Discussion:
Core-Knot has become popular in valvular surgery since its introduction
in 2009. While reducing cardiopulmonary bypass time is its prime
benefit, it has also been found to have better holding pressure than
manual knot tying.1 Lee et al. evaluated the strength,
consistency, and speed of prosthetic attachment sutures secured with
Cor-Knot and compared with those of manual knots.1They reported that suture holding pressures for the Cor-Knot fasteners
were significantly greater (median, 1008.9 vs 415.8 mm Hg, P <
0.001). Also, there was less variation in attachment pressures with
significant time savings occurred with the use of the Cor-Knot compared
with manual tying (12.4 vs 71.1 seconds per knot, P = 0.001). They
concluded that mitral annuloplasty ring sutures secured with the
Cor-Knot device were stronger, more consistent, and faster than with
manually tied knots.1
One of the first reported studies on Cor-Knot system was conducted
between 2008-2010. Rodriguez et al. evaluated the clinical outcomes of
minimally invasive mitral valve surgery with prosthetic attachment
sutures secured by Cor-Knot system.2 No patient had
evidence of thrombus formation, hemolysis, or perivalvular
leaks.2 One instance of mitral ring dehiscence was
noted, but the dehiscence was due to a tear in the mitral annulus and
not associated with the titanium fasteners, which all remained
intact.2 They concluded that at a minimum of one-year
follow-up, Cor-Knot system is safe and effective for securing prosthetic
attachment suture.2
Sazzad et al. quantified the incidence of valvular complications related
to Cor-Knot device.3 They reported trivial and/or mild
paravalvular leak (PVL) in immediate post-operative echocardiography and
no reported cases of valvular thrombosis, leaflet perforation, device
dislodgement or embolization, moderate and/or severe PVL during
hospitalization and follow-up echocardiography within 1
year.3
Lee et al. analyzed prosthetic fixation pressures in prosthetic aortic
valves, using Digital Pressure Mapping with 2D and 3D pressure maps
generated for all valves. None of the 288 Cor-Knot cases had any
decrease in intra-suture pressure, while 12 out of 144 manual-tying
cases that had pressure drop to less than 80 mmHg which is considered a
risk for paravalvular leaks (PVL) (P <
0.001).4 Therefore, it would be reasonable to use this
device at high pressure sites such as the aorta.