Feasibility and safety of transseptal puncture procedures for radiofrequency catheter ablation in small children weighing below 30 kg: single-centre experience

Advancing the science of management of arrhythmic disease in children and adult congenital heart disease patients within the last 25 years

This review article reflects how publications in EP Europace have contributed to advancing the science of management of arrhythmic disease in children and adult patients with congenital heart disease within the last 25 years. A special focus is directed to congenital atrioventricular (AV) block, the use of pacemakers, cardiac resynchronization therapy devices, and implantable cardioverter defibrillators in the young with and without congenital heart disease, Wolff-Parkinson-White syndrome, mapping and ablation technology, and understanding of cardiac genomics to untangle arrhythmic sudden death in the young.

Transseptal approach for catheter ablation of left-sided accessory pathways in children with Marfan syndrome: A case report

BACKGROUND

Left-sided accessory pathways (APs) can be accessed with either a transaortic (TA) or transseptal approach (TS). For children with Marfan syndrome (MFS) who have aortic disease, the use of TA can aggravate the disease, making TS the best choice for these patients.

CASE SUMMARY

A 10-year-old girl was hospitalized because of intermittent heart palpitations and chest tightness. She was diagnosed with MFS, supraventricular tachycardia, Wolff-Parkinson-White syndrome, and left-sided AP was detected by cardiac electrophysiological. Catheter ablation was successfully performed via TS under the guidance of the Ensite system. During the follow-up, no recurrence or complications occurred.

CONCLUSION

The TS for catheter ablation of left-sided APs can be considered in children with MFS. Adequate evaluation and selection of the appropriate puncture site are particularly important.

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.

Percutaneous transhepatic and transseptal dilatation of a surgically implanted Melody® Valve in the mitral position in a 2-year-old child

The use of the Melody^® (Medtronic, Minneapolis, MN, USA) biological prosthesis in mitral position has shown acceptable short-term results. Furthermore, it allows its expansion with a balloon when the patient grows up, and this procedure can be performed by a venous catheterization through transseptal approach through an interatrial communication or puncturing the septum. Patients with complex congenital heart disease undergoing multiple surgical and percutaneous interventions may present with vascular complications such as thrombosis of the femoral venous system that make percutaneous access impossible. In this situation, the transhepatic approach is a very useful alternative to access the heart.

Transseptal Approach Versus Transaortic Approach for Catheter Ablation of Left-Sided Accessory Pathways in Children

BACKGROUND

Catheter ablation is recommended to eradicate supraventricular tachycardia caused by left-sided accessory pathways (APs) in children. This study aims to compare the safety and efficacy of the transseptal approach (TS) and aortic approach (TA) for catheter ablation of left-sided APs in a pediatric cohort.

METHODS

Patients < 18 years of age with left-sided APs who had undergone ablation at Beijing Children's Hospital between 13 January 2018 and 7 January 2020 were included and randomly categorized into either TS or TA group (follow-up for 22 months). In all, 60 patients in TS group and 41 patients in TA group were included in this study. Principal endpoints were success rate, recurrence rate, complications, procedure time, and radiation dose.

RESULTS

For TS group versus TA group, success rate was observed in 100 versus 97.56% (p = 0.402). The procedure time was 27.0 (32.0-23.0) versus 29.0 (38.0-24.5) min (p = 0.092). The rate of success or the procedure time was similar, but for the patients with Aps located in left posterior septum (LPS) or left posterior lateral (LPL), the TS group had a shorter procedure time compared with TA group (p < 0.01). The radiation dose was 28.0 (20.0-41.75) versus 0 mGy (p < 0.001). After successful ablation, no recurrence and complication were observed in either group.

CONCLUSION

Both TS and TA for catheter ablation of left-sided Aps were shown to be safe and effective in children. Zero radiation and ease of mastery make TA the preferred choice. TS is recommended to be used by properly trained medical professionals, especially for patient with AP localized in the LPL or LPS. However, TS is a good alternative where patients have aortic lesions or when TA fails.

