Luigi Farina

Facoltà di Medicina e Chirurgia

Università “Sapienza” - Polo Pontino

Anno Accademico 2013-2014 – Esame di Inglese III – Prof. L. Herdon

Aortic Valve Replacement

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SUMMARY

Historical Background .............................................................................. 4

Heart Anatomy and Physiology ................................................................ 7

Aortic Valve Anatomy ............................................................................ 11

Steps of AVR - Open Heart Surgey ........................................................ 12

TAVR - TRANSCATHETER AORTIC VALVE REPLACEMENT .... 14

Preoperative management ................................................. 14

Patient selection ................................................................. 14

Preparation ........................................................................ 14

Operative techniques ......................................................... 14

Imaging .............................................................................. 14

Surgical access .................................................................. 16

Balloon valvuloplasty ........................................................ 18

Positioning ......................................................................... 19

Deployment ........................................................................ 19

Surgical closure ................................................................. 20

Conclusion ......................................................................... 20

FAQ......................................................................................................... 22

What causes a failure of the aortic valve? ......................... 22

There are signs of a failure of the alarm aortic valve? ..... 22

How do i know if i have to be at work aortic valve? ......... 23

There are differences between implants and mechanical

organic? ............................................................................. 23

How is the surgery performed? ......................................... 24

Why i need surgery? .......................................................... 24

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Alternatives to surgery ....................................................... 25

Results of treatment failure ................................................ 25

What 'the risk of surgery? .................................................. 25

What will my condition after replacing aortic valve? ....... 26

Article 1 – Surgical treatment of aortic valve endocarditis .................... 27

Article 2 – Aortic stiffness is an indicator of cognitive dysfunction ...... 28

Article 3 – “Fast-implantable” aortic valve ............................................ 29

Article 4 - Retrograde cardioplegia administration ................................ 30

Article 5 – mid-term results for aortic roof replacement ........................ 31

Article 6 – Percutaneous aortic valve replacement ................................. 32

Bibliography ........................................................................................... 33

Sitography ............................................................................................... 33

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HISTORICAL BACKGROUND

In folio 115 of the Corpus of the anatomical Studies Leonardo Da Vinci

shows numerous drawings of the aortic valve and the structures attached to

it. This folio is one of the richest examples of precise and accurate method

of Da Vinci, but also the most difficult to clarify the anatomical pages of

Leonardo. The constant Leonardo's interest in the aortic valve is shown by

the frequent recurrence of drawings of the structure of the tricuspid aortic

valve, pointing to the fact that he was particularly attracted by its symmetry.

In addition, he wrote: "Non permettere a nessuno che non sia matematico

di legere mja principles" ("Do not let anyone who is not a mathematician

read my principles"). Already in the school of Pythagoras, the circle in the

plane and the sphere in space, were considered the perfect figures for their

symmetry and rotation. In fact, in the drawings of Leonardo, the tricuspid

aortic valve, in a circle appeared to be a perfect example of symmetry and

rotation.

The interest in Leonardo, as a mathematician, not only ended with the

geometric symmetry of the aortic valve, but it also expanded to fluid

dynamics. When each component was analyzed, Leonardo guessed its

function with a vivid imagination and tried to reconstruct the whole.

Analyzing the flow through the vessel and breasts had been able to

understand how the task of the aortic valve was done, in particular for what

concerns the opening and closing.

The concept of morphological and functional unit of the aortic valve is

introduced already Leonardo with a simple question: “…Perchè il buso

della arteria aorto è triangolare?..." (" ... Why is the aortic artery orifice

triangular? ... ").

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It was probably Erasistratus, in the third century BC, who first described

the three membranes at the level of the aortic and pulmonary orifices. The

graphical representation of a tricuspid aortic valve (but also lung) is one of

the first in the history of medicine, although Leonardo did not exclude the

possibility that the valves had 4 or 2 flaps.

And 'certainly hard to believe that Leonardo had ever seen a Quadricuspid

or bicuspid aortic valve, while it is more likely that it was a result of his

fertile imagination. The fact is that the incidence of bicuspid aortic valve is

about 0.52% in each of the 100 infants and 0.008% in the case of valve

Quadricuspid. Surely, Leonardo had little chance to find a bicuspid valve

and a valve Quadricuspid even less likely in his 30 anatomical dissections,

if we consider that Simmonds reports only 2 cases of valve Quadricuspid in

a total of 25666 autopsies. Leonardo clear and clearly differentiated three

different anatomical configurations, which seem rather a geometric

reasoning that a reproduction of a direct experience. Determined that: "...

per la qual cosa langolo più ottuso è più forte chellangolo retto del

quadra..." ("... for this reason, the obtuse angle is stronger than the right

angle of the square ..."). Indeed, in a tricuspid valve closed, in the center of

the aorta each flap forms an angle of 120° while in the configuration with

four flaps is 90°. He explained that the orifice of the valve with four square

edges, is larger than the triangular orifice inserted in the same circle;

accordingly, the valve

leaflets Quadricuspid are

weaker, because the

corners of the closure are

more remote from the

base of the triangle. In

this way, Leonardo in a

simple way, anticipated

the concept of increased

stress of the flaps in the presence of congenital diseases. This concept was

recognized much importance in the design and construction of biological

prostheses or in cases of conservative surgery of the aortic valve.

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Leonardo clearly understood that the durability of the valve was largely

dependent on

the fact that the

aortic valve

leaflets were

shares of the

aortic wall.

