Surgical Aortic Valve Replacement (SAVR) is a cardiac procedure that involves removing a diseased aortic valve and replacing it with a new one. It is an effective treatment for individuals with aortic valve dysfunction. This article provides an overview of SAVR, detailing the valve’s function, the conditions that necessitate its replacement, the surgical process, and the recovery journey for patients.
Understanding the Aortic Valve and Conditions Requiring SAVR
The aortic valve is located between the left ventricle, the heart’s main pumping chamber, and the aorta, the body’s largest artery. Its role is to ensure that oxygen-rich blood flows in one direction, from the heart to the rest of the body, preventing backflow into the left ventricle. This valve usually has three leaflets that open and close with each heartbeat.
Two main conditions necessitate SAVR: aortic stenosis and aortic regurgitation. Aortic stenosis occurs when the aortic valve narrows, stiffens, or becomes calcified, restricting blood flow out of the heart. This narrowing forces the heart to work harder to pump blood, potentially leading to symptoms such as chest pain, dizziness, and shortness of breath. Over time, this increased workload can weaken the heart muscle.
Aortic regurgitation, also known as aortic insufficiency, occurs when the aortic valve does not close completely, allowing blood to leak backward into the left ventricle. This leakage causes the left ventricle to hold more blood than usual, requiring it to pump harder. Both conditions can lead to fatigue and, if left unaddressed, may result in heart failure.
The Surgical Procedure for Aortic Valve Replacement
The SAVR procedure is performed under general anesthesia. The surgeon typically begins by making an incision down the center of the chest, through the breastbone, a technique called a sternotomy. This approach provides direct access to the heart. While a full sternotomy is common, some procedures may utilize smaller incisions in less invasive approaches.
Once the heart is exposed, the patient is connected to a heart-lung bypass machine, also known as a cardiopulmonary bypass machine. This device temporarily takes over the functions of the heart and lungs, circulating and oxygenating the blood. This allows the surgical team to temporarily stop the heart, creating a still and bloodless field for the surgeon to work.
The diseased aortic valve is then removed. A new prosthetic valve is sewn into its place. There are two types of prosthetic valves: mechanical valves and biological (tissue) valves.
Mechanical valves are durable, made from materials like carbon and steel, but require patients to take blood-thinning medication for life to prevent blood clots. Biological valves, derived from animal tissues or human donors, typically last between 15 to 20 years and generally do not require lifelong anticoagulation. After the new valve is secured, the heart is restarted, and the patient is gradually weaned off the heart-lung machine. The breastbone is then reconnected, and the incision is closed.
Preparing for and Immediate Post-Operative Care
Preparation for SAVR involves a series of assessments. This includes a physical examination and various diagnostic tests, such as echocardiograms, electrocardiograms (EKGs), CT scans, and blood tests. These tests help the healthcare team evaluate heart function and overall health, guiding decisions about the most suitable surgical approach and valve type. Patients may also receive instructions on lifestyle adjustments, such as dietary changes or temporary medication adjustments, leading up to the procedure.
Immediately following SAVR, patients are typically transferred to the intensive care unit (ICU) for monitoring. This initial period, usually lasting one to two days, involves observation of heart function, blood pressure, and breathing. Patients may have various tubes and drains, including breathing tubes, which are typically removed once they can breathe independently. Pain management is a priority, and medications are administered.
As the patient stabilizes and begins to recover, they are encouraged to sit up and start movements, such as walking short distances. This early mobilization helps prevent complications and promotes recovery. After their time in the ICU, patients are usually transferred to a regular hospital ward. The typical hospital stay after SAVR is around five to seven days, depending on individual recovery progress and any complications. During this time, the care team monitors the patient and prepares them for discharge.
Recovery and Long-Term Patient Outcomes
Once discharged from the hospital, the recovery process for SAVR continues at home, typically extending over several weeks. Most patients regain strength and mobility within eight to twelve weeks, though complete healing and return to full activity can take up to three months. During this period, patients receive specific guidelines on activity restrictions, particularly regarding lifting heavy objects or strenuous physical exertion, to allow the breastbone to heal properly.
Cardiac rehabilitation plays a role in the recovery journey, often beginning a few weeks after surgery. These programs involve supervised exercise, education on heart-healthy living, and emotional support. Rehabilitation helps patients rebuild their strength, improve cardiovascular fitness, and make lasting lifestyle changes. Many individuals can resume light desk work within two to four weeks, while more physically demanding jobs may require a longer hiatus, up to eight weeks or more.
The long-term outlook for patients after SAVR is generally favorable, with most experiencing an improvement in symptoms and quality of life. The surgery relieves the strain on the heart, allowing it to pump blood more efficiently. Recent studies indicate excellent long-term survival rates, with a five-year survival rate of 93% observed in low-risk patients undergoing isolated SAVR. While the new valve is durable, ongoing follow-up care with a cardiologist is important to monitor valve function and overall heart health. Patients with mechanical valves will require lifelong anticoagulant medication, and all patients will need regular medical check-ups.