Operative Technique
The decision to proceed with AAG or ARR was based on individual surgeon
preference. However, several common factors were identified at this
institution as favouring root replacement over preservation of the
native aortic valve. In particular; younger age, known connective tissue
disease, dilation of the aortic root, moderate or severe aortic
regurgitation at presentation and a dissection tear extending into the
aortic root were considered variables favouring ARR.
All patients in this study underwent a median sternotomy to gain access
to the mediastinum. The right subclavian artery was used as the
preferred arterial cannulation site. Where this was not possible femoral
artery or direct aortic cannulation were used as alternatives. Venous
cannulation was routinely performed using the right atrial appendage.
Following stabilisation of patients on cardio-pulmonary bypass
cold-blood cardioplegia solution was given either retrograde via the
coronary sinus or antegrade directly into the coronary ostia. Patients
were then cooled to 18C prior to deep hypothermic circulatory arrest for
inspection of the aortic arch and ascending aorta.
In patients undergoing preservation of the native aortic valve the
portion of ascending aorta effected by the intimal tear was resected and
replaced with an interposition graft. The aortic valve commissures were
resuspended on the aortic wall using pledgeted sutures where necessary.
In cases where a decision was taken to replace the native aortic valve
the aortic root was excised, annulus sized and a composite valve graft
sewn into the annulus using interrupted sutures. The left and right
coronary buttons were then reimplanted into the graft. Where the intimal
tear extended into the aortic arch a hemi-arch or total arch replacement
were performed with reimplantation of the aortic branch vessels as
necessary. Patients undergoing total arch replacement where excluded
from inclusion in this study.