Access to the left atrium for delivery of radiofrequency ablation in young patients: retrograde aortic vs transseptal approach

Electroanatomic mapping-guided pediatric catheter ablation with limited/zero fluoroscopy

Objective:

The use of fluoroscopy in pediatric catheter ablation has decreased because of mapping systems. In this study, we present the efficiency and reliability of the electroanatomic mapping system in nonfluoroscopic pediatric catheter ablation.

Methods:

The medical records of patients aged <18 years who underwent ablation between November 2016 and April 2018 were evaluated. Fluoroscopy was not used in cases involving ablation of right sided-arrhythmia foci. Fluoroscopy was used only for trans-septal puncture or retroaortic approach/coronary angiography.

Results:

A total of 76 patients underwent catheter ablation for 78 supraventricular and ventricular tachyarrhythmia substrates under the guidance of EnSite Velocity system. Fluoroscopy was used in only 14 (18.4%) of these substrates. The mean fluoroscopy duration in these 14 procedures was 5.4±3.15 min. No complications were noted, except a temporary right bundle branch block in one patient and pericardial effusion in another following cryoablation. The acute success rate in achieving complete elimination of arrhythmia substrates was 97.4% (76/78). The recurrence rate was 5.1% (4/78) at follow-up.

Conclusion:

Fluoroscopy can be completely eliminated in most pediatric catheter ablation procedures with the use of mapping systems by achieving high acute success rates and acceptable low complication rates.

Transseptal Puncture for Catheter Ablation in Children

Transseptal puncture (TP) is used in pediatric patients to access the left atrium in left-sided arrhythmia catheter ablation. Performing this procedure can be difficult and risky, especially in small children. In this study, we aimed to evaluate the safety and feasibility of TPs in children ≤ 30 kg. Between April 2012 and April 2018, a retrospective evaluation was conducted of the clinical features, procedural outcomes, and follow-ups of ≤ 30 kg pediatric patients who required TPs for left-sided ablations at a pediatric electrophysiology center in which a three-dimensional mapping system was routinely used. A total of 45 pediatric patients who were ≤ 30 kg, underwent TPs: 10 patients ≤ 20 kg (Group 1) and 35 patients > 20 kg and ≤ 30 kg (Group 2). The TP success rate was 97.8%. The median procedure and fluoroscopy times were 120 min and 5.43 min, respectively. One patient developed self-limited pericardial effusion during the procedure; however, there were no incidences of cardiac tamponade. There was no significant difference between the two groups in terms of the procedure time and fluoroscopy time, and pericardial effusion was only observed in Group 2. TPs are safe and feasible in small children. These procedures can be performed with low complication rates in children weighing ≤ 30 kg.

Transseptal or retrograde approach for transcatheter ablation of left sided accessory pathways: a systematic review and meta-analysis

BACKGROUND

Transcatheter ablation is the most effective treatment for patients with symptomatic or high-risk accessory pathways (AP). At present, no clear recommendations have been issued on the optimal approach for left sided AP ablation. We performed this meta-analysis to compare the safety and efficacy of transaortic retrograde versus transseptal approach for left sided AP ablation.

METHODS AND RESULTS

MEDLINE/PubMed and Cochrane database were searched for pertinent articles from 1990 until 2016. Following inclusion/exclusion criteria application, 29 studies were selected including 2030 patients (1013 retrograde, 1017 transseptal) from 28 observational single Centre studies and one randomized trial. Patients approached by transseptal puncture presented a significantly higher acute success (98% vs. 94%, p = 0.040). The incidence of late recurrences (p = 0.381) and complications (p = 0.301) did not differ among the two groups, but the pattern of complications differed: vascular complications were more frequent with transaortic retrograde approach, while cardiac tamponade was the main transseptal complication. No difference was noted in terms of procedural duration and fluoroscopy time (p = 0.230 and p = 0.980, respectively). Meta-regression analysis showed no relation between year of publication and acute success (p = 0.325) or incidence of complications (p = 0.795); additionally, no direct relation was found between age and acute success (p = 0.256) or complications (p = 0.863).

