lecture khaja sir, NICVD

1. AORTIC VALVULAR DISEASES
PROF. KHWAJA N. MAHMOOD
HEAD OF THE DEPARTMENT
CARDIAC SURGERY, NICVD
1

2. Etiology of Aortic stenosis
1. Rheumatic – most common
2. Congenital-
 Valvular (calcified bicuspic valve)- next common
 Supravalvular
 subvalvular
1. Sclerotic- senile calcific aortic stenosis
2

3. Etiology of Aortic regurgitation
1. Primary valve
disease 2. Aortic root disease
a) Rheumatic AR Annular ectasia from
b) Congenital- bicuspid aortic valve
a) Chronic aortic aneurysm
or in association with VSD
c) Infective endocarditis b) Dissecting aortic aneurysm
d) Aortitis- syphilitic aortitis or Annulo aortic ectasia from
ankylosing spondylitis , Giant cell
c) Marfan’s syndrome
arteritis.
3

4. Causes depending on severitiy of AR
Acute ar Chronic ar
1. Infective endocarditis 1. Rheumatic AR
2. Congenital – bicuspid
2. Trauma
aortic valve
3. Dissecting aortic 3. Aortitis- syphilitic ,
aneurysm ankylosing spondylitis
4. Marfan’s syndrome
4

5. Natural history of AS & AR (surgically
untreated )
 AORTIC STENOSIS
 Natural history is incompletely known
 Severity & symptoms are gradually increased
 Patient with untreated severe AS
A. May die suddenly due to VF within 1-2 years ( 15-20% of all death in AS are
sudden)
B. May die from LVF – acute pulmonary edema within few hours or days of its
onset, which occurs within 5 years of diagnosis
C. May develop chronic heart failure
D. Occasionally complete heart block develops in patient with extensive calcification
5

6. Natural history of AS & AR (surgically
untreated )
AORTIC REGURGITATION- depends on severity
 Mild to moderate AR has very little effect on activity & life expectency
 Severe AR - develops symptoms and prognosis is limited because of symptoms
of cardiac failure, development of premature beats, Marked cardiomegally (CT
ratio > 0.6) and ECG evidence of LV hypertrophy which occurs within a
period of 3-10 years).
 Acute development of severe AR – natural history is less favorable, only
10-30 % survive more than 1 year.
6

7. PATHOPHYSIOLOGY OF AS
1. LV systolic pressure overload
 Increasing LV pressure
 Increasing large pressure gradient across the valve
 Concentric hypertrophy of LV -
 - Diastolic stiffness
 - Increased LVEDP
1. Angina pectoris
 Relatively low coronary diastolic pressure
 High LVEDP can impede flow to the subendocardium
 Lower duration of diastole because of tachycardia can lower subendocardial flow
Increased myocardial oxygen consumption due to increased muscle
mass
1. LV contractility
 Decreased contractility per unit muscle mass in AS
1. Role of LA is reduced
 Because of diastolic stiffness – increased LVEDP more than LAP
 Since 30% of LV filling is by contraction of LA (normally 20%) which will be absent
7

8. PATHO PHYSIOLOGY OF AR
1. LV under goes dilatation & concentric hypertrophy
• As compensatory mechanism
1. Sub endo-cardial ischemia and angina
• May occur even in normal coronary arteries because myocardial oxygen consumption is high
and decrease in diastolic pressure in aorta
1. LV contractility
• Remains in normal range until LV failure developes
• Patient with mild, moderate or severe AR can remain asymptomatic except for mild
dyspnoea.
 Despite dilatation and hypertrophy
 LVEDP, LAP & PCWP remain essentially normal
 EF is maintained in the normal range in AR until LV failure
8  EF <50% indicates severe impairment of LV contractility

9. Classification of AR
 On the basis of regurgitant fraction (RF)
1. Trival AR- RF less than 10% & regurgitant flow <1 litre/min
2. Mild AR- RF 10-40% & regurtitant flow around 1-3 litre/min
3. Moderate AR- RF 40-60 % & regurgitant flow 3-6 litre/min
4. Severe AR- RF more than 60% & regurgitant flow > 6 litre/min
9

10. Classification of AR cont….
ANGIOGRAPHIC CLASSIFICATION
o Grade -1:
a. Small regurgitant jet
b. Clear wash out of regurgitant
contrast in nest systole
o Grade-2:
a. Partial and faint opacification
of LV
b. Incomplete washout of
regurgitant contrast in next
systole
10