Observation of

his drawings

you understand that Da Vinci had also realized that the valve leaflets were

not connected in a circular manner but rather in the manner of the crown

(the fibrous skeleton) defining small triangular structures of the ventricle,

which have been recently re-evaluated.

Leonardo wrote that the aortic valve opens from the blood that "affect" and

close the blood that is "reflected". Also considered that the "impetus" of the

blood goes from the ventricle to the aorta and that this stretches and expands

the flaps upward. He also explained that the speed of the blood could depend

on the different diameters of the aorta: “...major velocita nella mjnor

larghezze dessa canna…”

("...the higher the speed

when the port is smaller,

less when it is larger ...").

For Da Vinci, the area of

coaptation was of vital

importance in

maintaining the cusps

closed, so that the blood

would not return back into the ventricle. I realized that was not the case in

the coaptation level of the free margin but at the level of the "belly" of the

flaps.

Thanks to the intuition and reasoning of Leonardo, the importance of the

area of coaptation in the efficiency and durability of the valve function are

underlined.

In conclusion, not only Leonardo understood the role of the flow of blood

through the sinuses of Valsalva, which represents the basis of the complex

mechanism of closure of the aortic valve, but also the lees a reference to the

importance of the stress at the level of the aortic valve leaflets, the

coaptation of the cusps and the concept of functional anatomy at the

microscopic level.

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HEART ANATOMY AND PHYSIOLOGY

The heart is an unequal organ, cable, consisting of involuntary striated

muscle tissue. Its main function is to set in motion the blood in the vessels;

for this is comparable to a pump, which, contracting, pushes the blood

towards the various tissues and organs. Has a shape that resembles an

upside-down pyramid. At birth, the heart weighs 20-21 grams and, in

adulthood, reaches 250 grams in women, and 300 grams in humans. The

heart lies in the chest, at the level of the anterior mediastinum, rests on the

diaphragm and is slightly shifted to the left. It is surrounded by the

pericardium, a sac serousfibrous, which has the task of protecting and

limiting distensibility. The heart wall is formed by three tunics

superimposed, from outside to inside are named:

Epicardium: It is the outermost layer, in

direct contact with the serous pericardium. It

consists of a surface layer of mesothelial cells that

rests on the underlying layer of dense connective

tissue, rich in elastic fibers.

Myocardium: It is the intermediate layer,

consisting of muscle fibers. The myocardial cells are

called cardiomyocytes. It depends both on the

contraction of the heart, both the thickness of the

heart wall. It is necessary that the myocardium is

properly perfused and innervated, respectively by a

vascular network and a nerve.

Endocardium: It is the lining of the heart chambers

(atria and ventricles), consisting of endothelial cells

and elastic fibers. A separate it from the

myocardium, there is a thin layer of loose

connective tissue

The internal shape of the heart can be divided into two halves: a left and a

right part. Each part consists of two cavities, or chambers, distinct, called

the atria and ventricles, within which the blood flows. Atrium and ventricle

of each half are placed, respectively, one above the other. On the right side,

you have the right atrium and the right ventricle; on the left side, you have

the left atrium and the left ventricle. A clear separation of the atria and

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ventricles of the two halves, there are, respectively, an interventricular

septal and one. Although the blood flow in the right heart is separated from

the left, the two sides of the heart contract in a coordinated manner: first the

atria contract, then the ventricles. Atrium and ventricle of a same half are in

communication between them and the orifice, through which the blood

flows, is controlled by an atrioventricular valve. The function of the

atrioventricular valves is to prevent reflux of blood from the ventricle to the

atrium ensuring unidirectional flow of blood. The mitral valve belongs to

the left half, and controls the flow of blood from the left atrium to the left

ventricle. The tricuspid valve resides, however, between atrium and

ventricle of the right side of the heart. In the ventricular cavities on both the

right and left, there are two other valves, called semilunar valves. Resides

in the left ventricle the aortic valve, which regulates blood flow in the

direction of the left ventricle-aorta; takes place in the right ventricle to the

pulmonary valve, which controls the flow of blood in the direction right

ventricular-pulmonary artery. As the atrioventricular valves, these must also

ensure unidirectional flow of blood. The vessels tributaries, ie those that

lead blood to the heart, "downloading" in the atria. To the left of the heart,

blood vessels are tributaries of the pulmonary veins. For the heart of the

right tributaries are the superior vena cava and the inferior vena cava. The

effluent vessels, ie, those that drain away the blood from the heart, branch

off from the ventricles and those are precisely controlled by the valves

described above. For the heart to the left, the vessel effluent is the aorta. For

the heart to the right, the effluent is the pulmonary artery.

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Blood circulation, starring the heart, is as follows. The right atrium, goes

through the caval veins, blood rich in carbon dioxide and low in oxygen,

which has just sprayed the organs and tissues of the body. The atrium, the

blood goes to the right ventricle and the pulmonary artery take. By this

pathway, the flow of blood reaches the lungs to oxygenate and rid of carbon

dioxide. Without this, the oxygenated blood returns to the heart, the left

atrium through the pulmonary veins. Passes from the left atrium to the left

ventricle, where it is pushed into the aorta, that is, the main artery of the

human body. Once the aorta, the blood goes to spray all the organs and

tissues, exchanging oxygen and carbon dioxide. Depleted of oxygen, the

blood turn into the venous system to return back to the heart, the right

atrium, to "recharge." And so it repeats a new cycle, equal to the previous.

The movements made by the blood occur following a relaxation phase

which follows a phase of contraction of the myocardium, ie the heart

muscle. The relaxation phase is called diastole; the contraction phase is

called systole.

