title: A biodegradable ring enables growth of the native tricuspid annulus.
abstract: OBJECTIVE
  The study aim was to assess the growth potential and function of the tricuspid valve (TV) annulus after annuloplasty with the intra-annular biodegradable ring.
  
  
  METHODS
  Among 11 children (median age 4.5 years; age range: 0.2-10.9 years) who underwent surgery for severe congenital TV regurgitation, valve repair was completed using a biodegradable annuloplasty ring. The children were followed regularly using transthoracic echocardiography, whereby the TV annulus lateral diameter (TVALD) and valve function were monitored. Rates of valve growth were derived from the slope of the regression equations which related TVALD to the natural logarithm of the body surface area (lnBSA).
  
  
  RESULTS
  The children's somatic growth was harmonious throughout the entire follow up period (mean 478 days; range: 171-1,477 days). The TVALD differed significantly at six months and at one and two years after surgery compared to the postoperative value at discharge, rising from 19 mm (range: 15.5-26.0 mm) to 24 mm (range: 19.0-30.0 mm) at the last control examination (p = 0.003), while the related Z-scores remained stable. A significant linear correlation between TVALD and lnBSA was found in 63.6% of patients. The median rate of growth for the whole cohort was 1.96-fold (range: 0.52-5.53-fold) higher than a norm, and correlated strongly and positively with age (r = 0.91; p <0.05). The median postoperative TV insufficiency fraction of 9.8% (range: 0-28.8%) remained constant during the follow up period. The postoperative TV maximal pressure gradient was 5.5 mmHg (range: 3.1-12.2 mmHg), and did not increase over time.
  
  
  CONCLUSIONS
  The implantation of a biodegradable ring does not restrict growth of the native TV annulus; this enabled its stabilization in proportion to the somatic growth in the majority of the children. The TV annulus began to change its dimension at six months postoperatively, which may coincide with its biodegradation. The rate of growth of the TV annulus differed from that in the normal population, and was proportional to the patient age. The increase in TV annulus diameter over time did not have any negative influence on the function of the repaired valve.
authors.affiliation: Department of Pediatric Cardiac Surgery, Poznan University of Medical Sciences, Poznan, Poland. wjmrow@amp.edu.pl
authors.forename: Wojciech
authors.initials: W
authors.lastname: Mrowczynski
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Mrozinski
authors.forename: Afksendiyos
authors.initials: A
authors.lastname: Kalangos
authors.forename: Beat H
authors.initials: BH
authors.lastname: Walpoth
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Pawelec-Wojtalik
authors.forename: Michal
authors.initials: M
authors.lastname: Wojtalik
mesh_terms: D020341:Absorbable Implants; D058385:Cardiac Valve Annuloplasty / Q000009:adverse effects / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D006801:Humans; D007223:Infant; D016018:Least-Squares Analysis; D011044:Poland; D011474:Prosthesis Design; D013997:Time Factors; D016896:Treatment Outcome; D014261:Tricuspid Valve / Q000000981:diagnostic imaging / Q000254:growth & development / Q000503:physiopathology / Q000601:surgery*; D014262:Tricuspid Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D014463:Ultrasonography