11. Classification of AR cont..
ANGIOGRAPHIC CLASSIFICATION cont…..
o Grade -3:
 Dense opacification of LV in 2nd
& 3rd diastole
o Grade-4:
 Dense & total opacification of
LV in only 1 diastole
NB. Grade III & IV AR- operation is required
11

12. Effects of AVR in Aortic regurgitation
LV contractility may be slightly depressed soon after AVR because-
1. Myocardial effects of CPB
2. Ischemic period (X-clamp time)
3. Residual effect of cardioplegic drug
4. Increse in impedence to LV ejection that occurs when AR is abolished,
especially in 1st few hour of bypass, when SVR is increased
12

13. Indication for surgery in AS
A. If symptomatic
 Classic symptoms of syncope, angina or heart failure. ( angina is present
in about half of the patients requiring AVR in AS, all 3 symptoms are present
in one third of patients of AS)
A. If asymptomatic
 If Aortic valve gradient is > 50 mmHg or
 If AVA is < 0.8 cm2
A. Urgent operation is indicated
 If patient has severe LVH & increasing pulmonary hypertension
13

14. Indication for surgery in AR
14

15. Indication for surgery in AR
ACUTE AR
1. Acute AR with CHF ( as in annular ectasia with aneurysm)
2. Acute infective endocarditis – vegetation of valve, recurrent embolisation,
systemic & persistent sepsis
N B. -
AVR can be done in all patients with AS, even with bad LV function with
later development. Whereas AVR may not give good result with long
standing ventricular dysfunction with bad LV ejection fraction in AR and
may kill the patient
15

16. Preoperative consideration
1. CAG should be performed if
• age > 40 years.
• Angina is present
• Positive in ETT
1. Judicious use of drugs is necessary in AS . Drugs that reduces preload &
afterload should be avoided (eg. GTN, Ca++ blocker, β blocker) since these may
lower cardiac output & may precipitate cardiac arrest in a patient with
critical AS
16

17. Contd.
3. Dental work should be performed before surgery to minimise the risk of PVE
4. Selection of appropiate procedure & valve type should be done beforehand.
Depending upon
• Age of the patient
• child bearing age
• Patient desires to avoid anticoagulant or not
• Contraindication to long term anticoagulant or not

18. AVR- operating techniques Tits & Bits
1. Approach
2. Vent
3. Cardioplegia
4. Aortotomy
5. Insertion of prosthesis
18

19. AVR- operating techniques Tits & Bits cont……..
1. Approach-
a) Standard sternotomy
b) Mini sternotomy
c) Heart port system with mini sternotomy
d) Robotic technique with use of heart port system
1. Vent- keeps LV dry, help in maneuver of replacement
a) Right superior pulmonary vein (most commonly used)
b) Left ventricular apex
c) Pulmonary artery
1. Cardioplegia
a) Antegrade selective cardioplegia to Rt & Lt coronary artery at 20
min interval
b) Antegrade + retrograde cardioplegia
c) Retrograde cardioplegia only
19

20. AVR- operating techniques Tits & Bits cont……..
4. Aortotomy-
a) 2 cm proximal to annulus in case of prosthetic valve
b) 4 cm downstream from RCA orifice for space for intra aortic
positioning of allograft or autograft valve and to avoid damage of
RCA ostium
Exception- In ‘Mini’ aortic root replacement with Autograft pulmonary
valve cylinder, since autograft pulmonary trunk is relatively short,
aortotomy can be made close to RCA anteriorly in an idea to
preserve as much aorta as possible
20

21. AVR- operating techniques Tits & Bits cont……..
5. Insertion of prosthesis
a) Interrupted pledgeted 2-0 mattress Ethibond suture are used except those on
commissures, where non pledgeted suture is used
b) Left coronary cusp area is done 1st, then RCC area & lastly NCC area.
c) Care should be taken while taking suture in commissural area between
RCC & NCC so that stich doesn’t penetrate more than 2 mm beneath
the annulus – to prevent injury to bundle of His.
d) For supra annular positioning, suture should come from ventricular side of the annulus
up into aorta and then passed through the cusp. At commisure stiches are placed from
aorta into ventricular side. For infra and intra annular positioning suture is passed
from aortic side through the annulus down to ventricle and then passed through cuff
of prosthesis.
21

