Comparison of a Radiofrequency Powered Flexible Needle with a Classic Rigid Brockenbrough Needle for Transseptal Punctures in Terms of Safety and Efficacy

Comparison of transseptal puncture using a dedicated RF wire versus a mechanical needle with and without electrification in an animal model

INTRODUCTION

Mechanical force to achieve transseptal puncture (TSP) using a standard needle may lead to overshooting and injury, and can potentially be avoided using a radiofrequency (RF)-powered needle or wire. Applying electrocautery to needles and guidewires as an alternative to purpose-built RF systems has been associated with safety risks, such as tissue coring and thermal damage. The commercially available AcQCross needle-dilator system (Medtronic) features a sharp open-ended needle for mechanical puncture, as well as a built-in connector to enable energy delivery for RF puncture. This investigation compares the safety and efficacy of the AcQCross needle to the dedicated VersaCross RF wire system and generator (Baylis Medical/Boston Scientific).

METHODS

In an ex vivo porcine model, VersaCross wire punctures were performed using 1 s, constant mode (approx. 10 W) with maximum two attempts. AcQCross punctures were performed by applying energy for 2 s using a standard electrosurgical generator at 10 W (max. five attempts), 20 W (max. two attempts), and 30 W (max. two attempts). Efficacy was assessed in terms of puncture success and a number of energy applications required for TSP. Safety was assessed quantitatively as force required for TSP, energy required to puncture, and incidence of tissue coring, as well as by qualitative assessment of puncture sites. Additional qualitative observation of tissue cores and debris were obtained from TSP performed in live swine.

RESULTS

RF TSP was 100% successful using the VersaCross wire with 1.0 ± 0.0 attempts. When power was used with the AcQCross needle, it failed to puncture at low (10 and 20 W) power settings; TSP was achieved with 30 W of energy with 91% success using 1.53 ± 0.51 attempts (p < .05 vs. VC) with greater variability (F1,33  = 9223.5, p < .0001). Compared to RF puncture using the VersaCross system, mechanical puncture, alone, using the AcQcross needle required six times more force (8 mm additional forward device displacement) to perforate the septum. Qualitative assessment of puncture sites revealed larger defects and more tissue charring with the AcQCross needle at 30 W compared to punctures with VersaCross wire. Tissue coring with the open-ended AcQCross needle was observed in vivo and measured to occur in 57% of punctures using the ex vivo model; no coring was observed with the closed-tip VersaCross wire.

CONCLUSIONS

The AcQCross needle frequently required higher energy of 30 W to achieve RF TSP and was associated with tissue coring and charring, which have been, previously, reported when electrifying a standard open-ended mechanical needle or guidewire. These findings may limit safety and effectiveness compared to the VersaCross system.

Comparing the safety and effectiveness of dedicated radiofrequency transseptal wires to electrified metal guidewires

Background

Application of electrocautery to a metal guidewire is used by some operators to perform transseptal puncture (TSP). Commercially available dedicated radiofrequency (RF) guidewires may represent a better alternative. This study compares the safety and effectiveness of electrified guidewires to a dedicated RF wire.

Methods

TSP was performed on freshly excised porcine hearts using an electrified 0.014″ or 0.032″ guidewire under various power settings and was compared to TSP using a dedicated RF wire with 5 W power (0.035″ VersaCross RF System, Baylis Medical). The primary endpoint was the number of attempts required to achieve TSP. Secondary endpoints included the rate of TSP failure, TSP consistency, the effect of the distance between the tip of the guidewire and the tip of the dilator, and effect of RF power output level. Qualitative secondary endpoints included tissue puncture defect appearance, thermal damage to the TSP guidewire or dilator, and tissue temperature using thermal imaging.

