Doctors & patients are saying about ''...

" is a great web site for patients, that is unequaled by anything else out there."

Dr. Douglas L. Packer, MD, FHRS, Mayo Clinic, Rochester, MN

"Jill and I put you and your work in our prayers every night. What you do to help people through this [A-Fib] process is really incredible."

Jill and Steve Douglas, East Troy, WI 

“I really appreciate all the information on your website as it allows me to be a better informed patient and to know what questions to ask my EP. 

Faye Spencer, Boise, ID, April 2017

“I think your site has helped a lot of patients.”

Dr. Hugh G. Calkins, MD  Johns Hopkins,
Baltimore, MD

Doctors & patients are saying about 'Beat Your A-Fib'...

"If I had [your book] 10 years ago, it would have saved me 8 years of hell.”

Roy Salmon, Patient, A-Fib Free,
Adelaide, Australia

"This book is incredibly complete and easy-to-understand for anybody. I certainly recommend it for patients who want to know more about atrial fibrillation than what they will learn from doctors...."

Pierre Jaïs, M.D. Professor of Cardiology, Haut-Lévêque Hospital, Bordeaux, France

"Dear Steve, I saw a patient this morning with your book [in hand] and highlights throughout. She loves it and finds it very useful to help her in dealing with atrial fibrillation."

Dr. Wilber Su,
Cavanaugh Heart Center, 
Phoenix, AZ

"...masterful. You managed to combine an encyclopedic compilation of information with the simplicity of presentation that enhances the delivery of the information to the reader. This is not an easy thing to do, but you have been very, very successful at it."

Ira David Levin, heart patient, 
Rome, Italy

"Within the pages of Beat Your A-Fib, Dr. Steve Ryan, PhD, provides a comprehensive guide for persons seeking to find a cure for their Atrial Fibrillation."

Walter Kerwin, MD, Cedars-Sinai Medical Center, Los Angeles, CA

The Hybrid: Surgery+Catheter Ablation

Steve’s Lists of A-Fib Doctors by Specialty

Steve’s Lists of A-Fib Doctors by Specialty 

Steve has prepared these lists of doctors treating atrial fibrillation patients by specialty to help you find doctors with a particular expertise.

  1. US EPs with FHRS-designation performing A-Fib ablations: Listed by State/City
  2. US EPs Using Cryoballoon Ablation
  3. US EPs Installing the Watchman Device
  4. US Surgeons performing Maze and Mini-Maze operations
  5. US Centers performing the Hybrid Surgery/Ablation procedure
  6. EPs Specializing in Persistent/Long-Standing Persistent A-Fib (US and International)
  7.  EPs Using Contact Force sensing catheters 
  8.  Hospitals and Medical Centers using Esophageal Cooling During Catheter Ablation

Return to Directory of Doctors Treating A-Fib: Medical Centers and Practices

Notice: Unlike other directories, offers no preferential listings or placement. No doctor or facility pays, provides services, etc. to be listed. We accept no fee, benefit or value of any kind for listing a specific doctor or medical center. is not affiliated with any practice, medical center or physician.

If you know the name of the doctor or practice, use the “Search our site” box (upper right on this page) to get to the right Directory page. Then, open your browser’s ‘Find on Page’ feature (‘CTRL+F’) to locate the name on the page.

Disclaimer: this directory is provided for informational purposes only. We make no endorsement of a specific physician or medical facility. Choosing a physician is an important decision and should be based upon your own investigation of each physician’s training, education and experience. These listings offer you the opportunity to locate and contact a healthcare professional directly is your independent source of unbiased information about Atrial Fibrillation, resources and treatments.

Last updated: Thursday, April 27, 2023

Cox Maze, Mini-Maze & Hybrid Surgeries – Atrial Fibrillation

The Cox-Maze & Mini-Maze Surgeries and the Hybrid Surgery/Ablation

Surgical Maze pattern of series of lesions

 Cox-Maze Surgeries

Developed by Dr. James Cox in 1987, the Cox Maze operation was the first treatment that made patients A-Fib free. In the Cox-Maze open heart “cut and sew” operation, the surgeon made numerous incisions in your atria. This “maze” of incisions divided your atria into electrically isolated segments, thereby blocking the electrical impulses that cause A-Fib from spreading throughout the heart. The atria continued to be activated by a regular signal from the sinus node.

The left atrial appendage is usually removed during this operation.

Dr. Cox developed a successor to the Cox Maze III called a “Radial Maze.” (also see 2006 BAFS: Dr. David Kess Advances in Surgical Therapy for A-Fib.”)

In a later version of the operation, the Cox Maze IV, most of the “cut and sew” incisions are replaced with linear ablation lesions created either with radiofrequency energy or cryothermy (freezing).1,2Access to the heart on pulmonary bypass can be through the sternum (breast bone) or through incisions in the chest. If access is through the chest, Dr. Damiano, Jr. calls it a Minimally Invasive Cox-Maze IV.

The Cox Maze IV operation does work and has a high success rate (“approximately 75% at two years”) but it hasn’t been used often because of the risks of open heart surgery, the danger of bleeding from the incisions, the pain, discomfort and prolonged convalescence from the operation, and the resulting reduced atrial function due to the incisions/lesions. (Voltage mapping of post-Maze patients may show that their left atrium has reduced or is entirely devoid of electrical activity because of the extensive scarring.)

According to Surgeon A. Mark Gillinov of the Cleveland Clinic, having the Maze surgery alone generally should be done only after other therapies have been tried.3

Final thoughts: Maze Surgeries for Atrial Fibrillation, a fib, afib, A-Fib

Cox Maze

However, if you have to undergo open heart surgery for another heart problem, you may want to go to a heart center that can perform the Cox Maze operation at the same time.

Note: If you have a left atrium larger than 6.0 cm or if you’ve been in A-Fib for over five years, the long term success of the “Cut and Sew” Maze operation is lower, under 80%.4

For more about the Cox Maze and Mini-Maze surgeries, you may want to read Boston AFib 2006/Advances in Surgical Therapy for A-Fib by Dr. David C. Kress.

