Patient with aortic stenosis should:
(a) Avoid overly stressful exercise
(b) Stop smoking
(c) Treated for high cholesterol
(d) Treated for hypertension
(e) Medications are used to treat symptoms of heart failure or abnormal heart rhythms
Adults who have aortic stenosis but no symptoms should:
(a) See their doctor regularly à echocardiogram is performed periodically to monitor the heart size and valve function à if heart size increases significantly or valve function worsens à doctor may recommend surgery
Adults who have aortic stenosis that causes fainting, angina, or shortness of breath during exertion:
(a) Aortic valve is surgically replace before the left ventricle is irreversibly damage à Echocardiography, usually performed periodically, can help doctors determine when to schedule surgery à Before surgery, heart failure is treated with diuretics
(b) People with an artificial valve must take antibiotics before a surgical, dental, or medical procedure to reduce the risk of infection (infective endocarditis)
Children who have severe stenosis:
(a) Surgery may be performed even before symptoms develop, because sudden death may occur à safe, effective alternatives to valve replacement are surgical repair of the valve and balloon valvuloplasty à however, later, when children are fully grown up, the valve must usually be replaced
There are 2 types of aortic valve surgery:
a) Valve repair surgery
b) Valve replacement surgery
Common valve repairs:
· Commissurotomy
Fused valve leaflets are separated to widen the valve opening. See illustrations to the right.
· Decalcification
Calcium deposits are cleaned off the valve leaflets, allowing them to be more flexible and close properly.
- Reshaping
Where the surgeon cuts out a section of a leaflet. Once the leaflet is sewn back together, the valve can close properly.
· Annulus support
If the valve annulus is too wide, it may be reshaped or tightened by sewing a ring around the annulus (annuloplasty). The ring may be made of tissue or synthetic material.
- Repair of structural support
Which replaces or shortens the cords that give the valves support (these cords are called the chordae tendineae and the papillary muscles). When the cords are the right length, the valve can close properly.
- Patching
Where the surgeon covers holes or tears in the leaflets with a tissue patch.
· Bicuspid aortic valve repair
If you have a bicuspid aortic valve (two leaflets instead of three), the surgeon may be able to repair the valve by reshaping the aortic valve leaflets, allowing the valve to open and close more easily.
Aortic valve replacement surgery
If your aortic valve is too damaged, you will need a new valve. This is called replacement surgery. Your surgeon will remove your aortic valve and sew a new one into place. There are two main types of new valves:
(a) Mechanical valve
(b) Biological valve
Mechanical valve replacement
Mechanical valves are made totally of mechanical parts which are tolerated well by the body. The bileaflet valve is used most often. It consists of two carbon leaflets in a ring covered with polyester knit fabric.
Advantages: Mechanical valves are very durable. They are designed to last a lifetime.
Disadvantages: Due to the artificial material involved, patients who receive these valves require lifelong treatment with a blood-thinning (anticoagulant) medication. Blood-thinners are medications (such as warfarin or Coumadin) that delay the clotting action of the blood. They help prevent clots from forming on the mechanical valve, which can cause a heart attack or stroke.
Biological valve replacement
Biological valves are made of human or animal tissue. Some valves may have some artificial parts to help give the valve support and to aid placement.
There are three types of tissue valves: pig tissue (porcine), cow tissue (bovine), and human (allografts or homografts).
Porcine stented valve
The valves are made from natural porcine aortic valves, but may be used for aortic or mitral valve replacement. They are trimmed and then fixed in buffered glutaraldehyde at high pressure. The valves are mounted on flexible stents (frames). The bottom of the valve is covered with a seamless knitted polytetrafluoroethylene cloth. This material helps to facilitate the healing and ingrowth of tissue around the implanted valve.
Porcine stentless valve
The porcine stentless valve is used for aortic valve replacement. The valve is made from a natural porcine aortic valve and is fixed in buffered glutaraldehyde solution at a low pressure.
No stents or synthetic sewing rings are used. Therefore, these valves are very similar to the homograft valve.
These valves are technically more difficult to implant but are useful in patients with small hypertrophied hearts.
The Carpentier-Edwards PERIMOUNT Pericardial Bioprosthesis
This valve is made of bovine pericardial tissue (tissue from a cow heart) that has been preserved in a buffered glutaraldehyde solution and mounted on a flexible frame and a sewing ring of molded silicone rubber, which allows the surgeon to sew the valve to the patient. Both the frame and the sewing ring are covered with a knitted polytetrafluoroethylene (PTFE) cloth.
