Mitral valve replacement

Overview

Mitral valve replacement is a surgical procedure to provide a new mitral valve. In certain cases, fixing the mitral valve can prevent the need for replacement, but if the damage is severe, replacement is required. Mitral valve replacement is a treatment for mitral valve diseases such as mitral valve regurgitation and mitral valve stenosis.

The mitral valve is a passage between the left atrium and left ventricle of the heart. These chambers hold oxygen-rich blood that comes from the lungs into the left atrium. Then, the blood passes through the mitral valve into the left ventricle, which pumps it out to the rest of the body through the aorta.

Individuals with mitral valve disease face challenges in their valve’s ability to perform its function, which places additional stress on the left side of the heart. This prolonged strain can result in damage to the heart and lungs over time.

Types

There are two primary types of replacement valves: mechanical valves and biological valves. Typically, age-related guidelines are used as an initial reference when determining the appropriate valve.

• Mechanical valves made of carbon and steel: This offers exceptional durability with a lifespan of 20 to 30 years. It decreases the likelihood of requiring additional valve surgery. However, lifelong use of blood-thinners or anticoagulants is necessary to lower the risk of blood clot formation, which is more common with mechanical valves compared to biological ones.
  Blood thinners can be risky for some people, like those who are pregnant or planning to conceive, at a higher risk of falling or injury, or have personal reasons for not wanting to take them. In these cases, a biological valve might be a better option. Mechanical valves are often recommended for people under the age of 50 or between ages 50 and 65.
• Biological or bioprosthetic valves made of tissues from pigs, cows, or humans: A bioprosthetic valve eliminates the lifelong requirement for blood-thinners unless needed for another medical issue. The risk of blood clots is lower. However, it is less long-lasting compared to a mechanical valve, and it typically necessitates another valve replacement surgery approximately 10 to 15 years down the line. This option may be recommended for people over the age of 50.

Reasons for undergoing the procedure

Mitral valve replacement is used to address the following medical conditions:

• Mitral valve regurgitation.
• Mitral valve stenosis.
• Degenerative mitral valve prolapse, which often necessitates valve surgery. In this condition, the valve flaps (leaflets) deteriorate gradually over the years, resulting in mitral regurgitation or leakiness. While this leakage might begin as mild, if it worsens over time, surgical repair or replacement may be required.

Mitral valve repair is often more favored than mitral valve replacement. Mitral valve replacement is only advised if the likelihood of success with repair surgery is limited. It is important to seek medical experts’ advice for a well-informed decision regarding the most suitable approach for one’s case, be it repair or replacement.

Repair may not be effective in cases where severe damage to the valve has been caused by conditions such as endocarditis or rheumatic heart disease, or when the valve has significant calcium deposits, scarring, or extensive damage to its supporting structures like the papillary muscles or chordae.

Risk

In most cases, if mitral valve replacement has been advised, it indicates that repairing the valve is not a viable option. It also signifies that the valve condition is deteriorating, and there is an increased risk of severe complications.

Similar to any cardiac surgery, mitral valve replacement carries inherent risks. Complications can occur shortly after the surgery or in the future. These may include:

• Irregular heart rhythms
• Bleeding
• Blood clots
• Stroke
• Infection
• Heart block
• Heart failure

Procedure

Mitral valve replacement is generally performed through open-heart surgery. It can also be performed alongside other heart procedures, including the commonly combined coronary artery bypass grafting (CABG), tricuspid valve repair or replacement, and aortic valve interventions.

For certain patients, there exists an alternative option known as Transcatheter Mitral Valve Repair or Replacement (TMVR). This minimally invasive procedure addresses the valve issue from inside the body, eliminating the need for traditional open-heart surgery.

Before the procedure

Prior to the surgery, certain medications to address specific conditions like congestive heart failure and atrial fibrillation may be prescribed. Patients may also be required to discontinue specific medications in the weeks leading up to the surgery and quit smoking and tobacco use.

Additional preparations may include cleansing the body with an antimicrobial soap the night before the procedure and refraining from eating and drinking after a designated time, often midnight on the night prior to surgery.

