Definition and Overview
Aortic valve replacement is a procedure performed on patients with malfunctioning heart valves. Doctors recommend it if the damaged aortic valve can no longer be repaired and is causing complications such as regurgitation. The procedure aims to replace the damaged valve with an artificial valve.
In the past, aortic valve replacement is only performed through highly invasive open-heart surgery. However, due to recent advances in technology and in the field of cardiology, the procedure can now also be performed using minimally invasive methods or those that do not require a huge incision in the chest.
Who Should Undergo and Expected Results
Aortic valve replacement surgery is recommended for patients whose aortic valves are damaged beyond repair or those who are suffering from:
Aortic stenosis, in which the aortic valve becomes narrowed leading to the obstruction of blood flow from the heart
Aortic regurgitation, in which the aortic valve leaks resulting in blood flowing back to the heart
If left untreated, aortic valve problems may eventually lead to heart failure. Thus, doctors usually recommend valve replacement following diagnosis to prevent the condition from worsening and save the patient from potentially life-threatening complications.
Following an aortic heart valve replacement, the artificial valve is expected to function the same way as the original heart valve. The patient is also expected to have a close to normal life expectancy. The risk of heart failure as well as other symptoms and cardiac issues caused by the condition are also expected to be resolved.
How is the Procedure Performed?
In an aortic valve replacement procedure, the damaged valve is replaced with an artificial heart valve, which could be:
Biological – These valves tend to last between 10 to 20 years. They do not require long-term blood thinning medications but may need to be eventually replaced.
Mechanical – These valves are made of man-made synthetic materials, the most common of which are titanium or carbon. They last longer than biological valves but require patients to take blood thinners for the rest of their lives.
As for the method in which the procedure is carried out, options include open-heart surgery and minimally invasive methods (minimally invasive aortic valve replacement).
Open-heart procedure (mechanical aortic valve replacement) - An open-heart procedure to replace a faulty or damaged aortic valve is performed under general anaesthesia and involves making a large cut (about 25cm long) in the chest to gain access to the heart. The heart is then stopped with its function turned over to a heart-lung bypass machine. The surgeon then removes the damaged aortic valve and manually replaces it with a new artificial one. The heart is then restarted and the chest incision is closed with stitches. Open-heart aortic valve replacement surgery usually takes a few hours and the patient has to stay in the hospital for about a week. The whole recovery period may take up to 2 to 3 months.
Percutaneous aortic valve replacement or transcatheter aortic valve replacement (TAVR) - Percutaneous or transcatheter aortic valve replacement surgery replaces a faulty or damaged aortic valve without making a large incision in the chest. It is usually performed using at least one small cut (about 2-3 inches) on the right chest near the breastbone. These minimally invasive surgeries take less time than open-heart surgery. They work by wedging a replacement valve into the place of the original valve. The artificial valve, which is fully collapsible, is delivered via a catheter. Once in place, the valve is expanded, an action that automatically pushes the damaged valve out of the way.
Transfemoral approach - The transfemoral approach is an alternative method used to perform transcatheter aortic valve replacement surgery. In this method, the catheter enters the body through the femoral artery (or the large artery in the groin) instead of through the chest.
Robotic-assisted heart valve surgery - This procedure can be performed through 2-4 tiny cuts in the chest using a special computer that controls robotic arms. The procedure is guided by a 3D view of the heart and the aortic valve displayed on a computer.
Following the procedure, the surgeon will place flexible tubes around the heart to prevent fluid build up in the treated area.
Since transcatheter aortic valve replacement procedures and other advanced techniques are fairly new, they are often only used for high-risk patients who are not healthy enough to undergo traditional open-heart replacement surgery.
Possible Risks and Complications
Potential aortic valve replacement complications include the following:
Wound infections (especially for open heart surgery with large chest incisions)
Lung or bladder infection
Heart valve infection (endocarditis)
Irregular heartbeat or arrhythmia
Reduced kidney function
Patients are also faced with the common risks of general anaesthesia, such as breathing problems and allergic reactions.
A transcatheter aortic valve replacement procedure is less risky as there is less pain and reduced blood loss after the procedure. The recovery period is also shorter than that of open-heart surgery.
Patients who have undergone aortic valve replacement surgery may need another surgery in the future. The length of time in between said procedures will depend on the type of artificial heart valve used during the first surgery.
There is also a small chance that an artificial heart valve will not work as expected after an aortic valve replacement procedure. Thus, patients are advised to follow their after-care plan closely and have their artificial heart valve checked regularly to make sure it is working properly.
Reardon MJ, Van Mieghem NM, Popma JJ, Kleiman NS, et al. “Surgical or transcatheter aortic valve replacement in intermediate risk patients.” The New England Journal of Medicine. http://www.nejm.org/doi/full/10.1056/NEJMoa1700456
Svensson LG. “Aortic valve replacement: Options, improvements, and costs.” Cleveland Clinic Journal of Medicine. 2013 April;80(4): 253-254. http://www.mdedge.com/ccjm/article/95959/cardiology/aortic-valve-replacement-options-improvements-and-costs
Malas T, Ruel M. “Cardiac Surgery: Current status of aortic valve replacement.” Division of Cardiac Surgery, University of Ottawa Heart Institute, Canada. https://www.omicsonline.org/cardiac-surgery-current-status-of-aortic-valve-replacement-2161-1076.S3-001.php?aid=8370