Many of the most serious health problems facing Americans involve the heart. Coronary artery disease, arrhythmias and heart attacks are just some of the heart-related maladies that afflict millions of people. Given that so many adults struggle with poor heart health, it’s not surprising that heart surgeries are so common. One such procedure is heart valve surgery, which is performed on 99,000 people every year.
Reasons for Surgery
The human heart contains four valves: the aortic, mitral, tricuspid and pulmonary. Each is tasked with regulating blood flow through the organ. Specifically, these structures allow blood to enter into the heart’s four chambers. After blood leaves the chamber, the valves must firmly close in order to prevent backflow. The tissue flaps that open and close the valves are known as leaflets.
There are a number of reasons why heart valve surgery is performed. In some patients, the valves do not close properly. This can cause the heart to experience regurgitation, a condition in which blood leaks back into the preceding chamber. Conversely, the valve may develop the opposite problem, becoming unable to fully open. As a result, the forward movement of blood is significantly impeded. Doctors refer to this condition as stenosis.
Another major reason for heart valve replacement is mitral valve prolapse (MVP). In fact, MVP is actually the most common problem to afflict the heart’s valves. Is it estimated that roughly three to five percent of the American populace has this abnormality. Mitral valve prolapses occur when the mitral leaflets either bulge upward or slip backwards into the left atrium (the left atrium is one of the heart’s four chambers, responsible for receiving oxygenated blood from the pulmonary veins). These abnormal movements occur as the heart contracts.
Though it may sound like a serious health problem, most cases of MVP are asymptomatic. Patients that do exhibit symptoms may encounter heart arrhythmia, dizziness, chest pains, fatigue and breathing difficulties. Given that this condition usually doesn’t cause any noticeable problems, the bulk of those with MVP do not need medical treatment. Valve replacement is necessary only if the heart is in very poor health, such as when the prolapsed valve allows a large amount of blood to leak into the left atrium.
Other conditions/circumstances which may necessitate valve replacement are listed below:
- Endocarditis, or infection of the valve
- The onset of significant cardiovascular problems (chest-pains, shortness of breath, fainting spells and heart failure) which are triggered by a defective valve
- The poor performance of a previously implanted valve
- Other problems that involve the heart valves, such as clots, bleeding and infections
Fixing the Heart
Before going under the knife, patients receiving new heart valves must be placed under general anesthesia. Traditionally, this type of operation has required open heart surgery. This means that, in addition to making a sizeable opening in the chest, the surgeon also has to stop the patient’s heart. To keep the patient’s body up and running during the procedure, a heart-lung bypass machine is connected to the heart. This device functions as a stand-in for the heart organ during the operation. Alternatively, a bypass pump might be used instead.
The open-heart technique is still used for many valve replacement operations. In recent years, however, some surgeries have utilized less-invasive methods to both repair and replace heart valves. A prime example of one of these procedures is robotically-assisted heart surgery. This method relies on robotic arms to make small yet precise incisions on the patient’s body.
A typical robotic surgical system includes several arms fitted with specific instruments, each containing wrists with human-like flexibility. The system also includes an arm equipped with a camera, providing the surgeon with a clear view of the surgical site. A few feet away the patient, the surgeon guides and maneuvers the arms with the aid of a 3D monitor.
As with other surgical procedures, robotically-assisted heart surgery is performed by a team of doctors, each with their own specific role. Aside from requiring a smaller incision in the patient’s chest, this surgical method also involves less blood loss and shorter hospitalizations. In addition, patients are able to resume their normal physical routines in less time.
Replacement Parts and Recovery Time
Surgeons do not always have to replace the patient’s valve. The two methods for repairing heart valves are known as ring annuloplasty or valve repair. The former requires the surgeon to sew a ring of plastic, cloth or tissue around the perimeter of the valve. A valve repair, in comparison, involves the restructuring or restoration of the valve’s leaflets.
If the valve cannot be salvaged, surgeons usually have two options for replacing this section of the heart. Mechanical valves are built with synthetic materials, such as various metals or ceramic, giving them excellent longevity. However, this benefit comes at a price – people who receive such valves must take blood-thinning medications for the remainder of their lives.
In contrast, some patients are given biological valves made with human or animal tissues. While these valves generally do not force people to take blood thinners, they are not as durable as their mechanical counterparts. Consequentially, patients must often have follow-up surgeries to implant new valves. The lifespan of biological valves usually ranges from twelve to fifteen years.
The recovery process for heart valve replacement can differ from patient to patient. Open surgery on the mitral valve, for instance, involves different challenges than minimally-invasive aortic valve surgery. The chart below illustrates some of these possible differences:
Type of Surgery
Aortic Valve Surgery
Mitral Valve Surgery