Klinik für Herz-, Thorax- und Gefäßchirurgie

Anatomy of the Aortic Valve and Root -

A (Pediatric) Cardiac Surgeon‘s View

Markus K. Heinemann

Universitätsmedizin Mainz

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Conflicts of Interest (?)

I am a surgeon for congenital heart disease by training.

„Pediatric“ cardiac surgeons tend to be peculiar.

Their views may be somewhat idiosyncratic.

Fortunately, I have also done research and published on

aortic dissection.

So it might be worth staying in the room after all.

Don‘t say you haven‘t been warned!

What exactly is the „aortic root“ ?

Wikipedia (what else ?):

The aortic root is the portion of the aorta beginning at the aortic annulus and extending to the sinotubular junction.

It is sometimes regarded as a separate entity from the rest of the ascending aorta.

Between each commissure of the aortic valve and opposite the cusps of the aortic valve, three small dilatations are called the aortic sinuses.

The sinotubular junction is the point in the ascending aorta where

the aortic sinuses end and the aorta becomes a tubular structure.

What shall we focus on, then?

Anulus

(the enigma)

Cusps

(aka „Leaflets“)

Sinus (yes, that‘s the plural)

Coronaries (lest we forget)

Ascending Aorta (where the root ends)

Anulus

Latin: aNulus, pl.: aNuli = small ring

Why we should have an aNNulus, but simply an aNus nobody knows.

A: complex, 3-dimensional, crown-shaped structure (surgical)

B: diameter at base of aortic root („unanatomical“, reference measure)

from: Pershad A, Stone D, Morris MF, Fang K, Gellert G

Aortic annulus measurement and relevance to successful TAVR

J Interv Cardiol. 2013 Jun;26(3):302-9.

Anulus – some harsh words

„Descriptions of the aortic root over the years have been BEDEVILED by accounts of a valve aNulus.“

„There are at least 2 RINGS within the root…“

„…we describe…the current problems which have arisen due to INDISCRIMINATE descriptions of a NONEXISTENT aNulus.“

Loukas M, Bilinsky E, Bilinsky S, Blaak C, Tubbs RS, Anderson RH. The anatomy of the aortic root.

Clinical Anatomy 2014;27:748-56

Anular Enlargement

Classic Surgery (AVR)

To prevent patient-prosthesis mismatch

Simple and efficient

The incision is directed toward the mid-mitral line (an imaginary line that divides

the anterior leaflet into two equal halves), down to the level where the roof of the

left atrium is attached to the fibrous curtain. A teardrop-shaped pericardial patch

is sutured to this extended aortotomy with a continuous 4-0 polypropylene

suture. Sommers KE, David TE. AVR with patch enlargement of the aortic annulus.

Ann Thor Surg 1997;63:1608-12

Anuloplasty

If you tighten your belt…

…you lift up your trousers

Anuloplasty increases coaptation height

Lansac E et al. An external open ring for isolated aortic

valve repair. Multimed Man Cardiothorac Surg 2011

Anuloplasty

Decreasing anulus diameter increases coaptation height and area

Measuring effective coaptation height helps to judge valve performance after reconstruction

Marom G, Haj-Ali R, Rosenfeld M, Schäfers HJ, Raanani E. Aortic root numeric model:

Annulus diameter prediction of effective height and coaptation in post–aortic valve repair.

J Thorac Cardiovasc Surg 2013; 145: 406-11

Cusps

EMBRYOLOGY

Fusion of outflow tract cushions

Appearance of intercalated cushions

Excavation of their distal margins

Ingrowth of non-myocardial tissue for sinus

Spicer DE, Bridgeman JM, Brown NA, Mohun TJ,

Anderson RH. The anatomy and development of the

cardiac valves. Cardiol Young 2014; 24: 1008–22

Cusps (anatomical)

Usually 3

Sometimes 2 („bicuspid“) – stenosis, ascending aortic aneurysm

Rarely 4 (quadricuspid) – regurgitation, pediatric population…

…or Syrian hamsters

López-García A, Fernández MC, Durán AC, Sans-Coma V, Fernández B.

