Transseptal Access: A Review of Contemporary Tools

Development of an atrial transseptal puncture procedure in horses to access the left heart: An ultrasound-guided jugular vein and transhepatic approach

BACKGROUND

Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein.

OBJECTIVES

To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach.

STUDY DESIGN

In vivo experimental study.

METHODS

Transseptal puncture was performed in 18 horses admitted for euthanasia and donated for scientific research under general anaesthesia: using a jugular vein approach (10 horses), a transhepatic approach (2 horses) or both (6 horses). Radiofrequency energy was applied on a guidewire to perforate the FO and allow sheath advancement under intracardiac and transthoracic echocardiographic guidance. Puncture lesions were inspected post-mortem.

RESULTS

Transseptal puncture was successful in 17/18 horses, of which 15/16 jugular vein approaches and 5/8 transhepatic approaches. Failure was due to technical malfunction, inability to advance the guidewire toward the heart and inability to advance the sheath through the FO. Intracardiac echocardiography was essential to safely guide the puncture process. Atrial arrhythmias caused by the TSP occurred in 13/18 horses. Puncture lesions were found in the right atrium in the FO region, and left atrium ventral to pulmonary vein ostium III.

MAIN LIMITATIONS

Because in several horses two approaches were tested consecutively, it cannot be excluded that the second TSP was performed at the previous puncture site. Due to the developmental nature of the study the approaches were not randomised and did not allow comparison.

CONCLUSION

Transseptal puncture is feasible in horses using ultrasound guidance and allows for electrophysiological exploration of the left heart. Further studies are needed to evaluate post-operative follow-up.

Needle-free atrial transseptal access: A safe and reproducible alternative for left atrial catheterization

Background

Left atrial catheterization is a common procedure in electrophysiology labs to treat arrhythmogenic substrates on the left side of the heart. Needle transseptal puncture is the standard approach, but it can lead to complications related to device design or operator technique. To reduce these complications, needle-free alternatives have been explored.

Objective

This study aims to report the first multicenter application of the needle-free transseptal access (NeFTA) approach, assessing its safety and efficacy in patients undergoing electrophysiological procedures.

Methods

This retrospective, observational multicenter study evaluated the safety and efficacy of the NeFTA approach in patients undergoing ablation of left arrhythmogenic substrates across 3 electrophysiology centers in Mexico. NeFTA uses only a guidewire, without a needle or sharp guidewire. The sheath, with a dilator, is guided into the fossa ovalis under fluoroscopic guidance, using anterior force and clockwise torque to allow the guidewire to puncture the septum with minimal risk.

Results

The NeFTA technique was used in 366 patients. Most sheaths were deflectable, with nondeflectable sheaths in 43.4% of cases. Left atrial access via NeFTA was successful in 96.18% of cases, with pericardial effusion as the only complication (0.55% rate).

Conclusion

This technique was reproducible and safe, achieving successful access on the first or second attempt in 96.18% of cases, regardless of the operator.

Transprosthetic Fenestration With Electrified Wires. Experimental Evaluation of Three Multifilament Endografts

PURPOSE

In situ fenestration of aortic endografts is an alternative endovascular technique for treatment of complex aortic aneurysms. While this technique has been carried out also to pass stent-grafts in individual cases, its feasibility and safety using different stent-grafts needs to be evaluated.

METHODS

In a saline bath at water temperature of 37°C, a 0.018" Astato 30 guidewire was advanced through 3 different stent-grafts (RelayPro, Zenith and Endurant II) by applying external current of 180 W via an electrosurgery pencil. Puncture efficacy and quality of the fenestration after ballooning with a 6 mm percutaneous transluminal angioplasty (PTA) catheter were assessed. Then, balloon-expandable covered stents were deployed in the fenestrations and evaluated for stenosis, using microscopy and radiography.

RESULTS

Crossing of the electrified guidewire was instantaneous in the Zenith (n:10) and RelayPro (n:10) groups but not in 3 of 10 punctures in the Endurant group (p<.05). The fenestration area created after PTA was significantly larger in the RelayPro (5.3 mm2 ± 1.8, interquartile range [IQR] 1.6) and Zenith group (6.7 mm2 ± 0.7, IQR 0.5) compared to Endurant (2.3 mm2 ± 0.4, IQR 0.5, p<.001). Fraying was observed in all groups while graft shredding was found in 8 cases after PTA of the Zenith and Endurant endografts and in 5 of the RelayPro group, but the difference was not significant. Vertical tearing was detected after RelayPro (2 out of 10) and Zenith (6 out of 10) fenestrations, no damage was found in the Endurant group (p<.01). Residual stenosis at the level of the fenestration after implantation of a 6 × 79 mm VBX stent had to be corrected in all Endurant cases with a high-pressure PTA catheter. No stenosis was found in the RelayPro and Zenith groups before and after flaring.

CONCLUSIONS

The "electrified wire" technique is a feasible tool that can be used to perform in situ fenestration by perforation of the endograft fabric. Based on this experimental evaluation the "ideal graft" for this technique could not be identified. Long-term fatigue tests and comparison with other fenestration techniques are required.

