Anatomy of aortic valve and root

Transcription

1 Anatomy of aortic valve and root Emmanuel Lansac, Isabelle Di Centa Cardiac Surgery Institut Mutualiste Montsouris, Paris, France

2 The aortic valve : a passive or dynamic structure? Leonardo da Vinci 1508 Quadr Anat IV Belhouse Cir Res 1969 In vitro Vortex formation Brewer JTCVS 1976 Interdependence of valve opening and root expansion Thubrikar JTCVS 1979 : In vivo 9% commissural expansion prior ejection Circular orifice Dagum Circulation 1999 Deformational dynamics of the aortic root (60Hz)

3 Sino-tubular junction The aortic annulus: a 3D structure Membranous septum Inter leaflets triangle 3D Aortic annular base 2D + 2D Sutton et al. ATS 1995 Anderson et al. ATS 1991

4 Aortic Root = 2 functional compartments SUPRAVALVULAR COMPARTMENT: STJ + ascending aorta Aortic Hemodynamics SUPRA VALVULAR SUBVALVULAR Aortic Hemodynamics LV Hemodynamics SUBVALVULAR COMPARTMENT: Aortic annular Base + Commissures (inter-leaflet triangles) LV Hemodynamics Sutton et al. ATS 1995 Lansac et al. EJTCS 2002

5 CHANGE IN AREA Aortic root expansion starts prior to ejection 36.7 ± 3.3% of root volume expansion SYSTOLE DIASTOLE IVC EJECTION IVR MID ISOVOLUMIC CONTRACTION max median B min C AA STJ N = B C STJ AA AORTIC ROOT LEVEL Lansac et al. EJTCS 2002; 22:

6 Aortic valve opening starts prior to ejection (2.1±0.5%) Related to annular base and commissural (subvalvular compartment) pre-ejectional expansion Correlated to LV pressure increase (r=0.95) Due to a redistribution of LV volume below the leaflets (inter-leaflet triangle) Optimize ejection Stressless opening Lansac et al. EJTCS 2002; 22:

7 Area (mm^2) Aortic valve opening is maximum during the 1/3 of ejection SYSTOLE DIASTOLE IVC Ejection EJECTION IVR Mid MID Diastole 70 Leaflet area Ao overshot Commissural area by 28.8±3.4% LV 20 = Clover-shaped SoV -30 orifice B STJ -80 C AA -130 Pressure (mmhg) Maximizes 0 hemodynamic performance unimpeded blood flow through the sino-tubular junction to the systemic circulation 6,55 6,6 6,65 6,7 6,75 6,8 Time (s) L -180

8 Pressure (mmhg) Tilt Angle (degrees) Aortic root expansion is asymetric Tilt angle of the aortic valve during cardiac cycle End diastole: 16.3±1.5 postero-left During systole:- 6.6±1.5 Alignement of LVOT and ascending aorta Maximize ejection During diastole:+ 6.6± Ao Tilt Angle LV 9 Shock absorber Time (s) 4 Lansac et al. JHVD 2005; 14:

9 Importance of Sinuses of Valsalva Leonardo da Vinci 1508 Quadr Anat IV Belhouse Cir Res 1969 In vitro Vortex formation Kilner Circulation D MRI Recirculating flows (vortices) accommodated by the sinuses contribute to efficient and smooth valve closure at end systole Katawama 2008

10 Aorto mitral junction dynamics : two to tango DIASTOLE Aortic Ø ±0.3% SYSTOLE T1 T2-11.5±2.3% T1 T ±2.3% Transverse Ø : -12.1±1.5% Antero Posterior Ø : -23.6±2.5% MAXIMIZE LV FILLING MAXIMIZE EJECTION Lansac et al. JTCVS 2002; 123:

11 Annulus excursion during cardiac cycle 13 ± 2.3 mm The angle between the mitral and aortic annulus reduces 11 in systole Annulus excursion contributes to an efficient cardiac output Sughimoto JHVD 2010 Alignement of LVOT and ascending aorta Maximize ejection Goetz Am J Physiol Heart Circ 2005, Asian CVT annals 2006