Safety of Transseptal Puncture for Access to the Left Atrium in Infants and Children

Transseptal puncture (TSP) is a standard procedure to obtain access to the left heart. However, data on TSP in infants and children particularly with congenital heart defects (CHD) is sparse. Safety and efficacy of TSP in infants and children < 18 years with normal cardiac anatomy and with CHD were assessed. 327 TSP were performed in a total of 300 individuals < 18 years from 10/2002 to 09/2018 in our tertiary pediatric referral center. Median age at TSP was 11.9 years (IQR 7.8-15; range: first day of life to 17.9 years). 13 subjects were < 1 year. Median body weight was 43.8 kg (IQR 26.9-60; range: 1.8-121 kg). CHD was present in 28/327 (8.6%) procedures. TSP could be successfully performed in 323/327 (98.8%) procedures and was abandoned in 4 procedures due to imminent or incurred complications. Major complications occurred in 4 patients. 3 of these 4 subjects were ≤ 1 year of age and required TSP for enlargement of a restrictive atrial septal defect in complex CHD. Two of these babies deceased within 48 h after TSP attempt. The third baby needed urgent surgery in the cath lab. Pericardial effusion requiring drainage was noted in the forth patient (> 1 year) who was discharged well later. Minor complications emerged in 5 patients. The youngest of these individuals (0.3 years, 5.8 kg) developed small pericardial effusion after anterograde ballon valvuloplasty for critical aortic stenosis. The remaining 4/5 patients developed small pericardial effusion after ablation of a left-sided accessory atrioventricular pathway (6.1-12.2 years, 15.6-34.0 kg). TSP for access to the left heart was safe and effective in children and adolescents > 1 year of age. However, TSP was a high-risk procedure in small infants with a restrictive interatrial septum with need for enlargement of interatrial communication.

Catheter ablation of left-sided accessory pathways in small children

BACKGROUND

Accessory pathways (APs) are a common reason for supraventricular tachycardia in small children. Trans-septal puncture (TSP) approach is commonly used for the ablation of left-sided APs, however it may be challenging in small children. The aim of this study was to assess the efficacy and safety of trans-septal approach radiofrequency (RF) ablation of left-sided APs in children weighing up to 30 kg.

METHODS

Of the 658 children who underwent catheter ablation of APs since 06/2002, 86 children had left-sided AP and weighed less than 30 kg. TSP approach guided with TEE and fluoroscopy was used for left atrium access.

RESULTS

The mean age, height, and body weight were 7.6 ± 1.9 years, 122.4 ± 9.3 cm and 24.0 ± 4.2 kg, respectively. Forty-three children (50%) were male, 46 of 86 (53%) had manifest AP, 17 of 86 (20%) weighed less than 20 kg and in 24 of 86 children (28%) a three-dimensional system (3DS) was used to reduce fluoroscopy time. The acute success rate was 98.8% (85/86), with a recurrence rate of 2.4% (2/85) in a mean follow-up of 66.2 ± 42.7 (9.1-184.2) months. The mean procedure time and fluoroscopy time were significantly lower for the 3DS group compared to the standard fluoroscopy group 131 ± 41 (55-262) and 2.4 ± 1.5 (1-6) minutes vs 164 ± 51 (62-249) and 27 ± 13 (8-77) minutes, P < 0.01 and P < 0.0001, respectively. There were no ablation-related complications.

CONCLUSIONS

RF ablation of left-sided APs using TSP approach in small children had an excellent efficacy and safety profile. The use of 3DS significantly reduces the procedure and fluoroscopy time.

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.

Catheter ablation for supraventricular tachycardia in children ≤ 20 kg using an electroanatomical system

PURPOSE

Catheter ablation is the only choice of treatment in some small children with medically refractory supraventricular tachycardia (SVT). Electroanatomical mapping systems (EMS) are more commonly utilized in electrophysiological procedures in recent years, which resulted in a significant decrease in fluoroscopy exposure. The potential benefit of EMS in small children has not been studied. Therefore, we investigated the outcomes of children undergoing catheter ablation weighing ≤ 20 kg using an electroanatomical mapping system.

METHODS

This study evaluated the outcomes, characteristics, and follow-ups of children ≤ 20 kg who underwent SVT ablations between April 2012 and April 2018 in a pediatric electrophysiology center where EMS were routinely used.

RESULTS

In a 6-year period, 1129 children underwent SVT catheter ablation under EMS guidance at our institution. A total of 84 of them were weighing ≤ 20 kg. The acute success rate was 97.6% in 85 tachycardia substrates. No fluoroscopy was used in 58 of the patients, while a median of 5 (4-14) min of fluoroscopy was used in the remaining 26 patients. Recurrences were seen in 4 patients (4.8%) at a mean follow-up of 3.89 ± 2.08 years. Five patients developed non-vital complications (2 right bundle block and 3 temporary complete block that spontaneously resolved during the procedure).

CONCLUSIONS

The outcome of catheter ablation with the guidance of EMS for the treatment of SVT in small children is favorable. Fluoroscopy exposure can be decreased and even eliminated in most patients.

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.