title: Cryoablation of right-sided accessory pathways in children: report of efficacy and safety after 10-year experience and follow-up.
abstract: OBJECTIVE
  The aim of this study was to report the 10-year experience of our Institution in cryoablation of supraventricular tachycardia due to a right accessory pathway (AP).
  
  
  RESULTS
  Seventy-one cryoablations of right AP were performed between July 2002 and October 2011 in our Institution in 66 patients (mean age 12 + 3 years, 56% males). Acute procedural success rate was 97%: 80% in patients with concealed AP and 100% in those with manifest AP (P < 0.05). Acute procedural success rate was not related to institutional experience. No permanent complication occurred. Sixteen patients had recurrences during the follow-up (18.6 ± 6.6 months; range 3-111), 13 within the first month of follow-up, 2 within the 6 months of follow-up, and 1 within 12 months of follow-up. Cox regression showed that sex, patient age, number of delivered cryo-bonus, and presence of manifest or concealed AP are not independent predictors of procedural success. Among the 16 patients with recurrences, in 10 a cryoablation redo was successful and with no further AP recurrences. The mean fluoroscopy time was 28.4 min (range 19.7-44.6) with a significant decrease (P = 0.033) in relation to the increase of the institutional experience. There were no permanent ablation-related complications.
  
  
  CONCLUSIONS
  Cryoablation of right-sided AP is effective and very safe in children. Better results are achieved in manifest AP. The learning curve has a real impact in the attempt to reduce the fluoroscopy time.
authors.affiliation: Arrhythmia Complex Unit, Medical and Surgical Paediatric Cardiology Department, Bambino Gesù Children's Hospital, Via Torre di Palidoro, snc, 00050 Palidoro, Fiumicino (Rome), Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Drago
authors.forename: Daniela
authors.initials: D
authors.lastname: Righi
authors.forename: Silvia
authors.initials: S
authors.lastname: Placidi
authors.forename: Mario Salvatore
authors.initials: MS
authors.lastname: Russo
authors.forename: Corrado
authors.initials: C
authors.lastname: Di Mambro
authors.forename: Massimo Stefano
authors.initials: MS
authors.lastname: Silvetti
authors.forename: Monica
authors.initials: M
authors.lastname: Prosperi
mesh_terms: D058606:Accessory Atrioventricular Bundle / Q000503:physiopathology / Q000601:surgery*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003452:Cryosurgery / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006801:Humans; D059032:Learning Curve; D008137:Longitudinal Studies; D008297:Male; D012008:Recurrence; D012044:Regression Analysis; D012189:Retrospective Studies; D013617:Tachycardia, Supraventricular / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Accessory pathway; Children; Supraventricular tachycardia; Transcatheter cryoablation