Illustration of the typical Mini-Maze incisions locations - Atrial Fibrillation -A-Fib, afib, a fib

Typical Mini-Maze incisions locations

 Mini-Maze Operations

In newer maze operations surgeons do not crack open the breastbone and stop the heart while putting the patient on a heart-lung machine as in the Cox Maze operation.

Instead the surgeons cut keyhole-sized incisions on the sides of the chest or go through the diaphragm to gain access to the heart. Using a tiny video camera the surgeons loop a bipolar clamp catheter around the outside of the heart. Each lung is temporarily deflated in turn to allow the bipolar clamp to be threaded around the pulmonary veins. The bipolar clamp creates lesions around the atrium cuff of the pulmonary veins that scar and block the electrical impulses causing the irregular heartbeat.5

Though not open heart surgery like the Cox Maze III (Radial Maze), the Mini-Maze operations are nevertheless very traumatic for the body and require general anesthesia.

To be effective the ablations (lesions, burns) have to be transmural; i.e., they have to penetrate all the way from the outside of the heart to the inside. But the inside of the heart varies in thickness, has ridges, etc. And epicardial (outside the heart) fat can also prevent transmurality. Even bipolar RF burns cannot guarantee transmural lesions.6 “Transmurality of a lesion set cannot be guaranteed with current ablation catheters on the beating heart.”7 Also, proving or confirming bidirectional block from outside the heart can be challenging.8

If you have a simple case of recent onset A-Fib that requires only the isolation of the Pulmonary Vein openings, the Mini-Maze operation may work for you.

The biggest drawback to Mini-Maze operations is that they can’t currently reach or isolate all areas of the heart where A-Fib signals may originate. If you have a simple case of recent onset A-Fib that requires only the isolation of the Pulmonary Vein openings, the Mini-Maze operation may work for you. But anything more complicated is questionable. Currently surgeons don’t have the ability to map inside the heart to identify sites where A-Fib originates. For example, patients with long-standing persistent (complicated) A-Fib tend to have relatively poor results. One study cites a 46.2% success rate after three months.9(In contrast, Dr. John Sirak, inventor of the Five Box Totally Thorascopic Maze surgery, reports a 91% success rate.)10

One considered advantage of the Mini-Maze operations is that the Left Atrial Appendage is cut out, stapled shut or closed off. Most A-Fib blood clots which cause stroke come from the Left Atrial Appendage (more on this topic further down the page). See 

VIDEO 1: Inside the O.R. for a Mini-Maze Surgery. Dr William Harris, cardiovascular surgeon, describes what he refers to as a mini-maze procedure, the minimally invasive Lone Atrial Fibrillation Ablation. Posted by Baptist Medical Center in Jackson, Miss. (4:49 min.)

Is Mini-Maze Overkill For Paroxysmal A-Fib?

Patients may ask if a Mini-Maze surgery is overkill for simple cases of Paroxysmal (occasional) A-Fib. Some surgeons would agree.

Surgeon Andy C. Kiser says about his practice, “when a patient has paroxysmal A-Fib and the left atrium is under 4.5-5.0 cm, we recommend percutaneous (through the skin) catheter ablation. In this population, simple pulmonary vein isolation may be effective in over 80% of patients.11,12

Surgeon James Edgerton does not normally perform surgery on Paroxysmal (Occasional) A-Fib patients. “I think they are very well treated with catheter ablation.” (See surgeon James Edgerton’s presentation Boston AF 2011/Hybrid Ablation.)

Maze Surgery is Recommended in Some Cases

In general, Maze surgical treatments for A-Fib are not recommended as a first choice or option by current guidelines. They are generally more invasive, traumatic and risky than catheter ablation.

Surgery, however, is recommended if one can’t tolerate blood thinners or if one is “morbidly obese.” With current imaging systems, it’s more difficult to see a clear image of the heart during a catheter ablation if someone is significantly overweight. Also, a Mini-Maze might be a better option is you’ve already had a stroke and are more in danger of having a stroke during a catheter ablation. And if you have to have a heart operation to, for example, fix a heart valve, the surgeon can often do a Maze operation at the same time.

Mini-Maze Risks

Mini-Maze surgeries “usually have significant risks compared with catheter-based electrophysiology procedures such as catheter ablation.”13 A study comparing catheter versus surgical ablation found that Mini-Maze surgeries had about a one in four chance of a major adverse event.14

Since 2008, there have been at least five U.S. patient deaths reported to an FDA database in A-Fib surgeries using AtriCure devices and one involving a Medtronic device. (That database doesn’t prove that the devices caused the deaths.) According to Thomas M. Burton of the Wall Street Journal, currently (2010) “there are no large studies comparing the safety of surgical ablation to that of other ways to treat A-Fib.”15 

Mini-Maze-type surgeries can also be very painful, including ongoing numbness and phantom pain at chest access sites.

In addition, deflating and re-inflating the lungs can be very difficult particularly for older people whose lungs are no longer very elastic. Possible complications include but are not limited to pericardial effusion, pleural effusion, pneumothorax (collapsed lung), herniated lung, heavy coughing, bronchitis, and pneumonia.

And approximately 6% of patients may require a pacemaker.”16

In a very unscientific survey at one center, when patients were asked whether or not they would undergo a Mini-Maze surgery again, 50% said no way, 30% said it was a lot harder than they thought it would be, but 1 out of 5 said it was worth it.

When patients were asked whether or not they would undergo a Mini-Maze surgery again, 50% said no way, 30% said it was a lot harder than they thought it would be, but 1 out of 5 said it was worth it.

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Extent of Scarring of the Left Atrium

Scarring in the heart permanently damages heart tissue and is usually avoided unless absolutely necessary. Circulation, nerve signal pathways, heart muscle fibers, transport function, the ability of the left atrium to contract, etc. may be affected. This is irreversible heart damage. Non-contracting scar tissue replaces normal heart muscle. This may weaken the heart and may later contribute to heart problems like congestive heart failure. Millions of patients today suffer from weak hearts due to heart muscle damage.

