621 TRANSVENOUS LEAD ADVANCEMENT IN PAEDIATRIC PACING TO OVERCOME GROWTH STRETCHING

Background One of the main complications of transvenous leads implanted in paediatric patients is the stretching of the lead caused by the somatic growth. It may cause pacing and sensing defects and lead dislodgement or even fracture. Absorbable lead ligature and atrial loop may reduce this risk. However, the loop may induce traction or may unroll too early and therefore impair lead function. Lead extraction and replacement is another solution, although it has some procedural risks in young patients. Lead advancement through pushing it from the pocket may solve growth-induced traction and spare the electrode throughout childhood until post-puberty. Objective of the study is the retrospective analysis of the outcome of the transvenous lead advancement in children with a pacemaker (PM) in a single tertiary paediatric center. Methods consecutive patients with a VVIR PM implanted for isolated congenital complete atrioventricular block (no structural heart disease) in alternative right ventricular (RV) pacing sites, with lead stretching underwent a trial of lead advancement during general anaesthesia, cefuroxime antibiotic profilaxis, from 2014 to 2021. After venous angiography showed venous patency, the PM pocket was opened, the lead was released from subcutaneous adherences and with a stylet was gently advanced to create a semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are expressed as median (25th-75th centiles). Results 8 patients underwent PM implantation at 6.8 (5.8-8.0) years of age, 20 (18-21) kg, 116 (106-120) cm, with the lead positioned at parahisian(3)/mid-septum (5 pts) sites. During a follow-up of 3 (1-5) years, advancement procedures were 1.5 (1.0-4.3) per patient. Between procedures, delta age was 16 (12-20) months, height 8 (7-11) cm and weight 5 (3-7) kg. All leads were successfully advanced without any procedural complications. Procedure time (skin to skin) was 96 (73-108) minutes, fluoroscopy was 0.5 (0.2-1.4) mGy, 16 (10-46) microGy/m2. Electrical lead parameters did not showed significant differences between consecutive control times. Conclusion the advancement of transvenous leads in children is a safe and effective procedure, with low fluoroscopy exposure, without significant acute and chronic complications. This procedure seems to preserve transvenous leads until growth has completed.