Aortic valve stenosis
Narrowing of the aortic valveHeart valve between the left ventricle and the aorta. It prevents the blood from flowing back into the left ventricle during the relaxation phase. is the most common acquired heart defect, caused by calcification and thickening of the valveValve. tissue at an older age. Other disease processes that can lead to aortic valve stenosisAcquired valvular heart defect. The aortic valve narrows so much due to inflammation and/or calcification that when blood leaves the (left) ventricle, it can only enter the aorta by overcoming a high resistance. This narrowing leads to an increased load on the left ventricle. are inflammatory processes of the inner lining of the heart (endocarditisThis is an inflammation of the inner skin of the heart (endocardium), which lines the heart cavities and forms the structure of the heart valves. Mostly bacteria are the cause, more rarely fungi. Endocarditis caused by viruses is not known. Symptoms: Fever over a longer period of time, cardiac rhythm disorders and cardiac insufficiency. People with congenital heart defects are particularly at risk (see endocarditis prophylaxis). Endocarditis can lead to acquired heart defects, especially valve defects in adulthood.) and rheumatic feverRheumatic fever is a secondary illness that begins about 2-3 weeks after tonsillitis has been overcome. Typical symptoms are fever, painful swelling of the joints and inflammation of the heart (myocarditis, endocarditis). The cause is a bacterial infection with Streptococci, against which the body produces antibodies. These defence substances also mistakenly attack the body’s own tissue, especially the surface of joints or the inner wall of the heart (endocardium), due to their similarity to tissue.. However, bicuspid aortic valveMalformation of the aortic valve: instead of three, there are only two valve leaflets.valve stenosisPathological narrowing of the heart valves caused by inflammation or calcium deposits. The blood flow is obstructed and the blood can only be forced through the narrowed valve with increased pressure., which is usually congenitalCongenital., is much rarer and causes symptoms mainly at a younger age.
Typical symptoms of a highly narrowed aortic valve are dizziness, brief loss of consciousness, shortness of breath, tightness or left thoracic pain. However, with a slight narrowing of the aortic valve, patients usually do not show any symptoms. The severity of aortic valve stenosisNarrowing of vessels or valves. is determined by ultrasoundHigh-frequency sound waves that are inaudible to the human ear. Ultrasound is used for the non-invasive examination of the heart. See also Sonography. examination of the heart (echocardiography). In symptomatic, high-grade stenosis of the aortic valve, surgery is indicated.
Aortic valve replacement
Surgical aortic valve replacement can be performed either via a complete transection of the sternum (median sternotomy) or via a minimally invasive approach. Minimally invasive approaches include only partial transection of the sternum (partial upper sternotomy) or the approx. 5 cm long incision in the area of the 2nd intercostal space to the right of the sternum (right anterolateral mini-thoracotomy). The patient is then connected to the heart-lung machine and the heart is stopped. After opening the aorta, the diseased valve is cut out and any remaining calcifications are removed. Measurement and selection of the appropriate prosthetic valve and implantation of a biological or mechanical prosthetic valve. After closing the aorta and checking the function of the inserted valve prosthesis, the patient is weaned off the heart-lung machine.
A special form of biological aortic valve prostheses are the “rapid deployment” bioprosthesesCollective term for artificial heart valves whose basic material consists of biological substances. They can be made from the heart valves of pigs or from pieces of tissue taken from the pericardium of animals., in which the valve prosthesisReplacement part for a missing or no longer functioning organ or body part, e.g. heart valve prosthesis. is fixed in a metal framework. These valves are not sewn in, but only fixed in the aortic valve annulus with three guide sutures and expanded by means of a balloon. A major advantage is the shortened implantation time of these prostheses and an associated shortened ischaemiaTissue or organ is not being supplied with blood properly, localised bloodlessness. time of the heart on the heart-lung machineEquipment that takes over the work of the lungs and the stopped heart during heart surgery. The blood is directed from the vena cavae and thus out of the body into the machine, where it is enriched with oxygen and then pumped back into the body. During this process, the blood is cooled down and warmed up again after the operation..
Aortic valve regurgitation
In aortic valve regurgitationLeakage or inadequate closure of the aortic valve. The result: part of the blood flows back from the aorta into the left ventricle immediately after a heartbeat. See also “Aortic regurgitation”., there is a leakage of the pocket valve with backflow of blood into the left ventricleLower chamber of the heart. A healthy heart has two ventricles (right and left).. The inability of the aortic valve to close results from diseases of the valve leaflets themselves or from dilatation1. Dilatation of the ventricles or aorta. 2. Widening of constrictions in vessels and valves. of the aortic root.
Aortic valve reconstruction
The primary goal of valve reconstruction is to preserve the patient’s own valve and to fully restore the aortic valve’s ability to close. The prerequisite for this is a preserved structure of the valve pocket tissue without severe calcification. Aortic valve reconstruction is individualised according to the valve’s leakage mechanism, with a variety of techniques available to repair the valve. In the context of aortic valve insufficiencyinsufficient fulfilment of a function (pumping weakness of the heart, leakage of the heart valves). with existing dilatation of the aortic root, especially with bicuspid aortic valves, valve-preserving reconstruction procedures with replacement of the aortic root (David or Yacoub procedure) can be used.
Surgical methods
David procedure
The David proceuder involves removing the abnormally dilated part of the aorta, including the base. In addition, the orifices of the coronary vessels are detached from the diseased wall of the aorta. After measuring the appropriate vascular prosthesis, it is slipped over the mobilised aortic valve and fixed to the aortic base. This is followed by the re-fixation (resuspension) of the preserved leaflets of the aortic valve in the vascular prosthesis so that a complete closure of the leaflets is achieved. In addition, the previously mobilised orifices of the coronary vessels are reimplanted into the new prosthesis so that the blood supply to the heart muscle is ensured.
Bentall procedure
If the leaflets of the aortic valve cannot be preserved with existing dilatation of the aortic base, the Bentall procedure is used. Here, after resectionSurgical removal or surgical reduction. of the diseased aortic valve, the base and the ascending part of the aortaThe main major artery in the body. Leads from the left ventricle via an arch in the thoracic cavity to the abdominal cavity. There it splits into two large iliac arteries., the coronary vesselsCoronary arteries. The left and right coronary arteries originate above the aortic valve from the aortic root and initially run along the outside of the heart muscle before branching out into many sub-branches and dipping into the heart muscle tissue as fine arterioles. are mobilised. This is followed by implantation of a valve-bearing vascularConcerning the blood vessels. conduitAn artificial vascular prosthesis that connects a ventricle to a vessel outside the heart. It is usually used to replace abnormally dilated main arteries. (aortic prosthesis and biological/mechanical prosthetic heart valveIn the inflow and outflow area of the heart chambers there are valves which prevent the blood from flowing back in the wrong direction. Each heart half has a sail valve and a pocket valve: 1. Tricuspid valve (between the right atrium and right ventricle) 2. Pulmonary valve (between the right ventricle and pulmonary artery) 3. Mitral valve (between the left atrium and left ventricle) 4. Aortic valve (between the left ventricle and the aorta).) with implantation of the coronaryConcerning the coronary vessels that supply blood to the heart muscle. vessels into the prosthesis.
