Prosthetic Heart Valves Flashcards
Two main types of prosthetic valves are
bioprosthetic valves: biological tissue valves - the animal tissue is chemically treated for tissue preservation and to prevent immunologic reactions
mechanical valves: synthetic valves
Valve repairs with valvular rings are utilized when possible, particularly in cases of ________ repair. Common brand names include:
MV
Carpentier rings
Duran rings
Bioprosthetic Prosthesis
Once implanted, tissue valves are estimated last ________, so this is a big consideration in the selection of process.
10-15 years
Bioprosthetic Prosthesis
Suitable for patients in whom…..
- long-term durability is less important = elderly patients
- chronic anticoagulant is not advised or those at an increased risk for thromboembolism
Mechanical Prosthesis
components of mechanical valves
titanium
carbon compounds
Teflon
Mechanical Prosthesis
advantage vs disadvantage
advantage: durability (last 30+ years)
disadvantage: increased risk of blood clots - constant use of anticoagulant is required and regular monitoring of the prothrombin through labs is also required
Mechanical Prosthesis
suitable for patients in whom….
- children, young adults EXCEPT women in childbearing years
- with renal failure, a small valve annulus, a high re-operative risk, or another reason for anticoagulation i.e. AFib
- requiring Ao Rt replacement due to aortic dissection/severe AR
Bioprosthetic (Tissue) Valves
3 types of Biprosthetic Valves are:
- heterograft (xenograft): transform animal to human
- autograft (self-to-self): transform from one position to another on the same individual
- homograft (allograft): transfer from one human to another
Bioprosthetic (Tissue) Valves
Heterograft (xenograft) biprosthetic valves are further broken down to 2 types, and they are:
stented heterograft
stentless heterograft
Bioprosthetic (Tissue) Valves
Stented heterografts include (2):
Porcine (pig) valve: uses three leaflets mounted on a supporting stent
Bovine (cow) pericardial valve: uses bovine pericardium mounted on a supporting stent
Bioprosthetic (Tissue) Valves
Stenless heterografts were developed to improve _____ and _____ of the bioprosthetic valve; also made from _____ or _____.
- hemodynamics
- durability
- porcine aortic valves
- bovine pericardium
Bioprosthetic (Tissue) Valves
Common brand names for heterograft bioprosthetic valves are:
Medtronic
Carpentier-Edward
Hancock
Edwards Prima Plus
Tronto SPV
Ionescu-Shiley (now discontinue)
Bioprosthetic (Tissue) Valves
Autograft (self-to-self) transfers from one position to another on the same individual. The individual’s ____ valve annulus & trunk are excised and relocated to the aortic valve position; involves repositioning the coronary arteries known as the _____.
pulmonic
Ross procedure
Bioprosthetic (Tissue) Valves
For Autograft (self-to-self), _______ is prepared and utilized as a bioprosthetic heart valve.
fascia lata (thigh muscle covering)
Bioprosthetic (Tissue) Valves
Homograft (allograft) involves transfers from one human to another and is developed from a/n ______ or _______.
It can be stented or stentless and appears very similar to a native valve.
aortic valve
dura mater (brain covering)
Percutaneous Bioprosthesis involves ______ which is a minimally invasive procedure that uses a balloon catheter with a stent-mounted valve crimped its tip.
TAVR (Transcatheter Aortic Valve Replacement): is thead from the femoral artery in th groin, to the aorta, and across AoV. Once the compressed valve is placed over the diseased AoV, the balloon at the end of the catheter is inflated. The expanded valve pushes aside the diseased leaflets and becomes anchored in the valve opening.
TAVR
Assessment of the native valve, calcification, and _annulus diamete_r are crucial prior to deployment. ____ is superior to TTE; however, _____ is the test of choice.
TEE
MSCT (multi-slice computed topography) : a recently developed technique for assessing the function of the heart and coronary arteries non-invasively. Cardiac MSCT uses X-ray beams and a liquid dye to form a 3-D image of the heart and vessels.