These ablation burns are normally not a problem in the Pulmonary Vein areas which function as pipes into the left atrium, but may be a problem in areas of the left atrium more involved in heart function and contraction.

Newer Mini-Maze surgeries, such as the Wolf Mini-Maze, Totally Thoracoscopic (TT) Maze, the Five-Box Thorascopic Maze Surgery, the Dallas Lesion Set, and the Biatrial Maze are one-size-fits-all surgeries which create a specific pattern of ablation lines/burns on the left atrium. But we don’t know if this scarring is necessary or appropriate for all cases of A-Fib. (The Wolf Mini-Maze name suggests it is related to the Maze operation. But it has nothing to do with the concept of using a maze pattern of lesions to treat A-Fib. It only isolates the PVs and removes the Left Atrial Appendage.)

Questions for your surgeon: Patients should ask their surgeons if this scarring of the left atrium is necessary to fix their type of A-Fib. And ask, Would a Pulmonary Vein Ablation procedure, for example, fix their A-Fib without the added risks of heart surgery and permanent heart damage?

For more see Questions for Doctors (and What the Answers Mean) - Atrial Fibrillation, A-Fib, a fib, afib


For more about the Cox Maze and Mini-Maze surgeries, you may want to read Boston AFib 2006/Advances in Surgical Therapy for A-Fib by Dr. David C. Kress.

To help you select a cardiologist, electrophysiologist or surgeon:
• see Questions for Doctors (and What the Answers Mean)
• download our free ‘Questions for Doctors Worksheet’ (in PDF format).
• see our ‘Questions for Surgeons’ in our book, Beat Your A-Fib: The Essential Guide to Finding Your Cure by Steve S. Ryan, PhD.

 The Hybrid Surgery/Ablation

Relatively new is the Hybrid Surgery/Ablation in which a surgeon and a cardiac electrophysiologist (EP) team up to work together on the same patient.17 The genius of the Hybrid approach seems to be its complementary nature: the surgeon works on the outside the heart and the EP on the inside of the heart. (Similar multidisciplinary ablation techniques are called ‘hybrid ablation technique’, ‘convergence process’, ‘Convergent Maze Procedure’ and ‘Convergent Ablation”’.)

The surgeon working on the outside of the heart can produce visible linear lesions much easier on the smooth outside surface of the heart than the EP working on the inside of the heart with point-by-point catheter ablations. The EP working inside the heart, on the other hand, is better equipped to tell if a surgical lesion is effective or not. They can then detect any gaps and correct them with catheter ablation. For example, if the surgeon’s “entrance and exit block lesions” were incomplete, the EP can identify the conduction gaps and ablate them.

To eliminate all A-Fib signals, “the goal is to treat the full thickness of the tissue,” says Dr. Paul Wang of Stanford Hospital & Clinics.18 According to Dr. Laurent Pison of The Netherlands, “in almost a quarter of patients, catheter ablation [is] needed to finish incomplete epicardial [outside the heart] surgical lesions by endocardial [inside the heart] touch-up.”19 Endocardial catheter touch-up is often necessary to achieve bidirectional block of the pulmonary veins (in about a third of patients), but even more so in the box (roof and floor) surgical lesions (about two-thirds of patients).20

Also, the EP can ablate in areas surgeons currently can’t reach such as making a Caviotricuspid Isthmus line in the right atrium to stop Atrial Flutter. In addition, the EP utilizes diagnostic mapping techniques to confirm that all abnormal electrical signals have been interrupted. EPs have years of experience and training in mapping, tracking down and ablating A-Fib signals found in areas other than the pulmonary veins, while this is difficult for surgeons working from outside the heart.

VIDEO 2: Introduction to the Hybrid Surgery/Ablation Procedure. Dr. Robert Joy gives an overview of the hybrid procedure in which a cardiothoracic surgeon and an electrophysiologist work together in a single procedure; How it opens up a new opportunity for A-Fib patients who are not good candidates for catheter-based procedures alone. Posted on the Ellis Medicine website (includes a brief promotion of their services.) (1:46) 

Access Techniques

Most often surgeons access the heart using the same method as the Mini-Maze surgery. Three or more small incisions are made between the ribs for insertion of their scope and instruments. While the EP usually accesses the heart by inserting a catheter through the femoral vein in the groin and threads the catheter up and into the heart.

Another minimally invasive surgical approach is to access the heart through the soft tissues of the abdomen and with a small hole made in the diaphragm. This “convergent” approach is intended to result in less discomfort and a more rapid recovery for the patient.

Three Variations of the “Hybrid” Approach

In this article we are describing a “sequential” Hybrid approach. First, the surgeon works on the patient, then the EP steps in and takes over to detect and correct any gaps, and ablates additional locations of A-Fib signals.
A second Hybrid variation is a “simultaneous” approach with both the surgeon and the EP working on the patient at the same time. As the surgeon makes a lesion on the outside of the heart, the EP monitors the inside of the heart. The EP can tell the surgeon immediately if a particular lesion is effective (complete) or not. The surgeon can adjust the lesion or the EP can ablate the area. According to Dr. Wilber Su of the Cavanaugh Heart Center at Good Samaritan Medical Center, “the simultaneous hybrid maze procedure combines the best of what surgeons have to offer…with the knowledge, testing and confirmation of ablation by the electrophysiologist.”
A third Hybrid variation is “non-synchronous” or two-staged; the surgeon and the EP work on the same patient but they do so at different times (and sometimes even different locations).
(For more, see 2011 Boston AF: Hybrid Ablation for Persistent A-Fib.)

Results of Hybrid Surgery

In a small study of 27 patients most of whom had long-standing persistent A-Fib (the most likely candidates for a Hybrid Surgery/Ablation), at six months 72.2% of patients were in sinus rhythm, and 66.5% were off of antiarrhythmic drugs. (Four patients were still in A-Fib and one developed right atrial flutter.) These results are comparable to the success rates of catheter ablation procedures.21

Risks of Hybrid Surgery

Patients should keep in mind that Hybrid surgery, though called “minimally invasive,” is still major heart surgery. It is invasive, traumatic, complicated, requires considerable surgical skills and experience, and is potentially risky. And added to this are the low but real risks of a catheter ablation. Combining these two levels of risk is probably more dangerous than the sum of the parts. Also, patients have to be on anticoagulants for at least 90 days after the surgery/ablation.

