Mitral Valve Surgery

Mitral valve controls unidirectional flow between the left atrium and the left ventricle. That is is undoubtedly one of the most complex heart structures because its function is a part of the valve itself, dependent on the left ventricle function. The valve closes during the myocardial contraction – systole, that ejects the blood into the aorta. During the myocardial relaxation phase – diastole, the mitral valve widely opens to provide the left ventricle filling.

Rheumatic mitral stenosis was the leading cause of the mitral valve disease. The widespread antibiotic use significantly reduced the incidence of rheumatic fever in developed countries. Therefore, the degenerative valve disuse becomes the primary mitral valve pathology today.

Valve tissue degeneration leads to the chordal elongation and rupture. Mitral leaflets are not closing correctly during the systole; therefore, allowing a portion of blood to regurgitate back into the left atrium. The left ventricle gets volume overloaded, dilates, and eventually fails. The main symptoms of mitral insufficiency are shortness of breath on effort, fatigue, and rhythm disturbances. Rest or supine position dyspnea are signs of advanced disease.

The second most common cause of mitral insufficiency is coronary artery disease due to myocardial infarction.

Mitral valve regurgitation is manly repaired today. Grace, to its anatomy it is possible to reshape the mitral valve tissue, making it functional without prosthesis implantation. Mitral valve reconstruction is the golden standard in degenerative mitral insufficiency. Repaired mitral valve patients do not need lifetime anticoagulation therapy and have less postoperative complications. The experienced surgical team could repair more than 95 to 98 % of degenerative mitral valves. In ischemic mitral valve insufficiency or rheumatic mitral disease, the repair is possible, although it is less feasible and has limited durability.

If impossible to repair, the mitral valve is replaced, of course, either with mechanical or tissue prosthesis. Mechanical valves are durable but require lifetime anticoagulation therapy. Tissue valves are less durable, but patients need no lifetime anticoagulation therapy and, therefore, used in patients over 65 years.

Astic Hasim, 67 years, Sarajevo, Bosnia and Herzegovina.

Mr Asotic sufered from severe mitral regurgitation due to huge dechiscence of previously implanted mechanical mitral valve prosthesis. He vas rejected for surgery from several hospitals due to signifacant operative risk, that was estimated above 30 % according to EUROSCORE 2 scale. Eventually, he was accepted for surgery and operated at Cardiocascular Institute „DEDINJE“ in Belgrade, Serbia by Prof Stojanovic Ivan. His prosthesis was replaced by a new one along with two aortocoronary bypasses. After few weeks of ICU recovery Hasim was dicharged form the hospital with implanted pace maker as well.

After postoperative recovery and COVID-19 pandemic shutdown Hasim returned to his craftsmen shop in famous Sarajevo bazzar of Baščaršija.

The first mechanical valve was implanted on 21st September 1960 by doctor Albert Starr, who designed it all together with engineer Mr. Lowell Edwards. This valve operated like a ball in a cage, similar to kids snorkels. The so-called Starr-Edwards prosthesis has been successfully implanted in more than 300 000 patients and reported to be functional in some patients more than 30 years after implantation. Meanvalve, the valve has been replaced by superior leaflet valves.

Mitral valve repair is a surgical procedure in which we reconstruct the mitral valve to restore its function. We preserve mitral valve leaflet tissue, and the only foreign material implanted is an annuloplasty ring, which is necessary for repair stability and durability. Several different surgical techniques are available nowadays to retail or reshape the mitral valve, making it fully competent.

Degenerative disease is the leading cause of mitral insufficiency today. Loss of collagen and elative fibers are the main features of the disease. Tendinous chordae gets elongated, therefore, and eventually rupture, leading to an incompetent valve that is regurgitating blood back into the left ventricle. That is is what we call the mitral leaflet prolapse. Insufficiency results in heart volume overload, heart chambers get dilated, and the myocardium began to fail over time. The left atrium enlarges as well, and arrhythmias, mainly the atrial fibrillations, appear meanwhile.

Marija Mitić, pregnancy after mitral valve repair

Pregnancy is possible but risky though after the valve replacemt with mechanical prosthesis due to teratogenic effects of Coumadine. This is why is important to make any effort to repair in women of childbearimng age. Marija Mitić is one of many weomen who had safe pregnancy and delivery due to mitral valve repair surgery

When compared to the replacement, the mitral valve repair has superior short- and long-term survival. Mitral valvuloplasty is superior to the replacement in terms of postoperative complications as well. Patients experienced less hemorrhagic, thromboembolic, and infective events postoperatively. Since there is a minimal amount of the foreign body implanted, the mitral valve repair patients need no lifetime anticoagulation therapy.  Coumadin based drugs, therefore, are taken only during the first three months after the surgery.

Mitral insufficiency is operated in the early stages of the disease if there is a high probability for the repair. An experienced surgical team with a high volume of mitral repairs performed annually is the best choice for the success of the procedure.

Repair durability in degenerative mitral valve prolapse is excellent, though, with  90 – 98 % of repaired valves fully functional twenty years after the surgery. In non-degenerative valve disease, the mitral repair is less durable. For example, around 70 % of rheumatic valves repaired are functional 15 years after the surgery.  In ischemic mitral disease, the repair possibility and durability are highly dependent on the left ventricle dysfunction, leading to 30 % of the repair failure within six months after the surgery. The decision of repair or to replace such a valve depends on surgical experience, left ventricle dysfunction, and valve anatomy itself, and should be fully cleared with the patient preoperatively.

“Port – access” surgery is a less invasive cardiac surgery procedure in which we use endoscopic techniques to operate the heart through a small chest wall incision. Although mainly used for the mitral valve repair surgery, but tricuspid valve, some congenital defects, and heart tumors could be removed this way as well.