During diastole:

The heart muscles of the atria and ventricles, both right and left, is

relaxed.

The atrioventricular valves are open.

The semilunar valves of the ventricles are closed

The blood flowing through the vessels tributaries, at first, in the atrium

and then the ventricle. The transfer of blood is not the case in its entirety,

as a share remains in the atrium.

During systole:

It takes place or the contraction of the cardiac muscle. They start the atria

and, subsequently, the ventricles. We speak more accurately, of atrial

systole and ventricular systole:

The amount of blood that was left in the atria is pushed into the

ventricles.

The atrioventricular valves close, preventing backflow of blood in

the atria.

They open the semilunar valves and ventricular muscle is

contracted.

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The blood is pushed into their effluent vessels: pulmonary veins

(right heart), if it is to oxygenate; aorta (left heart), if it is to reach

the tissues and organs.

The semilunar valves are closed again after the blood has crossed.

Diastole and systole alternate during the blood circulation and the behavior

of cardiac structures, regardless that the blood is in the right half or the left

half of the heart, are the same. To complete this overview on the heart,

remain to be mentioned two other issues of great importance. The first

concerns how and where does the nervous signal of myocardial contraction.

The second concerns the vascular system that supplies blood to the heart.

The nerve impulse that produces contraction of the heart comes from the

heart itself. In fact, the myocardium is a particular muscle tissue, with the

capacity of autocontrarsi. In other words, the cardiomyocytes are able to

generate by itself the nerve

impulse to the contraction. The

other striated muscles in the

human body instead need to

contract, a signal from the

brain. If you interrupt the nerve

network that leads to this

signal, these muscles do not

move. The heart, however,

presents, at the junction

between the superior vena cava and the right atrium, a natural cardiac

pacemaker, known as the sinoatrial node (SA node). In general, it is called

pacemaker referring to artificial devices, capable of stimulating the

contraction of the heart of patients with certain heart diseases. In order to

properly conduct the nerve impulse, born in the SA node, the ventricles, the

myocardium has other key points: in succession, the generated signal passes

through the atrioventricular node (AV node), the bundle of His, and the

Purkinje fibers.

The oxygenation of cardiac cells is up to the coronary arteries, right and left.

They originate from the ascending aorta. One of their failure results in

ischemic heart disease. Ischemia is a condition, pathology, characterized by

the absence or insufficient blood supply to a tissue. The blood, once

exchanged oxygen with the cardiac tissues, take the venous system of the

cardiac veins and the coronary sinus, thus returning to the right atrium. The

entire vascular network of the heart resides on the surface of the

myocardium, in order to avoid their constriction at the time of cardiac

muscle contraction; situation, the latter, which would alter the blood flow.

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AORTIC VALVE ANATOMY

The aortic valve, or aortic semilunar, is located in the orifice that connects

the left ventricle of the heart and the aorta. It plays a fundamental role:

regulating the flow of oxygenated blood from the heart to organs and tissues,

ensuring unidirectional. At the time of ventricular systole, in fact, the aortic

valve is open and allows the passage of blood into the aorta. A transition

took place, the valve closes, preventing reflux. The mechanism of opening

and closing is dependent on the pressure gradient, the pressure difference

existing between the ventricular compartment and the aorta. in fact:

The aortic valve is composed of the following anatomical elements:

The orifice tube is delimited from the ring. The surface extent of the

orifice, in the adult, a value between 2.5 and 3.5 cm2.; it’s diameter,

instead, measure 20 mm.

It is tricuspid, that has three flaps (or cusps) of the lunate form. The

cusps are arranged, on the ring valve, in a staggered manner, such as to

prevent blood reflux, once the valve is closed. The flaps are made up of

loose connective tissue rich in collagen and elastic fibers. As for the

other heart valves, tissue vascularization does not have its cusp, and,

even, a kind of nervous and muscular control.

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STEPS OF AVR - OPEN HEART SURGEY

1. Engraving chest, sternum and

divergence

2. Opening the pericardium and

stripped of the heart and blood

vessels

3. Cannulation of the ascending aorta.

The blood begins to circulate in the

heart-lung machine

4. Opening the right auricle and

cannulation for the machine

5. Preparation cardioplegia

6. Aortic cross-clamping and cardiac

arrest

7. Aortotomia and access to the valve

8. Introduction ring gauge to choose

the right size of the valve

9. Finishing ostium valve prosthesis

to accommodate

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10. Positioning stitches detached cardinal points ostium valve

11. Suture of the sutures on the ring

where the valve will be implanted

with the device

12. Suture of the prosthesis that will

be positioned ostium prepared

13. Valve positioning and fastening of

points of closure

14. Placing implants in the seat

15. Cut points and elimination

cardioplegia

16. Spontaneous and gradual onset of

cardiac activity

17. With Defibrillation you have the

normal recovery of cardiac

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TAVR - TRANSCATHETER AORTIC VALVE REPLACEMENT

Successful TA-TAVR is discussed in eight sequential steps: Patient

selection, Preparation, Imaging, Surgical access, Balloon valvuloplasty;

Positioning; Deployment and Surgical closure.

PREOPERATIVE MANAGEMENT

PATIENT SELECTION

Patient selection is the single most important step that can determine success

or failure of TA-TAVR.

PREPARATION

The patient is placed in the supine position and elevation of the left chest is

not routinely required. All electrical cardiogram leads and defibrillator pads

are placed appropriately but out of the way of the anticipated fluoroscopy

sites and allow access to the sternum and left thorax. Lines for continuous

arterial blood pressure monitoring and oximetry are placed before the

patient goes under a general anaesthetic and is intubated. TA-TAVR can be

performed without general anaesthesia, however, very limited experience

has been reported at the present time.