Who Should Consider Hybrid Surgery?

The Hybrid Surgery/Ablation can be an effective option for highly symptomatic patients with persistent atrial fibrillation and longstanding persistent atrial fibrillation who have failed one or two catheter ablations, for someone with a significantly enlarged left atrium, or for someone who is morbidly obese (making it difficult to create imaging maps necessary for catheter ablations). (For more, see 2011 Boston AF: Hybrid Ablation for Persistent A-Fib”.)

Final Thoughts about the “Hybrid”

Final thoughts about the Hybrid Procedures - Atrial Fibrillation, a fib, afib, A-Fib.

Final thoughts: Hybrids

Is the “Hybrid” Surgery/Ablation better and more effective than current advanced catheter ablation strategies?22Or the Mini-Maze?

Only time will tell. This is a relatively new operation with little long-term research or history of patient tracking.23  Dr. Hugh Calkins of Johns Hopkins Hospital writes, “It is clear that more research is needed…a much larger, multicenter trial of “hybrid AF ablation” that targets a population of patients with long-standing persistent AF… .”24Dr. Pison and colleagues note that the longer-term impact of this Hybrid Surgery/ablation strategy on atrial systolic function remains unknown.

Dr. Calkins also points out a logistical problem. It’s extremely rare to have tremendous expertise with catheter ablation and surgical A-Fib ablation at the same institution. Most centers are expert at one or the other. This will limit the number of facilities offering the Hybrid Surgery/Ablation approach, making it harder for patients to access this treatment choice. (See Steve’s Lists: Centers Performing the Hybrid Surgery/Ablation procedure.)

And finally, from a risk/reward perspective, if the Hybrid approach and advanced catheter ablation strategies have similar success rates, the advanced catheter ablation strategies might be preferable to Hybrid Surgery/Ablation.

A last thought, a prediction really, from Dr. M. Clive Robinson, a cardiothoracic surgeon with Bridgeport Hospital. Dr. Robinson, who performs the “hybrid”, has said “it is likely that the new hybrid ablation procedure will make Mini-Maze [surgery] obsolete,”25

Steve's List - Doctors by Specialty - Atrial Fibrillation - a fib, afib, A-Fib

Doctors by Specialties

 Steve’s Lists

 Doctors by Specialty

I’ve compiled several specialty lists from the Directory of Doctors & Facilities called ‘Steve’s Lists‘.

For surgeons performing Maze/Mini-Maze operations, see Doctors & Facilities/Steve’s Lists Doctors by Specialties and more specifically, US Surgeons performing Maze and Mini-Maze operations.

For centers performing the Hybrid Surgery/Ablation, see Steve’s Lists: Centers Performing the Hybrid Surgery/Ablation procedure.

 Additional Readings

Advantages of the Convergent Procedure by Dr. James Edgerton
• FAST Trial: Surgical Versus Catheter Ablation―Flawed Study, But Important Results for Patients
• Advances in Surgical Therapy for A-Fib by Dr. David Kess
• Role of the LAA & Removal Issues

 Beware of Profit Incentives

 Mini-Maze Marketing

Beware: Mini-Maze Marketing & Profit Incentives


Be advised that some hospitals, medical services, web sites, etc. may promote the Mini-Maze over catheter ablation, because current reimbursement rates are higher for surgery (currently around $15,000 in the US) than for catheter ablation. Mini-Maze-type surgeries represent a huge and growing market and an important income source for hospitals, surgeons, medical device companies, web sites, etc.

Some hospitals, medical services, web sites, etc. may promote the Mini-Maze over catheter ablation, because current reimbursement rates are higher for surgery (currently around $15,000 in the US) than for catheter ablation.

Some 25,000 patients underwent Mini-Maze-type surgeries in 2009. Surgical devices to treat A-Fib have sales of about $100 million a year.26

Profits may influence doctors to use medical devices for “off-label” treatments. (Companies are only allowed to market them for the uses for which they have been FDA-approved. The idea behind this restriction is to limit the number of U.S. patients exposed to experimental, relatively untested treatments.)

For example, AtriCure, of West Chester, Ohio, in 2010 agreed to pay $3.8 million to resolve allegations it marketed its surgical ablation devices for the unapproved purpose of treating irregular heartbeats (A-Fib). According to an article in Mass Device.

“The [U.S. Dept. of Justice, DOJ] lawsuit accused AtriCure of offering kickbacks to induce surgeons and hospitals to use its inpatient cardiac ablation procedure rather than less expensive, outpatient alternatives (such as catheter ablation). The company was accused of promoting the spread between Medicare reimbursement rates for its procedure and the cost to hospitals, and doling out kickbacks including free equipment, discounts, free advertising, marketing, and referral services and training for surgeons on its procedure.”27

According to Jacqueline Bell of

“The DOJ also alleged that AtriCure pushed heart surgery using the company’s medical devices when less-invasive alternatives were appropriate, and suggested to hospitals how to pump up Medicare reimbursement claims for surgical procedures using the company’s devices.”28

From Thomas S Burton, The Wall Street Journal:

AtriCure did not admit wrongdoing.29

And in another settlement:

Estech (Endoscopic Technologies), of San Ramon, California, agreed to pay $1.5 million to settle similar charges with the Justice Department, also without admitting wrongdoing30

Read how others have dealt with their A-Fib - see 'Personal Experiences' for stories of hope and inspiration.

