Stepwise Fluoroless Journey at Royal Devon University Hospital

EP LAB DIGEST. 2023;23(4):1,8-10.

The increasing pressure of cardiac procedure waiting lists, worsened by the COVID-19 pandemic and populated by deteriorating patients, is one that is likely felt at some level within all cardiac centers. With these unprecedented challenges come the possibility and requirement for substantial service changes. The Royal Devon University Hospital has 3 cardiac catheterization laboratories, one of which is used for cardiac electrophysiology (EP). Our EP lab runs 6 days a week, with time split between EP cases and cardiac device implants. Sharing this lab time was a limiting factor in providing timely catheter ablation treatment for patients with arrhythmias, and was detrimentally affecting the waiting list for cardiac device patients. To increase capacity, a novel solution was presented in the design of a fully fluoroscopy-free procedure room: an innovative, forward-thinking answer and a first for a team in the United Kingdom dedicated to keeping wait times low in an otherwise pressurized environment for the catheterization laboratories.

Background

Cavotricuspid isthmus (CTI) ablation is recommended for all symptomatic, recurrent episodes of typical atrial flutter (AFL).¹ It is a routine and low-risk procedure, with a serious complication risk of .1%-1% nationally and .6% locally (out of 505 CTI-dependent flutter ablations), with a success rate of 96.04%. In 2021, the success rate at Royal Devon University Hospital for CTIs was 97.67%.

Beginning in February 2019, 20 of 34 CTI-dependent AFL ablations were performed without fluoroscopy. Recognizing the potential in this workflow, the team aimed to transfer their zero fluoroscopy approach to a standard noninvasive procedure room within the cardiac department to address the growing typical AFL waiting list, which was approximately 13 months in 2019. Through the learning experience of fluoroless CTI ablation, mean fluoroscopy time for typical AFL reduced from 8 minutes in 2014 to .9 minutes per procedure in 2021.

Use of 3-dimensional (3D) mapping has allowed us to visualize ablation lesions, identify areas of poor lesion formation, review lesion locations and impedance changes, and perform rudimentary timing/voltage maps if required, all of which has reduced our RF and procedure times. Compared to procedures using fluoroscopy, the average procedure and radiofrequency (RF) times for fluoroless procedures were lower, with 65.8 minutes (without fluoroscopy) compared to 87.7 minutes (with fluoroscopy) for procedure time (Figure 1), and 12 minutes, 56 seconds (without fluoroscopy) and 18 minutes, 28 seconds (with fluoroscopy) for RF times (Figure 2).

Setup of the Procedure Room

Creating a new clinical space, with functionality to perform fluoroless 3D cardiac mapping procedures, required the involvement of multiple teams. Infection control, estates, cardiology management teams, governance, and the radiography team (in case of emergency) were crucial in the planning and delivery of the new procedure room to pull together organizational, logistical, and clinical expertise. The team also worked in partnership with Biosense Webster, Inc, and Johnson & Johnson to design a procedure room that was safe, efficient, and fit for purpose within a time frame of 7 months.

The space selected was a clinic room previously used for echocardiography and other noninvasive cardiac diagnostics, situated within the footprint of the cardiac department, cardiac catheterization laboratories, and cardiac wards. Importantly, this allowed the procedure room to remain both visible and accessible in terms of additional kit, specialized cardiac staff, and the main EP lab. Key equipment was identified and procedure flow mapping allowed a layout of the room to be designed that reflected the team’s movement during the procedure—screen visibility, nurse access to patient cannula and monitoring equipment, cable reach, safety equipment, and manual handling—as well as ensuring a focus that was centered around patient experience, safety, comfort, and dignity, while also making use of available space.

Since patient safety is paramount, emergency equipment (Figure 4) and procedures were established in line with the existing cardiac catheterization laboratory’s standard operating procedures and protocols. Consideration was also given to how the physical space impacted human factors: communication, ergonomics, team expectations of the environment, and hazard prevention.

Patient Selection Criteria

Through many years of using low fluoroscopy and then becoming fluoroless in the main EP lab for right atrial (RA) procedures, robust patient selection criteria was developed for the procedure room. The patient’s arrhythmia is assessed with a 12-lead electrocardiogram (ECG) or ambulatory monitoring, as is the same prior to referral for all EP procedures. The patient’s body mass index (BMI) and other factors that may indicate they are higher risk of requiring assistance with their airway during sedation, such as sleep apnea or previous difficulty with airway management during anesthesia, are also assessed. It is preferable for these patients to have planned general anesthetic in the larger main lab. Any patient with a transvenous pacemaker or implantable cardioverter-defibrillator is excluded due to the risk of lead displacement during catheter manipulation, and listed in the main lab.

Procedure Workflow

AFL ablation is performed with 3D mapping using the Carto system (Biosense Webster, Inc, a Johnson & Johnson company), with the option of real-time intracardiac echocardiography (ICE) imaging if complications arise.

A navigation ablation catheter is introduced via the femoral vein to the superior vena cava (SVC) and geometry is collected of the SVC, RA, coronary sinus (CS), and inferior vena cava (IVC), paying particular attention to the CTI. The His and annular points are also marked (represented by the yellow and blue lesion, respectively, in Figure 5).