Early in the development of the procedure, the left lung was collapsed to

allow for better visualization of the left ventricular apex. However, it has

subsequently been found that the left lung rarely interferes with exposure of

the ventricular apex. Lung isolation is no longer required. Pulmonary

arterial catheter for continuous cardiac output monitoring is reserved for

patients with poor ventricular function.

For precautionary reasons, an important part of the preparation process is

the presence of perfusionist and a primed cardiopulmonary bypass circuit,

in the event of hemodynamic instability and surgical misadventures.

OPERATIVE TECHNIQUES

IMAGING

TA-TAVR was performed in the operating room using a portable C-arm

fluoroscope. However, the image quality was found to be rather poor to the

point where it was difficult to visualize the aortic valve. A greater quantity

of dye injection at the aortic root was used to better define the native aortic

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valve (AV) and this was of some concern as a large dye load can be

hazardous in patients with compromised renal function. Moreover, poor

visualization can be a major causative factor for valve malpositioning,

paravalvular regurgitation and embolization. With this in mind, it is strongly

advised that TA-TAVI should only be undertaken in a hybrid operating

room or catheterization laboratory with high-definition fluoroscopic

equipments and multiple monitors. As well, it is imperative that

transesophageal echocardiography (TEE) or intracardiac echocardiography

(ICE) be available to access ventricular, valvular functions and the annular

size. In addition, TEE is an invaluable tool to help with the positioning of

transcatheter valve

stent prior to its

deployment.

Defining the

implant angle,

where the bases of

all three aortic

cusps reside on the

same plane is

crucial to a

successful

implant. An initial

root aortogram

performed with a 7

French (F) pigtail

catheter at the base of the non-coronary cusp at an angle of AP and caudal

10o should guide the operator to define the optimal line of perpendicularity.

Several imaging software systems, such as DynaCT, Innova HeartVision

System and C-THV utilize 3-D rotational angiography to better define the

aortic root anatomy and identify the line of perpendicularity. Preoperative

multi-slice computer tomography (MSCT) can provide valuable

information on annular size and implant angle.

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SURGICAL ACCESS

The left ventricular apex is located by placing the tip of a hemostat on the

patient at the apex location as seen on fluoroscopy. This method has been

found to be reproducible and more useful than palpation for the apex beat,

particularly in patients of high body mass index. Preoperative CT guided or

intra-operative surface echocardiography is used by some groups. Sixth

intercostal space (ICS) is the most common access site, followed by 5th

ICS. Over the previously determined

location of the apex, a 3 cm incision is

made. The incision is made over the

top of the rib to avoid trauma to the

neurovascular bundle. When it is

possible, using the lower ICS is more convenient in terms of a straighter

trajectory to the aortic valve. The left lung, as previously mentioned, does

not usually interfere with the exposure of the left ventricular apex. A soft

tissue retractor, Alexis Retractor is inserted into the incision to retract the

soft tissue without spreading the ribs. This method greatly reduces post-

operative pain.

The pericardium is then incised and opened near the left ventricular apex

and pericardial retraction sutures may aid further exposure. In cases where

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the patient has a history of previous cardiac surgery, dissection of

pericardial adhesions is avoided.

As with all procedure, transapical

TAVR has an Achilles heel and that is

haemostatic control of the left

ventricular apex. Particular care must

be taken when placing two large

pledgeted orthogonal mattress sutures

using 3-0 MH polypropylene sutures

to obtain full thickness of the left

ventricular wall. Each of the two

mattress sutures are snared and passed

through tourniquets that can be

tensioned at the time of sheath

removal. The sutures are appropriately placed to allow space for the largest

sheath, initially an Ascendra sheath with an internal diameter (ID) of 33 F

sheath and more recently a smaller (24 F ID) Ascendra II Plus delivery

system. The true apex should be avoided, as it is frequently thin and covered

by adipose tissue. A ‘bare spot’ lateral and cranial to the true apex should

be used to avoid catastrophic ventricular rupture.

Rapid ventricular pacing is required for the implantation of balloon-

expandable prosthesis, in order to decrease forward flow during the

valvuloplasty and valve deployment. One unipolar epicardial pacing wire is

placed directly onto the left ventricle and another on patient’s chest wall.

Alternatively, transvenous pacing lead can be implanted into the right

ventricle. Pacing rate of

140 to 200 beat per

minute frequently results

in 1:1 ventricular capture

and lowers the pulse

pressure and forward

flow. The rapid pacing

periods and episodes must be minimized to ensure hemodynamic stability,

especially in patients with depressed left ventricular function and/or non-

revascularized coronary artery disease.

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Hemostasis of the apex is ensured prior to the administration of

unfractionated heparin to achieve an activated clotting time of greater 250

seconds. A 14-gauge Seldinger needle is positioned in the centre of the

mattress sutures’ square and advanced to enter

the chamber of the left ventricle. The angle of

entry should be pointing toward the right

shoulder, whereby crossing of the native aortic

valve can be easily achieved. Correct placement

can be confirmed by the visualization of bright

red blood spurting with each ventricular

contraction. If oxygenated blood does not spurt

despite advancement of the needle, this suggests

the needle may be in the interventricular septum. Also, the needle could be

inadvertently embedded into the hypertrophied ventricular wall if the angle

of introduction was too obtuse. If pulsatile venous blood is visualized, this

is indicative that the septum has been crossed and the needle has passed into

the right ventricle. Once oxygenated blood is visualized, a soft wire is used

to cross the native aortic valve. A 7F sheath is introduced over the short

wire using Seldinger technique across the AV. A 260 cm, 0.035- inch

Amplatz extra stiff wire is exchanged and maneuvered down the descending

thoracic aorta.

