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.