Extracardiac Fontan fenestration using the SafeSept transseptal guidewire and snare-controlled diabolo-shaped covered-stent placement

Extra-cardiac and complex Fontan baffle fenestration using radio frequency current via surgical electrocautery

BACKGROUND

Fontan baffle punctures and creation of Fontan fenestration for cardiac catheterisation procedures remain challenging especially due to the heavy calcification of prosthetic material and complex anatomy.

OBJECTIVES

We sought to evaluate our experience using radiofrequency current via surgical electrocautery needle for Fontan baffle puncture to facilitate diagnostic, electrophysiology, and interventional procedures.

METHODS

A retrospective chart review of all Fontan patients (pts) who underwent Fontan baffle puncture using radiofrequency energy via surgical electrocautery from three centres were performed from January 2011 to July 2021.

RESULTS

A total of 19 pts underwent 22 successful Fontan baffle puncture. The median age and weight were 17 (3-36 years) and 55 (14-88) kg, respectively. The procedural indications for Fontan fenestration creation included: diagnostic study (n = 1), atrial septostomy and stenting (n = 1), electrophysiology study and ablation procedures (n = 8), Fontan baffle stenting for Fontan failure including protein-losing enteropathy (n = 7), and occlusion of veno-venous collaterals (n = 2) for cyanosis. The type of Fontan baffles included: extra-cardiac conduits (n = 12), lateral tunnel (n = 5), classic atrio-pulmonary connection (n = 1), and intra-cardiac baffle (n = 1). A Fontan baffle puncture was initially attempted using traditional method in 6 pts and Baylis radiofrequency trans-septal system in 2 pts unsuccessfully. In all pts, Fontan baffle puncture using radiofrequency energy via electrocautery needle was successful. The radiofrequency energy utilised was (10-50 W) and required 1-5 attempts for 2-5 seconds. There were no vascular or neurological complications.

CONCLUSIONS

Radiofrequency current delivery using surgical electrocautery facilitates Fontan baffle puncture in patients with complex and calcified Fontan baffles for diagnostic, interventional, and electrophysiology procedures.

A North American, single-center experience implanting fenestrated atrial devices and atrial flow regulators into a heterogeneous group of pediatric pulmonary hypertension patients

INTRODUCTION

The clinical deterioration commonly experienced by pediatric patients with pulmonary arterial hypertension (PAH) has motivated a shift in the treatment of pulmonary hypertension (PH) through innovations in surgical salvage interventions. The Occlutech fenestrated atrial septal defect (FASD) Occluder and the atrial flow regulator (AFR), which provides a protective, atrial-level shunt during hypertensive crises, have found an important role in treating pediatric patients with PAH. Other groups of pediatric patients with PH may also benefit from a similar protective physiology. The primary aim of this work is to present a single center's experience with AFR and FASD devices for managing a heterogeneous group of pediatric PH patients. A secondary goal is to identify hemodynamic changes and complications following device implantation.

MATERIALS AND METHODS

We performed a retrospective review of all pediatric PH patients who, after being found suitable, either successfully or unsuccessfully received an FASD or AFR device between January 2015 and December 2021 at the Stollery Children's Hospital in Edmonton, Canada.

RESULTS

Fourteen patients (eight female) with a median age of 4.6 (range 0.3-17.9) years and a median body mass index of 15.1 (Q₁ = 13.8, Q₃ = 16.8) kg/m² underwent device implantation: five received FASDs, eight received AFRs, and one was ultimately unable to receive an implant due to thrombosed iliac vessels and required surgical intervention. Of the fourteen patients, seven were in group 1 (PAH), one was in group 3 (lung disease), and six were in group 5 (primarily pulmonary hypertension vascular disease) under the World Symposium PH classification. All patients were on mono-, dual-, or triple-drug PH therapy. Device stabilization was not possible for two patients, who then required a repeat catheterization. Of the group 1 patients, three AFR and three FASD implants were successful, while one FASD implant was unsuccessful due to thrombosed vessels. At a six-month clinical assessment, all group 1 patients had patent devices and improved WHO FCs.

CONCLUSION

This work presents a single center's experience with AFR and FASD implants in a heterogeneous group of fourteen pediatric patients with severe PH. This treatment strategy is novel in the pediatric population and so this work provides momentum for future studies of interventional cardiac catheterization procedures for pediatric patients with PH. Further collaborations are required to develop criteria to identify ideal pediatric candidates and optimally time interventions in order to maximize the benefits of this treatment.

Usefulness of a Radiofrequency Transseptal Needle in the Second Puncture of Fontan Extracardiac Conduit

We performed a second puncture of the extracardiac conduit in an 11-year-old Fontan patient to assess the patency of the stent previously deployed in the left pulmonary vein. For the first puncture, a mechanical Brockenbrough needle was selected to puncture the Gore-Tex conduit, an electrical insulator. For the second puncture, the location of that previous hole was detected as an indentation covered with atrial tissue, which is an electrical conductor. The second puncture was performed safely using a radiofrequency transseptal needle.

