Aortic Valve: investigation by engineering tools Universit degli - - PowerPoint PPT Presentation

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Biomechanics

Aortic Valve: investigation by engineering tools

Università degli Studi di Pavia - Structural Mechanics Department

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The procedure requires high technical expertise Procedure Planning

Effects of Aortic root delation

• Coaptazion area reduction
• Valve incompetence

Aortic Valve

AORTIC VALVE SPARING PROCEDURE

1) Excision of aortic root in

• rder to achieve an ad hoc

structure containing the native valve 2) Anchoring of the prosthesis tube, replacing ascending aorta, and excised aortic valve 3) Whole re-implanted aortic valve, within prosthesis tube, presenting mercedes star like shape

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Image analysis Approach 1: closed configuration Approach 2: open configuration Patient Medical images

Geometric model

Finite element analysis Output Boundary conditions

K1,..,Kn

Aortic Valve

GENERATION OF GEOMETRIC MODEL

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METHOD FOR THE MESH GENERATION

Aortic Valve

Parametric model reproduces 1/6 of the aortic valve Mirroring operation

• 1/3
• f the aortic valve

Finally, by a circular replication

• whole model of the aortic valve in
• pen configuration

5 Rb Rb Ht Ht F

• Aortic Valve

Hr F

PARAMETERS OF THE MODEL (1/6 OF VALVE)

Different views of the same element:

• base radius, Rb

[13 mm] *

• total height, Ht [16.8 mm]
• maximum height of the aortic root, Hr [10.8 mm]
• slope of the aortic root,

[6° ]

• slope of the leaflet,

[7° ]

• parameters of the “intermediate-line” function

* Parameter Values based on Labrosse et al. 2006

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Image analysis Patient Medical images Geometric model

Finite element analysis

Output Boundary conditions

Aortic Valve

NUMERICAL SIMULATIONS – “HEALTH” VALVE

Bottom view Side view

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Aortic Valve

NUMERICAL SIMULATIONS – PATHOLOGIC VALVE

Bottom view Side view Top view Side view Bottom view

Valve is not able to close completely Pathologic aortic valve model is generated enlarging aortic root