The treatment options include valve repair & valve replacement. Valve repair can be performed in any age group but needs to be done early in the disease process before the valve is severely damaged. This always is the best option because it preserves the native valve. However, this is not frequently possible because it requires special surgical expertise as well as good intraoperative facilities like transesophageal echocardiography. The repair needs to be durable in the long term otherwise it necessitates a repeat operation to replace the valve which not only involves the additional cost but also a much higher risk than the first operation.
When valve replacement is recommended, the choice of a valve depends on multiple important factors which need to be discussed in details with the patient. Unfortunately, it is not done. There are two types of valve replacement devices, mechanical & bioprosthetic.
Types of Valve’s
Mechanical Valves
There are many kinds of mechanical valves available in the market. Which particular valve to use depends on the Surgeons comfort & track record of the valve. The cost of the valve may be a consideration in some cases. Mechanical valves are made of a special kind of metal called pyrolitic carbon. It is the same metal that is used to make the exterior of spacecraft. There are two types of mechanical valves, single leaflet & bileaflet. All the valves are made in the western countries except Chitra mechanical valve which was invented by Dr. S.Valiathan from the SriChitra Tirunal Institute of medical sciences at Thiruvananthapuram.
Any foreign object in the bloodstream induces clot formation. Likewise, a mechanical valve in the heart can get obstructed by clot formation. Therefore it is necessary to anticoagulate the patient lifelong with the help pf medicines like warfarin or acitrom. The dose of the anticoagulants depends on the position of the implant of the valve & associated medical conditions. Monitoring the level of anticoagulation is extremely important as it depends on multiple factors. Anticoagulation is affected by the drug dose, type of drug, drug interactions with other medicines taken by the patient, daily diet, exercise routine etc. Under or over-anticoagulation can be lethal. Underanticoagulation can block the valve & over anticoagulation can cause spontaneous bleeding anywhere in the body. Anticoagulation testing is available in most pathological laboratories in major cities.
Laboratory to laboratory variation exists; therefore it is important to get blood tested from the same reliable laboratory every time. Frequent testing is advisable to ensure adequate anticoagulation. Mechanical valves last a lifetime. Therefore if the anticoagulation is properly managed the patient should not need a second operation to replace that valve. However, there are disadvantages to be on blood thinners. Trivial injuries will bleed a lot more than normal people. Emergency operations are dangerous from the bleeding point of view & need elaborate preoperative preparation. Anticoagulation is contraindicated for pregnant women or for those who wish to conceive because it can cause intrauterine bleeding, cerebral hemorrhage in the fetus, causing a stillbirth or life-threatening bleeding from the uterus at the time of delivery. The associated medical condition makes also contraindicate anticoagulation like patients with intracranial bleed, peptic ulcer etc. Therefore detail medical history prior to surgery is of vital importance.