22. AVR- operating techniques Tits & Bits cont……..
Insertion of prosthesis continued….
e) Prosthetic valve is slided down to aortic annulus.
f) Sutures are 1st tied in the RCC then LCC & then NCC.
Advantage is if RCC stich or LCC stich breaks then the valve can be lifted
and it is easy to place another stich. If a suture breaks while tying RCC
stiches one can salvage the situation by giving a pledgeted stich from
outside of the aorta up through the aortic valve seweing ring.
g) Valve opening is tested to detect any restriction of movement of cusp. If
any restriction of opening is noted valve is rotated
22

23. AVR- operating techniques Tits & Bits cont……..
Insertion of prosthesis continued….
h) Deaeration :
i. LV vent is stopped
ii. Aortic root vent is placed
iii. Head end is lowered
iv. Valsalva maneuver is done with simultaneous compression of heart
to expel air through aortic root vent & pressure on RCA is applied
not to allow air to enter into it.
v. Aortic X-clamp is removed
vi. LV vent stopped again & needle to aspirate the dome of LA & apex
of LV is done
vii. Partial X-clamp on aorta is placed to allow air to pass through
aortic root vent, when heart starts beating.
23

24. Surgical option of AS
1. AVR- is the standard treatment. It should be considered in all patients with
severe AS, no matter how bad is EF, because these patients will certainly do
better after AVR. Whereas this may not be true for long-standing ventricular
dysfunction with AR.
2. Repairative procedure - like commisurotomy & debridement either with
mechanical or ultrasonic device have been performed but result is not good due
to high prevalence of recalcification & restriction . This is only done in children
24

25. Surgical option of AR
1. AVR
2. Bioprosthetic valve
3. Stent mounted Allograft
4. Valved conduit
5. Pulmonary Autograft
6. Pulmonary Allograft
7. Freehand cryopreserved or antibiotic preserved Allograft
8. Insertion of Allograft as a cylinder inside the aorta
9. Mini aortic root replacement
10. Aortic valve reconstruction procedure
25

26. Surgical option of AR continued…
1. AVR- can be done with prosthetic mechanical valve with anticoagulant
2. Bioprosthetic valve – which may be
a) Sent mounted Xenograft /Heterograft ( porcine or bovine pericardial) or
b) Stenless Xenograft (porcine) valve. This has lower transvalvular gradient,
goes near to Homograft valve
3. Stent mounted Allograft- is not satisfactory for AVR due to dehisence of the
Allograft from the struts
4. Valved conduit (prosthetic)- is placed in patients with annular ectasia
from chronic aortic aneurysm or aortic dissection (Bental procedure)
26

27. Surgical option of AR continued…
5. Pulmonary Allograft cylinder
6. Pulmonary Autograft- (Ross procedure)
27

28. Surgical option of AR continued…
7. Freehand cryopreserved or antibiotic preserved allograft
(Homograft)
 Indication: mandatory in prosthetic valve endocarditis, also in young
women contemplanting pregnancy
 Contraindication: dilated aortic root (>30mm)
 Less desirable:
a) When ascending aorta is diffusely enlarged and thin walled
b) When severe uncontrolled systemic HTN is present
 Advantage:
a) Absence of gradient
b) Removal of increased risk of AV rupture
28

29. Surgical option of AR continued…
What is freehand Allovital Homograft?
Valve that are implanted within 48 hours of death of the donour (also
known as fresh homograft)
Current recommendation for storage is by cryopreservation in liquid
nitrogen at minus(-) 1960 C.
Alternatively valves are procured & treated with antibiotics to decrease
the amount of early failure due to thinning & tearing of leaflets, which are more
common when formaldehyde, chlorhexidine or Gamma radiation is used
29

30. Surgical option of AR continued…

31. Surgical option of AR continued…
10. Aortic valve reconstruction procedure in AR has been recommended by few
surgeons, but have not widely acceted, particularly after development of
prosthetic valves. Stil repair in AR is more promising than AS.
a) Trussler repair
b) Aortic cusp retraction (by fibrosis or calcification) is treated by extending
or replacing the cusp with gluteraldehyde treated bovine or autologous
pericardium
c) Cusp prolapse is treated with a triangular resection of prolapsed cusp
d) Cusp perforation is repaired with pericardial patch.
 Aortic valve repair is well established in children but not in adults
31