BALLOON VALVULOPLASTY

Balloon valvuloplasty can be performed with a 14 F Cook or the Ascendra

sheath under rapid ventricular pacing. A 3 cm, 20 cc BAV balloon from

Edwards LifeSciences is used for all cases

regardless the size of the annulus. BAV

facilitates the crossing of the stenotic AV and

retrieval of the transcatheter valve if it is

accidentally advanced past the native valve.

Further, BAV improves the aortic valve area

and allows flow around the valve stent during

positioning, thus minimizing hemodynamic

instability. BAV also rehearses the

deployment steps, allowing synchronization

of the team.

Close observation of the movement of the calcified leaflets relative to the

coronary Ostia during BAV may help to exclude patient with high-risk

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anatomy for coronary occlusion. A root aortogram can be performed with

an inflated balloon in situ to better define the structures.

POSITIONING

The Edwards SAPIEN balloon expandable transcatheter valve is

constructed of trileaflet bovine pericardium on a metal stent. It is crimped

onto the delivery balloon. The correct orientation of the transcatheter valve

with the Dacron ring at the base of the valve on the ventricular outflow side

and open stent on the aortic side must be ensured. After engaging the

delivering system, the valve is advanced beyond the tip of the Ascendra

sheath under fluoroscopic guidance.

Withdrawal of the pusher catheter is

then carried out. The SAPIEN valve

is positioned within the native AV.

The SAPIEN prosthesis is ideally

placed 1/3 below the base of aortic

sinuses, the bottom of the valve stent

positioned ventricularly relative to

the line of perpendicularity with the

aide of repeat aortic root angiograms. TEE provides additional images that

further refine the positioning. Aligning the ventricular end of the valve stent

to the aorto-mitral fibrous curtain, the “hinge point’ of the anterior leaflet

of the mitral valve, confirms the ideal landing zone. If accurate positioning

cannot be achieved due to brisk cardiac motion, rapid pacing with root

injections may assist in positioning.

DEPLOYMENT

It is extremely important to ensure

accurate positioning of the valve prior to

its deployment to avoid malpositioing,

embolization and significant perivalvular

leak. Once acceptable positioning is

confirmed using echocardiography and

fluoroscopy, the pigtail catheter is

withdrawn to the ascending aorta, the

pacing protocol is again initiated and the

valve is slowly deployed. During

deployment, fine adjustment can be made

to ensure optimal placement. Full

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emptying of the inflation syringe and maintaining full pressure ensures

symmetric deployment and prevents stent recoiling. The balloon is quickly

deflated and pacing is ceased. The balloon is pulled back out of the valve

stent into the delivery sheath, preventing interference with leaflet function.

Once the valve is deployed, echocardiography reports on the stability,

location and function of the valve stent, and the degree of perivalvular

regurgitation. If valve position is satisfactory and more then moderate

degree of perivalvular regurgitation exists, a second attempt with slight

higher balloon inflation volume may be attempted. If the degree of central

regurgitation through the valve is difficult to evaluate with the Amplatz wire

across the valve, it too is withdrawn into sheath. Completion aortogram is

seldom perform to minimize the dye load that may adversely effect renal

function.

SURGICAL CLOSURE

With systolic pressure less than 100 mmHg, the delivery sheath is removed

with snugging of the mattress sutures. Then

the other orthogonal mattress suture is

subsequently tied. Persistent hypertension can

be controlled with ventricular pacing at a rate

of 100 to 140 bpm. Any blood collections are

aspirated from the left chest and local

bupivacaine is injected into the intercostal

muscles. A small-bore chest drainage tube

brought out through a small stab wound is left

behind in the left chest. The intercostal

muscles are approximated and the skin closed

with absorbable subcuticular suture.

CONCLUSION

Within the last decade, transcatheter aortic valve replacement (TAVR) has

come from relative obscurity to become a procedure that is practiced at most

major health centres worldwide and the technical details of this procedure

have been described by many. The rapid adoption of TAVR in medical

practice makes it one of the fastest therapeutic modalities incorporated and

evaluated by randomized control trial. Transfemoral (TF-TAVR) retrograde

and transapical (TA-TAVR) antegrade approaches were the most widely

practiced. TA-TAVR is the preferred procedure where the peripheral access

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is limited due to size, calcification and torturosity. TA-TAVR provides a

more stable platform for TAVR, due to the more direct and shorter distance

to the native aortic valve. Access via the subcalvian artery and ascending

aorta are emerging to be viable alternatives. Procedural technique can be

very important in high-risk patients and remains among the few modifiable

factors. Therefore, it is worthwhile to describe the intricacies of the TA-

TAVR approach, with the aid of photographs. The technique described is

intended for transapical implantation of the SAPIEN transcatheter valve

using the Ascendra delivery system.

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FAQ

WHAT CAUSES A FAILURE OF THE AORTIC VALVE?

The aortic valve can not work for various reasons. For example, may be

abnormal from birth (congenital aortic valve), or may become ill with age

(acquired aortic valve disease).

The most common congenital abnormality is a bicuspid aortic valve. The

normal aortic valve has three flaps, but a bicuspid valve has only two.

