Achieving Hemostasis and Early Ambulation in Pulsed Field Ablation for Atrial Fibrillation With Successful Deployment of the MYNX Control Venous Closure Device: A Case Study and Workflow Example
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EP LAB DIGEST. 2025;25(4):1,8-10.
Joseph M Bumgarner, MD, FACC, FHRS
North Carolina Heart and Vascular, Raleigh, North Carolina
Pulmonary vein isolation (PVI) is a safe and effective treatment option in patients with symptomatic, drug-refractory atrial fibrillation (AF).1 Current guidelines and an ever-growing body of research support AF ablation for many patients.2 While radiofrequency ablation and cryoablation have been used in the United States for many years, pulsed field ablation (PFA) is an emerging therapeutic modality recently approved by the US Food and Drug Administration (FDA) with comparable efficacy and improved safety.3
Some PFA platforms require large-bore intravenous access, which may prolong time to hemostasis and lengthen post-procedure bed rest protocols. While manual compression remains the standard of care to achieve hemostasis in many centers, some operators are now using figure-of-8 suture placement, suture-based devices, or collagen plug-based devices to achieve hemostasis.4-8
The MYNX CONTROL VENOUS Vascular Closure Device (MYNX VCD, Cordis) delivers a novel bio-inert polyethylene glycol (PEG) sealant to the vessel surface, achieving rapid hemostasis (Figure 1). Patients can ambulate within about 2
hours of deployment and return home shortly after an ablation procedure.9
The MYNX VCD is designed for 6 French (F) to 12F sheath sizes; however, some PFA platforms require outer diameter sheath sizes of up to 16.8F. This article outlines our workflow for achieving successful hemostasis and early ambulation following large-bore access in PFA using the MYNX VCD.
Case Presentation
The case involves a 67-year-old woman with increasing episodes of symptomatic paroxysmal AF who had been unable to tolerate antiarrhythmic medications due to bradycardia and fatigue. She had a history of hypertension and was taking apixaban due to her moderate risk of stroke (CHA2DS2-VASc score of 3). After our discussion of treatment options, she elected to proceed with catheter ablation. Due to reduced risk of esophageal and phrenic nerve injury, she expressed an interest in PFA, and she was felt to be a good candidate for this modality. Her body mass index was 35.3 kg/m2.
On the day of the procedure, she shared with us a desire for a short post-procedure bed rest due to chronic back pain and interest in same-day discharge (SDD). The decision to use the MYNX VCD for post-ablation hemostasis was based on our experience with the device, which we have found allows many patients to achieve early ambulation and SDD while avoiding potential complications from other closure methods. For this procedure, the FARAPULSE PFA system (Boston Scientific) was used. This system incorporates the FARAWAVE ablation catheter with the FARADRIVE steerable sheath, which has a 16.8F outer diameter.
Vascular Access
The procedure was performed under general anesthesia. Under ultrasound guidance, percutaneous femoral venous access was obtained using a modified Seldinger technique. Prior to sheath placement, ultrasound was also used to confirm an appropriate trajectory for each wire entering the femoral vein. A short 8.5F sheath was placed in the right femoral vein and short 9.5F and 8.5F sheaths were placed in the left femoral vein.
Procedural Considerations
We proceeded with our usual PFA workflow, which included placement of an intracardiac echocardiography (ICE) probe in the right atrium and a DECANAV mapping catheter (Johnson & Johnson MedTech) in the coronary sinus (CS) via the left femoral vein. CARTO 3 Version 8 (Johnson & Johnson MedTech) was used for electroanatomical mapping and to minimize fluoroscopy use. After confirming the absence of a pericardial effusion, heparin was bloused and infused to maintain an activated clotting time (ACT) of 350 seconds. The short, right-sided femoral sheath was exchanged for the FARADRIVE steerable sheath and a VersaCross radiofrequency transseptal wire (Boston Scientific) was used for transseptal access under ICE guidance. A 3-dimensional electroanatomical shell of the left atrium was created with CARTOSOUND and an OCTARAY mapping catheter (Johnson & Johnson MedTech). After delineation of the 4 PVs, posterior wall, anterior ridge, and septum, we proceeded with PVI using the FARAWAVE ablation catheter. After completion of the PVI, the OCTARAY mapping catheter was used to confirm entrance and exit block around each of the 4 PVs with infusion of adenosine and pacing from the mapping catheter and the CS. Catheters were then withdrawn from the left atrium and protamine was given to reverse the ACT.
Preparing for Vascular Closure
The ICE and CS catheters were withdrawn from the body and the FARADRIVE steerable sheath was returned to its neutral position. Each sheath was flushed with heparinized saline and the groins were inspected to confirm no evidence of hematoma, bleeding, or vascular injury (Figure 2).
The VersaCross wire was then reinserted through the FARADRIVE sheath to the level of the superior vena cava and the FARADRIVE sheath was exchanged for a short 11F sheath, after which the guidewire was removed (Figure 3). The short sheath was allowed to dwell for 2 minutes, and visual inspection confirmed no bleeding or evidence of hematoma formation around the smaller sheath.
