Heart valves regulate blood flow according to pumping characteristics by being located between chambers of heart or main veins and heart chambers. Heart has four valves. Heart has aortic and mitral valves on its left side where clean blood loaded with oxygen is pumped to the body and tricuspid and pulmonary valves on its right side where venous blood is pumped to the lung. Leaflets of the mitral and tricuspid valves hold onto the walls of chambers with beams called "chorda". Aortic and tricuspid valves are with trileaflet and mitral and pulmonary valves are with bileaflets.
Surgical Valve Diseases
1-2 % of all deaths in the world corresponds to heart valve diseases. In recent years, effective and permanent treatment opportunities have been developed in heart valve surgery thanks to rapid advances in artificial valve technology.
In cases where valve allows passage of blood, pathologies constituting regurgitation in cases where blood is held and preventing this process entail surgical correction after a certain stage. Damages likely to occur in annulus tissue around the valves, valves or beams lead to valve diseases.
Disease may be present in only single valve and at the same time multiple valves may be also affected. In this case, disease generally starts in one valve and it then disrupts other valves per working principles of heart. Main reasons of heart valve disease are congenital defects, rheumatic fever, infections, age-related deterioration, coronary heart diseases and aortic aneurysm.
When valve diseases reach surgical phase, mostly both stenosis (narrowing) and regurgitation have occurred.
Stenosis (narrowing): It is a pathology preventing sufficient transition of blood where leaflets get thick, deformed or stuck together. Chordae may be affected at the same time. If the amount of blood passing drops below a critical level, surgical intervention may be required.
Regurgitation: Closure of valve is not fully achieved as a result of expansion in annular tissue, deformation in leaflets or elongation of chordae and a little blood retreats. If the amount of blood retreated exceeds a critical level, surgical intervention may be required.
Symptoms of Valve Diseases
Shortness of breath, palpitations, arrhythmias, chest pain, fainting, swelling in the legs, coughing up bloody sputum, failure of supine posture may be a sign of a failing heart valve disease. Some of these symptoms are usually present simultaneously. Becoming clear of symptoms of heart valve disease is of high importance in surgical decision making process.
Valvular disease can be determined by echocardiography and angiocardiography to be applied to the patients applying for a cardiologist with complaints. Valve diseases not requiring surgery can be followed up with periodical echocardiographic examinations. Sometimes valve disease may be incidentally diagnosed during investigation of another heart disease.
Aortic Valve Surgery
Aortic valve is located between left ventricle of heart and main aorta delivered from heart. It is with trileaflets and it has discharge holes of coronary arteries feeding heart over it from aorta.
Causes of Aortic Valve Stenosis
Rheumatic Aortic Stenosis: This is the most common cause of aortic valve stenosis and it develops after throat infections not duly and sufficiently treated. It may not pose any symptoms until the age of 40.
Degenerative Aortic Stenosis: This the second most common cause. This occurs with the addition of tissue calcification over valve tissue deteriorating together with age. Specific narrowing occurs following 60 years of age.
Calcific Congenital Aortic Stenosis: This is the narrowing of valve as a result of severe calcification due to deteriorated calcium balance over congenital abnormal bileaflet aortic valve.
Causes of Aortic Valve Regurgitation
Rheumatic Aortic Valve Regurgitation It causes regurgitation causing constriction and deformation in leaflets.
Myxomatous Disease of Aortic Valve: This is a type of regurgitation in aortic valve not fully closed due to relaxation in leaflet tissues.
Anuloaortik Ectasia: This is an expansion due to genetic reason in valve annulus and aortic tissue starting just over aortic valve. Marfan syndrome and cystic medial necrosis with familial transition are the most common causes.
Aortic Valve Endocarditis: This is an infection of valve tissue and it causes valve regurgitation with abscess formation around annulus, puncture and deformation in leaflets.
Other Reasons: The causes such as rupture in aortic valve leaflets as a result of trauma and other factors causing aortic aneurysm may lead to valve regurgitation.
To whom surgical intervention is performed in aortic valve diseases?
• For those diagnosed with moderate or severe aortic narrowing and symptoms,
• When gradient between front and rear side of aortic valve is 50 mmHg and more,
• Even if there is no complaints, aortic valve area less is less than 0.75 cm2.
• This means that it is time for surgery. The patients with no complaints but having progressive ventricular enlargement are candidates for surgery.
In aortic regurgitation:
• Presence of left ventricular function impairment in patients with no or minimal symptoms require surgery.
• Surgery is decided according to the severity of cardiac measurement in patients with onset of symptoms.
Aortic Valve Surgeries
Generally replacement surgery (replacing valve) is applied in patients to which aortic valve surgery is to be implemented. In very rare cases, repair may work. In replacement, artificial valve valves are mostly used. Primarily, deformed and non-functioning leaflets are removed. Valve surgeries have options of mechanical valve and biological valve. It would right to prefer biological valve in patients with below 15 years of age and over 70 years of age or patients not using coumadin due to social or psychic reasons, patients with severe brain aneurysm, women below 40 years of age planning pregnancy and patients with chronic liver disease. Nevertheless, final decision will be given ny the surgeon based on current state of the patient. Composite graft may become compulsory to use in cases where again aorta is aneurysmal aorta (mechanical valve mounted on artificial vessel).
