classification of mechanical valves, types of caged ball valve, single leaflet valve , tilting disc valve, bileaflet valve, ttk chitra valve,ST jude valve, ATS ap valve, On x valve ,carbomedics,

1. Mechanical valves
By
Dr Vasanthi
DNB CTVS
Madras medical mission

4. Classification
Caged ball – Starr Edwards, Smeloff cutler,
Braunwald cutler

5. Hufnagel valve
Housing – methacrylate
Ball – silicone
Unique design – sutureless
fixation
Miscellaneous – placement in
descending aorta

6. Star edwards
Housing – stellite (cobalt,chromium,molybdenum,nickel)
Ball – silastic(silicone) rubbber
Unique design – bare metal cage
Miscellaneous – first clinical mitral ball valve
When blood pressure in the chamber of the heart exceeds
that of the pressure on the outside of the chamber the ball
is pushed against the cage and allows blood to flow.
At the completion of the heart's contraction, the pressure
inside the chamber drops and is lower than beyond the
valve, so the ball moves back against the base of the
valve forming a seal.

9. Tilting disc :
• Bjork- Shiley valve
• Lillehei Kaster valve
• Medronic Hall
• Omincarbon
• Monostrut
• Chitra valve

12. CHITRA VALVE
Manufactured by TTK (Tiruvellore Thattai
Krishnamachari )
Materials of construction:
• Frame(cobalt based alloy of chromium,
nickel tungsten)
• Disc-occluder
• Ring

13. • Opening angle : 60-75 degree
• The strut attaches disk eccentrically so that
the backpressure on a larger segment of
the disk will tend to close the valve.
• Eccentric disc position produces two
orifices of different sizes and shapes: A
major orifice and a minor orifice.

14. Orientation
• mitral position- major orifice is directed posteriorly.
• If chordal preservation - major orifice faced
anteriorly
• Normally during diastole, flow acquires a laminar
pattern and enters the left ventricle through the
posterior portion of the mitral inflow tract.
• Anatomic orientation of a tilting-disk prosthesis at
the mitral position mimics a “trapdoor” effect of the
natural anterior mitral leaflet and preserves the left
ventricular physiologic vortices during diastole
• Aortic : large orifice oriented towards greater
curvature

16. Available models

17. Advantages
• Complete structural integrity
• Absence of cavitation related damage
• Rotatable within the sewing ring to assure
Its freedom to rotate if repositioning is
required
• Low profile
• Low cost

18. Bileaflet valves :
• Gott-Dagett valve
• Lillehi Kalke valve
• SJ Medical valve
• ON X
• ATS medical open pivot
• Carbomedics

20. Parts of bileaflet valve
1) two semicircular
occluders/leaflets
2)annular housing
3)hinge region
4) gaps. A)
peripheral B) leaflet
5)sewing ring

21. ST JUDE MECHANICAL
VALVE
First bileaflet valve introduced in 1977 by st
jude medical inc.
Low profile, bileaflet
mechanical valve.

22. DESCRIPTION:
Leaflets –
Contains 2 semicircular leaflets retained within the ring
by hinges
leaflets & orifice ring -pyrolytic carbon coated with
graphite substrates
Leaflets are impregnated with tungsten for radiopacity

23. Sewing cuff –
• Double velour knitted polyester fiber in the polyester
cuff
• Allows rapid, controlled endothelial ingrowth.
• Sewing cuff has suture markers – provides reference
markings for the placement of the sutures and valve
orientation.
• 3 suture markers in aortic valve prosthesis(120 apart)
• 4 suture markers in mitral valve prosthesis (90 apart)

25. MASTERS HP(HEMODYNAMIC PLUS)
SERIES –
• Facilitates supra-annular placement,
allowing for an increase in orifice size
for a given tissue annulus diameter
MASTERS SERIES-
•Intra- annular cuff
REGENT FLEXCUFF –
•The flexcuff is flanged and
more pliable than the standard
cuff.
•Supra-annular valve placement

26. ORIFICE-
• One central rectangular orifice
• Two lateral orifices
Supraannular placement will
increase EOA for given tissue
annulus diameter

27. MECHANISM:
• Opens by pivot mechanism
• When the blood passes through the leaflets, it opens at an angle of 80-90
• Closing angle 30
• Large effective orifice area contributes to normal flow profile with reduced
obstruction and turbulence.
• The central rectangular orifice provides simple laminar flow and better
hemodynamic performance.
• When closed, small amount of blood regurgitates through the recess area

28. VALVE IMPLANTATION:
St jude sizers are available to determine the valve
prosthesis size
Sizer is a double ended tool with
• A cylindrical end – annulus size replica end,
should pass the annulus without resistance.
• Flanged end – sewing cuff replica end

29. BLOOD FLOWS WITHIN THE PIVOT GUARD
BLOOD
FLOW
PIVOT
GUARD
LEAFLETS
PIVOT
GUARD
BLOOD
FLOW
MITRAL AORTIC

30. PROPERTIES :
• Excellent durability
• Low thrombo-embolic events
• Facilitated rotation intra operatively
• Mr conditional
• Low turbulence
•Limitations:
• Valve clicking sound
• Recess, where thrombus can form.

