Oregon Health & Science University
  • Jai Raman, M.D., F.R.A.C.S., Ph.D.Jai Raman, M.D., F.R.A.C.S., Ph.D.
    Dr. Raman specializes in complex heart surgery. He has pioneered many new procedures, including the use of arterial grafts (as opposed to veins) in bypass surgery, minimal access surgery for valves and bypass, better chest closure methods and improved patient management. He is passionate about personalized care of patients.

Minimally invasive surgery for atrial fibrillation

We often think of atrial fibrillation as an expected condition of older adults. In fact, about 5 percent of the population over age 65 can have primary atrial fibrillation, or AFib. In patients younger than 65, primary atrial fibrillation is uncommon. Instead, AFib usually accompanies another heart condition, frequently a mitral valve or other valve abnormality.

Atrial fibrillation surgery in historical context

Surgery is typically the treatment of last resort for atrial fibrillation. Today, this surgery is done with a thoracoscopic (“keyhole”) approach, with a single small incision; or robotically, with additional chest openings. These approaches evolved from early thoracic surgery, in which surgeons approached the lung from the side. Over the years, millions of patients have undergone these types of thoracic procedures. As the field has evolved toward less invasive approaches, we have gone back to performing surgery without opening the chest through a conventional opening of the breastbone/sternum in the front.

Implications for treatment of more than one heart defect

For patients with atrial fibrillation and associated heart defects, the underlying disease — for example, mitral disease — and atrial fibrillation can both be treated through a single small incision in the patient’s side. This is possible as long as the patient does not have significant blockage in the coronary arteries.

When AFib causes other heart disease

Conversely, in patients with longstanding atrial fibrillation, valve disease may arise as a secondary condition. This is due to years of rapid, erratic heartbeats causing enlargement of the cardiac muscle and supporting structures of the valves at the back of the heart. These patients are candidates for surgical repair of both conditions together.

Steps to surgery for atrial fibrillation

In a patient older than 65 with primary AFib, the most common treatment is blood thinning medication to mitigate the associated stroke risk. If patients continue having bouts of AFib, the next step is cardioversion to shock the heart into normal sinus rhythm. While this works for a few patients, or might work temporarily, many return to AFib. The teacher’s adage, “Atrial fibrillation begets atrial fibrillation,” reminds us that the longer a patient stays in AFib, the more likely that the condition will persist. Effective treatment must break the cycle of irregular beats.

Catheter ablation is the next treatment step after cardioversion. The electrophysiology team works to locate the abnormal foci in the back of the heart and create scar tissue to block the signal. Patients may have this procedure more than once without success. At this point, they seek surgical treatment.

The maze procedure

Atrial fibrillation surgery can be done through a small incision on one side, or one on each side. If the atrial fibrillation is intermittent, surgeons may treat just one or two abnormal areas. You should be aware thatsome patients are candidates for this limited operation, or “modified maze procedure.”

In the standard operation, the surgeon creates a maze of scars at the back of the heart, encompassing the left and right atrium to block abnormal impulses. We also close off the left atrial appendage, a small blind recess where clots tend to form. In years past, surgeons performed a “cut and sew maze procedure,” creating scars by making incisions. Today, the procedure is done with radiofrequency or cryoenergy, with good results. Other energy sources such as high-intensity focused ultrasound (HIFU), laser and microwave have also been studied.

High volume at the OHSU Knight Cardiovascular Institute

The OHSU Knight Cardiovascular Institute treats more than 1,000 adult patients each year, of whom approximately 200 have AFib. As a tertiary referral center, we perform maze procedures on most of these patients. The procedure can be done as a stand-alone or as part of surgery for other heart defects.

When surgery is complete, we test the region to ensure the scars have full thickness, creating a solid “insulated wall” to block irregular electrical impulses that cause AFib. Surgical expertise and checking for effective barriers are important for long-term outcomes.

When to refer a patient

Patients with the following conditions may be referred relatively early, without undergoing the clinical steps noted above.

  • Unable to take blood thinners — Medications are dangerous or contraindicated for the patient.
  • Tendency to form clots at the back of the heart — As shown on echocardiography.
  • Under 65 with other heart conditions, such as valve disease.

Is surgery not an option?

Patients who have multiple comorbidities may not be suitable candidates for even minimally invasive atrial fibrillation surgery. However, the AFib may simply be a warning sign of other heart problems, and patients with more than one heart condition may have atrial fibrillation surgery during another procedure.

Contact us

We are happy to consult with you on all types of heart disease or simply on symptoms of concern. The OHSU Knight Cardiovascular Institute includes specialists in all types of cardiac disease. If you have questions or would like to refer a patient, please call the OHSU Physician Consult & Referral Service at 800-245-6478 or fax to 503-346-6854.

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