CONCLUSIONS

Left sided AP transcatheter ablation is effective in around 95% of the cases, with a very limited incidence of complications. Transseptal access provides higher acute success in achieving AP ablation; late recurrences are rare but observed similarly following both approaches. Retrograde approach is affected by a relatively high incidence of vascular complications.

Transseptal puncture for radiofrequency catheter ablations of left-sided arrhythmias in a paediatric population

Puncturing the atrial septum is frequently used in adults. In children, the transseptal puncture is less common, technically more demanding, and the rate of complications is not well described. We studied the feasibility and safety of this procedure in a retrospective analysis of 157 consecutive children undergoing transseptal puncture for radiofrequency catheter ablation of left atrial targets in two tertiary-care centres between 2005 and 2013. The median age of the patients at intervention was 12.5 years (1.1-18 years), with median weight of 42 kg (range 9.0-97.0 kg). Pre-excitation was found in 102 procedures, accessory pathway with exclusively retrograde conduction in 41, focal atrial tachycardia in nine, left-sided permanent junctional/reciprocating tachycardia-like accessory pathways in three, and atypical atrioventricular nodal re-entry tachycardia in two. All the procedures were guided by fluoroscopy. Additional imaging by transoesophageal echocardiography was used in three patients. Successful transseptal puncture was possible in 99.4% of the cases, ablation in 97.4%. The median time, including mapping and radiofrequency ablation, was 120 minutes (range 60-450), the median fluoroscopy time 10.8 minutes (range 1.8-75), and the median radiation dose 3 Gy cm2 (range 0.3-35). In total, five patients (3.2%) had a recurrent arrhythmia during the observation period of a median of 40 months (range 1-103). No complications associated with the transseptal puncture were observed. Transseptal puncture is a feasible and safe procedure in children. This access allows successful and efficient radiofrequency ablation of arrhythmia of the left atrium in the vast majority of the patients and might be considered as the first-line approach in this population.

Transseptal access in pediatric and congenital electrophysiology procedures: defining risk

PURPOSE

Transseptal puncture (TSP) is commonly used to access the left heart for catheter ablation procedures. The specific complication risk of this procedure has not been determined. This study assesses the risk of TSP using a single standard technique during electrophysiology study (EPS) in pediatrics and congenital heart disease (CHD).

METHODS

Retrospective cohort study of patients undergoing TSP during EPS at the University of Michigan Congenital Heart Center between 1999 and 2011.

RESULTS

There were 373 left heart ablation procedures during the study period. Excluded were six adults without CHD, five procedures using an alternative imaging modality, five procedures using retrograde aortic access, one transhepatic access, and one where TSP was performed during a prior procedure. Included were 321 pediatric (≤18 years old without CHD) TSP procedures (median age 13 years) and 34 TSP procedures in patients with CHD (median age 28 years). There was one complication directly attributable to TSP: needle perforation of the left atrium without development of effusion in the pediatric group. Post-procedure echocardiograms were performed in 351 (99 %) cases, showing only trivial effusions in seven (1.9 %).

CONCLUSIONS

This single center experience over 12 years shows the risk of TSP in pediatric and CHD patients to be low, with a 0.3 % (95 % confidence interval (CI) 0, 0.9 %) risk for complications directly related to TSP using only single plane fluoroscopy for visualization.

Limiting left-sided catheter dwelling time using 3-D NavX to mark and reaccess the left atrium via prior transseptal puncture site

INTRODUCTION

Ablations requiring transseptal access to the left heart place patients at increased risk for stroke, bleeding, and post-procedural cognitive dysfunction and other complications. Diminishing left atrial catheter dwelling time may decrease these risks. 3-D NavX can be used to facilitate reaccess of transseptal puncture sites to allow catheter removal from the left atrium immediately after ablation, with reaccess through the prior transseptal site if required. Here, we describe the techniques employed and our experience using 3-D NavX to limit left atrial catheter dwelling time by marking and reaccess of the left atrium via the previously marked transseptal puncture site, a potentially radiation-free technique.

