Florida Medical Center (FMC), one of the oldest hospitals in the area and site of the first coronary artery bypass surgery in Broward County, has recently witnessed major renovations and additions to its cardiovascular services. The comprehensive endovascular service line at FMC includes EP procedures as well as coronary, structural, and peripheral interventions. We also have a comprehensive stroke center. We work collaboratively with anesthesiologists as well as with cardiothoracic, neuro, and vascular surgeons to provide comprehensive endovascular and surgical cardiac services to our patients.
In addition to the cardiac ORs, FMC has 5 labs: 2 coronary cath labs, a biplane room for neurointerventions, a hybrid OR for structural interventions and extractions, and a new, fully equipped EP lab. We also plan to add a second EP mapping system to make the hybrid room truly multifunctional.
In August 2018, a visually guided laser balloon (VGLB) (HeartLight Excalibur Balloon, CardioFocus) was added to our armamentarium, with FMC being the first in Broward County to use it.
For the last 20 years, pulmonary vein isolation (PVI) has remained the cornerstone for atrial fibrillation (AFib) ablation. While this can be achieved with point-by-point radiofrequency energy delivery or cryoballoon ablation, the use of laser balloon offers a unique advantage. Specifically, it allows us to directly visualize the pulmonary vein antra and appreciate the anatomical complexity of the areas targeted for ablation, allowing for complete and reliable isolation of the PVs. Included here is an overview of our initial experience with the technology.
The procedure is performed under general anesthesia. After double transseptal puncture is performed under fluoroscopic and intracardiac echocardiography, intravenous heparin is administered to maintain an activated clotting time of ≥300 seconds. A circular mapping catheter is used to create the left atrial (LA) geometry and record PV activity before and after laser ablation. A 12 French steerable transseptal sheath is used to advance the deflated balloon, which is positioned sequentially into the target PVs. Adjustable filling of the balloon allows it to conform to each unique anatomy and obtain truly circumferential contact around each target PV. The incorporated 2 Fr endoscope allows for direct visualization and accurate energy delivery. Accurate esophageal temperature monitoring is performed during energy delivery, and phrenic nerve stimulation is performed to monitor for potential injury during right-sided ablation. No preprocedural imaging is performed.
The next-generation HeartLight Excalibur Balloon is then gradually filled with deuterium oxide (heavy water) until adequate occlusion of the PV is achieved. The catheter shaft houses a 980 nm laser diode delivering a 20- or 30-second burst of laser energy. In order to achieve a contiguous lesion set around each PV ostium, individual lesions are overlapped by 30-50%. Laser energy can be titrated from 5.5 to 12 Watts depending on left atrial wall thickness and nearby extracardiac structures (e.g., esophagus), as well as lower energy if contact to wall is suboptimal. Rotating, advancing, or retracting the laser beam allows for a tailored lesion design.
Electrical isolation is verified after balloon deflation using the circular mapping catheter. During ablation of the right PVs, phrenic nerve pacing is performed to monitor right phrenic nerve function. The procedure is then terminated, and all catheters and sheaths are removed. Hemostasis is accomplished with manual compression. Heparin is reversed routinely with protamine.
Our initial experience at FMC has been extremely favorable, achieving acute success and a rapid drop in procedural time. As workflow improved with our first 10 cases, we have seen procedural time decrease to approximately 60-70 minutes, and only 2 veins required RF ablation to complete isolation in the first 3 cases. No complications have been observed. We’re very pleased with these outcomes, and feel that visually guided laser balloon ablation offers reliable and anatomically individualized PVI to patients with paroxysmal and early atrial fibrillation.
The first prospective multicenter study on the use of the VGLB in patients with paroxysmal atrial fibrillation was published in 2009; of 116 targeted PVs, 105 (91%) were acutely isolated, resulting in a one-year freedom from recurrent atrial fibrillation (60%).1
More recent single-center reports have validated this technology, with increased evidence for durability and very favorable clinical outcomes. Dukkipati et al demonstrated durable isolation in 61/68 (90%) PVs at three months following the index PVI procedure.2 The HeartLight study, a multicenter, randomized controlled trial, enrolled 353 patients with drug-refractory paroxysmal atrial fibrillation to PVI using radiofrequency or laser balloon ablation; the 12-month freedom from recurrent atrial arrhythmias was 63.5% in the VGLB group and 63.9% in the conventional arm (P=0.94).3 Published results led to U.S. FDA premarket approval of the HeartLight Endoscopic Ablation System in April 2016.
A 2013 study also compared clinical and procedural outcomes between older generation cryo and laser balloons, with longer fluoro times noted with cryoablation, but no significant difference in 12-month follow-up for AFib freedom.4
There have been additional studies published this year on laser balloon ablation for AFib. A meta-analysis of 17 studies of AFib ablation using the laser balloon found that of 1188 patients, successful acute vein isolation occurred in 98.8% and 12-month freedom from AFib was found in 74.3% of paroxysmal patients; transient phrenic nerve palsy occurred in 2.6% of patients.5 A randomized study also assessed the acute reconnection rate post isolation with the laser balloon versus radiofrequency, using adenosine provocation testing, and revealed a significantly lower reconnection rate with laser ablation (10.8% vs 30.9%).6
Further technical refinement with the third-generation balloon with an automated laser drive will likely lead to improvement in procedure time. Further validation of outcomes will establish visually guided laser balloon ablation as a first-line therapy in patients targeted for pulmonary vein isolation.
Disclosure: Dr. Osman has no conflicts of interest to report regarding the content herein.
1. Reddy VY, Neuzil P, Themistoclakis S, et al. Visually-guided balloon catheter ablation of atrial fibrillation: experimental feasibility and first-in-human multicenter clinical outcome. Circulation. 2009;120:12-20.
2. Dukkipati SR, Neuzil P, Skoda J, et al. Visual balloon-guided point-by-point ablation: reliable, reproducible, and persistent pulmonary vein isolation. Circ Arrhythm Electrophysiol. 2010;3(3):266-273.
3. Dukkipati SR, Cuoco F, Kutinsky I, et al; HeartLight Study Investigators. Pulmonary Vein Isolation Using the Visually Guided Laser Balloon: A Prospective, Multicenter, and Randomized Comparison to Standard Radiofrequency Ablation. J Am Coll Cardiol. 2015;66(12):1350-1360.
4. Bordignon S, Chun KR, Gunawardene M, et al. Comparison of balloon catheter ablation technologies for pulmonary vein isolation: the laser versus cryo study. J Cardiovasc Electrophysiol. 2013;24(9):987-994.
5. Reynolds MR, Zheng Q, Doros G. Laser balloon ablation for AF: a systematic review and meta-analysis. J Cardiovasc Electrophysiol. 2018;29:1363-1370.
6. Ücer E, Janeczko Y, Seegers J, et al. A RAndomized Trial to compare the acute reconnection after pulmonary vein ISolation with Laser-BalloON versus radiofrequency Ablation: RATISBONA trial. J Cardiovasc Electrophysiol. 2018;29:733-739.