Therefore, it may not open or close completely. The bicuspid aortic valve is

a common abnormality and is present 1-2% of the population. For frequency,

it is the second leading cause of aortic disease that requires surgical

treatment. such valves can function normally for years before they begin to

be dysfunctional (stenotic and / or insufficient). People with a bicuspid

aortic valve require antibiotic prophylaxis before interventions to the teeth

but are not generally required other special precautions in addition to

periodic monitoring by a cardiologist qualified. The most common cause of

aortic disease that requires treatment surgery is called "senile aortic

calcification." The valve is namely ruin with age. When a valve begins to

deteriorate, the body calcium deposits on it for unknown reasons. The

football narrows diameter and restricts the movement of the valve leaflets.

This may hinder the valve opening (causing stenosis) or closing (causing

insufficiency or regurgitation). Less common causes of valve disease aortic

diseases of the ascending aorta, the main vessel blood that comes out from

the heart and which carries the blood to the rest body: the aneurysm,

dissection and Marfan syndrome.

THERE ARE SIGNS OF A FAILURE OF THE ALARM AORTIC VALVE?

Alteration of the aortic valve can cause a variety of symptoms, which

include shortness of breath, chest pain (angina pectoris), dizziness and loss

of consciousness (fainting). A valve stenosis causes an increase of the work

that the heart has to do to pump blood around the body. a failure of the valve

results in a return of blood in the heart after it has been pumped out. The

heart muscle must therefore pump more blood to go forward, even one that

is returned back. All of these conditions can cause symptoms super job of

heart failure, such as shortness of breath, which at the beginning can be

appreciated only under stress, but that later, with the progression of the

disease, may also occur with activity light or at rest. Many patients can not

sleep lying in bed or can wake up to the shortness of breath. Another sign

of heart failure, which can occasionally appear, it is the swelling of the feet,

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particularly evident in the late afternoon or evening, although other

conditions such as varicose veins can cause such disorder. The super work

that the heart has produced, can also cause pain angina pectoris or chest

similar to the symptoms of a heart attack. It can be difficult to tell the

difference between a disease and valvular stenosis of the blood vessels of

the heart (arteries coronary arteries). The disease of the aortic valve can

therefore cause dizziness, light-dizziness or even fainting periodicals.

HOW DO I KNOW IF I HAVE TO BE AT WORK AORTIC VALVE?

The decision to proceed with surgery should be taken with his medical team

is usually composed of the cardiologist and by the cardiac surgeon. The His

doctors probably base their recommendations on her symptoms and the

results of some tests including an echocardiogram and cardiac

catheterization times. An echocardiogram allows you to see an enlargement

of the heart and can help to measure the degree of stenosis or insufficiency.

A Cardiac catheterization provides similar information, but it can also

identify possible stenosis of the coronary arteries.

THERE ARE DIFFERENCES BETWEEN IMPLANTS AND MECHANICAL

ORGANIC?

Today there are numerous excellent prosthetic valves mechanical. Most

surgeons have a preference for a specific valve in relation to some of the

technical factors (for example: how they apply in the home, as did the suture

ring, etc.). Although from the point of view of the patient is small the

eventual difference between the various models. The main advantage of

mechanical valves is their excellent lifespan. From a practical point of view,

never wear. The main disadvantage is that there is a tendency of blood to

clot on all mechanical valves. Consequently, patients with such valves must

take anticoagulants or "blood thinners" for the rest of their lives. So there is

a small but well-defined risk of blood clotting, which can cause the

prosthesis stroke. There is a large variety of biological valves that can be

used to replace a diseased valve. They all have in common a reduced risk

of formation of blood clots, but all are less durable than mechanical valves.

Past a certain time, all will be consumed. The choices in this category

include the xenograft, valves made from animal tissue (most of the times of

pig aortic valves or valves "built" with pericardium cattle), the homograft

or allograft valves prepared from cadavers human, and l '"pulmonary

autograft", a self transplant, their valve moved from the pulmonary artery

on the right side of the heart, the seat Aortic on the left side.

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The decision on the type of valve to be used should be taken into accordance

with his cardiologist and cardiac surgeon. Ultimately the choice depend on

the preferences of the patient, his lifestyle and individual risk determined

by age and other medical conditions.

HOW IS THE SURGERY PERFORMED?

The replacement of the aortic valve is an intervention that is performed only

by the cardiac surgeon. Is performed under general anesthesia general.

Before being asleep are inserted cannuline in certain veins of the arm, for

the infusion of drugs, and in artery for continuous measurement of blood

pressure. The traditional technique requires a longitudinal aperture

(vertical) of the anterior wall of the chest through the breastbone that is cut

into two parts. This incision is called a sternotomy vertical midline. Through

this opening, the surgeon can see all your heart and the ascending aorta. The

surgery requires that the patient is connected to the machine heart-lung. To

do this, two cannulas are inserted, one in the the upper part of the ascending

aorta and the right atrium. They carry the blood from the patient to the

machine, where it is enriched with oxygen, and vice versa. Started the extra

corporeal circulation, the heart can be stopped with a special blend of

chemicals call cardioplegia.

At this point, the aorta is opened, the diseased valve removed and the His

place was inserted a prosthesis (mechanical or biological). and then the

aorta is closed. Just receive back the blood, the heart begins spontaneously

to contract. The patient can then be removed from the machine.

WHY I NEED SURGERY?

