Joseph S. Coselli, M.D.?

Surgical Anatomy of the Aortic Valve and Root

AATS International Cardiovascular Symposium 2017Session 6: Basic Principles of Aortic Valve Disease

Sao Paulo, Brazil • Friday, December 8, 2017

Vice-Chair, Department of SurgeryProfessor, Chief, and Cullen Foundation Endowed Chair

Division of Cardiothoracic SurgeryBaylor College of Medicine

DisclosureMedtronic, Inc PI Clinical Trials

ConsultantVascutekTerumo

ConsultantPI Clinical TrialsRoyalties Coselli branched graft

WL Gore & Associates

PI Clinical Trials Consultant

Bolton Medical PI Clinical Trials

Thubrikar, M.J. . The aortic valve. CRC Press (1990) pp. 11–20

Understanding AV and Root Geometry

Thubrikar, M.J. . The aortic valve. CRC Press (1990) pp. 11–20

Understanding AV and Root GeometryRIDICULOUS

The Aortic Root

A Dynamic Structure

5 Key Components:

• Sino-Tubular Junction• Sinuses of Valsalva• Annulus• Sub Aortic Segment• Aortic Leaflets

8

What is the definition of aortic root?

Basal attachment of aortic valve leaflets

Sinutubular junction

Parasternal Long Axis

Left ventricle

Aorta

Root extends from the basal attachments of the aortic valve leaflets (green line) to the sinutubular junction (blue line)

Slide courtesy of Nicolo Piazza, MDAnderson MMCTS 2006

Aorticsinus

Surgical Anatomy• Aortic root is

anchored between the pulmonary root anteriorly and mitral and tricuspid posteriorly

• Fibrous skeleton of the heart

Pulmonaryvalve/root

Aorticvalve/root

Posteromedial trigone (right)

Carpentier’s Reconstructive Valve Surgery Ch 5, 2010

Diastole shown

10

1: Sinutubular Junction

“Crown” formed by attachment of semilunar valve leaflets

2: Anatomic ventriculo-aortic junction

3: Virtual basal ring“echo” annulus

Membranousseptum

Aorta

Slide courtesy of Nicolo Piazza, MDAnderson MMCTS 2006

Aortic Root: Crown and 3 “Rings”

1

3

2

Sinuses of Valsalva

Anterolateral trigone

Aorto-mitral curtainMitral valve

Posteromedial trigone

Membranous septum

Annulus

Scallop-shaped fibrous structure attached to the trigones the aorto- mitral curtain and the muscular and membranous septa.

Aortic Root Function

Early systole Late systole Diastole

Sinuses of Valsalva

Collagen → Elastin• More collagen at base• Progressive increase in elastic lamellae superiorly as approach sinutubular junction

Antonio Maria Valsalva 1666-1723

Sinuses of Valsalva

• When pressurized, the sinutubular junction is larger than that of annulus 1 : 1.3 ratio of diameters

• When not under pressure, the annulus is larger than sinutubular junction 1 : 1.15 ratio of diameters

Antonio Maria Valsalva 1666-1723

Sinuses of Valsalva: Role?“The aortic sinuses have no effective on valve competence, but are important in reducing mechanical stress on the aortic cusps during the cardiac cycles by creating eddies and currents between the cusps and the sinus walls.”T. David Nat. Rev. Cardiol 2013

Furukawa ATS 1999Bellhouse Nature 1968

De Paulis ATS 2001Aybek JHVD 2005

Flexible Heart Valves Modeled Using FIDAPSchool of Mechanical Engineering, University of Leeds

Sinuses of Valsalva

Sinuses of Valsalva

Force (stress) = Pressure x Area

The Sinuses of ValsalvaCoronary Artery Positions.Distance from nadir (mm)Smallest

