Pathology:
The Aorta is main blood vessel (Artery) that carries blood from heart to the rest of the body. The Aortic Valve is located at junction of Heart and Aorta. Being a one way valve, it regulates flow of blood in one direction, that is from heart towards body. However, in certain diseases or genetic disorders, the Aortic Valve malfunctions either blocking blood from flowing towards body from heart (Aortic Stenosis) or letting it flow back into the heart (Aortic Regurgitation).
Complications:
The following complications are observed in patients
- Aortic Stenosis: As the disease progresses, leaflets of Aortic Valve thicken leading to reduced mobility and narrowing of the opening reducing flow of blood from heart to body. The arteries supplying blood to the heart (Coronary Arteries) connect to the Aorta immediately after the Aortic Valve. A reduced flow of blood through these Coronary Arteries can cause chest pain (Angina on Exertion). The ascending Aorta further connects to three arteries which supply blood to both the hands and the brain. Reduction of blood flowing into the brain causes fainting or passing out (Syncope). Increase in back-pressure due to obstruction to flow of blood in the heart and lungs causes Breathlessness.
- Aortic Regurgitation: As the disease progresses or due to infection of the leaflets, the Aortic valve may lose their ability to close completely. This results in blood flowing back into the heart from the Aorta leading to increased back-pressure in the heart and lungs causing Palpitation and Breathlessness.
Treatment:
The usual investigations needed to diagnose & plan treatment for Aortic Stenosis and Aortic Regurgitation are ECG, 2D Echo and occasionally, CT Scan with Contrast (CT Aortogram). This condition is corrected by procedure called “Aortic Valve Replacement (AVR)”.
- Minimally Invasive Aortic Valve Replacement (MICS)
A small incision is made through the right side of the rib cage or small vertical split in upper section of chest bone (Sternum) to access the heart. The procedure requires special instruments and techniques. The defective Aortic Valve is replaced by an artificial (Prosthetic) valve.
The 2 types of Prosthetic Valves available are:
- Mechanical Valve: Made from a composite of Pyrolitic Carbon and Titanium, the Mechanical Valve is generally recommended for younger patients below 60 years of age. The Mechanical Valve is durable and lasts longer. As the material used in construction is inorganic, the patient has to consume blood thinners (Anti Coagulants) all through their life as well as regular blood testing (PT/INR), sometimes as frequent as monthly, to assess the thinness (Anti-Coagulation) status.
- Bio-Prosthetic (Tissue) Valve: The Bio-Prosthetic Valve is made up of biological tissue, usually of Bovine or Porcine origin. This valve is recommended for patients ideally above 65 years of age. The Bio-Prosthetic Valve, which as per manufacturers claim lasts 15 to 18 years, is much lesser than Mechanical Valve. Incase of degeneration of Bio-Prosthetic Valve, patient may have to again undergo Aortic Valve Replacement Surgery (Redo Surgery). At the same time, patient has to consume blood thinners (Anti Coagulants) for just 3 months after surgery.
Minimally Invasive Aortic Valve Replacement Surgery
An incision of approximately 2 to 3 inches is made in between the ribs on right side of chest (Mini-Thoracotomy) or small vertical split in upper section of chest bone (Hemi-Sternotomy) to access the heart . The Operation Theater used to perform this procedure has to be equipped with specially designed Surgical Instruments. The Surgeon and his team have to be experienced and trained to perform these surgeries.
The Surgeon determines whether a patient is suitable candidate for Minimally Invasive Aortic Valve Replacement Surgery based on following:
- Physical examination and attributes of Patient
- Detailed medical history of Patient
- Results of specific investigations
All patients do not meet the criteria required for Minimally Invasive Aortic Valve Surgery. In rare cases, if the Surgeon feels that it is not safe to continue with the planned minimal invasive approach, they might convert the procedure to Conventional Aortic Valve Replacement (AVR) Surgery.
Salient Features of Minimally Invasive Aortic Valve Replacement Surgery
- Irrespective of the type of Aortic Valve used, the patient is able to return to an active and healthy life after receiving the prosthetic valve.
- Patients display significant symptomatic improvement after Aortic Valve Replacement Surgery.
- As the size of incision is significantly smaller than conventional surgery, the patient recovers faster, spends lesser time in the hospital and quickly returns to their normal routine.
- The patient experiences significantly lesser pain after surgery.
- The patient has lesser blood loss.
- Minimally Invasive Aortic Valve Replacement Surgery leaves a smaller scar.