12 What are the normal diameters of the aortic root? Roman 1987 Kim 1996 Nistri 1999 Varnous 2003 Maselli 2005 Babaee 2007 Tamas 2007 Soncini 2009 Bierbach 2010 Zhu 2011 N Annular Ø STJ Ø STJ/ annulus 24.5 (± 3) 27.5 (± 3) 23.4 (± 2.4) 28.1 (± 3.2) 22.7 (± 2.7) 24.7 (± 2.8) (± 3) 31.2 (± 3.7) 24.4 (± 4.1) 22.3±1,4 ( ) 25.4 (± 4.1) 26.7±2.2 ( ) 1.2±0.1 ( ) 21.8±2.4 21± 3 21,6 21±2,8 20,3±8,7 29.5±3.1 27± 4 27,3 25± 3,7 23.4±3, ,3 1,2 1,1 Dilated 35 mm Dilated 25 mm STJ> Annulus Ratio = 1.2 ( )

13 Expansibility of the aortic root Leygh 1999 Echo De Paulis 2002 Echo Varnous 2003 Echo Kazui 2004 Echo Maselli 2005 Echo Matsumori 2007 Echo De Heer 2011 CT scan N Zhu 2001 Echo Annular base 9.6±1.5% 7.7% 2.55% 5.7% 5.1% ( ) 6.8% 7±1.8% 4.6% 2.7% SoV 10.3±3.4% 4.4% 2.1% 4.3% 0.5% ( ) 3.7% 7.2±1.8% 2.1% 4% STJ 7.0±1.8% 5.3% 2.8% 5.4% 5.7% ( ) 5.9% 9.8±6.2% 1.7% 5% 5.7% 5.4% Aortic annulus and STJ expansion

14 Parameters for valve coaptation STJ ch eh gh ch= 4-5 mm eh= >9 mm Aortic annular base gh Bicuspid : nonfused 24±2 mm Tricuspid : NC : 21±2 / LC : 20±2 / RC 20±2 annulus Ø from mm eh from 10.9 to 8.0 mm ch from 3.3 to 0.3 mm Correlates with body height, weight, BSA, sinus Ø, aortoventricular Ø Tamas JHVD 2007 Bierbach EJTCVS 2010 Schäfers JTCVS 2012 Marom JTCVS 2012

15 What is the aortic annulus from a surgical point of view? From Anderson R. with permission

16 External Dissection of the Subvalvular Plane

17 R NC L Aortic annuloplasty can be performed in the subvalvular plan, except at the level of the infundibulum where the dissection stops 1,4±1,8 mm above the nadir of the right coronary sinus (80% below or within 3mm above the nadic of the R ) Khelil et al ATS 2015

18 NC Leaflet LC leaflet 2.02 ±0.47 L At ±0.81 External aortic annuloplasty induces a minimum of 5 mm reduction of aortic annular base diameter, corresponding to tissue thickness RC leaflet Left-right commissure 3.34 ± ±0.81 Khelil et al ATS 2015

19 Aortic valve Tricuspid Bicuspid valve Type 0 0 raphe Type 1 1 raphe Unicuspid valve Type 2 2 raphes Commissures 120 Good candidates Commisures 180 for repair Commisures NC-LC NC-RC

20 Landmarks to AV conduction system Right coronary aortic leaflet Non-coronary aortic leaflet Membranous septum Left bundle branch descends from nadir of hinge of right coronary leaflet From Anderson R. with permission

21 Left bundle branch Membranous septum Ventricular septum Branching atrioventricular bundle From Anderson R. with permission

22 From Anderson R. with permission Left bundle branch Right coronary aortic sinus Non-coronary aortic sinus Atrioventricular node

23 Right coronary aortic sinus Non-coronary aortic sinus Membranous septum & interleaflet triangle

24 Dynamic anatomy Valve repair Aortic Root expansion = Stress less opening and closure of the valve Dilated STJ > 35 mm Treatment of dilated diameters Aortic annular base Ø STJ Ø Clover shape orifice Preserves root dynamics Neosinuses of valsalva Systolic expansion (interleaflet triangles) Cusp effective height Annulus < STJ Ratio 1.2 Dilated annulus >25 mm Restores cusp effective height Restores ratio Durability of a native valve Durability of repair