noted to be around 10–40%
(6). Transcatheter closure as a bail- out or salvage where redo surgery
weighs more risk than benefit may provide an attractive and less
invasive therapeutic strategy for residual defects (7),
contraindications being defect size >35 mm, basal VSR near
mitral or aortic valves, and apical VSD without sufficient margins.
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) (8-13). 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 (14).
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
(Supplemental 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.