Cardiochirurgia - insufficienza mitralica

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With mitral regurgitation, as the mitral valve leaks, blood flows

backwards into the left atrium and the veins bringing blood back

from the lungs. The heart must therefore pump more blood with

each beat to satisfy the needs of the body. The left side of the heart

is overloaded with volume as a result. The heart may function well

with this volume overload for many months or years, but it will

eventually become weaker as the size of the left ventricle and left

atrium increase and as pressure increases in the left atrium and the

veins returning blood from the lungs. Heart failure will eventually

occur. A more complete description of the functional causes of

mitral regurgitation is available by clicking here.

Insufficienza mitralica primitiva

Acuta Post-infartuale

 Rottura dei muscoli papillari Post-traumatica

Spontanea

 Rottura delle corde tendinee Traumatica

Post-endocarditica

 Rottura dei lembi Post-traumatica

INDICAZIONE AD INTERVENTO CHIRURGICO CON CRITERIO DI

URGENZA

Patologie della valvola mitralica

Area normale 4-6 cmq

Insufficienza mitralica:

1° criterio (area jet al color)

Lieve: < 4 cmq

Moderata: –

4 8 cmq

Severa: > 8 cmq

2° criterio

Rapporto tra area jet al color ed area dell’atrio sinistro:

Lieve: fino al 20%

Moderata: fino al 40%

Severa: > 40%

3° criterio se c’è inversione del flusso sistolico in vena polmonare

Insufficienza severa

Insufficienza mitralica primitiva

Cronica

Dilatazione dell’anello mitralico Idiopatica

 Post reumatica Sindrome di Marfan

 Accorciamento delle corde tendinee

 Allungamento delle corde tendinee

 Post-ischemica

INDICAZIONE AD INTERVENTO CHIRURGICO CON CRITERIO DI

ELEZIONE

Controindicazione: miocardiopatia dilatativa

This is Carpentier’s classification of mitral regurgitation:

It helps to understand the techniques of mitral valve repair that are possible for

individual patients by breaking down the cause or causes of the valve leakage into

various types. Dr. Alain Carpentier, the father of modern mitral valve repair

techniques, first described this system. It helps to understand this system by thinking

of the mitral valve as a pair of double-doors surrounded by a frame, with strings

attached to the doors that prevent them from opening in the backwards direction.

Carpentier’s functional classification is based on the opening and closing

motions of the mitral leaflets. Type I has normal motion of the leaflets and mitral

regurgitation is on the basis of the leaflet perforation or annular dilatation. In

type II dysfunction (increased leaflet motion) the free edge of the leaflet travels

above the plane of the mitral annulus during systole due to chordal elongation or

rupture. Type IIIa dysfunction implies restricted opening leaflet motion during

diastole and systole due to rheumatic changes. Type IIIb dysfunction correlates

to restricted leaflet motion during systole secondary to papillary muscle

displacement. Mitral Regurgitation Type I

In this situation, you have enlargement

of the ring (annulus) of tissue around

the valve. In our example, image that You can also have a hole in one of the

the doorframe is enlarged, pulling the mitral leaflets. This is equivalent to

two doors apart. Even though the having a window in one of the doors with

doors open and close normally, the a missing pane of glass. The hole in the

space between the doors allows blood door allows blood to flow backwards.

to flow backwards. This is Type Ia and This is Type Ib and is common in people

is common is people with enlarged with infections of the mitral valve

hearts due to one of the many causes (endocarditis).

of heart failure, such as coronary artery

disease or cardiomyopathy.

Mitral Regurgitation Type II

This is the most common disease that we see of the mitral valve and it is called

Type II dysfunction or leaflet prolapse. Imagine that one of the doors swings too

far backwards past the doorframe during the squeezing phase of the heart cycle

(systole). Since one of the leaflets comes above the other one, they do not join

in the doorframe to make a connection.

Mitral Regurgitation Type III

Here is an example where a patient has a

valve that is frozen down inside—one of

the doors is stuck open. So now the valve

leaflets cannot come together up into this

black line and create the red surface. This

is Type IIIa mitral regurgitation.

Mitral Regurgitation Type III

In many patients, the mitral valve is basically OK, but

enlargement of the pumping chamber of the left heart (the left

ventricle) causes the problem. The chamber enlargement pulls

the leaflets open and prevents them from coming together.

Imagine that the doors are being held partially open by strings

that prevent them from closing fully. In this patient, look how

restricted the leaflets are.

Mitral Regurgitation Type III

The problem with a valve that has (Type IIIb) leakage due to heart failure and

doesn’t

left ventricle enlargement is that it get better with medication or even

with improved blood flow to the heart with angioplasty, stents, or coronary

artery bypass surgery. The left atrial chamber is enlarged and the pressure inside

the veins in the lungs is higher because of blood going backwards. And as the

left ventricle continues to enlarge, it further restricts the blood flow to the heart,

and that causes the ventricle to dilate even more in a vicious cycle. The only

way to interrupt the deterioration is to fix the valve.

Techniques of Mitral Valve Repair

There are three major stages in the repair of the mitral valve:

Leaflet correction (fixing holes and excess tissue)

Subvalvular adjustment (fixing the chords that attach to the left ventricle)

Annuloplasty (fixing the ring that supports the valve)

EACTS Post graduate Course 2004

R Dion

Should all mitral valves be repaired?

• Comorbidity

• Difficult Access

• Difficulties at valve level

• Difficulties at subvalvular level

Comorbidity

• Precarious clinical condition

• Need for concomitant procedures

• Demanding and lengthy repair

Dispensa di Cardiochirurgia con analisi dei seguenti argomenti: insufficienza della valvola mitralica, anatomia della mitrale, fisiologia della mitrale, anatomia chirurgica della valvola mitrale, patologie della valvola mitrale, stenosi mitralica lieve, moderata, severa, stenosi pura, stenosi funzionale, sintomi della stenosi, insufficienza mitralica.