Last updated: Saturday, January 8, 2022

Back to the Top

Return to Treatments for Atrial Fibrillation

Footnote Citations    (↵ returns to text)

  1. MediFocus Guide “Atrial Fibrillation #CR004m July 10, 2009. p. 40.
  2. Damiano, Jr, Ralph J and Bailey, Marci. “The Cox-Maze IV procedure for lone atrial fibrillation.” Multimedia Manual of Cardiothoracic Surgery. MMCTS (July 23, 2007). doi:10.1510/mmcts.2007.002758
  3. Burton, T. Surgical-Device Firms Walk Fine Line. The Wall St. Journal. March 2010.  Last accessed Nov 4, 2014. URL:
  4. Kiser, A C. Advantages of the Convergent Procedure UNC Cardiac Surgery and Electrophysiology Services, Last accessed Aug 27, 2015. URL:
  5. Wolf R, Schneeberger E, Osterday R, et al. (2005). “Video-assisted bilateral pulmonary vein isolation and left atrial appendage exclusion for atrial fibrillation”. J Thorac Cardiovasc Surg 130 (3): 797–802. doi:10.1016/j.jtcvs.2005.03.041. PMID16153931.
  6. Brugge, E. et al. “Comparison of bipolar and unipolar radiofrequency ablation in an in vivo experimental model”. Eur J Cardiothorac Surg. 28 2005:76-82.
  7. La Meir, M.  Surgical options for treatment of atrial fibrillation. Annals of Cardiothoracic Surgery. Vol 3, No 1 January 2014. doi: 10.3978/j.issn.2225-319X.2014.01.07
  8. Lockwood, D. et al. “Linear left atrial lesions in minimally invasive surgical ablation of persistent atrial fibrillation: techniques for assessing conduction block across surgical lesions”. Heart Rhythm. 6 2009:S50-S63.
  9. Cui YQ et al. “Video-assisted minimally invasive surgery for lone atrial fibrillation: a clinical report of 81 cases.” Journal of Thoracic and Cardiovascular Surgery 1 February 2010 (volume 139, issue 2, Pages 326-332.
  10. Sirak, John H.
  11. Kiser, A C. Advantages of the Convergent Procedure UNC Cardiac Surgery and Electrophysiology Services, Last accessed November 5, 2012 from
  12. Feld, G. K., “Hot Topics: A Review of the 2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation.” Atrial Fibrillation A CardioSource Clinical Community, April 09, 2012. Accessed Friday, January 11, 2013 URL:
  13. Cohen, Todd J. “A Patient’s Guide to Heart Rhythm Problems.” A Johns Hopkins Press Health Book. Johns Hopkins University Press, Baltimore. 2010, p. 36. Mini-Maze surgeries “usually have significant risks compared with catheter-based electrophysiology procedures such as catheter ablation.”
  14. Borsama, L.V.A. et al. “Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST).” CIRCULATION. 111.074047 Published online before print November 14, 2011.
  15. Burton, T. Surgical-Device Firms Walk Fine Line. The Wall St. Journal. March 2010.  Last accessed Nov 4, 2014. URL:
  16. Schouchoff, Barbara. “Surgical Approaches for Atrial Fibrillation.” Critical Care Nursing Quarterly. July/September 2007, Volume 30, Number 3, pages 233-242. 
  17. In January, 2014, at the Boston A-Fib Symposium in Orlando I was privileged to attend a live demonstration via satellite from the Netherlands of a Hybrid Surgery/Ablation.
  18. Wang, Paul. Hospital Offers Innovative, Hybrid Procedure for Difficult Cases of Atrial Fibrillation. Stanford Hospital & Clinics Press Release, February 14, 2011. Last accessed February 24, 2014, URL:
  19. Pison L, et al. Hybrid Thoracoscopic Surgical and
    Transvenous Catheter Ablation of Atrial Fibrillation. J Am Coll Cardiol.
    2012;60(1):54-61. doi:10.1016/j.jacc.2011.12.055.
  20. Kurfirst, V. et al. Two-staged hybrid treatment of persistent atrial fibrillation: short-term single-centre results. Interact Cardiovasc Thorac Surg. 2014 Jan. 12 [Epub ahead of print]
  21. Zembala M, et al. Minimally invasive hybrid ablation procedure for the treatment of persistent atrial fibrillation: one year results. Kardiol Pol. 2012;70(8):819-28. PubMed PMID: 22933215. Last accessed Feb 22, 2014, URL:
  22. Such as the Bordeaux Five-Step Protocol or ECGI mapping/ablation system.
  23. There appears to be at least two research trials underway of epicardial-endocardial convergent procedures for the treatment of atrial fibrillation: a multicenter trial called the CONVERGE IDE (see and a trial by Inova Health Care Services (see
  24. Calkins, H. Clinical Research: Heart Rhythm Disorders: Editorial. J Am Coll Cardiol. 2012;60(1):62-63. doi:10.1016/j.jacc.2012.01.068
  25. Bridgeport Hospital first in New England to perform hybrid ablation for atrial fibrillation. Bridgeport Hospital Press Release, July 6, 2011. Last accessed February 23, 2014, URL
  26. Burton, T. Surgical-Device Firms Walk Fine Line. The Wall St. Journal. March 2010.  Last accessed Nov 4, 2014. URL: 
  27. Update: AtriCure finalizes settlement in federal whistleblower case. February 2, 2010. Last accessed Jan 11, 2013 URL:; United States of America ex rel. Doe v. AtriCure Inc., case number 4:07-cv-02702, U.S. District Court/Southern District of Texas.
  28. Bell, J. AtriCure Settles Medicare Fraud Claims For $3.8M Last Accesse7 Jan 11, 2013, URL:
  29. Burton, T. Surgical-Device Firms Walk Fine Line. The Wall St. Journal. March 2010.  Last accessed Nov 4, 2014. URL:
  30. Ibid.

Role of the Left Atrial Appendage & Removal Issues

Left Atrial Appendage heart illustration; Source: Boston Scientific Inc. educational brochure

The Role of the Left Atrial Appendage (LAA) & Removal Issues

By Steve S. Ryan, PhD

In the first trimester or two of our time in the womb, The Left Atrial Appendage (LAA) was originally our left atrium (LA). When the final real Left Atrium (LA) formed gradually from the conjunction and evolutionary development of the four pulmonary veins, the actual LA chamber grew and ballooned out, pushing the smaller remnant LA up to the left top of the Left Atrium where it became known as the Left Atrial Appendage (LAA) with its own functions and behaviors.