As the day of the surgery nears, it is essential to prepare for the post-surgery return home, including arranging transportation from the hospital, enlisting support from family, friends, or neighbors, and planning for childcare and pet care as necessary. These are essential as some people may take time to recover.

During the procedure

Mitral valve replacement is a challenging procedure that demands precise surgical skills. It typically takes about two to four hours to complete. This procedure entails removing the impaired valve and inserting a new one in its position.

During mitral valve replacement, the patient is given anesthesia to induce unconsciousness for the surgery. Antibiotics is administered through an intravenous (IV) line. The healthcare provider will employ transesophageal echocardiography during the procedure, which assists in directing their actions and ensuring the success of the surgery. The patient is also linked to a cardiopulmonary bypass machine, which temporarily takes over the functions of their heart and lungs.

The surgery proceeds as follows:

• An incision in the chest is made, with most valve replacements requiring a median sternotomy, which provides access to the heart. An additional incision will be made in the left atrium to reach the mitral valve.
• The healthcare provider will retain healthy tissue and remove damaged portions. Various surgical methods can be utilized to preserve as much of the original valve tissue as feasible, including the supportive chords, which contribute to the effective function of the new valve and enhanced left ventricle performance.
• Secure the new valve in place using specific suturing techniques.
• Following the placement of the new valve, the healthcare provider will ensure the proper movement of the valve’s leaflets without any obstructions during closure.
• The left atrium will be sewn closed and gradually wean the patient off the cardiopulmonary bypass machine, completing the mitral valve replacement procedure.

In cases when one undergoes additional procedures simultaneously, such as CABG, the surgery will encompass additional steps to address those specific needs.

After the procedure

Following the surgery, the initial recovery phase involves spending one to two days in the Intensive Care Unit (ICU), where the vital signs and overall condition will be closely monitored. Then, one will be required to stay for several days in a regular hospital room for further recovery. Most individuals typically require a hospital stay of approximately one week after mitral valve replacement surgery.

Anticoagulation therapy, typically involving warfarin, to mitigate the risk of blood clots will begin after the surgery. If one received a biological valve, this therapy is typically administered for up to three months, while those with a mechanical valve often require lifelong anticoagulation treatment.

Patients may receive treatment for an irregular heartbeat (arrhythmia), which is common after valve replacement. Medications to regulate the heart rhythm, and in some cases, a temporary pacemaker may be prescribed.

As part of the recovery, patients may explore cardiac rehabilitation programs that will help facilitate a quicker return to normal activity and provide a supportive community. Guidance on the proper care of the surgical incision for at home recovery will also be provided.

Outcome

Mitral valve replacement comes with several advantages, such as a shorter surgical duration compared to repair procedures, a reduction in surgical complexity (though it remains a complex surgery), and a lowered risk of needing additional surgeries in the future.

The recovery period after valve repair surgery usually ranges from four to eight weeks, although some patients may need more time to recover fully. Healthcare providers will arrange follow-up appointments to evaluate the performance of the newly implanted valve.

The healthcare provider will also offer guidance on when it is advisable to resume activities like driving, lifting heavy objects, and participating in exercises or walks, ensuring that the recovery proceeds as intended.

The duration of recovery is influenced by a variety of factors. These can make recovery slower or require a person more time to regain strength. This may include:

• Initial severity of the mitral valve condition
• Overall health condition before the surgery
• Having heart or kidney problems
• Complexity of the surgery, especially when performed alongside other procedures like coronary artery bypass grafting (CABG)

Patients are advised to monitor for any complications. Seek immediate medical attention when any of these signs and symptoms occur:

• Fever or chills
• Chest pain
• Breathing difficulties
• Dizziness
• Severe headache
• Vomiting and nausea
• Lower leg pain, redness, or edema
• Persistent pain in the incision area
• Irregular heartbeat
• Infection symptoms, such as redness or seepage around the incision
• Green or yellowish mucus when coughing
• Coughing up blood
• Signs of stroke

People taking blood thinners should promptly consult their healthcare provider if they have a fall, experience significant bleeding in any part of their body, such as the nose or gums, or notice multiple unexplained bruises on their skin.