Quadricuspid aortic valves in Syrian hamsters and their formation according to current

knowledge on valvulogenesis. Japanese Journal of Veterinary Research 2015; 63: 37-43

Cusps (mathematical)

Cusp geometric height (gH) higher than presumed ?!

Non-fused cusps in bicuspids larger than in tricuspids

In case of retraction forget repair

Schäfers HJ, Schmied W, Marom G, Aicher D.

Cusp height in aortic valves.

J Thorac Cardiovasc Surg 2013;146:269-74

Labrosse MR, Beller CJ, Robicsek F, Thubrikar MJ.

Geometric modeling of functional trileaflet aortic valves:

Development and clinical applications

J Biomechanics 2006; 39: 2665–72

Sinus

= bay, bulge

Plural: Sinus (U-declination)

the area behind the cusps

providing room for the cusps

sort of Hidden Valleys

Antonio Maria Valsalva (1666-1723)

„anatomist and surgeon“

Sinus

Loukas M, Bilinsky E, Bilinsky S, Blaak C, Tubbs RS, Anderson RH. The anatomy of the aortic root.

Clinical Anatomy 2014;27:748-56

Green – sinotubular junction

Blue – mid-sinus level (widest)

Red – basal cusp attachment

Red dot – „echo“ annulus

Sinus

Largest diameter of root anyway

Pear / onion in connective tissue disease (Marfan etc)

Dilation in bicuspids

Enlarged in cyanotic CHD with limited pulmonary blood flow (ToF!) – redirection towards one outlet already in fetal life

Kim TS, Na CY, Baek JH, Yang JS. Aortic root and ascending aortic aneursym in an adult with a

repaired tetralogy of Fallot. Korean J Thorac Cardiovasc Surg 2011;44:292-3

„root aneurysm“

Sinus

Loukas M, Bilinsky E, Bilinsky S, Blaak C, Tubbs RS, Anderson RH. The anatomy of the aortic root.

Clinical Anatomy 2014;27:748-56

Kirklin, Barrat-Boyes, Cardiac Surgery

„Sinus Valsalva Aneurysm“

Coronary Arteries

Part of the root

Remember the Alamo (here: early TAVI experience)

Always in the way

Make the David / Yacoub procedures tedious / unpopular

May have abnormal pattern

Coronary Arteries

EMBRYOLOGY (Oh no – not you again…!)

Observations by Raymond Vieussens

(1635 – 1715)

Ingrowth rather than Outgrowth

Debated by RH Anderson (of course)

ALCAPA - how can it happen?

Bogers AJJC, Gittenberger-de Groot AC, Dubbeldam JA, Huysmans

HA.The inadequacy of existing theories on development of the proximal

coronary arteries and their connexions with the arterial trunks.

Int J Cardiol 1988;20:117-23

Spicer DE, Henderson DJ, Chaudhry B, Mohun DJ, Anderson RH.

The anatomy and development of normal and abnormal coronary

arteries. Cardiol Young 2015;25:1493-1505

Ascending Aorta

Starts at Sino-tubular junction

Is the first really tubular part of the aorta

Contains more elastic fibers than the rest…

…and is therefore happy to dilate

May be replaced „supracoronarily“ (if justified)

…but is often inseparable from its root

Langer F, Aicher D, Kissinger A,

Wendler O, Lausberg H, Fries R,

Schäfers HJ. Aortic valve repair

using a differentiated strategy.

Circulation 2004;110:II67–II73

Ascending Aorta

Aortic Dissection Type A

Ascending aortic aneurysm

Dilation in bicuspids

Extension of root pathology

Children: supravalvular aortic stenosis (media) !

(Williams-Beuren syndrome, aortoplasty Doty, Brom)

Stamm C, Friehs I, Ho SY, Moran AM,

Jonas RA, del Nido PJ. Congenital

supravalvar aortic stenosis. A simple lesion?

EurJCTS 2001;19:195-202

Ascending Aorta

More MATHS…:

Tirone‘s Rule for graft diameter in ascending aortic replacement

1. Take circumference of sino-tubular junction

2. subtract diameter at brachiocephalic trunk take-off

3. multiply by zero

4. and add 28.

(CFstj – Dbrc) X 0 + 28 = Dgraft

Luckily, Life‘s not just mathematics…

Enjoy the course !