Art Valves

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

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

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 mitraliskunstklep	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	Paravalvular aoi
Scanning valve ring for paravalvular leakage	Fistulas, abscesses

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