Once a satisfactory geometry is collected, a decapolar catheter is introduced and positioned in the CS, and standard pacing maneuvers are performed.

Dual views are used, with a right anterior oblique (RAO) and left anterior oblique (LAO) projection to enable the operator to visualize the CTI line and His. The LAO projection is manually rotated to achieve the maximum distance between the most lateral annular point and the His. This allows direct visualization of the tricuspid valve as a clock face and identification of the 6 o’clock position. The LAO projection is then rotated prior to ablation into a caudal position, to look up at the CTI from an inferior view.

Once sinus rhythm is achieved and the CTI line is complete, standard pacing maneuvers are performed to confirm bidirectional block plus or minus a rudimentary timing map with the ablation catheter while pacing from the CS (Figure 3).

The presence of dormant conduction is assessed with adenosine,² negating the need for a post-RF waiting period in the lab, and allowing for a more streamlined workflow and optimized lab time. Because adenosine is contraindicated in patients with asthma, a standard 20-minute wait period is preferred.

Impact

Use of the procedure room has had a significant positive impact for the Royal Devon University Hospital’s EP team and cardiac department in numerous and measurable ways. The procedure room opened in February 2022, and over a 6-month period, 66 CTI-dependent AFL ablations have been completed. Improving access to patient care is a proud achievement for the department, and the most important outcome of this innovative, solution-focused project is the effect on the waiting list. As of November 2022, the AFL waiting list now stands at 2 weeks, compared to 13 months in 2019.

In addition to improving access to AFL treatment, completing this comparatively low-risk workload in the procedure room allowed crucial and limited cardiac catheterization laboratory space to be reallocated to more complex procedures, including atrial fibrillation ablation, ventricular tachycardia ablation, and cardiac device implants—all of which are time-sensitive procedures with a recognized negative impact of long diagnosis-to-treatment wait times.³ When EP is not being performed in the procedure room, this has provided an improved patient environment for procedures such as implantable loop recorder implants and explants. It has also offered increased capacity to the wider cardiac team for ajmaline testing and transesophageal echocardiography (TTE).

Education and Training

Implementation of the procedure room for ablation has not only improved capacity for consultants to treat patients, but doubled the department’s capacity to train team members in EP: this is vital at a time when staff shortages are adding to the growing pressure on cardiac departments. This has specifically allowed the most specialized members of the clinical team to shorten their learning curve to independent practice—fellows and cardiac physiologists are able to increase their exposure, improve their skillsets, and gain hands-on training from experienced consultants in an environment that is demonstrably protected from emergency patients, list changes, and interruptions that can impact training in a faster-paced main lab. The procedure room has also allowed for simulator training to be completed in a true-to-life lab environment without the need for after-hours lab use or empty main lab sessions, demonstrating a much improved use of resources and facilitating high-quality continuing professional development.

Future Directions

Continuing the stepwise fluoroless journey at Royal Devon University Hospital, more complex procedures will also see a conversion to a workflow without fluoroscopy; initially in the main lab while skills are honed and then to the fluoroless procedure room. While working in the procedure room, areas needing modification are identified to allow for more complex procedures to be performed. Close collaboration with a multidisciplinary team will be necessary to implement these changes as soon as possible to maximize the use of the room while ensuring patient safety.

The goal is to perform 3-wire EP studies in this room as a progression from the fluoroless work already performed in the main lab, with the assistance of ICE for transseptal punctures. ICE is a fundamental element of fluoroless workflows in ablation. Providing real-time chamber views guides safe catheter placement and navigation, allows assessment for thrombus or effusion, and provides anatomical location of key structures, which validates the geometry collected by 3D mapping.

Colleagues from other centers are welcome to visit and experience this fluoroless approach to CTI and collaborate to further develop this technique. We would also like to perform an official study to review benefits to patients relating to reduced wait times, as well as all aspects of the fluoroless workflow. 

Acknowledgements for data collection. Nikolaos Spinthakis, MBBS, MRCP, MD, ST7 Registrar in Cardiology, Royal Devon University Hospital, Devon, England, and Fiona Escott, MSc, Cardiac Physiologist, Royal Devon University Hospital, Devon, England.

Disclosures: The author has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. She has no conflicts of interest to report regarding the content herein. Outside the submitted work, she reports support from Abbott and Biosense Webster for attending meetings and/or travel as well as use of equipment equipment and mapping software in their EP lab.

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References

1. Brugada J, Katritsis DG, Arbelo E, et al, ESC scientific document group. 2019 ESC guidelines for the management of patients with supraventricular tachycardia. The Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J. 2020;41(5):655-720. doi:10.1093/eurheartj/ehz467

2. Vijayaraman P, Dandamudi G, Naperkowski A, Oren J, Storm R, Ellenbogen KA. Adenosine facilitates dormant conduction across cavotricuspid isthmus following catheter ablation. Heart Rhythm. 2012;9(11):1785-1788. doi:10.1016/j.hrthm.2012.07.008

3. Kirchhof P, Camm AJ, Goette A, et al. Early rhythm-control therapy in patients with atrial fibrillation. N Engl J Med. 2020;383:1305-1316. doi:10.1056/NEJMoa2019422