Deployment of the MYNX VCD
The MYNX VCD was prepped and then inserted into the 11F short sheath. The sheath catch sidearm was then placed around the side port of the short sheath. The device’s 6-mm semi-compliant balloon, now inserted and distal to the
venotomy site, was fully inflated with the locking syringe. Full inflation of the balloon was confirmed with visualization of the “white-black-white” indicator on the proximal end of the MYNX VCD (Figure 4).
The device and sheath were then retracted with light and steady force, bringing the inflated intraluminal balloon toward the venotomy site. It is important to ensure the right hand cradles the MYNX VCD such that its buttons are facing straight up, and the fingers of the left hand are positioned at the groin site to apply gentle and stabilizing downward pressure as the device and sheath are retracted in a flat angle, parallel to the patient’s leg. Once the sheath is retracted and counterforce from the balloon within the vessel is felt in the right hand, slight additional downward pressure may be applied with the left hand at the insertion site as the right hand prepares to depress button 1. During this time, the tension indicator is carefully monitored as the balloon approaches the venotomy site. Continuing to slowly retract the device, the tension indicator becomes aligned (Figure 5), and button 1 should be fully depressed, thereby deploying the PEG hydrogel over the venotomy site.
At this point, a 2-minute dwell time allowed expansion of the water-soluble sealant inside the tissue tract, sealing the access site (Figure 6).
Following the 2-minute dwell time, the balloon was deflated while gently stabilizing the device. Button 2 of the device was depressed which retracted the balloon (Figure 7), and finally the device was completely removed. Manual pressure was maintained for an additional minute to allow the sealant to fill the lumen left by the device and achieve complete hemostasis (Figure 8). Observation of the site confirmed final hemostasis (Figure 9).
After completing 2 hours of bed rest, the patient ambulated in the hallway and hemostasis was confirmed over the femoral venous access sites. Apixaban was continued. She was discharged home in normal sinus rhythm under the care of
her family 3 hours post procedure with instructions to avoid lifting for 1 week.
Discussion
To our knowledge, this is the first published report of successful closure of a large-bore PFA delivery sheath with the MYNX VCD. Our experience with the device in sheath sizes up to 12F has been positive, with improved patient comfort, early ambulation, and successful SDD following catheter ablation procedures, and so downsizing from larger sheath sizes of up to 16.8F presented a reasonable next step in the development of our PFA workflow.
The French catheter scale is defined as 0.33 mm per unit. The MYNX VCD utilizes a 6-mm inflatable balloon that occludes the venotomy site and provides temporary hemostasis while the water-soluble, resorbable, extravascular PEG hydrogel solidifies and creates a functionally hemostatic seal over the vessel puncture site. We would expect the 6-mm balloon to occlude venotomy sites up to 18F, and in our experience, its use with the 16.8F FARADRIVE sheath has been successful.
We have learned it is important to allow a few minutes for the smaller short sheath to “dwell” after exchanging out the FARADRIVE sheath. This allows the more compliant venous
blood vessel wall to relax and close around the smaller sheath. We routinely use this dwell time to close the smaller right-sided access sites with 2 additional MYNX VCDs. We have also learned to be sure to fully inflate the MYNX VCD balloon to its maximal size, providing the largest occlusive balloon diameter to achieve successful hemostasis. For additional guidance on the device’s use, its Instructions for Use should be consulted.
Summary
Using the MYNX VCD in large-bore PFA cases provides reliable hemostasis, early post-procedure ambulation, and fits well in our SDD protocol. It also avoids the pain experienced by patients who undergo figure-of-8 suture closure and minimizes risk of embolization, which may occur with the use of intravascular closure methods. The hydrogel sealant fully reabsorbs within 30 days and does not prevent re-access in the femoral space when needed.
Disclosure: Dr Bumgarner has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. He reports receiving consulting and advisory support from Cordis and Johnson & Johnson, payment or honoraria for education, presentations, and manuscript writing from Cordis, support for attending meetings and/or travel from Cordis and Johnson & Johnson, and participation on a data safety monitoring board or advisory board from Cordis and Johnson & Johnson.
This content was published with support from Cordis.
References
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6. Okada M, Inoue K, Tanaka K, et al. Efficacy and safety of figure-of-eight suture for hemostasis after radiofrequency catheter ablation for atrial fibrillation. Circ J. 2018;82(4):956-964. doi:10.1253/circj.CJ-17-1213
7. Matsunaga-Lee Y, Egami Y, Yanagawa K, et al. Limited efficacy of a figure-of-eight suture for hemostasis after cryoballoon atrial fibrillation ablation with uninterrupted oral anticoagulants. J Cardiol. 2020;76(1):30-34. doi:10.1016/j.jjcc.2020.01.012
8. Freedman BL, Yang S, Shim D, d’Avila A, Waks JW, Tung P. Feasibility and safety of same-day discharge and shortened bedrest after atrial fibrillation ablation. J Interv Card Electrophysiol. 2022;65(1):209-217. doi:10.1007/s10840-022-01255-4
9. Summers J, Swarup V, Parker I, et al. Safety and efficacy of a novel sealant-based vascular closure device following electrophysiology procedures: ReliaSeal Trial. J Cardiovasc Electrophysiol. 2025 Mar 17. Online ahead of print. doi:10.1111/jce.16623
