Prostethic Valves Flashcards
What does this image represent?
Single tilting disk - Bork Shiley valve
What does this image represent?
Bileaflet Tilting disk
What does this image represent?
Bileaflet mechanical mitral valve
What does this image represent?
Mechanical Valve hemodynamics
What does this image represent?
What does this image represent?
Scented Bioprosthetic valve
What does this image represent?
Bioprosthetic stentless freestyle valves
What does this image represent?
Ross procedure
What does this image represent? What does the arrow point to?
- Annuloplasty ring
- The arrow Mimics MAC
What does this image represent?
TAVR (Transcatheter AV replacements)
What does this image represent?
Edge to edge repair
Why would someone have a prostatic valve?3
Implanted when the patient has hemodynamically significant valvular disease such as
- Stenosis
- Regurgitation
- Aortic dissection/ severe AI
In terms of prosthetic valves, when are valvular rings or other devices used?
When possible
What is the role of echo in prosthetic valves during pre-procedure?2
- Assess the need for repair/replacement
- Assess suitability of the type of repair/ replacement
What is the role of echo for prosthetic valves during the procedure?
May be used during transcatheter procedure to assess prosthesis placement before procedure completion
What is the role of echo post procedure for prosthetic valves?4
Assess for complications such as
1. Thrombus
2. Leakage
structural failure
3. Endocarditis
4. Dehiscence
What are the advantages of mechanical valves?3
- Durable
- Due to durability, risk for reoperation is low
- Easier surgical implantation
Why is mechanical valves durable?
- Made from biocompatible metal, plastic or cermiclike material
- Lasts 10-25 years
What is the disadvantage of mechanical valves?
- Risk of thrombus formation and pannus growth
- Valve may make an audible click
- Produces a blood flow pattern that is resistant or high flow
What is the most common disadvantage of mechanical valves?
Thrombus formation which leads to lifelong anticoagulation
Pannus growth can lead to what?
Regurgitation or stenosis
How can we size the valve to use?
Echo used in pre-procedure to determine the choice of valve size
Reported size of the valve refers to what?
Outer diameter
What is valves measured in?
Milimeters
What is a single tilting disk made of?3
- Circular ring of metal
- Disk
- Sewing ring
Single tilting disks tilt at what degree?
60 degrees
What is flow like in a single tilting disk?
Eccentric
Single tilting disks have a history of what?
Fracture and sewing ring leak
What is the most common mechanical valve?
Bileaflet tilting disk
What does the bileaflet tilting disk consist of in terms of design?
- 2 Occluders + sewing ring
- Align parallel when opening
What does bileaflet tilting disk color doppler demonstrate?3
- 3 jets
- Central flow with peripheral turbulence
The bileaflet tilting disk is a valve made to have a built in what?
Regurg
What does the built in regurg of the bileaflet tilting disk do?
- “washes” the valve
- Decrease thrombus
What does MR look like for Bileaflet tilting disk?
2 jets
Why is it frustrating to image mechanical valves?
Can be frustrating due to artifacts such as
1. Reverberation
2. Shadowing
What should we do when we image mechanical valves? 3
- Account for the motion of the occluder’s
- Use zoom/ magnifaction
- Evaluate the sewing ring
What can we do in terms of imaging mechanical valves to help assess regurgitation?
Scanning off axis
What are three types of tissue valves in terms of bioprosthetic?
- Homograft (allograft)
- Autograft
- Heterograft (xenograft)
What is a homograft?
Graft from one human to another
How common are homografts?
Rare
How do we obtain homografts?
From cadavers
How common are autografts?
Rare
What are autografts?
Graft of tissue from one site to another in the same patient
What is a heterograft?
Graft from different species?
What are examples of heterografts?
- Animal to human
- Porcine heart valve (pig)
- Bovine pericardium (cow)
How long does hetergrafts last?
5 years
What are the advantages of bioprosthetics? 3
- Anticoaguation not required, therefore may provide better quality of life
- valves do not click
- May be candidates for percutaneous valve in valve procedures at a later date
What are disadvantages of bioprosthetic valves?
- Not as durable as mechanical valves
- Prone to calcifications
Young person receiving a bioprosthetic valve may require what?
Reoperation
What happens with bioprosthetics in terms of calcifcaitons?
Stenosis with increased gradient across valve
What are components of bioprosthetic valves?
- Leaflet
- Sewing ring
+/- stents/ struts
When we image bioprosthetic valves what is the structure of the leaflets?
Trileaflet structure
In terms of imaging bioprostetic valves, what might cause an artifact?
Sewing ring and struts
What do we evaluate the sewing rings for?2
- Dehiscence
- Paravalvular leak
Between bioprosthetic valves and mechanical prosthesis, which is easier to image?
Bioprosthetic valves
What are some considerations for choice of prosthetic valves?7
- Rate of structural failure
- Effect of age very young or old
- Co-morbid conditions
- Anticoagulation with mechanical valves
- Patient preference (young, religion)
- Physical activity
- Women of childbearing age
What are 4 different types of valve replacement/ repairs?
- Ross procedure - AV replacement
- MV/TV annulplasty rings
- TAVR - transcatheter AV replacement
- Edge to edge repair
What components generally seen in a ross procedure?
Autograft + Homograft
- Patients PV and root becomes the new AV and root
- Donor PV valve and root is implanted
Who is ROSS procedure performed on?
Young people and women of childbearing years
What are some advantages of ross procedure?
- No long term anticoagulation
- Can grow with the patient
- Less immune response post operation
- Long surgery
What does Annuloplasty ring (for valve repair) treats?
Valve regurgitation such as MV and TV
What is annuloplasty ring designed to do?
- Restore the size and shape of the normal valve annulus
- Prevents recurrent dilation