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On-X
®
Prosthetic Heart Valve | Instructions for Use
11
Figure 13. Sewing ring cross-sections
(A)
Aortic
(B)
Mitral
(D)
Aortic
Conform-X
and Aortic
Anatomic
(C)
Mitral
Conform-X
Housing
Titanium
Rings
Layered
Cloth
Housing
Titanium
Rings
Layered
Cloth
Figure 14. Removing the valve holder
WARNING: DO NOT size the sewing ring of the size
19 mm through 25 mm aortic valve to fit within the
annulus.
Size 27/29 mm aortic valves of standard, Conform-X, and
Anatomic sewing ring configurations are designed to
be placed in an intra-annular position and have a replica
sizer to mimic this placement.
All mitral valves, including the On-X Mitral Conform-X
Prosthetic Heart Valve, are designed to be placed in a
supra-annular position (Figure 12).
CAUTION: Avoid oversizing the valve, as this could
lead to interference with valve function.
Figure 12. Supra-annular valve positioning
9.5 Suturing Techniques
The suturing techniques vary according to the
preferences of the implanting surgeon and patient
condition. The aortic valve is designed to have the tissue
annulus abut the orifice flare. The general consensus
among surgeons is that the non-everting interrupted
mattress suture technique, with or without pledgets,
provides the best conformation of the valve annulus to
the outer surface of the flare.
The mitral valves have generally been implanted using a
pledgetted or non-pledgetted everting mattress suture
technique, although non-everting and continuous suture
techniques have also been used with success.
CAUTION: When seating the valve, ensure that no
suture material or anatomic structures interfere with
leaflet motion. The valve’s rotation capability may be
helpful in avoiding abnormal residual pathology that
could interfere with leaflet motion.
The sutures should be passed through the mid-point of
the sewing ring. This allows the sewing ring to remain
flexible and conform to the annulus. It also prevents the
suture needle from contacting the titanium rings that lie
within the sewing ring (Figure 13). The orientation marks on
the sewing ring may be used to aid in suture placement.
CAUTION: For the Anatomic sewing ring, the sutures
at the three valve commissures must correspond to
the three orientation marks on the sewing ring.
When all the sutures are in place, the valve is advanced
into the annulus and the sutures are tied down. For
aortic valves, it is suggested that the first 3 knots be tied
equidistant to one another and midway between the
commissures to stabilize the valve in the annulus. The
holder is removed from the valve by carefully cutting the
retaining suture as shown in Figure 14, then gently lifting
the valve holder with handle out of the valve.
WARNING: Do NOT attempt to reinsert the valve
holder into the valve once it has been removed.
CAUTION: Suture ties should be cut short to avoid
any potential interference with leaflet motion.