Largest

Left coronary sinus

Right coronarysinus

LCA RCAPost-Mortem (n=51)Arq Bras Cardio 2003;81:359

12.6 ± 2.6 mm 13.2 ± 2.6 mm

MSCT (n=169)JACC Img 2008;1:321-330

14.4 ± 2.9 mm 17.2 ± 3.3 mm

Angiography (n=63)Rotterdam experience

13.6 ± 2.2 mm 15.7 ± 2.3 mm25

Aortic Root: Coronary Ostia

Average HeightConsiderable Variation

Nicolo Piazza, MD Anderson MMCTS 2006

Sub Aortic Segment

Left bundle branch

Right coronary arteryLeft coronaryartery

Tricuspid valve

MembranousseptumNon-coronary sinus

AV node

Mitral valve

Right fibrous trigone

Aortic Leaflets

Coaptingsurfaces

BellyHingeAnnulus

Valve Leaflet Properties• Fibrous core (spongiosa and fibrosa)

covered by fibroelastic layer on arterial and ventricular sides

• Less elastin than ascending aorta but surprisingly elastic

• Loose gelatinous layer, the spongiosa, is sandwiched by two fibrous layers

• Permits folding & unfolding

Ventricularis → Preload

Fibrosa → Tensile StrengthCircumferentially oriented collagen fibers

Compliant, dense sheet of elastic fibers

Spongiosa → FlexibilityLoose connective tissue: permits “shearing”

Vesely ▪ J Biomechanics 1998 [Image]Tseng ▪ Acta Biomaterialia 2011

Rad

ial

Circumferential

Hinge

Images: Rubin EJCTS 2009

Godefroid Eur J Echo 2006 Wang 2010 ATS

Anatomic Variants

1

4 5

2

unicuspid bicuspid

penticuspidquadricuspid

30Roberts Circulation 1970; 42: 91-97

Range of Morphology: Leaflets

Aortic Valve Disease

Netter

Stenosis

Regurgitation

Calcification Rheumatic Congenital

Dilated root may also dissect~3 per 10,000 persons per yrHagan JAMA 2000

~5 per 10,000 persons per yr

Medline

Most prevalent AV disease2% of persons > 65 yrshave frank diseaseCarabello Lancet 2009

de Kerchove and El Khoury ACS 2013

Functional Classification: Aortic Regurgitation

FAA=functional aortic annulusSTJ=sinutubular junctionSCA=subcommissural annuloplasty

Bicuspid Aortic Valves• Most common congenital

cardiovascular defect• 0.9% to 2% prevalence

3-6 million US citizens Males affected 4:1

• Genes involved include NOTCH 1 and ACTA2

• Majority of BAV patients develop complications over time• Stenosis, regurgitation, or both• Aortic dilatation/dissection possible

• Cause of about 50% of adult aortic valve stenosis

• Dilatation of aorta not uncommon Responsible for more morbidity and

mortality than all other congenital disorders combined

“crown” shape of bicuspid (top) differs from normal tricuspid (bottom) shape

Valve Opening: 2-cusp vs 3-cusp

Robicsek Ann Thorac Surg 1991Robicsek Ann Thorac Surg 2004

Circumference = 2 π r = 6 r

2r

2r

Total ~ 4r

r

Total ~ 6r

rrr

r r

~

Sievers 2007; 304 Surgical specimens and OR collected over 5 years

Sievers Classification of Bicuspid Aortic ValvesType O: No Raphe Type 1: 1 Raphe Type 2: 2 Raphes

13% 14% 28% 45%

Fazel 2008 JTCVS

Fazel/Miller Classification

64 patients from surgical and radiological databases; 4 clusters of aortopathy observed

Aortic Root Tubular Aorta Tubular Aorta/Arch Diffuse

BAV Aortopathy

Verma 2014 NEJM Review Article

• Most common pattern• Associated with R-L cusp

fusion

R

L

Wall stress differs by fusion patternR-L: Right anterior wall of ascending aorta

Verma 2014 NEJM Review Article

R

N

Wall stress differs by fusion patternR-N: Posterior wall, affects arch?

There is no substitute for knowing the anatomy and physiologic function

Obrigado!