But as we age and as heart disease/A-Fib, etc. start to set in, the LAA can turn into “the most lethal, no longer essential appendage in the human anatomy,”according to Shannon Dickson of

One considered advantage of the Mini-Maze operations is that the Left Atrial Appendage (LAA) is closed or cut off. Most A-Fib blood clots which cause stroke come from the Left Atrial Appendage. By closing off the LAA, most but not all risk of stroke is eliminated even if you are still in A-Fib. Removing the LAA can reduce the risk of stroke from 7 percent to 5 percent, according to Dr. Richard Whitlock,

Failure to Completely Close Off the LAA is Common

However, in a study by Surgeons, “both suture exclusion and stapler exclusion had extraordinarily low success rates. In fact, none of the patients with stapler exclusion had successful closure…This study presents clear evidence of the inadequacy of these techniques.”1

According to Dr. Marc Gillinov of the Cleveland Clinic, staplers “can be hard to apply to the appendage and tend to leave a little cul-de-sac and also cause bleeding and tearing, so they are not particularly safe or effective.”2

However, the AtriClip device (FDA approved June, 2010) makes it much easier for surgeons to close off the LAA during open heart surgery. The surgeon positions the rectangular-shaped device around the LAA and then closes it like a clamp. Blood no longer flows into and out of the Left Atrial Appendage.3

AtriCure has developed a version of the AtriClip which can be used in Mini-Maze surgery.

Should the LAA be routinely cut out, stapled shut or closed off in all A-Fib patients?

The rationale for closing off the LAA is that, in case the operation fails which happens occasionally, the patient is still protected from having an A-Fib stroke. 90%-95% of A-Fib strokes come from clots which originate in the LAA. In A-Fib, blood stagnates in the LAA and clots tend to form.

VIDEO: See our library of videos about Atrial FibrillationWatch an endoscopic view of stapling and removal of the Left Atrial Appendage  (1:34 min.) Go to video->

Another important consideration, even if a person is no longer in A-Fib, is that closing off the LAA may still prevent a stroke. The LAA is where most clots originate. If a surgeon is already working on the heart, why not close off the LAA and reduce the patient’s chance of having a future stroke? (If a surgeon didn’t close off the LAA, they could be sued if a patient later had a stroke, even if the patient was no longer in A-Fib.) Life (no stroke) is more important for most people than a possible reduced exercise intolerance.

In the future even people without A-Fib may have their Left Atrial Appendage closed off if it prevents or reduces the risk of a stroke. This may become a way to prevent stroke in older people, particularly women, who are more at risk of stroke as we age. There are currently a variety of devices, surgical and non-surgical, which can do this. LAA closure may become an important new way to reduce strokes, particularly in the elderly.

Functions of the Left Atrial Appendage

But some question the need or benefit of removing the Left Atrial Appendage (LAA) if someone is no longer in A-Fib. For a patient made A-Fib free, would their heart function better or more normally if they still had their LAA? In the words of Dr. Pierre Jais of the Bordeaux Group at the 2020 AF Symposium, “We have ablated too much…Those patients when they have the (Left Atrial) Appendage taken out, they have very poor residual LA (Left Atrium) function. I don’t want that to happen anymore. If we can avoid it, I think we should.” Dr. Jais later added, “Sinus rhythm is by definition superior to persistent A-Fib. But the best ablation strategy is the one that restores sinus rhythm at the least tissue cost, thereby preserving as much as possible the LA function.”

LAA Functions Like a Pressure Release Valve

Also, the LAA functions like a reservoir or decompression chamber or a surge tank on a hot water heater to prevent surges of blood in the left atrium when the mitral valve is closed.4 Without it, there is increased pressure on the pulmonary veins and left atrium which might possibly lead to heart problems later.

Losing the LAA Reduces Blood Pumped by the Heart

Cutting out or stapling shut the LAA also reduces the amount of blood pumped by the heart and may result in exercise intolerance for people with an active life style. (In dogs the LAA provides 17.2% volume of blood pumped.5) This is usually not a problem for patients with Persistent (Chronic) A-Fib, whose LAA has stopped contracting along with the fibrillating atrium. Cutting out or stapling shut the LAA won’t affect their cardiac output.

But this may not be the case for patients with Paroxysmal A-Fib who still have large amounts of normal rhythm and whose LAA still functions normally.

But would a non-functioning LAA return to normal when someone with, for example, longstanding persistent (Chronic) A-Fib becomes A-Fib free?

I’m not aware of any surgeons (or EPs) who do pre- and post-LAA closure measurements of exercise ability, heart pumping function, etc. with and without the LAA. 

Losing the LAA May Worsen Blood Pressure

The LAA also has a high concentration of Atrial Natriuretic Factor (ANF) granules which help to reduce blood pressure.6 Some preliminary research indicates that when the LAA is closed or cut off, the Right Atrial Appendage produces more ANF to compensate for the lost of the LAA.

Editor’s comment: If you are thinking of having a Cox Maze or Mini-Maze, discuss removing the LAA with the surgeon. Ask if they close off the Left Atrial Appendage and with what: sutures, stapler or the AtriClip.

Whitlock, Richard. A simple surgery reduces the risk of stroke in people with atrial fibrillation. Bottom Line Health, August 2021 Vol 35/No 8, p. 2.

