The ideal theoretical graft oversizing in valve-sparing aortic operations with a standard tubular or a Valsalva graft

Objective: We sought to determine, by a mathematical model, the ideal theoretical degree of ascending aortic graft oversizing needed to obtain normal sinuses dimension in the reimplantation type of valve-sparing aortic operations. Methods: To define a normal-range value, size of sinuses of Valsalva was conventionally expressed as the area surrounding fully opened aortic cusps, the so-called beyond leaflets area (BLA), and measured in 50 healthy subjects. A mathematical relationship between aortic annulus diameter, aortic sinuses diameter and resulting BLA was defined. By simulating intra-operative scenarios, the effect of different degrees of a standard or Valsalva graft oversizing on BLA extension was tested. Results: The same degree of graft oversizing resulted in a bigger beyond leaflets area for the Valsalva graft than for a standard graft. Oversizing degrees exceeding +7 mm for a standard graft and +3 mm for the Valsalva graft resulted in a beyond leaflets area over normal limits. Results were expressed in a visual form as two different normograms, one for the standard graft and one for the Valsalva graft. Conclusions: A less pronounced graft oversizing is needed to achieve normal-range sinuses size when using a Valsalva graft, the ideal theoretical graft oversizing was +7 mm for a standard graft and +3 mm for the Valsalva graft, our normograms can be helpful in selecting a proper graft size when performing a valve-sparing aortic procedure.