Results

The RF wire required on average 1.10 ± 0.47 attempts to cross the septum. The 0.014″ electrified guidewire required an overall mean of 2.17 ± 2.36 attempts (2.0 times as many as the RF wire; p < .01), and the 0.032″ electrified guidewire required an overall mean of 3.90 ± 2.93 attempts (3.5 times as many as the RF wire; p < .01). Electrified guidewires had a higher rate of TSP failure, and caused larger defects and more tissue charring than the RF wire. Thermal analysis showed higher temperatures and a larger area of tissue heating with electrified guidewires than the RF wire.

Conclusion

Fewer RF applications were required to achieve TSP using a dedicated RF wire compared to an electrified guidewire. Smaller defects and lower tissue temperatures were also observed using the RF wire. Electrified guidewires required greater energy delivery and were associated with equipment damage and tissue charring, which may present a risk of thrombus, thermal injury, or scarring.

The transseptal puncture experience: Safety insights from FDA MAUDE database

BACKGROUND

There is a paucity of literature on safety and efficacy of various transseptal puncture (TSP) needles.

OBJECTIVES

To assess the reported mechanisms of failure, complications, and outcomes among the most frequently used transseptal needles in the United States.

METHODS

We queried the Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database between January 2011 and January 2021 for reports on the most commonly used transseptal needles: NRG (Baylis Medical, Montreal, Canada), and BRK (St. Jude, Saint Paul, MN)]. The primary outcome was the mechanism of failure. Secondary outcomes included clinical consequences of device failure.

RESULTS

The final analysis included 306 reports of failure/complication with TSP needles (NRG n = 70, BRK n = 236). The most commonly reported mode of failure was detachment of the needle component (i.e., clip, hub, stopcock, shaft, spring, or needle tip) (14.7% overall; 17.8% BRK; and 4.3% NRG). Among these reports, cardiac perforation was the most common complication (69.9% overall; 69.1% for BRK; and 72.9% for NRG). Pericardiocentesis was the second most commonly reported complication (45.1% overall; 48.3% for BRK; and 34.3% for NRG). The procedure was successfully completed in 33.3% of all cases (36.4% for BRK and 22.9% for NRG), while surgical conversion was needed in (13.4% overall; 14% for BRK and 11.4% for NRG) of the reports. Death occurred in 3.9% of all cases overall (3.4% for BRK and 5.7% for NRG).

CONCLUSIONS

Needle detachment was the most common mode of failure, and cardiac perforation was the most common complication reported with TSP needles. Future efforts should focus on innovative TSP needle design, best practice guidelines, including role of imaging guidance, and increased TSP training.

Use of a radiofrequency guidewire to simplify workflow for left atrium access: a case series

PURPOSE

Transseptal puncture (TSP) is widely used in catheter-based cardiac procedures to gain left atrial access, but its workflow has remained largely unchanged in the last 50 years. This study evaluated the safety and efficacy of a novel, simplified technique for TSP with a radiofrequency (RF)-powered guidewire that eliminates multiple exchanges required with standard needles.

METHODS

TSP was performed in 84 patients undergoing left-sided procedures (72 atrial fibrillation ablations [32 RF, 40 cryoballoon], 4 atrial tachycardia ablations, 2 ventricular arrhythmia ablations, 6 left atrial appendage closure) utilizing a stiff, exchange length RF guidewire. Under fluoroscopic and echocardiographic guidance, the RF guidewire was used to facilitate septal puncture with RF energy and provide a rail for advancing catheters to the left atrium without exchange. All procedures were performed under general anesthesia or sedation.

RESULTS

TSP was achieved in all patients with no complications. The RF guidewire allowed catheters to be tracked back up to the superior vena cava without exchange in cases where another dropdown was desired to locate a preferred puncture site. The stiffness of the wire provided adequate support to advance all sheaths to the left side regardless of outer diameter.

CONCLUSION

TSP was performed safely and successfully for various left heart procedures with a RF guidewire that served as an RF transseptal device and a stiff guidewire. This allowed for a more efficient and potentially safer technique without the need for re-wiring or an over the wire sheath exchange. This provides substantial savings in both time and materials.