TAVR is preferred in _______
high risk surgical patients in attempt to improve their quality of life
Bioprosthetic Valve complications:
- calcification/degeneration with age
- all prosthetic valves are inherently stenotic
- thrombus results from particles that become trapped on the stents or leaflets - might lead to obstruction/stenosis/regurgitation
- PVE (prosthetic vale endocarditis) results from areas of turbulent flow
- perivalvular leak
- dehiscence
- valve annulus abnormality i.e. abscess - leading to dehiscence and perivalvular leak
- physiologic prosthetic regurgitation is common (*single, small, central jet is considered normal)
Bioprosthetic (Tissue) Valves
advantages
- Less obstructive; better hemodynamics
- Fewer complications due to thromboembolism
- May not require anticoagulation
Bioprosthetic (Tissue) Valves
disadvantages
- Less durable than mechanical valves (10-15 years)
- Leaflets may become regurgitant or stenotic due to tissue degeneration and calcification
- Limited availability of homografts
- PVE (prosthetic valve endocarditis) turbulent flow creates a perfect environment for bacteria to latch on faster
- Perivalvular leaks may be caused by dehiscence
- Valve annulus problems such as ring abscess may cause a leak or dehiscence
Bioprosthetic (Tissue) Valves
common stented valve names & their characteristics
- Hancock (porcine or bovine pericardium)
- Carpentier-Edwards
porcine-3 leaflets mounted on a supporting stent
bovine-pericardial valve uses bovine pericardium mounted on a support stent
central flow, trivial/no regurgitation
Bioprosthetic (Tissue) Valves
common stentless valve names (*intended for aortic or pulmonary position) their characteristics
- St. Jude Tronto
- Medtronic Freestyle
- Biocor
- Edwards Prima
- Shiley (discontinued)
improved hemodynamics and durability (porcine & bovine)
porcine, very low mean gradient
Bioprosthetic (Tissue) Valves
Percutaneous Bioprosthetic
TAVR
What is autograft and its characteristics?
- Tissue(valve) transferred or transplanted from one location to another within one’s own body
- Ross procedure – native pulmonary valve sewn into aortic position
- Central flow
- Valve retains ability to grow
- Trivial or no regurgitation
- Very low mean gradient
What is homograft and its characteristics?
- Tissue (valve) transplanted from a human donor
- Typically harvested as a block of tissue (aortic valve, root, and ascending aorta) and trimmed as needed
- Central flow
- Trivial or no regurgitation
- very low mean gradient
Classification and Characteristics Mechanical Valves
What type of valve is this and its characteristics?
Bileaflet Tilting Disk
- Two semicircular disks attached to a rigid valve ring by small hinges
- Flaps pivot open 75o - 90 o
- Two large lateral and one small central orifices create central flow
- Least obstructive/stenotic mechanical prosthesis; allows more laminar blood flow
- Normal leakage volume at margin of central discs and at the periphery between disc and sewing ring.
Classification and Characteristics Mechanical Valves
Most common bileaflet mechaical valve brand names in the US?
St. Jude
*note: CarboMedics, ATS Open Pivot, On-X, and Conform-X are the other brand names
Classification and Characteristics Mechanical Valves
What type of valve is this and its characteristics?
Tilting (single) disk
- Single circular disk rotates within a rigid annulus, with the disk secured by lateral or central metal struts that is mounted on a sewing ring
- creates major & minor orifice
- Disc tilts from 60o - 80o to open a major and minor orifice.
- Low velocity, normal leakage volume; predominantly central with smaller peripheral jets
- Bjork-Shiley disc was the original (discontinued)
Classification and Characteristics Mechanical Valves
Common tilting mechaical valve brand names?
Bjork-Shiley (discontinued)
Medtronic- Hall
Omnicarbon
Lillehei-Kaster
Classification and Characteristics Mechanical Valves
What type of valve is this and its characteristics?