32. Surgical option of AR continued…
What are the 3 techniques for Homograft valve insertion?
1. Sub coronary:
o Requires scalloping of the Homograft valve
1. Cylindrical (mini-root technique):
o Implantation of an intact cylinder, less prone to geometric distortion
1. Aortic root replacement:
o Least subject to geometric distortion
o Root replacement with Homograft is performed as Bental’s procedure
32

33. Management of small Aortic Annulus
1. If prosthetic valve are used one size larger than aortic annulus cab be used by
a) Supra annular positioning- placing pledget on ventricular side by taking suture
from ventricle to aorta
b) Tilting the valve along the non coronary sinus. Here suturing the valve along the
annulus of left and right coronary sinus pledgeted mattress sutures are placed
from outside in of aorta
c) St. judes HP (hemodynamic plus) valve achieves larger orifice area for a given
size. The effective orifice are (EOA) of St. judes 19mm HP has nearly EOA of
standard St. judes 21mm valve.
2. Freehand aortic allograft (Homograft) is the best device because small size Allograft is
available in graft bank. (down to 16mm size). It can be inserted with minimal gradient
3. When supraannular AS a patch graft into the non coronary sinus of valsalva is used
(preformed pericardium)
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34. 4. When sub valvar discrete stenosis due to fibro muscular ring- excision of fibrous band
is necessary ( care must be taken not to injure th AML below, aortic valve above & IVS)
5. When supra annular & annular enlargement is necessary it can be done in 2 method
a) Manoguian proecedure: done by extending the aortotomy through left coronary
noncoronary commisural area and into the underlying aortico mitral annulus.
The incision doesn’t reach the hinge point of mitral leaflet. A broad tear drop
shaped patch is positioned
b) Nicks et al- continues aortic incision into the noncoronary sinus, dividing the
aortic annulus & extended only as far as the origin of the AML.
NB. Aortic valve annulus is usually widened a few mm & one size larger than aortic
annulus can be positioned
34

35. Management of small Aortic Annulus
continued….
35

36. Management of small Aortic Annulus
continued….
7. In congenital obstruction of LVOT
Mcgoon; Cooley et al., Bernhard et al., used a conduit between left
ventricle and ascending, thoracic and abdominal aorta
7. An alternative to all these method is replacement of the aortic valve and
first part of the ascending aortra with either
i. Allograft aorrtic valve cylinder or
ii. Autograft pulmonary valve cylindr
NB. A 24-26 mm cylinder will fit in 17-19 mm aortic root
36

37. Effects of AVR in AS
1. LVEDP decreases – fall in pulmonary capillary pressure
2. Myocardial oxygen consumption decreases –due to fall in systollic and
diastolic LV wall tension
3. Slight increase in diastolic coronary pressure
4. LV contractility increases- after AVR . Due to reduction of hypertrophied LV
 NB. There may be slight decrease of LV contractility immediately after
AVR, possibly due to myocardial effects of CPB, which may persist for
first 4 post operative day
37

38. Effects of AVR in AS cont…
5. Transvalvular gradient
o Depends on size and type of the valve
o Systolic transvalvular gradient across aortic valve is not eliminated
after AVR
NB. Small 19 mm valve has more gradient.
15-20 mmHg in monoleaflet with EOA 0.98 -1.06 cm2
3-28 mmHg in bileaflet SJM with EOA 1.09-1.22 cm2
Less gradient in freehand Autograft or cryopreserved Allograft
38

39. Effects of AVR in AR
LV contractility may be slightly depressed soon after AVR,
because
A. Myocardial effects of CPB
B. Residual effects of cardioplegic drugs
C. Ischemic period (X-clamp time)
D. Increase in impedence to LV ejection that occurs when AR is
abolished, especially in first hew hours after bypass, when SVR is
increased.
39

40. Modes of death after AVR
1. Late death due to cardiac failure & myocardial infarction- commonest
modes of death
2. Sudden death- occurs in 20% of late death and may be due to
thromboembolism
3. Some deaths, perhaps 20% are related to the device inserted
o Thromboembolism
o Prosthetic thrombosis
o Anticoagulant related hemorrhage (10%)
o Prosthetic valve endocarditis
o Device failure like bioprosthetic degeneration
40

41. Results after AVR
Overal survival is about
 75% at 5 years
 60% at 10 years
 40% at 15 years
41

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