Impact of graft size and resuspension level of the commissures on aortic insufficiency after reimplantation of the aortic valve.

Background: In addition to the size of the graft, the resuspension of the commissures has been described as important for valve function in valve-sparing aortic root replacement procedures. This study describes the influence of a stepwise reduction of the fixation level of the commissures within the graft as well as a stepwise reduction of graft size on valve insufficiency.

Method: Porcine aortic valves were reimplanted into a tubular graft and the height of the commissures was reduced in a stepwise manner. In a second series of experiments, the diameter of the grafts was reduced by 30 % and 50 %.

Results: A reduction of the commissure heights by 10 % and 20 % caused a significant increase in reflux water. Using the criteria of homograft preparation, a 10 %, but not a 20 %, reduction was tolerated. The coaptation level of the valve became increasingly lower, indicating a higher risk for late valve incompetence. A reduction of the prosthesis diameter by 30 % and 50 % did not result in insufficiency of the valve but it lowered the coaptation level.

Conclusion: Resuspension of the commissures within the graft has a more important impact on early failure rates than the choice of graft size.