Ball cage (aka: caged ball): Starr-Edwards
- Circular sewing ring with several metal struts that “cage” a small hollow ball
- Rarely used after 1980
- Blood flows around the spherical occlude
- Changes in chamber pressure causes ball to move back and forth
- Least optimal hemodynamics
- Normal closing volume regurgitation
- High profile limits use in patients with small ventricles.
what is valve conduits?
creating a channel for conveying blood flow via mechanical or tissue prosthesis attached to a vessel graft
What is Ross procedure?
a diseased aortic valve is replaced with the person’s own pulmonary valve. A pulmonary allograft is used to replace the patient’s own pulmonary valve.
What is Fontan extracardiac?
direct connection of the SVC to the pulmonary arteries and placement of a tube graft outside of the heart from the IVC to the pulmonary arteries.
Mechanical Valves complications:
- all prosthetic valves are inherently stenotic
- physiologic regurgitation is common *The amount is determined by the make and model
- thrombus results from particles that become trapped and proliferate on the stents or disks
- Pannus ( a fibrous ingrowth of tissue) may lead to regurgitation and/or stenosis
- perivalvular leak - abnormal and may cause for concern
- dehiscence - occurs if the sutures in the sewing ring loosen or break. This causes the valve to rock and may lead to perivalvular leak
- abnormalities of valve annulus i.e. abscess
- PVE
- mechanical failure
- hemolysis - RBCs become damages as they pass through the mechanical valve
A baseline echo should be acquired soon after (within 30 days) the valve repair/replacement. Comparison of serial echo exams is vital to recognize new abnormalities versus pre-existing abnormalities.
T or F ?
T
Prosthetic Valve Dysfunction
stenosis/obstruction etiology
- Gradient varies with : Valve type, Valve size, Anatomic position, Cardiac output
- Etiology of obstruction: Leaflet changes (thickening or calcification), Thrombus or pannus growth, Patient-prosthesis mismatch
What is Perivalvular (Periprosthetic) regurgitation?
- Leakage from outside the sewing ring
- Usually eccentric, high velocity and turbulent flow
- Usually due to valve bed abnormalities or endocarditis
Prosthetic Regurgitation
Thromboembolism: Higher risk with
- Mechanical valves
- Atrial fibrillation
- Large LA
- LV dysfunction
Prosthetic Regurgitation
Hemolysis / anemia caused by
- Mechanical trauma to red blood cells
- Some degree present with all mechanical prostheses
- Periprosthetic leaks, eccentric regurgitant jets, and obstruction are common culprits (cause of defect)
Prosthetic Regurgitation
Patients with prosthetic valves are higher risk of ______ and ______ is recommended.
SBE: Subacute bacterial endocarditis is an infection of the inner lining of the heart and the heart valves
Prophylaxis: action taken to prevent disease, especially by specified means or against a specified disease
Prosthetic Regurgitation
Pannus growth rarely affects tissue prostheses. ______ and _____ valves are particular prone
Disc and bileaflet valves
Valve bed abnormality – often a complication of endocarditis such as:
- Pseudoaneurysm
- Ring abscess
- Fistula
- Dehiscence
Prosthetic valve complications:
identify A, B & C
A: Pannus
B: Thrombus
C: Degeneration
What are the parameters for examination of a prosthetic valve?
Clinical information
Imaging of the valve
Doppler echocardiography of the valve
Previous postoperative studies, when available
Echocardiographic Assessment
Acoustic shadowing or artifacts from mechanical prosthesis or struts; may require multiple, unconventional imaging planes and extensive image adjustment; TEE should be considered especially for mitral prostheses.
T or F ?