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Return to Index of Articles: Maze, Mini-Maze, Convergent, LAA Closure Surgeries

Last updated: Monday, July 19, 2021

Footnote Citations    (↵ returns to text)

  1. Damiano, Jr., RJ. “What Is the Best Way to Surgically Eliminate the Left Atrial Appendage?” Journal of the American College of Cardiology 2008, Sept. 9; Vol. 52, No. 11:930-1.
  2. AtriCure’s AtriClip system receives FDA 510(k) clearance (press release). June 14, 2010. 
  3. Ibid.
  4. Al-Saady, N M, et al.  Left atrial appendage: structure, function, and role in thromboembolism
  5. Hondo T. et al. “The Role of the left atrial appendage. A volume loading study in open-chest dogs.” Jpn Heart J 1995 Mar;36(2):225-34.
  6. Atrial natriuretic peptide. Last accessed April 13, 2014, URL:

Advantages of the Convergent (Hybrid) Procedure

Convergent Procedure lesion pattern

Convergent Procedure lesion pattern

Advantages of the Convergent Procedure

UNC Cardiac Surgery and Electrophysiology Services

Andy C. Kiser, MD  Paul Mounsey, MD, Updated March 2014

(Reproduced with permission.)

Cardiac surgeons continually strive toward less invasive procedures which avoid approaches like full median sternotomies and thoracotomies. However, reports of minimally invasive cardiac surgical procedures may include hemi-sternotomies, mini-thoracotomies, or full median sternotomies without cardiopulmonary bypass.

True minimally invasive procedures must not only be defined by the size of the incision, but also by the invasiveness into the patient’s daily lifestyle and the impact on their quality of life.

There are a variety of techniques and devices in use for the surgical treatment of atrial fibrillation (AF). The current gold standard for the surgical treatment has been the Cox cut and sew maze procedure. There have been variations through the years leading to a host of other surgical AF procedures, such as the Wolf mini-maze1, practiced by many surgeons. Other techniques create myocardial lesions using some form of radiofrequency energy, laser, cryothermy or high-frequency ultrasound. All of these techniques require access to the heart through either a full sternotomy or less-invasive approaches with incisions on the left and/or right side of the chest. Some techniques require cardiopulmonary bypass and sometimes cardioplegia to stop the heart entirely.2,3 Until recently, no current technique or device provided access to the posterior left atrium directly.

Pericardioscopy is a totally endoscopic technique that provides direct visualization of, and access to, the epicardial surface of the beating heart without the need for cardiopulmonary bypass or prolonged postoperative recovery. Unlike a subxyphoid approach, pericardioscopy provides access to the heart via the central tendon of the diaphragm. This allows direct vision of the posterior cardiac structures with minimal hemodynamic compromise. Such access and visualization of the epicardial cardiac surface has enabled epicardial ablation techniques, like the Convergent Procedure, as a treatment for atrial fibrillation.4,5 Pericardioscopy eliminates the need for sternotomy or thoracotomy when access to the epicardial surface is necessary.

Convergent Procedure - Transdiaphragmatic Pericardioscipic Access

Transdiaphragmatic Pericardioscipic Access



The surgical treatment of atrial fibrillation (AF) is based upon the creation of an anatomical pattern of myocardial scar. The Corridor Procedure 6, the Radial Maze Procedure,6 and the Cox maze I-III7,8 are anatomical patterns designed to disrupt the re-entry circuits of AF by dividing the atria into non-conductive segments. Electrophysiologists, in comparison, use endocardial catheters and electrodes to identify the triggers causing AF and direct their treatments towards these foci of abnormal electrical activity in the atria. The individual success of these approaches, either surgical or endocardial, has been limited by technical complexity and/or less than desirable outcomes.

A truly successful and adoptable AF treatment has always seemed to be just out of reach. The acclaimed gold standard cut and sew maze procedure reports exceptional outcomes but remains a complex procedure that is rarely performed.9,10 The mini-maze11 and pulmonary vein isolation12reduce procedural complexity by decreasing the number of lesions and by eliminating cardiopulmonary bypass. However, both the surgeons and the cardiologists have demonstrated that when treatment is limited to the left atrium, outcomes suffer as a consequence.13,14 The endocardial, catheter-based AF ablations, not unlike the surgical procedures, remain long and technically difficult procedures performed by relatively few electrophysiologists. The high rate of repeat procedures and less than desirable long-term outcomes have been disappointing.15 Unfortunately, surgeons and cardiologists seldom collaborate in the development of new technologies and innovative approaches to overcome these individual procedural shortcomings.

The Convergent Procedure has been developed by a multidisciplinary team of cardiologist and cardiac surgeons to address the procedural and communication barriers. The Convergent Procedure is the simultaneous creation of a surgeon’s PEX epicardial ablation pattern and electrophysiologist’s endocardial ablation pattern (Figure 1).

Convergent Procedure - Convergent Procedure Lesion Pattern

Convergent Procedure Lesion Pattern


The surgeon’s ability to effectively create visible, and therefore contiguous, epicardial ablation lines has greatly reduced the amount of endocardial tissue which must be ablated to complete a successful trans-septal catheter procedure. The integration of a surgeon’s anatomical approach to AF with the physiological approach of the electrophysiologist’s has led to the development of the Convergent Procedure.

This convergence of technologies and expertise provides or allows for:

1. The creation of a complete, bi-atrial, endocardial and epicardial ablation pattern without a chest incision or cardiopulmonary bypass;

2. Intra-operative metrics to confirm procedural success;

3. Integrated patient care by cardiology and cardiac surgery; and

4. Decreased length of hospital stay and the number of repeat ablation procedures.


At the UNC Center for Heart & Vascular Care, we have created a multidisciplinary service that integrates the care of Arrhythmia patients. Evaluation of each case by the multidisciplinary team of arrhythmia experts ensures an individualized, yet consensus, treatment plan. Without this integrated approach, the best treatment option may not be available or may require much longer wait times, more travel and more inconvenience and delay for the patient.

The patient’s clinical presentation is vitally important to developing the multidisciplinary treatment plan. Left atrial size, AF type and AF duration are significant contributory factors. We advocate a 24-hour Holter monitor on all patients under evaluation to document the degree of AF burden. Additional evaluation includes a trans-thoracic echocardiogram and cardiac catheterization or stress test to exclude structural heart disease in the setting of AF.