CLINICAL IMPACT

In situ endograft fenestration can be a useful technique in emergent aortic repair. Recently, the electrified wire technique has been proposed as alternative option to laser, radiofrequency and needle-based techniques. In comparison to these methods, the use of electrified wires can be performed without modifications of routine equipment. Additionally, the material costs can be substantially reduced. However, the effectiveness of this approach for fenestration of different prosthetic grafts is unknown. Based on our experimental studies, the electrified wire technique is feasible but the Endurant endograft requires more attempts, and the placement of a bridging stent should be completed with high-pressure balloons.

Interventions for Pulmonary Vein Stenosis

Pulmonary vein stenosis (PVS) is a rare and unique disease of infants and young children. PVS is attended by high morbidity and mortality, and for many decades, effective therapy eluded the practitioner. However, in the most recent era, interventional techniques when employed in combination with systemic (primary) therapy have had a remarkable impact on outcomes in these at-risk children. Despite apparent complete relief of PVS in a discrete region of a pulmonary vein, stenosis reliably recurs and progresses. In this review, we discuss the current state-of-the-art interventional techniques, through the lens of our collective experiences and practices.

Integrated dilator-needle transseptal crossing device in atrial fibrillation cryoballoon ablation procedures

INTRODUCTION

In cryoballoon ablation (CBA) procedures, transseptal access (TSA) is generally achieved using a standard sheath and needle system that is exchanged for the cryoballoon delivery sheath and dilator over a long wire. Sheath exchange has been related with air embolic events. Recently, an integrated dilator-needle system assembled to the cryoballoon sheath was introduced. We aimed to evaluate the efficacy and safety of an integrated TSA tool compared with the traditional approach in atrial fibrillation CBA procedures.

METHODS

Patients scheduled for CBA procedures were randomized 1:1 to traditional TSA (t-TSA) or integrated TSA (i-TSA). TSA time was defined as time from superior vena cava to LA insertion of the cryoballoon delivery sheath, after sheath exchange (t-TSA) or directly (i-TSA).

RESULTS

Ninety-seven patients (76 males, mean age 59 ± 10 years) were randomized, 48 patients underwent t-TSA, and 49 i-TSA. Mean TSA time was 5 min 59 s ± 5 min 36 s in the t-TSA group and 2 min 59 s ± 2 min 14 s in the i-TSA group (p < .001). Total fluoroscopy time, skin-to-skin procedure time, and LA dwell time were respectively 15 ± 6, 69 ± 16, and 44 ± 12 min in the t-TSA group and 13 ± 6, 65 ± 15, and 43 ± 11 min in the i-TSA group (p = ns). No clinically significant acute complications related to TSA were noted in both cohorts.

CONCLUSION

This is the first randomized study comparing both TSA approaches. TSA in CBA procedures using this integrated tool enables a safe and efficient workflow, reducing TSA time and avoiding sheath exchange.

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.

Angioplasty Guidewire-Assisted vs. Conventional Transseptal Puncture for Left Atrial Appendage Occlusion: a multicentre randomized controlled trial

AIMS

This study was performed to compare the usability, efficiency, and safety of a modified angioplasty guidewire-assisted transseptal puncture (TSP) technique vs. the conventional approach in facilitating access into the left atrium during left atrial appendage occlusion (LAAO) procedures for the treatment of atrial fibrillation.

METHODS AND RESULTS

The ADVANCE-LAAO trial (Angioplasty Guidewire-Assisted vs. Conventional Transseptal Puncture for Left Atrial Appendage Occlusion) was an investigator-initiated, prospective, multicentre, randomized controlled trial (NCT05125159). Patients with atrial fibrillation who underwent LAAO were prospectively enrolled from four centres and randomly assigned to an angioplasty guidewire-assisted TSP group (n = 131) or to a conventional Brockenbrough needle TSP group (n = 132). The primary endpoint was the one-time success rate of TSP. We also analysed the TSP procedure time, failure rate of the assigned TSP type, radiation dose, contrast dose, and procedural complications in both groups. All patients in the guidewire-assisted group underwent successful TSP, whereas five in the standard conventional group switched to the guidewire-assisted approach. The guidewire-assisted puncture improved the one-time success rate (92.4 vs. 77.3%, P = 0.001), shortened the TSP procedure time (109.2 ± 48.2 vs. 120.5 ± 57.6 s, P = 0.023), and tended to have a higher rate of good coaxial orientation of the sheath with the left atrial appendage during the LAAO procedure (66.4 vs. 54.5%, P = 0.059). No TSP-related complications occurred in the guidewire-assisted TSP group, whereas two complications occurred in the conventional TSP group. There was no significant difference in the failure rate of the assigned TSP type, the total procedure time, the total radiation dose, the rate of successful LAAO implantation, or the procedural complication rate between the two groups (all P > 0.05).

CONCLUSION

This study confirmed that angioplasty guidewire-assisted puncture can effectively improve the success rate of TSP during LAAO procedures. This novel technique has high potential for application in interventional therapies requiring TSP.

Solving difficulties in transseptal sheath crossing: The shoehorn technique

The shoehorn technique is a simple and safe maneuver that can help to solve difficulties in challenging transseptal sheath crossing for atrial fibrillation cryoablation procedures.

Cardiac Tamponade with Transseptal Puncture: Cross with Care

Transseptal catheterization has become a routine part of left atrial interventional electrophysiologic procedures. This article is protected by copyright. All rights reserved.