31. MEDTRONIC ATS VALVE
The ATS(advancing the standards) open
pivot bileaflet valve
low profile mechanical valve consisting of
pyrolytic carbon orifice ring and leaflets.

32. DESCRIPTION:
Leaflets – pyrolytic carbon coated over a graphite substrate,
impregnated with 20% tungsten for radiopacity.
Pivot area – located within the orifice ring , thus decreasing the
overall height of the valve
Sewing cuff – Made up of double velour polyester fabric mounted on
the orifice using titanium stiffening ring and titanium locking wire.
• Contains 3 markers in aortic and 4 in mitral valve prosthesis.

33. IT IS AVAILABLE IN TWO CONFIGURATIONS
• Standard
• Advanced peformance – AP SERIES
ATS standard aortic valve – intra-annular valve
• Valve sizes ranging from 19 mm to 31 mm
ATS standard mitral valve – 25 mm to 33 mm

34. ATS AP VALVE –Supra-annular compact cuff
configuration for excellent suturability and
conformability
ATS AP 360 VALVE - Supra-annular flanged
cuff configuration for added flexibility, needle
penetration, and conformability

35. MECHANISM :
• The pivot guide in the orifice ring controls the
movement of the leaflets.
• Leaflets works by hinge mechanism and opens at an
angle of 85
• It allows near laminar flow.
• The closing angle is 20  to the plane of the orifice
ring
• The hinge mechanism allows rapid closure with very
low regurgitant volume and very low noise level
• Implantation methods are same as in st jude
mechanical valve, whereas to measure the annulus
size, one should use the ATS valve sizer.

36. EXCEPTIONAL PROPERTIES
• Open pivot structure has no recess or
cavities , where thrombus can form.
• Wider orifice area – improved hemodynamic
performance
• Improved durability
• Exceptional implantability
• Rotatable orifice
• Quiet valve function
• Mr conditional

37. On x valve
Leaflet and housing – pure pyrolytic carbon (devoid of
silicon)
No Other Mechanical Valve Has:
90° leaflets:1 promotes laminar flow
Pure pyrolytic carbon: reduces thrombogenicity
Flared inlet: organizes flow; prevents pannus

40. A shorter leaflet closing angle
2point leaflet contact and an actuated pivot(closure is
assured when leaflets are open to the full 90°)
A length to diameter ratio similar to native valve(is the
only mechanical valve with features that mimic
natural valve length and inlet flow rate)
A low L/D ratio creates more flow resistance because
of increased turbulence
These features have translated the valve into
*Increased strength
*Improved valve hemodynamics
*Reduced hemolysis
*Thrombogenicity

42. Characteristics
STATE OF ART ON X VALVE:
 Elongated orifice with flared inlet
 Supra annular sewing cuff
 Flare organizes and increases flow
ON X VALVE ANNULUS MAINTENANCE:
The on x valve annular flare maintains
annulus shape and protects the implanted
valve from tissue enroachment

43. ANNULUS MAINTENANCE

44. ON X DESIGN ANNULUS
MAINTENANCE

45. ON X- ACTIVATED PIVOT
Drag force
from change
in blood flow
direction
pushes
leaflet tab
upwards
along closing
...and
6°toward
closedposition
......
....which initiates
rapid closure.

47. ON X VALVE DESIGN- TWO
POINT LEAFLET CONTACT
Soft landing
Reduced orifice
Contact velocity
Reduces blood damage

48. Sizing of aortic on x valve
The On-X aortic valve cylindrical sizer is 0.8
mm larger than the stated size.
19 sizer is 19.8 mm outer diameter
21 sizer is 21.8 mm
23 sizer is 23.8 mm
25 sizer is 25.8 mm
The On-X aortic replica sizer is the exact
sizeof the valve.RIGHT SIZE-all gradients <
10mmHg

49. Valve sizing

50. On x mitral sizing:
Sizes 23 and 25 On-X mitral valve sizers are
cylindrical in shape.
Sizes 27/29 and 31/33 On-X mitral valve sizers are
conical in shape
These sizers will accommodate the large sized
mitrals.
ON X VALVE ORIENTATION: aligned anti-
anatomically-the same as all bi-leaflet mitral
valves.The gap in the leaflet guard will be
positioned toward the LVOT or the aortic valve in
this orientation.

51. ON X VALVE MITRAL
SIZING:

52. CARBOMEDICS
VALVE:
Housing -a solid pyrolite carbon
Leaflets - pyrolite carbon coated graphite that is
impregnated with tungsten
Stiffening ring composed of titanium which virtually
eliminates the risk of leaflet escape.
The standard aortic valve prosthesis has the sewing cuff
located at the outflow level of the valve cylinder.

53. A high performance valve, the
Carbomedics TopHat valve for
supraannular implantation, is a
standard aortic valve
prosthesis where the sewing
cuff has been transferred to
the inflow level of the valve
cylinder. So effective flow
orifice over the entire outflow
tract.
This is particularly
advantageous compared to an
intraannular position, where
part of the effective flow orifice
is taken up by the housing and
the sewing ring

54. SPECIAL FEATURES:
Biolite carbon-covered blood contacting
surface on the sewing ring,
valve pivot design with absence of pivot
guards,
Closing angle - 25 degrees
Opening angle - 53 degrees from the closed to
the open position, or 78 degrees from the
plane of the ring.