Septal myectomy is a surgical procedure doctors use to treat hypertrophic cardiomyopathy (HCM). HCM is a condition that causes your heart muscle to thicken.

Sometimes, the heart muscle can become so thick in its inner wall (septum) that blood has a harder time leaving the heart to get to the rest of your body. The effect is known as left ventricular outflow tract obstruction. Doctors recommend septal myectomy to correct this complication.

Keep reading to learn more about HCM and how septal myectomy may improve your symptoms.

What is hypertrophic cardiomyopathy?

Cardiomyopathy is a condition that affects your heart muscle (myocardium). “Hypertrophic” means something is enlarged.

HCM is a form of inherited cardiomyopathy in which your heart muscle is thicker than usual. This enlargement usually occurs in your left ventricle.

People with HCM will have changes to their hearts with no other potential explainable cause.

The changes in the heart that occur from HCM can cause complications that range from mild to severe. An estimated 1 in 500 people have this condition. Few people have HCM’s rare complications that can lead to severe congestive heart failure or even sudden cardiac death.

If a doctor diagnoses HCM, a septal myectomy is one of several treatment options.

Doctors don’t recommend septal myectomy for all people with HCM. Instead, you must have significant symptoms and problems due to your condition. These may include:

  • shortness of breath
  • chest pain
  • lightheadedness
  • affected activity levels that don’t respond to medications

Because septal myectomy is an invasive procedure, a doctor will not recommend it unless your HCM is severe and you’re likely to have a good surgical outcome.

To ensure a good outcome, a doctor will likely order many tests to determine the severity of your condition. Examples of these tests include:

  • blood tests to determine your overall blood counts and whether you might need a blood transfusion during or after surgery
  • echocardiograms to determine how well your heart is currently working, how thick the heart muscle is, and the effect of blood flow through the heart
  • electrocardiograms to determine whether you have any abnormal heart rhythms
  • cardiac MRI to view the heart in more detail

Consider asking your doctor about the risks, benefits, and expected recovery time for the procedure given your current overall health.

A septal myectomy is an open heart procedure. It requires general anesthesia (when you’re completely asleep) to perform. While there are different approaches, a general description of the steps includes:

  1. The surgeon will make a large incision in your chest. They will also cut through your breastbone, splitting it in two. This allows them to see your heart.
  2. They’ll insert special catheters into the areas where blood flow enters and exits your heart. The catheters connect to a special heart-lung machine known as a cardiac bypass machine. This allows the surgeon to work on your heart while keeping you alive.
  3. The surgeon will remove the thickened part of your heart’s septum. Since HCM can also affect your mitral valve, the surgeon will repair this valve if needed.
  4. They will then reestablish blood flow from the cardiac bypass machine. They will make sure your heart beats again on its own.
  5. The surgeon will put your breastbone back together before closing the incision with sutures.

Because the procedure is invasive, you can expect to stay in the hospital for a few days. You’ll likely be in an intensive care unit at first before moving to an inpatient room.

According to a 2020 observational study from a referral center for septal myectomy, the average hospital stay after the procedure was 4.9 days.

The most common complication following surgery is atrial fibrillation (AFib), an irregular heart rhythm. AFib can increase the time you need to spend in the hospital. In the same 2020 study, AFib increased the average length of stay after surgery to 5.8 days.

Healing after a septal myectomy will take time. You’ll likely need to limit your activities for 6 to 8 weeks (sometimes more) following surgery.

Your doctor will continue to monitor your heart rhythms and recovery to determine whether your HCM symptoms are resolving after surgery.

Complications from a septal myectomy are not common. The complication rate for the procedure is one of the lowest for any open heart procedure at 0.6% at experienced centers.

While complications are uncommon, some of the risks include:

  • AFib
  • incision infection
  • bleeding
  • new-onset heart block, a type of arrhythmia that may require a pacemaker

In a 2022 multicenter study with people who underwent a septal myectomy, 4% of them required a pacemaker after surgery.

According to a 2022 analysis, septal myectomy helps improve HCM symptoms in more than 90% of people who undergo the procedure. An estimated 75% of people find their symptoms resolve completely following surgery.

Still, 5% of people do continue to experience problems with daily functioning related to their HCM after the procedure.

If your HCM doesn’t respond to the surgery, a doctor may recommend other interventions. These can range from a pacemaker to a heart transplant.

A history of certain comorbidities may reduce your chances of a successful septal myectomy. Such conditions include pulmonary hypertension and obesity.

The following are some frequently asked questions regarding septal myectomy surgery.

How long does a septal myectomy take?

The amount of time septal myectomy takes depends on how complicated your surgical case is.

The surgery will take several hours. Preparation and recovery will add even more time. Your surgeon can advise you on how long your procedure may take based on your medical history and specific circumstances.

Is septal myectomy open heart surgery?

Septal myectomy is usually an open heart surgery. That means a surgeon must open your chest and directly view the heart to perform the procedure.

There have been recent studies about minimally invasive approaches. These approaches use a smaller incision. Even though full open heart surgery remains the gold standard, studies from 2017 and 2018 suggest minimally invasive approaches may be just as successful.

Are there alternatives to a septal myectomy?

Septal myectomy has been the “gold standard” of treatment for HCM since the 1950s. But surgeons developed a new approach in the 1990s called alcohol septal ablation (ASA).

ASA is a catheter-based approach. It’s less invasive than septal myectomy. Since ASA is not open heart surgery, it carries less risk of bleeding or infection.

But according to 2022 research, ASA has a higher long-term death rate, though this may be due to patients’ individual factors more than the procedure itself.

A doctor may recommend ASA if you have frailty or certain comorbidities. It’s usually less effective than septal myectomy and carries a higher risk of heart block.

What is the cost of septal myectomy?

Experts estimate the average cost of hospitalization for septal myectomy to be $41,715. This number may not include other related costs, such as fees for anesthesia.

Please note that this cost doesn’t reflect what insurance or Medicare might cover. Check with your insurance company to see what your out-of-pocket cost will be.

It’s unclear what the lifetime cost of managing HCM without surgery is.

If you have HCM and experience symptoms that affect your daily life, you might be a candidate for septal myectomy. Although it’s an invasive procedure, the success rate is very high. The complication rate is very low when performed at experienced centers.

Keep in mind that certain underlying conditions may reduce your risk of success. You and your doctor will discuss the pros and cons of this surgery for your unique case.

If you’re not a candidate for septal myectomy, talk with your doctor about alternatives, such as ASA.