METHODS

With the use of 3-D NavX, a right atrial geometry is created. The patent foramen ovale is marked by using a standard EP catheter, or the transseptal puncture site is marked using 3-D NavX by creating a unipolar electrode on the transseptal needle at the time of puncture and at the time of catheter withdrawal of the ablation catheter from the left atrium. Marking the access site allows the catheter to be removed from the left side of the heart immediately after the ablation. If reaccess to the left atrium is required, the previously marked transseptal site is used to navigate the ablation catheter to reaccess the left atrium. All patients <30 years who had undergone this technique were evaluated. Data gathered included patient demographics, need for and success of transseptal reaccess, left atrial catheter dwelling time, and complications.

RESULTS

The transseptal site was marked by 3-D NavX in 54 patients. We were able to successfully reaccess the transseptal puncture site using 3-D guidance in all 10 patients where it was desired. In these 54 patients, the complication rate was low with one small post-procedural pulmonary embolism and one right bundle branch block. No other complications were noted. The median procedure time was 105 min (range 58-446 min), the median total fluoroscopic time for the entire procedure was 1.3 min (range 0.0-30.8 min), and the median left-sided catheter dwelling time was 21 min (range 6-112 min).

CONCLUSIONS

In our retrospective review, reaccess of transseptal puncture site was reproducible, and early removal of the catheter from the left side was without the need for repeat transseptal punctures. This technique decreases the time the catheter dwells in the left atrium, which could decrease risks such as clotting, bleeding, and cognitive dysfunction.

Retrograde catheterization of the right heart in patients with occluded femoral veins

BACKGROUND

Occlusion of the femoral veins is a frequent complication of cardiac catheterization in small children. If the venous femoral approach is not available, a jugular approach is generally used for catheterization of the right heart.

AIMS

To describe and evaluate an alternative retrograde approach for catheterization of the right heart in small children with a ventricular septal defect or single ventricle.

METHODS

Between January 2004 and January 2007 we attempted retrograde catheterization of the right heart via the femoral artery using a 4 French sheath in eight children with occluded femoral veins. The procedure was planned under awake sedation.

RESULTS

Median age was five months (range 4-60) and median weight was 5 kg (range 4-10). Diagnoses were as follows: single ventricle (n = 6); pulmonary atresia and ventricular septal defect (n = 1); complex transposition of the great arteries (n = 1). The procedure was successful in six patients, enabling measurement of pulmonary arterial pressure and pulmonary angiography. The procedure was abandoned in two patients because of ventricular arrhythmias. One patient had concomitant dilatation of aortic recoarctation and one had embolization of aortopulmonary collaterals. With the exception of transient ventricular arrhythmias, no acute or late complications occurred. In particular, transient or permanent atrioventricular block, occurrence of new aortic insufficiency, and acute or late thrombosis of the femoral artery were not observed.

CONCLUSION

Retrograde catheterization of the right heart in small children is feasible and relatively safe. This technique can be performed without general anaesthesia and avoids a jugular approach.

Magnetic Navigation in Left-Sided AV Reentrant Tachycardias: Preliminary Results of a Retrograde Approach

INTRODUCTION

A novel magnetic navigation system allows remote guidance of floppy radiofrequency (RF) ablation catheters. We evaluated the feasibility of mapping and ablation of left-sided accessory pathways (APs) using the retrograde transaortic approach with this system. This might open the gate to retrograde ablation of left atrial arrhythmias.

METHODS AND RESULTS

Twenty consecutive patients were included. A Helios II was used in five and in 15 a Celsius RMT RF catheter with higher magnetic mass and different flexibility was used. Mapping and ablation were attempted. The learning curve was analyzed. Ablation was acutely successful in 60% of the patients using the Helios II and in 80% using the Celsius RMT. Median procedure time was 158 minutes, with median patient and physician fluoroscopy times of 26 and 4 minutes. In the last 10 patients, procedure times became significantly shorter (median 122 minutes, only Celsius RMT catheters) and standard catheters had to be used only twice. No complications occurred.

CONCLUSIONS

Remote retrograde transaortic RF ablation of left-sided APs is feasible, safe, and reduces the physician's fluoroscopy exposure. There is a very steep initial learning curve, with the success rate increasing from 50% in the first 10 cases to 80% in the last 10 cases. Different catheter configurations may influence the outcome.