Benefits, risks of minimally invasive TAVI procedure
(8 months ago)
New Delhi , Nov 6 : Aortic stenosis is an ailment that leads to the narrowing of the aortic valve of the heart, which normally allows blood flow to be pumped from the main chamber of heart to the rest of body.
The narrowing of this valve can lead to an increased amount of stress and pressure on the heart muscle, which in turn can lead to symptoms of chest discomfort, shortness of breath, leg swelling, fatigue, lightheadedness, syncope, and even sudden death.
The most common cause of aortic stenosis is calcification of the valve, caused due to degeneration that comes with age.
Other causes include damage to the heart valves due to diseases like rheumatic heart disease, or congenital heart defects like bicuspid aortic valve, misshapen tricuspid aortic valve, or a unicuspid valve.
TAVR or TAVI stands for transcatheter aortic valve replacement or implantation. It is a relatively new technology which serves as an alternative to standard aortic valve replacement surgery.
This procedure is a minimally invasive procedure that allows the cardiologist to cure a severely narrowed aortic valve without opening up the patient's chest by replacing the valve without removing the old, damaged valve.
Instead, a replacement valve is wedged into the aortic valve's place. Somewhat similar to a stent placed in an artery, the TAVI approach delivers a fully collapsible replacement valve to the valve site through a catheter.
Once in place, the new valve is expands, pushing the old valve leaflets out of the way, taking over the old valve's job of regulating blood flow.
People with aortic stenosis may have a "murmur" that can be detected during a regular doctor's visit and general physical examination. This may alert the physician to order an ultrasound (echocardiogram) of the heart. This echocardiogram test confirms the presence of aortic stenosis and its severity.
Additionally, the doctor may also perform an electrocardiogram, a computed tomography (CT) scan, and an angiogram to completely assess the situation in the heart, and decide if the patient will benefit from this procedure.
The TAVI procedure has been done in over 50,000 patients worldwide. It was FDA approved in November 2011 for patients with symptomatic aortic stenosis who are not fit for or carry high risk for conventional surgical aortic valve replacement. This is a savior to these patients, as the prognosis of severe symptomatic aortic stenosis worsens the longer it is left untreated. In general, 50% of patients will not be alive after two years from the onset of their symptoms.
BGS Gleneagles Global Hospitals recently implemented the procedure on an 81-year-old patient.
He had a history of undergoing coronary artery bypass grafting, multiple percutaneous transluminal coronary angioplasties and stenting procedures. He also suffered from a severe left ventricular dysfunction, diabetes and renal dysfunction.
This medical history posed him as an unfit candidate for conventional surgery, making him an ideal candidate for TAVI. He underwent successful TAVI procedure and achieved very good clinical improvement without any complications.
Conventional surgical aortic valve replacement requires surgical opening of the chest, known as sternatomy, and putting the patient on heart lung bypass machine under general anesthesia. The diseased valve is removed and new valve is sutured. The TAVR or TAVI procedure can be done through femoral puncture under local anesthesia.
A catheter about the size of a pen is inserted through the femoral artery in the groin and carefully passed up into the heart, where the replacement valve is implanted inside the narrowed valve resulting in a normal functioning aortic valve. The replacement valve is made of bovine or porcine tissue and supported on a metal stent. With this procedure, the patient does not need general anesthesia, opening of a chest or heart lung machine.
The patient's experience with the TAVI procedure may be comparable to an angioplasty in terms of down time and recovery, and requires a shorter hospital stay. As per research, it has been seen that this procedure significantly allows patients to live longer and with a better quality of life as compared to treatment solely through medication.
As with any heart procedure, TAVI has its own risks. These risks are similar to those involved in any heart procedure such as vascular injury, arrhythmia, and temporary obstruction of the coronary artery. The risks of mortality, stroke, bleeding, duration of hospital stay, and recovery period are much less with TAVI as compared to surgical aortic valve replacement.
Currently this procedure is reserved for those people for whom an open-heart surgery procedure poses high risk, or they are not suitable. For these reasons, TAVI is recommend to elderly patients more than 70 years and those with concomitant severe systolic heart failure or coronary artery disease.
Patients with complications such as cerebrovascular and peripheral arterial disease, chronic kidney disease, and chronic respiratory dysfunction are also good candidates for this procedure as these complications pose risks to the procedure of open-heart surgery.
At times, this procedure may also be suggested to patients who are apprehensive about undergoing surgical interventions. TAVR can be an effective option to improve quality of life and increase the longevity in patients who otherwise have limited choices for repair of their aortic valve.