T
Echocardiographic Assessment
Bioprosthetic Valves
- evaluate leaflet mobility and thickness
- rule out calcification, degeneration, stenosis, thrombus, endocarditis, regurgitation, perivalvular leak, dehiscence, and annulus abnormalities (Extraneous echoes)
Cardiac chamber size and function
- Stability of sewing ring: stable versus excessive or rocking motion
Echocardiographic Assessment
Mechanical Valves
- TTE is somewhat helpful in evaluating mechanical valves; however, artifact from the valve components can severely limit the image of the valve itself especially MV location - TEE is recommended
- evaluate disc motion; Stability of sewing ring: stable versus excessive or rocking motion
- rule out thrombus, pannus ingrowth, stenosis, endocarditis, regurgitation, dehiscence, mechanical failure, and annulus abnormalities
*TEE probe is on atrial side of MV prosthesis, so mitral prosthetic regurgitation can be more clearly defined
Echocardiographic Assessment
Doppler assessment
Echocardiographic Assessment
M-mode
useful for evaluating the prosthetic poppet/disc motion
Echocardiographic Assessment
Patients should carry an identification card with their valve’s description. The charts from manufacture ( determine if the values fall within the normal range for each particular prosthetic valve) and previous echo report are vital to prosthesis statistics and overall function.
T or F ?
T
Doppler assessment of Aortic Valve prosthesis #1
Doppler assessment of Aortic Valve prosthesis #2
Doppler assessment of Aortic Valve prosthesis #3
Doppler assessment of Mitral Valve prosthesis #1
Doppler assessment of Tricuspid Valve prosthesis
Assessment of Prosthetic/Periprosthetic valve regurgitation
Transfer from animal to human
-Animal tissue chemical treated for preservation and prevention of immunological reactions
This describes a _______
heterograft/xenograft
This is a _________________________ bioprosthetic valve.
stented
_____________is the current Test of choice prior to procedure (TEE is second and better than TTE) to reassess calcification, native valve and annulus diameter
MSCT (multi-slice computed tomography)
This is an example of a ________________valve.
bileaflet tilting
This is a ___________ bioprosthetic valve.
stentless
List 4 disadvantages of a biologic prosthetic valve.
1. ____________________________
2. ___________________________
3. ___________________________
4. _____________________________
- less durable (last 10-15 yrs)
- leaflets may degenerate and calcified
- limited stock (limited availability)
- PVE (prosthetic valvular endocarditis)
- ring abscess
- perivalvular leak
List 4 disadvantages of mechanical prosthetic valves.
1. _________________________________
2. _________________________________
3. _________________________________
4. _________________________________
- inherently more abstructive
- higher risk of thromboembolism
- require anticoagulant
- risk of mechanical failure
- hemolytic anemia
All of the following changes can be suspicious for prosthetic valve dysfunction except:
- progressive chamber dilatation
- low mean gradient
- increased intensity of CW Doppler signal
- intermittent flow variations
2
There are 25 Different Brand names worldwide with more than 44 different models of prosthetic valves in sizes ranging from 17-35 mm.
T or F ?
T
List 3 mechanical prosthetic valves:
1. ______________________
2. ______________________
3. _______________________
- bileaflet
- single tilting disk
- caged ball
TAVR is an acronym for _________________________
transcatheter aortic valve replacement
During the ________________________ a direct connection of the SVC to the pulmonary arteries and placement of a tube graft outside of the heart from the IVC to the pulmonary arteries.
Fonta extracardiac
TEE is the current Test of choice prior to valve replacement procedure to reassess calcification, native valve and annulus diameter. (MSCT -multi-slice computed tomography is second best).
T or F ?
F
List 3 advantages to a biologic prosthetic valve.
1. ______________________________
2. ______________________________
3. _______________________________
- less obstructive, better hemodynamics
- fewer complication due to thromboembolism
- may not require anticoagulant
This mechanical valve is the most frequently used in 2022.
T or F?
F
*the first mechanical valve used in 1960s
This is an example of a __________________________.
single tilting disk
A tissue (valve) transplanted from a human donor is a(n) ___________________________.
allograft/homograft
Mechanical prosthetic valves are not extremely durable and this is considered to be a disadvantage.
T or F?
F
List 4 causes of regurgitant flow in a prosthetic valve.
- leaflet degeneration
- thrombus/pannus growth
- endocarditis
- dehiscence
- perivalvular leak
List 3 biologic stented prosthetic valves:
1._________________________________
2._________________________________
3._________________________________
- porcine xenograft
- bovine xenograft
- pericardial xenograft
The _____________ is a replacement method used when a diseased aortic valve is replaced with the person’s own pulmonary valve. A pulmonary allograft is used to replace the patient’s own pulmonary valve.
