Introduction

Epicardial access (EA) through subxiphoid puncture,¹ using an exposed large-bore needle can be challenging and carries significant risk of serious adverse events, including right ventricle (RV) free-wall puncture as the most common, resulting in significant pericardial bleeding.^2-4 Many variations have been proposed, including different needles and approaches to the pericardial space with improved safety,^5-7 but the risk of complications related to EA has not been eliminated completely. With conventional technique, a needle is pushed forward through the tough fibrous pericardium to enter the space. The inward-moving needle creates forward momentum and shearing forces, potentially injuring the RV and causing complications. This study evaluates feasibility of EA with a novel blunt-tip concealed-needle device (BTCND) that pulls the parietal pericardium outward away from the RV, facilitating a safe entry into the pericardial space, minimizing the risk of injury.

Methods

This is a prospective, single-arm, single-center, first-in-human feasibility study ( NCT05006157) in 11 human subjects. The study was approved by appropriate local ethics committees and national competent authorities. Written informed consent is obtained from all participants before initiation of study procedures.

Device description

The BTCND ViaOne (CardioVia) comprises a handle that houses the device controllers, a mechanical pulsatile pressure indicator (position indicator), and a procedure-status window. The patient-contacting elements include, from the innermost to the outermost part, a 1.1-mm inner diameter lancet needle, a stainless-steel spring-assisted telescopic tube (engagement element tube) featuring a rotatable serrated disk (engagement element) structure at its distal end to capture the parietal pericardium, a stainless-steel tube terminating with 3 petals to hold the retracted pericardial tissue (inner tube), and a 146-mm–long stainless-steel tube (leading channel) to pave the path to the pericardium. An inner lumen passing through the fixated concealed needle allows for guidewire insertion into the pericardial sac. A detailed description of the device components is presented in Supplemental Figure 1.

Epicardial access technique

All procedures were performed under general anesthesia. Figure 1 demonstrates the steps involved. 1) After sterile preparation and draping, a 3-mm skin incision was made before the tool insertion. The channel entry was typically 2 to 3 cm below and slightly lateral to the xiphoid process. 2) A 4-5 cm–long leading channel was created with a blunt steel tunneling tool (length 14.8 cm, outer diameter 3.78 mm, placed inside an 11-F peel-away sheath) in the left lateral fluoroscopic view. Slow, deliberate movement of the tunneling tool is continuously monitored under fluoroscopy, staying coaxial to the sternal plate to guide directionality. The channel was directed over the diaphragm dome toward the mid-left clavicle, aiming at the anterior cardiac silhouette. Care was taken to avoid entering abdominal cavity or surrounding soft-tissue structures. The tip of the tunneling tool was brought in close proximity to the cardiac border and then withdrawn, leaving the peel-away sheath next to the pericardium. 3) One mL of contrast material was then injected into the peel-away sheath to visualize the created channel and introduce BTCND. 4) Once the leading channel of the device exited the sheath, the inner tube was exposed, the engagement element tube was shifted forward, and the device was gently advanced until a pulsating movement of the position indicator was observed or sensed by the operator; the engagement element was then rotated to grab a small portion of the pericardial sac. 5) The captured parietal pericardium was pulled outward into the inner tube away from the RV while visualizing under fluoroscopy and punctured with the fixated concealed needle. These steps are repeated if the initial attempt was unsuccessful. 6) A 0.035-inch guidewire is introduced through the needle into the pericardial space. All systemic anticoagulants were stopped for appropriate duration, but antiplatelet agents were continued before the procedure (Videos 1A and 1B).

Endpoints and definitions

The primary endpoint is the rate of successful pericardial space access. The secondary endpoint is the incidence of the device and procedure-related adverse events. All adverse events are recorded and assessed for relatedness to the investigational device or the procedure.

Statistical analysis

For analysis, we used descriptive statistics, including mean, median, SD, and extreme values. Differences among subgroups were assessed using nonparametric Mann-Whitney U test.

Results

Eleven subjects (3 women, 8 men) with a mean age of 56 ± 16 years and ejection fraction of 38% ± 15% were enrolled. EA was needed for ventricular tachycardia (VT) ablation in 9 subjects and displace the right phrenic nerve away with a balloon for right atrial arrhythmia in 1 subject. One additional subject had EA for mapping and ablation for recurrent left atrial arrhythmia after previous ablations. Detailed demographic and clinical characteristics are presented in Supplemental Table 1. Successful EA was attained in 91% (10 of 11), and no significant secondary adverse events were noted. In 1 subject, even though epicardial space was entered, the guidewire could not be further advanced because of adhesions. There were no device-related complications. There was clinically insignificant blood-tinged pericardial effusion (<80 mL; hematocrit 15%) related to ablation and catheter manipulation while attempting to break the adhesions during VT ablation in 1 subject.

Discussion

This is the first limited human experience of successful use of BTCND for EA without significant safety issues. Since the introduction of Sosa’s technique,¹ EA complications range from 5% to 14%,² with the risk of inadvertent RV puncture, acute hemopericardium, and tamponade reaching 17%, 11%, and 6%, respectively.³ Several modifications have been proposed that aim to reduce these risks, including—among others—the anterior approach,⁴ use of a micropuncture needle,⁵ CO₂ insufflation,⁶ or needle with pressure monitoring.⁷ With BTCND, the outer blunt portion sites outside pericardium and the inner grasper pulls pericardial tissue away from the RV, creating a small space, and the concealed- needle punctures the pulled tissue, allowing the guidewire to pass into the pericardial space. The method by which the access device interacts with the pericardium is depicted in the Central Illustration.

With the Sosa approach, a large bore (15-gauge) needle is pushed forward toward the pericardium. Force exerted at the point of penetration of the tough fibrous parietal pericardium can create substantial forward momentum, leading to the needle tip encountering the RV wall, thereby causing a complication. Subsequently, this approach has been modified to use a micropuncture needle (21-gauge) technique with a smaller tip that can penetrate the pericardium more easily and lower risk of RV tear and related complications.⁵ CO₂ insufflation has the added benefit of increasing the size of the space being accessed and identifying pericardial adhesions before access attempts. Adhesions were a limitation in our series as well. The BTCND investigational device makes use of a needle that is fixated and concealed throughout the entire length of the procedure, puncturing the parietal pericardial layer retracted into the device rather than pushing forward toward the heart. The investigational device also brings the tissue to the needle and away from the heart muscle and accompanying blood vessels, potentially reducing EA risk.

Study limitations

This is a small single-center feasibility study whose results need to be validated in a larger population.

Conclusions

Epicardial access with a novel concealed-needle blunt-tip device appears to be feasible and safe in this early human experience.

Footnotes