Advancing EP Services with a Closed-Chest Hybrid Approach for AF Ablation: Experience at The Heart Institute at Staten Island University Hospital

Physicians at The Heart Institute at Staten Island University Hospital have developed a successful hybrid program for the treatment of atrial fibrillation (AF). Most recently, we have been performing the majority of our hybrid ablations using laparoscopic (transdiaphragmatic) epicardial radiofrequency (RF) combined with an endocardial cryoballoon. Our program was the first in New York City to perform ablations with this specific combination, and we feel it is a viable option for many patients with this chronic disease. The nContact system is utilized for the laparoscopic portion of the procedure, and the Arctic Front Advance cryoballoon (Medtronic, Inc.) is used for the endocardial portion (and occasionally RF as well). In this article, we review our process for setting up our hybrid program and detail the hospital course of the patient. The Arctic Front Advance cryoballoon (Medtronic, Inc.) is used for the endocardial portion (and occasionally RF as well). In this article, we review our process for setting up our hybrid program and detail the hospital course of the patient.

The Need for a Hybrid Program

Hybrid ablation is a collaborative approach involving an electrophysiologist performing endocardial ablation and a cardiac surgeon performing epicardial ablation. This combined approach can significantly improve the likelihood of success in treating patients with longstanding persistent atrial fibrillation, who are unlikely to respond to medical treatment or catheter-based techniques alone. Unlike paroxysmal atrial fibrillation, which is often triggered by foci largely isolated to the pulmonary veins, persistent atrial fibrillation is characterized by more diffuse changes. This includes widespread substrate modification in the tissues of the atrial walls, especially in the posterior left atrium.¹ In these patients, failure of endocardial pulmonary vein isolation alone is thought to be due to reconnection, persistence of triggers in non-venous sites of the atria, or lack of lesion transmurality.² Epicardial ablation allows for complete electrical obliteration of the posterior left atrium and pulmonary veins, and thereby covers a large territory of tissue that cannot be easily treated endocardially. Endocardial ablation of this entire territory is very time-consuming, and can allow for multiple gaps in between the multiple lesions. More importantly, endocardial ablation in this area is potentially dangerous as the esophagus underlies it. However, epicardial ablation directed inward, into the natural heat sink of the heart, guards against this. 

Therefore, in this hybrid approach, endocardial ablation is focused primarily on pulmonary vein isolation using the cryoballoon, which we have found to be very successful. However, the right atrium, coronary sinus, and cavotricuspid isthmus are also treatable endocardially. The combined epicardial/endocardial approach allows for the creation of transmural blocking or substrate transforming lesions over a large area, silencing the AF triggers on the posterior left atrium. Initial studies have revealed freedom of recurrence from persistent atrial fibrillation on antiarrhythmics of approximately 80% at one year after hybrid procedures.^3-5

Initial Setup and Preparation: The Heart Institute at Staten Island University Hospital

Staten Island is one of the five boroughs of New York City with a population of approximately 500,000. Interestingly, it has the highest incidence of cardiovascular morbidity in New York state. This is at least partially due to an unusually high incidence of tobacco use in the borough (18.5%)⁵ as well as other lifestyle trends (dietary). In our patient population, approximately 70% of patients with atrial fibrillation are persistent. We identified an unmet need for effective management of symptomatic longstanding persistent atrial fibrillation, and therefore, initiated our hybrid program.

Staten Island University Hospital is a 700-bed teaching hospital, with two campuses. Dr. Joseph T. McGinn is CMO and the Chairman of Surgery, and Dr. Soad Bekheit is the director of the Division of Electrophysiology. Two physicians are directly committed to the program’s development and to conducting the procedures: Dr. Marcin Kowalski is the electrophysiologist, and Dr. Alexander Wohler is the cardiac surgeon.

Of note, it is imperative to create and maintain a cooperative and seamlessly collaborative relationship between the departments of electrophysiology and cardiothoracic surgery. Mutual respect and benevolent cooperation comprise the cornerstone for the implementation of a successful program. Furthermore, it is of vital importance to involve the administration of the hospital to foster support and to ensure logistical success. We also preemptively met with Quality Management to identify and address potential issues with respect to safety and medicolegal concerns. It is also necessary to ensure proper training for each step of the procedures. We met with representatives from industry, and complied with all training and certification requirements. 

Once we knew we had sufficient support and all of the major pieces in place, we began to work on the details, and picked a tentative date for the first procedure. We identified several patients who were appropriate candidates, and we worked to ensure that the staff and other physicians involved were prepared. Two in-service sessions were held with the OR staff. Industry representatives were intimately involved in this training process. We also met several times with the anesthesiologists who would be working with us, including the chief of Cardiac Anesthesia, Dr. Scott Sadel. 

Finally, a dry run was performed one week prior to the first scheduled procedure. We identified a few logistics issues and corrected them appropriately. Then, a repeat dry run was performed. After all were satisfied, we scheduled and performed the first procedure in late August 2014. We will have performed 5 successful cases to date (mid December 2014), with 4 cases remaining in normal sinus rhythm for the past 3 months.