Ross procedure
Echocardiography with Doppler is currently the method of choice for the noninvasive assessment of prosthetic valves.
T or F ?
T
Another name for a homograft is a ________________________.
allograft
A(n) ___________________________ is a tissue (valve) transferred or transplanted from one location to another within one’s own body.
autograft
Valve repairs with Carpentier rings & Duran rings are utilized when possible, particularly in cases of MV repair.
T or F ?
T
A mechanical prosthesis is selected for _____
- children and young adults
- patients with a large valve annulus
- patients with mild AR
- all of the above
1
- patients with a large valve annulus - small
- patients with mild AR - severe
Prosthetic valves are implanted when the patient has hemodynamically significant valvular heart disease (i.e. stenosis, regurgitation, infective endocarditis etc..).
T or F ?
T
Stentless heterografts were developed to improve hemodynamics and durability of the biosthetic valve; they are made from a porcine aortic valve or bovine pericardium. Common brand: Medtronic, Carpentier-Edwards, Hancock, Edwards Prima Plus, Toronto SPV.
T or F ?
T
if the patient’s PV annulus and trunk are excised and relocated to the aortic position, they have a(n):
- allograft
- autograft
- heterograft
- homograft
autograft (self-to-self)
*allograft = homograft
*xenograft = heterograft
_______ is developed from a human aortic valve or dura mater and appears very similar to a native valve.
- autograft
- heterograft
- homograft
- TAVR
homograft
If the patient has a porcine valve in the mitral position, ______ should be ruled out.
- abnormal degree of stenosis and/or regurgitation
- calcification
- dehiscence
- all of the above
4
An elderly woman is admitted to the ER with fever, chills, and dizziness. She is certain that she had a valve replaced but does not have a scar on her chest, and there is no previous echo report available. Echo findings include a very bright AOV annulus with an unusual cusp and moderate aortic regurgitation; what is most likely the diagnosis?
a. mechanical AOV with pannus
b. native AOV with IE
C. porcine AOV with PVE
d. TAVR with PVE
d
If the patient has a stentless autograft, what type of valve do they most likely have?
a. bileaflet valve
b. valve from another human
c. valve from the patient’s own fascia lata
d. valve from a pig
c
_________ is a known complication of the bioprosthetic heart valve.
a. Thrombus
b. Hemolysis
c. Mechanical failure
d. All of the above
a
TAVR is preferred in high risk surgical patients in an attempt to improve their quality of life.
T or F ?
T
The manufacturer’s prosthesis statistics and the patient’s previous echo reports should be used as a Comparison during serial echo exams.
T or F
T
Assessment of the AOV, calcification, and annulus diameter are crucial prior to TAVR; TEE images are superior to MSCT.
T or F?
F
*MSCT (multi-slice computed tomography) is the test of choice
The patient presents with a bioprosthetic valve and a new perivalvular leak is detected on echo, this may be to prosthesis dehiscence, an annulus abnormality,or PVE.
T or F?
T
_____________ can occur when a mechanical prosthetic valve damages the red blood cells
a. Dehiscence
b, Hemolysis
c. Mechanical breakdown
d. Mechanical failure
b
Most mechanical valves have a physiologic amount of stenosis and/or regurgitation.
T or F?
T
The patient presents with a St. Jude bileaflet tilting disc in the mitral position and the MVA has decreased significantly compared to last year’s echo results; what is most likely the diagnosis?
a. hemolysis
b. perivalvular leak
c. physiologic stenosis
d thrombus
d
The cardiac sonographer should not calculate the prosthesis valve area and pressure gradient because that information is available on the patient’s prosthetic valve identification card.
T or F?
F
M-mode is not useful in the evaluation of prosthetic disc motion because there is too much artifact
T or F?
F
CFD may be difficult with mechanical valves due to artifact: therefore, the sonographer must utilize a single window to evaluate regurgitation.
T or F?
F