The consensus opinion by the Heart Rhythm Society Task Force states that, “stand-alone AF surgery should be considered for symptomatic AF patients who prefer a surgical approach, have failed one or more attempts at catheter ablation, or are not candidates for catheter ablation.” Left atrial size and AF duration are important factors in this decision process. When the left atrium is larger than 6.0 cm or the duration of AF is greater than 5 years, the long term success for the Cut and Sew maze procedure are under 80% (Figure 2). It is difficult for the electrophysiologist to consistently and effectively complete pulmonary vein isolation when the left atrium is greater than 5.0 cm. Therefore, when a patient has paroxysmal AF and the left atrium is under 4.5-5.0 cm, we recommend percutaneous catheter ablation. In this population, simple pulmonary vein isolation may be effective in over 80% of patients.16

Patients with paroxysmal AF and a left atrium greater than 4.5 cm and those with persistent and long-standing persistent AF demonstrate the best outcomes when a bi-atrial lesion pattern is created. Surgeons who have experience with minimally invasive approaches choose the ablation technology best suited for their technique. Whichever approach and device is used, a comprehensive lesion pattern of contiguous and transmural lesions are essential. Persistence and intra-operative verification of lesion and pattern integrity is crucial. The Convergent Procedure has established new criteria for lesion integrity by the verification of procedural completion by endocardial electrophysiologic metrics. The Convergent Procedure is not complete until pulmonary vein isolation and posterior left atrial exclusion is confirmed, the coronary sinus is ablated, and a cavo-tricuspid isthmus lesion is created. These metrics provide confidence of procedural success and set new standards for the hybrid treatment of persistent and long-standing persistent AF.

Left: Success Decreases with Left Atrial Size>6.0cm; Right: AF Duration Predicts Sinus Rhythm Restoration Post Maze Procedure

Left: Success Decreases with Left Atrial Size>6.0cm; Right: AF Duration Predicts Sinus Rhythm Restoration Post Maze Procedure



There have been many minimally invasive approaches to treat AF, all based primarily upon the original work by Cox and his maze procedure. By integrating electrophysiology and cardiac surgery in a hybrid AF treatment, new procedural and perioperative standards have been established at our institution. The initial outcomes utilizing this multidisciplinary approach are excellent and patient satisfaction is overwhelmingly positive.

Reproduced with permission.17

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Return to Index of Articles: Maze, Mini-Maze, Convergent, LAA Closure Surgeries

Last updated: Sunday, February 15, 2015

Footnote Citations    (↵ returns to text)

  1. Wolf RK, Schneeberger EW, Osterday R, Miller D, Merrill W, Flege JB Jr, Gillinov AM. Video-assisted bilateral pulmonary vein isolation and left atrial appendage exclusion for atrial fibrillation. J Thorac Cardiovasc Surg. 2005; 130:797-802
  2. Henry L, Ad N. The Maze procedure: a surgical intervention for ablation of atrial fibrillation. Heart Lung. 2008 Nov-Dec;37(6):432-9.
  3. Chitwood WR Jr, Wixon CL, Elbeery JR, Moran JF, Chapman WH, Lust RM., Video-assisted minimally invasive mitral valve surgery, J Thorac Cardiovasc Surg. 1997 Nov;114(5):773-80; discussion 780-2
  4. Kiser AC, Wimmer-Greinecker G, Chitwood WR. Totally extracardiac maze procedure performed on the beating heart. Ann Thorac Surg 2007;84:1783-85.
  5. Kiser AC, Wimmer-Greinecker G, Kapelak B, Bartus K, Sadowski J. Paracardioscopic ex-maze procedure for atrial fibrillation. Innovations 2008; 3:117
  6. Nitta T, Lee R, Schuessler RB, Boineau JP, Cox JL. Radial approach: a new concept in surgical treatment for atrial fibrillation I. Concept, anatomic and physiologic bases and development of a procedure. Ann Thorac Surg. 1999 Jan;67(1):27-35.2
  7. Cox JL, Schuessler RB, D’Agostino HJ Jr, et al.The surgical treatment of atrial fibrillation. III. Development of a definitive surgical procedure. J Thorac Cardiovasc Surg. 1991 Apr;101(4):569-83,
  8.  Cox JL, Boineau JP, Schuessler RB, et al. Modification of the Maze procedure for atrial flutter and atrial fibrillation: I. Rationale and surgical results. J Thorac and Cardiovasc Surg 1995; 110:485-495
  9. Prasad SM, Maniar HS, Camillo CJ, et al. The Cox maze III procedure for atrial fibrillation: long-term efficacy in patients undergoing lone versus concomitant procedures. J Thorac Cardiovasc Surg. 2003; 126(6):1822-8
  10. Kosakai Y. Treatment of atrial fibrillation using the maze procedure: the Japanese experience. Sem Thor Cardiovasc Surg. 2000; 12:44-52.
  11. Wolf RK, Schneeberger EW, Osterday R, Miller D, Merrill W, Flege JB Jr, Gillinov AM. Video-assisted bilateral pulmonary vein isolation and left atrial appendage exclusion for atrial fibrillation. J Thorac Cardiovasc Surg. 2005; 130:797-802
  12. Edgerton JR, Edgerton ZJ, Weaver T, et al. Minimally Invasive Pulmonary Vein Isolation and Partial Autonomic Denervation for Surgical Treatment of Atrial Fibrillation. Ann. Thorac. Surg. July 2008; 86:35-39
  13. Barnett SD, Ad N. Surgical ablation as treatment for the elimination of atrial fibrillation: a meta-analysis. J Thorac Cardiovasc Surg. 2006 May;131(5):1029-35.
  14. Calo I, Lamberti F, Loricchio ML, et al. Left atrial ablation versus biatrial ablation for persistent and permanent atrial fibrillation: a prospective and randomized study. J Am Coll Cardiol 2006;47:2504-2512.
  15. Cappato R, Calkins H, Chen SA, et al. Worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circulation. 2005;111:1100-1105
  16. Haissaguerre M, Jais P, Shah DC, Takahashi A, et al. Spontaneous initiation of atiral fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998; 339:659-666.
  17. Kiser, A., Mounse, P. Advantages of the Convergent Procedure.UNC Cardiac Surgery and Electrophysilogy Services. Accessed September 03, 2012. URL:

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