The aortic valve is the valve out of the left side of the heart. It opens during

systole (when the ventricle contracts and pushes blood into the aorta and the

rest of the body). When the aortic valve is too narrow (stenotic), the

ventricle must work hard to push the blood around the body. This extra-

work consumes considerable amounts of energy and ultimately requires a

blood flow in more to nourish the heart itself. If there is a sufficient arrival

of the blood, the heart becomes ischemic with resulting in anginal chest pain.

Aortic stenosis is usually progressive and gets worse with time. When the

valve becomes very narrow, the heart has to work harder and harder until

that an certain point no longer able to compensate. Appear as episodes of

low blood pressure (hypotension crises), syncope (loss of consciousness),

congestion and pulmonary edema. Even when the aortic valve is insufficient

(loses), the heart works harder and you create the same problems. The

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ventricle must pump more blood with each contraction to produce the same

thrown forward. This creates a condition called overload volume. The heart

can compensate for this overload for many months or even years, provided

that the failure to develop slowly. By the time the heart starts to break down

and appear to lack breath and weakness. The possible benefits could be the

disappearance of the anginal symptoms, heart failure and syncope. The

chances of successful treatment in the absence of complications, are 95%

(failure rate of 5%).

ALTERNATIVES TO SURGERY

Are there alternatives to surgical treatment and that the facility valvular

trans-apical (TA-TAVI), namely the implantation of an endoprosthesis tube

through a cannulation of the apex of the heart with a mini access chest or

with the introduction of an endoprosthesis valve through the femoral artery

in the groin catheterization. These methods, however, at present, are

indicated only for patients with severe impairment of the general condition

or patients terminals, that is not amenable to conventional treatment.

RESULTS OF TREATMENT FAILURE

The predictable outcome of not treating are worsening progressive heart

failure and angina with an increase functional limitations, increased

frequency of episodes syncopal and the possibility of cardiac death.

WHAT 'THE RISK OF SURGERY?

The risk cardiac surgery depends on the conditions, the general conditions,

the presence of other comorbidities and functional status of the major organs

and body systems. Among these are:

circulatory failure can not be controlled with medication, for which

must resort to mechanical systems support.

sudden occlusion of a coronary by-pass with the eventual need for a

new surgery;

malfunction of prosthetic valve;

heart attack directly associated with the transaction;

paralysis (temporary or permanent) in the arms and / or legs (for

example due to an insufficient blood supply);

complications of the gastro-intestinal tract;

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cerebral complications (results in impaired speech and movements

up to coma) caused by a blood supply defective due to poor

circulation or blood clots;

thrombosis, embolism (blood clots and subsequent vessel

occlusion);

bleeding: from surgical sutures and / or from abnormal coagulation

of the blood;

infection and suppuration intractable arrhythmias or forms that may

require further medicines, or the implantation of a pacemaker;

Pouring liquid into the pleural cavity and / or in the pericardium,

which must be drained;

shortness of breath due to paralysis of the diaphragm;

broncho-pneumonic complications.

WHAT WILL MY CONDITION AFTER REPLACING AORTIC VALVE?

After successful aortic valve replacement, patients can expect to return

quickly to the conditions preoperative. As a result of their condition should

definitely improve. The anticoagulant ("blood thinning") with a drug

(Sintrom or Coumadin) should be prescribed for 2-3 months in patients with

biological prosthesis, for the whole life in those with valve mechanics.

When surgical wounds will be healed, there will be few or no restrictions

on its activity.

27

ARTICLE 1 – SURGICAL TREATMENT OF AORTIC VALVE ENDOCARDITIS

ABSTRACT

Endocarditis of the aortic valve is a surgical

operation that is applied since 1965 This article

presents a retrospective study of all the operations

and the results obtained in 174 aortic valve

replacements affected by endocarditis, in 26 years

of business in Kartal Kosuyolu Heart and Research

Hospital in Istanbul. 282 interventions were

performed, of which 230 have been replacements of aortic valves (with and

without endocarditis). The hospital mortality was 15.5% (27 cases). The

survival rate for 10-15 years after surgery was equal to 74.6 + 3.7% (in

patients with a reduced cardiac output) and to 61.1 + 10.3% (for patients

who have had a cardiac arrest). This study found that the operation has a

significant mortality and risk factors are: emergency operations, female

gender, renal failure and reduced cardiac output. The risk of recurrence and

the need for new operations is low.

Kartal Kosuyolu Heart and Research Hospital, Istanbul - Turkey

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ARTICLE 2 - AORTIC STIFFNESS IS AN INDICATOR OF COGNITIVE DYSFUNCTION

ABSTRACT

This article presents a study on patients had cognitive dysfunction, after

operation of the AVR (Aortic Valve Replacement) for Aortic Stenosis (AS).

These disorders are frequent in patients operated on at the aortic valve due

to the risks associated with the surgery, which are: the systemic

inflammatory response syndrome, hypoperfusion, microembolization. Even

in patients undergoing "successful interventions" were presented

postoperative cognitive problems. In the face of these data, it was decided

to evaluate whether aortic stiffness is related to cognitive dysfunction in

patients undergoing surgery for aortic

stenosis. The aortic pulse wave

velocity (PWV) was used as a

measure of aortic stiffness and

cognitive function was assessed using the computerized Cambridge

Neuropsychological Test Automated Battery (Cantab). Patients with normal

PWV were: higher mental retardation, visual sustained attention and

executive function comparable to patients with high PWV. The immediate

memory and decision-making were similar in the two groups. After surgery,

the improvement of cognitive function was more pronounced in patients

with higher PWV compared to patients with normal PWV. The conclusion

is that the intervention AVR can not be associated with an effect on

cognitive process. The PWV could be useful as an additional marker of

cognitive function before and after surgery for AS.

