Art Valves: Difference between revisions

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!Valve profile in different types of mechanical prosthetic valves
!Valve profile in different types of mechanical prosthetic valves
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Surgical replacement of the aortic valve is an effective treatment modality for patients with degenerative aortic stenosis and calcification. In an aging population, however, there are more and more patients in whom surgery poses a high risk. Due to recent developments, there is a less invasive alternative possible, resulting in a prosthesis (bioprosthesis) of the aorta, through the femoral artery or transapical can be inserted.
Surgical replacement of the aortic valve is an effective treatment modality for patients with degenerative aortic stenosis and calcification. In an aging population, however, there are more and more patients in whom surgery poses a high risk. Due to recent developments, there is a less invasive alternative possible, resulting in a prosthesis (bioprosthesis) of the aorta, through the femoral artery or transapical can be inserted.


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!Edwards Sapien<cite>2</cite>
!Edwards Sapien<cite>2</cite>
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Preoperative [[Aorta|aortic dimensions]] is all well mapped with an echocardiographic examination, so that the interventional cardiologist knows exactly where the implant is to be placed.<cite>3</cite>
Preoperative [[Aorta|aortic dimensions]] is all well mapped with an echocardiographic examination, so that the interventional cardiologist knows exactly where the implant is to be placed.<cite>3</cite>


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Latest revision as of 09:39, 2 April 2014

Different types of valve art

Before starting with echocardiographic evaluation of a valve prosthesis it is necessary to be aware of the different types of valve prostheses. There is a difference in the kind and in the type and diameter. Thus, each manufacturer has its own characteristics. And there is a difference in whether the prosthesis is biologically or mechanically created.

Click here for normal mechanical prosthesis

Click here for normal biological prostheses

Mechkunstkleppen.jpg
Mechanical prosthetic valves
Advantages and disadvantages of mechanical and bioprosthetic
Mechanical Biological
Advantages
  • Durable
  • No anticoagulation needed
  • Less obstruction of the blood flow
  • No Leakage
  • Inaudible
  • Hemodialysis
  • Less risk of infection in the ring or edge flap
  • No pannus (tissue ingrowth)
Disadvantages
  • Anticoagulation needed
  • Any obstruction of the blood flow
  • Leakage (leakage backflow after valve closure, closure backflow flap for closure.
  • Audible (ticks).
  • Hemodialysis (blood cells break down by colliding with mechanical valve.
  • Infection in ring or rim valve (endocarditis).
  • Pannus (tissue ingrowth)
  • Degeneration is 10-15 years
NB: For all valve prostheses is indicated in some cases endocarditis prophylaxis.[1]

Types of mechanical prosthetic valves

Klep profiel v2.svg
Valve profile in different types of mechanical prosthetic valves

Features of the different prosthetic

Type of prosthetic valve[1] Brand Obstruction Leakage
Ball in Cage
  • Starr-Edwards
Many Little
Tilting disc
  • Bjork-Shiley
  • Medtronic Hall
  • Sorin
Little Many
Bileaflet
  • St. Jude Medical
  • Sorin-Bicarbon
  • Carbomedics
Little Many
Homograft
  • (Donor Valve)
No No
Unstented bioprosthesis
  • Medtronic Freestyle
No No
Stented bioprosthesis
  • Carpentier-Edwards
  • Hancock
  • Medtronic Intact
Many No

Postoperative ultrasound

After valve replacement have to be at the time that a patient is stable (hemodynamic and metabolism, "no anemia") to be an output echo is made for capturing of valve parameters. Here it is to calculate with use of the art valve diameter, a valve surface is important so that a size is recorded regardless of the cardiac output. (Fever creates a hyperdynamic circulation so the gradients will increase, not the calculated valve area).

Bioprostheses also have their own characteristics that must be recorded postoperatively. Every patient has some hi-profile bioprostheses the struts and the structure of the stabbing valve in the outflow tract. It may be some LV outflow obstruction occur. The main problem with bioprostheses is the degeneration. This can be both progressive obstruction occur as tearing of leaflets which there is a major failure occurs.

Data needed for evaluation of mitral prosthetic valve Data needed for evaluation of aortic prosthetic valve
Maximum and mean gradient Maximum and mean gradient
MVA calculated with VTI MV, VTI LVOT + LVOT diameter AVA calculated with VTI Ao, LVOT VTI, valve size to use for LVOT diameter
Pressure halftime Para valvular aoi
Scanning valve ring para valvular leakage Fistulas, abscesses
Video Video
Too much mobility MKV Resulting in serious leakage MKV

Percutaneous Aortic Valve

Surgical replacement of the aortic valve is an effective treatment modality for patients with degenerative aortic stenosis and calcification. In an aging population, however, there are more and more patients in whom surgery poses a high risk. Due to recent developments, there is a less invasive alternative possible, resulting in a prosthesis (bioprosthesis) of the aorta, through the femoral artery or transapical can be inserted.

Edw sapien.gif Med corevalve.png
Edwards Sapien[2] Medtronic Core Valve[3]

Echocardiogafie in percutaneous aortic valve

Preoperative aortic dimensions is all well mapped with an echocardiographic examination, so that the interventional cardiologist knows exactly where the implant is to be placed.[3]

Med-corevalve2.svg

Postoperatively is always an echocardiographic examination is necessary to exclude paravalvular leakage. Shortly after placement of a percutaneous valve is almost inevitable that there paravalvular leak is present because the aortic wall where the prosthesis against them is not smooth and round but rough and irregular. A slight paravalvular leakage is still accepted and usually disappears after a few weeks if tissue has grown over the prosthesis. In severe paravalvular leakage is the probability that the prosthesis becomes loose it big so it must be replaced.

Video Video
Paravalvular leakage

References

  1. R.B.A, van den Brink ‘Kunstkleppen' in "Praktische echocardiografie",Hamer, J.P.M, Pieper P.G, et al, 2e druk, 2009, Houten, Bohn Stafleu van Loghum, DOI: 10.1007/978-90-313-7565-3_9, Print ISBN: 978-90-313-6235-6

    [1]
  2. [2]
  3. [3]