Introduction
Aortic Valve Sparing (AVS) is a surgical technique aiming at restoring the valve competence by a reconstruction of the aortic system maintaining the native valve. The procedure can be resumed in two main steps: 1) excision of the dilated aortic root; 2) integration of the native valve in a Dacron tubular prosthesis. Benefits related to the use of native valves (e.g. anticoagulant avoidance and physiological aspects) have their counterparts in the high level of technical skills required to perform the procedure. In fact, remodeling and matching both the shape and the size of valve leaflets and tube prosthesis are critical aspects and they have an impact on the efficiency and durability of the treatment [R1-2-3]. Currently, the surgeon measures, directly or by medical images, different geometrical dimensions of the diseased valve to be treated, and then he/she chooses the remodeling strategy and the target features to reconstruct a competent valve. The difficulty in obtaining satisfactory medical measurements and, consequently, the difficulty in recognizing abnormal components, combined to the extreme complexity of the surgical technique, make the procedure success strongly related to surgeon expertise remaining, in some aspects, “more art than science” [R4].
Goal
The main goal of our research is to furnish useful indications for AVS operation planning in advance. The engineering support to surgical practise aims at indicating the optimal prosthesis size apt to restore valve competence.
Methods
Finite Element Analyses are run to simulate the surgical procedure: a dilated aortic valve model is integrated within Dacron tubular prostheses. Different type and size can be assessed. Consequently, we are able to evaluate the coupling between the valve and the prosthesis in terms of coaptation length and height as well as stresses and strains of the leaflets.
Results
References
- [R1] Kunzelman K.S., K.J. Grande, T.E. David, R.P. Cochran, and E.D. Verrier. Aortic root and valve relationships: impact on surgical repair. Journal of Thoracic and Cardiovascular Surgery, 107:162-170, 1994.
- [R2] Grande K.J., R.P. Cochran, P.G. Reinhall, and K.S. Kunzelman. Recreation of sinuses is important for sparing the aortic valve: a finite element study. Journal of Thoracic and Cardiovascular Surgery, 119:753-763, 2000.
- [R3] G. Matalanis. Valve sparing aortic root repairs: An anatomical approach. Heart Lung and Circulation, 13S:S13-S18, 2004.
- [R4] T.E. David and C.M. Feindel. An aortic valve-sparing operation for patients with aortic incompetence and aneurysm of the ascending aorta. Journal of Thoracic and Cardiovascular Surgery, 103:617-621, 1992.
Group publications
- [P1] Totaro P., S. Morganti, C.L. Ngo Yon, R. Dore, N. Castiglioni, M. Conti, F. Auricchio, M. Viganò. Computational finite element anal- yses to optimize graft sizing during aortic valve sparing procedure. Journal of Heart Valve Disease, 21:141-147, 2012.