St. Mary's Hospital, London - England

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ARTICLE 3 – “FAST-IMPLANTABLE” AORTIC VALVE

ABSTRACT

This article presents a new type of valve that can be implanted during an

intervention with concomitant mitral valve replacement. Two bioprosthetic

heart valves may interfere for their design or for space dimensions. With the

new valve Intuity (who has a stent under the ring) there is no interference

with an existing mitral valve. The valve

has been tested on pigs before and then

after signing the informed consent, two

patients. The first was a woman of 82 years

of which have been replaced both valves,

the aortic and mitral stenosis, without

interference observed on chest

radiographs. The second case was also

replaced both valves via two venous grafts

without presenting postoperative

interference. In the light of these results it

has been claimed that the valve Intuity is

much faster to implant (does not need all the stitches of the prosthesis

standard) and its plant does not increase the risk of displacement of the

mitral valve. The time to plant is 8-1o minutes and this significantly lowers

the probability of an ischemic cardiac arrest.

University of Lausanne, Lausanne - Switzerland

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ARTICLE 4 - RETROGRADE CARDIOPLEGIA ADMINISTRATION

ABSTRACT

This article emphasizes the importance of the administration of retrograde

cardioplegia in a particular case. The Routes of administration of

cardioplegia are three:

• Aortic Bulb: seat of election, with the exception of aortic insufficiency

because refluirebbe in the ventricle;

• Coronary Osti: using this access route in the case of aortic

insufficiency;

• Breast coronary artery (retrograde): you use this access route even

when the coronary ostia are obstructed or otherwise there is a multi-

axial obstructive coronary artery disease.

The coronary sinus can be reached directly with a video-assisted

cannulation and at pressures lower than 40 mmHg, or indirectly through the

right atrium (little used because it would cause excessive dilation of the

atrium or the right ventricle).

In this case the patient, 66, had been admitted into the local clinic for the

treatment of aortic stenosis. Angiography showed variations in coronary

narrowing. At the same time it was found that the anterior branch had a

separate start dall'ostio descending artery. Because of the complex

anatomical situation of the aortic valve was decided to change the strategy

to protect the myocardium against ischemia. The procedure was performed

in moderate hypothermia at 32 ° C and the heart was stopped with cold

retrograde cardioplegia. The result showed no postoperative ischemic

damage in the patient.

Akademicki Szpital Kliniczny, Wrocław - Poland

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ARTICLE 5 – MID-TERM RESULTS FOR AORTIC ROOF REPLACEMENT

ABSTRACT

This article shows the results of 201 interventions for aortic root

replacement with biological prosthesis and stent. The patients had a mean

age of 66 years old and had

undergone surgery for:

annuloectasia or aortic aneurysm

of the ascending aorta with

concomitant valve endocarditis.

The hospital mortality was 4.5%

and the rate of cardiac mortality

related to the intervention, after

1-5 years, 3-6%. No patient

presented over the years

thromboembolic events. The 1%

of patients presented a slight

structural deterioration of the

valve without clinical symptoms.

In light of these results it can be stated that in the medium term, the aortic

root replacement with biological prosthesis self-assembling is interesting.

The hemodynamic results are excellent and the need to redo the operation

is remarkably low. The long-term results will clarify fully the real risks of

surgery.

University Hospital Berne, Berne - Switzerland

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ARTICLE 6 – PERCUTANEOUS AORTIC VALVE REPLACEMENT

ABSTRACT

To be eligible for the TAVR is a

variable number of patients. 30% of

patients with severe aortic stenosis

who require appropriate action, not

receive it. Given the aging of the

global population, patients who will

need TAVR will be more and more.

Clearly, the choice between TAVR

and AVRbyOS will be dictated mainly by the costs and organization of each

country. On the one hand you have a very high risk of doing AVSbyOS in

cases of emergency and the other with the TAVR is likely a left bundle

branch block. In addition, patients who need a pacemaker after the operation

are those made with TAVR; the same ones who have the most frequent

postoperative stroke. Instead, ischemic defects are more frequent in patients

operated with AVRbyOS because the aorta is manipulated. It can be

concluded that on both sides there are risks to consider but lacks a

randomized clinical trial to know the follow-up of patients 10-15 years after

surgery. When these data will be collected you will have the chance to make

a change of direction towards the TAVR intervention that is less invasive

and with fewer postoperative complications.

Hospital Universitario “Fundación Favaloro” - Argentina

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BIBLIOGRAPHY

Autori vari, Trattato di Anatomia Umana, Volume I e II, Edizione 2009,

Edi-ermes.

Guyton A. e Hall J. E., Fisiologia Medica, Edizione 2010, Elsevier.

Nelson D. L. e Cox M. M., I principi di Biochimica di Lehninger, Edizione

2010, Zanichelli.

Andreoli, Carpenter, Griggs, Benjamin, Cecil Essential of Medicine,

Edizione 2007, Elsevier.

SITOGRAPHY

PUBMED:

http://www.ncbi.nlm.nih.gov/pubmed

NEW ENGLAND JOURNAL OF MEDICINE:

http://www.nejm.org

CARDIO EXPERT CHANNEL:

http://www.youtube.com/channel/UCeaM0YzToLcfeCiBkJQCqhA

http://www.ucl.com

http://www.cardiochirurgia.org/sva.html

http://my.clevelandclinic.org/services/heart/disorders/valvetreatment/aort

icvalvesurgery