Introduction
While ablation procedures in both adult and pediatric populations have high success rates and relatively low risk of significant complications [1,2,3], pediatric procedures pose additional technical challenges due to smaller size and unique congenital heart disease (CHD) [4]. Unintended catheter movement during ablation procedures can risk creating unwanted lesions or intracardiac injuries especially during ablations performed close to the compact atrioventricular (AV) node such as cases of septal accessory pathways or AV-nodal re-entrant tachycardia (AVNRT) [3, 5, 6]. The complication rate for catheter ablation procedures has been documented between 1 and 6% in adult patients [7,8,9] with more complex ablations resulting in higher complication rates. Likewise, infants, children, and patients with both repaired and unrepaired CHD may present as more complex cases due to the smaller distance between vital structures, unusual anatomy, and unpredictable location of the AV node in certain congenital heart lesions.
Poor ergonomics of current ablation catheters and ablation techniques create an additional potential risk due to operator muscle fatigue and catheter tip instability. Most electrophysiology and ablation catheters used in standard procedures are small in size (1–3 mm diameter) and require manual catheter manipulation several feet from the catheter tip. Lengthy ablation procedures that require multiple lesions may lead to an increase in operator muscle fatigue from repeated intense muscle usage. This can lead to a decline in performance throughout the procedure [10] and increase the risk of instability. Catheter stability has been directly correlated to the success of cardiac ablation procedures as well as the length of the procedure [11, 12]. Improved catheter stability and reduced operator fatigue has the potential to increase procedural efficacy, reduce anesthesia time, and decrease the risk of complications.
Some groups have attempted to improve catheter stability with remote navigation systems [13, 14]; however, increased procedure times and high start-up costs [15] have led to manual manipulation remaining the preferred method despite the risks of instability. We have previously described a novel catheter torque tool (Fig. 1) that securely attaches to the exterior of electrophysiology and ablation catheters ranging in size from 3 to 9 French. This tool is placed near the insertion point and provides a larger surface area and diameter for gripping the catheter, reducing the force necessary to torque the catheter and improving the translation of rotation applied without damaging the electrical integrity [16]. The tool is intended to be operated by the physicians left hand (though it can be used by either hand), while the right hand remains on the catheter handle as with typical catheter use (Fig. 2). The objective of this study is to evaluate usage of the catheter torque tool with regard to skeletal muscle fatigue and user experience during a simulated electrophysiology study and ablation procedure.