How to perform VSRRR in patients with TAAAD?
There are several options for VSRRR in TAAAD including remodelling,
remodelling with subannular ring, and reimplantation Some of the
technical aspects of the operation are shared among the three
alternatives with the differences being primarily in how the root is
reconstructed. In the remodelling procedure the graft is fashioned into
three tongues that are sutured to the remnants of the aortic root with
subannular stabilisation that can be added with a external ring
annuloplasty. In the reimplantation procedure the remnant tissue of the
native aortic root and the valve are telescoped inside the graft with
subannular anchoring of the graft.
In general cardiopulmonary bypass (CPB) is established, in our
institution was use the axillary artery and the right atrium. At target
temperature, circulatory arrest is established and the arch is
reconstructed with an aggressive hemiarch replacement unless the arch is
>4.5 cm in diameter. Following arch reconstruction,
attention is paid to the aortic root and an initial inspection of the
valve is carried out. If there is obvious degeneration or abnormalities
that preclude VSRRR then valve preservation is abandoned. Otherwise the
aortic sinuses are excised leaving 4-5 mm of root tissue. The
commissures are suspended using 4/0 Polypropylene sutures that are put
under radial tension. Subsequently the valve is inspected carefully for
fenestration, evidence of prolapse, degeneration, or cup retraction. We
measure the three cusps from the nadir to the centre of the free margin
and the formula 2*[Hcusp*2/3]+8 to 10 is used to
choose the graft size. The root is subsequently dissected to the nadir
of the cusps with the anatomical limitation in mind. Six 2/0 Polyester
sutures are placed in the subannular plane at the commissures and the
nadir of each cusp, except at the non-coronary/right coronary cup
commissure where the suture is placed externally. The valve is
telescoped inside the graft and the graft is anchored to the 2-0
Polyester sutures, which are then secured. We visually determine optimal
height of commissural implantation based on the appearance of the valve,
water-test and suction test on the cusps. Once the optimal commissural
height is determined the aortic root rim is sutured to the inside of the
graft starting at the nadir using 5/0 Polypropylene sutures. Afterward,
we assess the valve and determine if any leaflet repair is required.
Prolapse is corrected either by adjustment of the commissural height or
central plication of the leaflets. If the repair is deemed satisfactory
the aortic root prosthesis is sutures to the distal Dacron graft and the
operation is conducted as usual. We give cardioplegia into the root and
assess for evidence of regurgitation by means of manual root pressure
and volume returned through the right superior pulmonary vein vent prior
to releasing the aortic cross clamp. TEE is evaluated for evidence of AI
after releasing the cross clamp prior to discontinuing CPB.
TEE is evaluated after weaning from CPB for evidence of AI. If AI is
detected the AI jet degree, direction, cusps motions and gradient across
the valve are assessed to determined if re-clamping is needed and plan
additional repair of the cusps. Our strategy is to re-clamp if there is
evidence of more than 1+ AI.