Mitral Valve Surgery
Mitral valve is located between left atrium heart and left ventricle. It is of two leaflets and it is attached with bonds called "chorda" to two papillary muscles in the ventricle (muscle bulge). A great number of important veins and vascular pathways pass around annulus.
Causes of Mitral Valve Stenosis:
• It frequently occurs due to rheumatic heart disease.
• Severe mitral annular or leaflet calcification
• Congenital mitral anomalies
• Endocarditis (infection inside heart)
• Left atrial thrombus, tumor in left atrium
• Metabolic and carcinoid syndrome leading to deformation
• Commissurotomy interventions undergone
• Mitral valve replacement undergone
Causes of Mitral Valve Regurgitation
• Myxomatous degeneration of mitral valve
• Rheumatic heart disease
• Infectious endocarditis
• Mitral annular calcification
• Idiopathic (of unknown cause) chordae rupture
• Ischemic (depending on coronary failure)
To Whom Surgical Intervention Is Performed In Mitral Valve Diseases?
In Mitral Stenosis;
• The patients whose valve area is more than 1cm² and minimal complaints are followed up and the women planning pregnancy can be operated as an exemption.
• All patients with mitral stenosis providing clinic findings have been made to be a candidate for operation.
• Even if there is no finding, the patients whose valve area is less than 1cm² can be operated.
• If the patients with surgery indication during diagnosis, 5 year life expectancy is only 50 %.
In mitral regurgiation;
• The patients developing acute mitral regurgitation should be operated at once due to papillary muscle rupture following heart attack.
• The patients with not specific complaints should be prepared for surgery by having a coronary angiography if left ventricular dysfunction is determined.
• he patients with specific complaints should be operated as soon as possible without affecting seriously left ventricle functions.
Mitral Valve Surgeries
Mitral valve surgery is performed with cardiopulmonary bypass under general anesthesia (using a heart-lung machine) and by stopping heart. For this end, median sternotomy (opening the chest from front) is performed and right thoracotomy is performed in some patients. (below right breast)
In the first place, repair possibility is evaluated in mitral valve diseases (valvuloplasty) and if not possible, valve is replaced.
Mitral valvuloplasty: Chorda shortening, chorda transfer, chorda replacement, ring annuloplasty, commissurotomy are the procedures to be applied in mitral repair surgeries. In ring annuloplasty, a metal ring is stitched to valve annulus with insoluble stitching material. It is recommended that these patients use Coumadin for a short period. Correction (commissurotomy) can be provided without any need of replacement with an intervention to stuck leaflet commissure in some patients with mitral stenosis.
Mitral Valve Replacement: An important portion of patients to whom mitral valve replacement surgery is to be applied requires replacement. Even if biological valves are a good alternative in aortic valve replacement, these artificial valves are subject to deformation more quickly in mitral position and for this reason, it can be applied for in very exceptional circumstances. Apart from that, mechanical valve is replaced at once. Bileaflet mechanical valves produced from pyrrhotite carbon and titanium are the ones that are frequently preferred. Deformed leaflets in replacement are sometimes protected and are generally removed and mechanical valve is mounted to annulus with insoluble stitching material.
Tricuspid Valve Surgery
Tricuspid valve is located between right leaflet of heart (atrium) and right ventricule. It is trileaflet. Three muscles bulge (papillary muscle) in right ventricle support the valve via chordae. Primary diseases of tricuspid valve itself are rare. It is generally damaged afterwards depending on other valve or heart disease.
The most common cause of tricuspid valve disease is rheumatic heart disease (rheumatic pancarditis), infective endocarditis, traumatic degenerative, collagen vascular diseases, rheumatic tricuspid valve disease. Tricuspid valve regurgitation develops as secondary to other valve diseases rather than always organic change.
To whom surgical intervention is performed in tricuspid valve disease?
If there is severe tricuspid regurgitation in the patients to whom mitral valve replacement is to be applied, mitral replacement and tricuspid ring annuloplasty are required.
If there is regurgitation alone in tricuspid valve regurgitation and moderate right heart failure clinic findings, ring annuloplasty is required and if there are severe right heart failure findings, tricuspid valve regurgitation is required.
If there are right heart regurgitation findings in infective endocarditis and traumatic injuries, replacement or repair should be considered as the case may be.
Tricuspid Valve Surgeries
These are surgeries performed in most of time in beating heart and opening right atrium in mitral valve replacement while it is applied as additional surgical procedure in mitral valve surgery. The interventions to be performed to tricuspid valve alone are performed under general anesthesia by being connected to heart-lung machine and with median sternotomy or right thoracotomy.
Tricuspid Valve Repair: These are repair methods applied with a metal ring or without ring. This is applied in 3 different ways as Bicuspidization repair, DeVega Annuloplasty, Kay annuloplasty.
Tricuspid Valve Replacement: This is mounted with bileaflet mechanical valve insoluble stitching used in generally mitral positions by leaving leaflets of the patient in their places. In very rare cases, bioprosthetic valves are also used in tricuspid valve replacements. Coumadin will ensure long-term function of valve by preventing clot formation over valve and prevent emboli discharge from these clots formed. The patients treated with mechanical valve replacement must conduct PTZ-INR test each month and must adjust their doses and must us Coumadin throughout their lives.