The Procedure

On the day of the procedure, the patient is first brought to cardiac OR for the laparoscopic portion of the procedure. Ideally, both portions of the procedure are done in a hybrid suite, such that the patient does not need to be moved in between. However, as we are currently without a hybrid room, we perform the surgical portion in the cardiac OR and then transfer the patent (intubated) to the EP lab once hemodynamic stability and hemostasis are ensured. Of note, this was one of several issues thoroughly reviewed by Quality Management. 

Importantly, the patient is fully prepped and draped as if a sternotomy were being performed. We feel that it is imperative to ensure that all available resources are immediately available should a complication occur. A sternal saw and all necessary cardiac instruments are at hand. We have perfusionists and a cardiopulmonary bypass pump on standby as well. An esophageal temperature probe is inserted by the anesthesiologist, and its position is confirmed by x-ray. This is used to ensure that the esophagus is not subjected to excessive heat during the ablation.

Once prepped and draped, a Hassan trocar (for the laparoscope) is introduced via a one-inch incision approximately two fingerbreadths below the xiphoid. Insufflation ensues. Two 5mm ports are placed for the instruments. With a harmonic scalpel, the diaphragm and pericardium are opened (anterior to the liver in the tendinous portion of the diaphragm). The Hassan is then removed and replaced by a long cylindrical trocar for the nContact system. The scope is then intruded through this trocar to help guide it into the opening in the pericardium. Using a continuously irrigated (to guard against esophageal injury) unipolar RF ablation device (EPi-Sense, nContact, Inc.), epicardial lesions are created along the entirety of the posterior left atrium, between the right and left pulmonary veins (Figure 1). Usually 15 to 30 linear lesions are created to ensure completeness. Depending upon the preferences of the electrophysiologist and surgeon, lesions can be made anterior to the PVs as well.

After satisfactory epicardial ablation, the patient is transferred to the EP lab to perform cryoballoon endocardial ablation. Prior to cryoballoon ablation, the left atrium is electrically mapped to assess any electrical activity using either the Achieve catheter (Medtronic, Inc.) or a lasso circular mapping catheter (Biosense Webster, Inc., a Johnson & Johnson company) (Figure 2). The pulmonary veins are then isolated using the Arctic Front Advance cryoballoon (Medtronic, Inc.). Isolation is confirmed by demonstrating exit-and-entrance block and no dormant conduction after adenosine infusion. Depending on the discretion of the EP, additional lesions may be created in various sites. 

After completion of the procedure, the patient is transferred to and monitored in the cardiothoracic ICU. A single pericardial drain is left in place for 24-48 hours. NSAIDs are administered for prophylaxis against pericarditis. The patents are typically discharged after 48-76 hours. Generally, patients describe having minimal post-op pain.

The patient is followed up in the cardiac surgical clinic as well as in the EP clinic approximately 2 weeks after the procedure and monthly thereafter for the initial 6-month period.

Key Actions for Establishing a Successful Hybrid Ablation Program

1. Assess the need for and feasibility of a program (patient population, referral patterns, hospital support, etc.).
2. Ensure that the physicians potentially involved have a strong interest in the program and are earnestly dedicated to work in a cooperative and collaborative manner.
3. Decide upon specific technology/procedures to be utilized. We suggest planning on performing the majority of procedures in a similar fashion with similar technology. Assess support capability/interest of industry. Ensure necessary certification for performing the procedures.
4. Engage and align with the hospital administration, highlighting the potential for enhanced patient care — as well as the high profile and marketability of hybrid procedures. Use potential of volume, revenue, and impact to the community to build your case.
5. Involve the hospital’s Compliance Committee and Quality Management to facilitate the process and to minimize medicolegal risk. Gain hospital administrative support to avoid departmental conflicts (billing, scheduling, etc.).
6. Ensure that all necessary training is completed and that the individuals involved are well prepared to perform their role. Initial failures and complications can have a dramatic effect on the momentum of the program.
7. Perform initial ‘dry runs’ with all involved, and evaluate for any potential logistical issues. ■

Disclosures: The authors have no conflicts of interest to report regarding the content herein. Outside the submitted work, Dr. Kowalski reports personal fees (consultancy) from Medtronic, Inc.

References

1. Calkins H, et al. 2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design: a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation. Developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology (ESC) and the European Cardiac Arrhythmia Society (ECAS); and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). Endorsed by the governing bodies of the American College of Cardiology Foundation, the American Heart Association, the European Cardiac Arrhythmia Society, the European Heart Rhythm Association, the Society of Thoracic Surgeons, the Asia Pacific Heart Rhythm Society, and the Heart Rhythm Society. Heart Rhythm. 2012;9(4):632-696.e21. 
2. Kowalski M, Grimes MM, Perez FJ, et al. Histopathologic characterization of chronic radiofrequency ablation lesions for pulmonary vein isolation. J Am Coll Cardiol. 2012;59(10):930-938. 
3. Gehi AK, Mounsey JP, Pursell I, et al. Hybrid epicardial-endocardial ablation using a pericardioscopic technique for the treatment of atrial fibrillation. Heart Rhythm. 2013;10(1):22-28. 
4. Welniak C. Hybrid Procedure May Offer Better Outcomes for Persistent and Longstanding Persistent Atrial Fibrillation. StopAfib.org. Published February 9, 2011. Available online at https://bit.ly/1sgdq6X. Accessed December 9, 2014.
5. New York City Department of Health and Mental Hygiene. New York City Youth Risk Behavior Survey 2013.