The benefit of this valve is enhanced durability, which is related to the use of pericardium and the specific bioengineering involved in the valve design.
Aortic Valve Allograft - the Homograft Valve
A homograft (also called allograft) is a valve that has been removed from a donated human heart, preserved and frozen under sterile conditions.
Homografts are ideal valves for aortic valve replacement, especially when the aortic root is diseased or there is infection. The heart's natural anatomy is preserved and patients do not need to be on any blood-thinner medications. Although the limited availability is a drawback in some settings, we maintain a large supply and have extensive experience with these valves.
Ross Procedure
Sometimes, a patient's own tissue can be used for valve replacement (called an autograft). The Ross procedure involves switching your pulmonary valve to the aortic valve position and then placing a pulmonary homograft. This is a very complex procedure; however it has many benefits, especially for young patients with aortic valve disease. Techniques, such as the Ross Procedure are examples of innovative ways surgeons are able to treat valve disease while protecting the heart's natural functioning. There are advantages and drawbacks to biologic valves.
Advantages: Most patients do not need to be on lifelong blood-thinner medication, unless they have other conditions (such as atrial fibrillation) which warrant it.
Drawbacks: Biologic valves, traditionally, were not considered as durable as mechanical valves, especially in younger people. Previously available biologic valves usually needed to be re-replaced after about 10 years
There are 2 methods to perform the surgery:
(a) minimally invasive aortic valve surgery
(b) traditional aortic valve surgery (open)
Aortic valve surgery – minimally invasive
Before your surgery you will receive general anesthesia. This will make you unconscious and unable feel pain.
There are several different ways to do minimally invasive aortic valve surgery. Techniques include laparoscopy or endoscopy, robot-assisted surgery, and percutaneous surgery.
- Your surgeon may make a 2-inch to 3-inch-long incision (cut) in the right part of your chest near the sternum (breastbone). Muscles in the area will be divided to so your surgeon can reach the valve. This allows the surgeon to reach your heart and aortic valve.
- For the endoscopic, or “keyhole, approach, your surgeon makes 1 to 4 small holes in your chest. Then your surgeon uses special instruments and a camera to do the surgery.
- For robotically-assisted valve surgery, the surgeon makes 2 to 4 tiny cuts (less than 2 inches) in your chest. The surgeon uses a special computer to control robotic arms during the surgery. The surgeon sees a 3-dimensional view of the heart and aortic valve on the computer. This method is very precise.
You will not need to be on a heart-lung machine for any of these surgeries, but your heart rate will be slowed by medicine or a mechanical device
Once the new or repaired valve is working, your surgeon will
- Close the small cut to your heart or aorta
- Place catheters (flexible tubes) around your heart to drain fluids that build up
- Close the surgical cut in your muscles and skin
The surgery may take 1 to 3 hours.
Aortic valve surgery – open
Before your surgery you will receive general anesthesia. This will make you unconscious and unable to feel pain.
- Your surgeon will make a 10-inch-long cut in the middle of your chest.
- Next, your surgeon will separate your breastbone to be able to see your heart and aorta (the main blood vessel leading from your heart to the rest of your body).
- Most people are connected to a heart-lung bypass machine or bypass pump. Your heart is stopped while you are connected to this machine. This machine does the work of your heart while your heart is stopped.
Once the new or repaired valve is working, your surgeon will
- Close your heart and take you off the heart-lung machine.
- Place catheters (tubes) around your heart to drain fluids that build up.
- Close your breastbone with stainless steel wires. It will take about 6 weeks for the bone to heal. The wires will stay inside your body.
This surgery may take 3 to 6 hours.
Balloon Valvuloplasty
Balloon valvuloplasty is a procedure in which a narrowed heart valve is stretched open with a small balloon which is inserted and inflated to stretch and open a narrowed (stenosed) heart valve.
Valvuloplasty is used for the patients who have mitral valve stenosis or pulmonary valve stenosis and cannot undergo an open heart surgery. It is also a procedure of choice in older or debilitated patients with aortic stenosis who are considered high risk for the major surgeries of heart. Valvuloplasty is also indicated in children with congenital aortic stenosis, until the child is old enough to have Heart Valve Replacement surgery.
The procedure is performed in a cardiac catheterization laboratory and takes up to four
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