New developments in catheter ablation for patients with congenital heart disease

Introduction: There are numerous challenges to catheter ablation in patients with congenital heart disease (CHD), including access to cardiac chambers, distorted anatomies, displaced conduction systems, multiple and/or complex arrhythmia substrates, and excessively thickened walls, or interposed material. Areas covered: Herein, we review recent developments in catheter ablation strategies for patients with CHD that are helpful in addressing these challenges. Expert opinion: Remote magnetic navigation overcomes many challenges associated with vascular obstructions, chamber access, and catheter contact. Patients with CHD may benefit from a range of ablation catheter technologies, including irrigated-tip and contact-force radiofrequency ablation and focal and balloon cryoablation. High-density mapping, along with advances in multipolar catheters and interpolation algorithms, is contributing to new mechanistic insights into complex arrhythmias. Ripple mapping allows the activation wave front to be tracked visually without prior assignment of local activation times or window of interest, and without interpolations of unmapped regions. There is growing interest in measuring conduction velocities to identify arrhythmogenic substrates. Noninvasive mapping with a multielectrode-embedded vest allows prolonged bedside monitoring, which is of particular interest in those with non-sustained or multiple arrhythmias. Further studies are required to assess the role of radiofrequency needle catheters and stereotactic radiotherapy in patients with CHD.

Creation of a defined and stable Fontan fenestration with the new Occlutech Atrial Flow Regulator (AFR®)

This report describes the first clinical experience with the new Occlutech Atrial Flow Regulator (AFR®) device for implementation of a late Fontan fenestration. The AFR® device secured a defined diameter of the fenestration without spontaneous re-occlusion of this extra-anatomic perforation. This ensured a permanent clinical improvement of our failing Fontan patient.

Utility and safety of the SafeSept™ transseptal guidewire for electrophysiology studies with catheter ablation in pediatric and congenital heart disease

PURPOSE

The atrial transseptal procedure is used in catheter ablation of left-sided arrhythmias. Studies in adult patients have shown the SafeSept™ transseptal guidewire (SSTG) to be effective in atrial transseptal procedures. We analyzed our 5-year experience with SSTG use in pediatric and congenital heart disease patients undergoing catheter ablation.

METHODS

This is a single-center retrospective analysis of patients undergoing catheter ablation from 2009 to 2014. We identified all procedures where SSTG was used for atrial transseptal or trans-baffle access. Success of transseptal access and complications were recorded and compared to the standard transseptal approach without the SSTG.

RESULTS

One hundred twenty-seven patients underwent 132 attempted atrial transseptal or trans-baffle procedures using SSTG. Median age was 14 (1.2-38) years. Arrhythmia substrates included AV reentrant tachycardia (90.2%), atrial tachycardia (4.5%), ventricular tachycardia (2.3%), and AV nodal reentrant tachycardia (2.3%). Transseptal or trans-baffle access was successful in 96.2% of the SSTG cases compared to 98.9% in the standard transseptal group without SSTG (p = NS). The youngest patient with successful atrial transseptal procedure using SSTG was 4 years old. SSTG was used to successfully cross a surgically created atrial baffle in a patient who had undergone the Mustard procedure. There was one major complication in both groups, 0.8% in the SSTG group compared to the standard transseptal group without SSTG, 1.1% (p = NS). The major complication in the SSTG group occurred when the SSTG crossed the aorta into the coronary artery system and mimicked placement in the left atrial appendage, with subsequent placement of a transseptal sheath into the aorta, requiring sternotomy and surgical intervention.

CONCLUSIONS

SSTG is effective for use in atrial transseptal and surgical trans-baffle access in pediatric and congenital heart disease patients. Placement of the SSTG into the pulmonary vein is necessary to avoid major complications, and if not achieved requires additional methods to determine appropriate left atrial placement.

Unusual method of creation of a transcatheter fenestration in an extracardiac conduit Fontan circulation

Failing Fontan physiology in univentricular hearts manifest with protein-losing enteropathy, plastic bronchitis, low cardiac output, and recurrent effusions. Transcatheter creation of fenestration in a failing Fontan may be useful in alleviating the symptoms by improving the cardiac output. It is traditionally achieved by puncturing through the conduit from femoral or jugular venous access. In the absence of good venous path, transhepatic access provides a direct route for needle puncture of the conduit. If marked intimal ingrowth into the conduit results in increasing rigidity and makes the conduit nonyielding, alternative approaches may be needed. A successful creation of pulmonary artery to atrial roof communication through the potential space of transverse sinus using a covered stent is presented.