Off the pedal: Fluoroless transseptal puncture in pediatric supraventricular tachycardia ablation

BACKGROUND

Fluoroless transseptal (TS) puncture may represent the final step toward elimination of fluoroscopy in pediatric supraventricular tachycardia ablation in normal hearts. We aimed to demonstrate the safety and feasibility of fluoroless TS puncture in pediatric patients and compare procedural timing with the fluoroscopic approach.

METHODS

We performed a retrospective cohort analysis of all TS procedures performed without fluoroscopy at our institution; fluoroless TS procedures were performed under intracardiac echocardiography (ICE) guidance after the creation of a 3D electroanatomic map and identification of fossa ovalis (FO) on 3D map. TS procedure times reported are the time from sheath insertion (8.5F short sheath for ICE catheter and SL-1 for TS needle) to the time of confirmed left atrial access. Prior TS procedures performed by the same operator utilizing a combination of ICE and fluoroscopy and by a second operator utilizing fluoroscopic guidance alone were used for comparison.

RESULTS

Fluoroless TS puncture was performed in nine patients (mean age 13.8 years); the site of TS puncture was within 2 mm of the FO identified on the EA map. The mean TS procedure time was 22.2 minutes (range 10-45). There was no significant difference in TS procedure times between the three groups. There were no complications related to any TS procedure.

CONCLUSION

Fluoroless TS procedures utilizing ICE can safely be performed in pediatric patients without adding substantial procedural times compared with those utilizing fluoroscopic guidance.

Transseptal puncture - Review of anatomy, techniques, complications and challenges

In recent years, the transseptal puncture approach has enabled passage of increasingly large and complex devices into the left atrium. Traditional tools remain effective in creating and dilating the initial puncture, with an acceptable safety profile. Even for skilled operators, the procedure is technically demanding and requires sound understanding of atrial anatomy. Intracardiac echocardiography is useful in cases of previous septal repair, poorly defined fossa ovalis anatomy or when considering patent foramen ovale portal crossing. Iatrogenic atrial septal defect (iASD) is the most commonly encountered long-term complication and there is increasing evidence that larger devices are leading to symptomatic defects. The size of the sheath crossing the septum is the strongest predictor of iASD formation but other factors such as longer procedure times, significant catheter manipulation and high pulmonary pressures also contribute. Transcatheter mitral valve repair involves the use of large 22 Fr catheters which carry alarmingly high rates of defect persistence with precipitation of symptoms and possible influence on mortality. Long-term follow up data, particularly beyond the 12-month period are lacking and resultantly, evidence to guide management is sparse. Refinements of conventional instruments, as well as innovations to puncture the septum without mechanical pressure, herald a progressively safer future for the transseptal technique.

Novel Solutions Applied in Transseptal Puncture: A Systematic Review

Access to the left atrium is required for several minimally invasive cardiac interventions in the left heart. For this purpose, transseptal puncture (TSP) technique is often performed, perforating the atrial septum under fluoroscopic or/and ultrasound imaging guidance. Although this approach has been used for many years, complications/failures are not uncommon mainly in patients with abnormal atrial anatomy and repeated TSP. Thus, this study presents an overview of methods and techniques that have been proposed to increase the safety and feasibility of the TSP. A systematic review of literature was conducted through the analysis of the articles published between 2008 and 2015. The search was performed in PubMed, Scopus, and ISI Web of Knowledge using the expression “transseptal puncture.” A total of 354 articles were retrieved from the databases, and 64 articles were selected for this review. Moreover, these 64 articles were divided into four categories, namely: (1) incidence studies, (2) intraprocedural guidance techniques, (3) preprocedural planning methods, and (4) surgical instruments. A total of 36 articles focused on incidence studies, 24 articles suggested novel intraprocedural guidance techniques, 5 works focused on preprocedural planning strategies, and 21 works proposed surgical instruments. The novel 3D guidance techniques, radio-frequency surgical instruments, and pre-interventional planning approaches showed potential to overcome the main procedural limitations/complications, through the reduction of the intervention time, radiation, number of failures, and complications.