title: Surgical Repair of Mitral Valve Disease in Children: Perioperative Changes in Respiratory Function.
abstract: OBJECTIVE
  To assess the profile of changes in airway and respiratory tissue mechanics within a follow-up study performed in children with mitral valve disease, before and after surgical valve repair.
  
  
  METHODS
  Perioperative measurements in a prospective, consecutive cross-sectional study.
  
  
  METHODS
  University hospital, tertiary care teaching hospital
  
  
  METHODS
  The study comprised 24 children with congenital or post-rheumatic mitral valve insufficiency.
  
  
  METHODS
  Input impedance of the respiratory system during spontaneous breathing was measured before and 5 days and 3 weeks after mitral valve surgery. In addition, airway and respiratory tissue mechanics and pulmonary arterial pressure were assessed with the patient under general anesthesia preoperatively and immediately postoperatively. Respiratory tissue elastance and changes in airway measurements were estimated from forced oscillatory impedance data by fitting an appropriate model.
  
  
  RESULTS
  Relating airway and respiratory tissue mechanics to previously established reference values obtained in age-matched healthy control patients revealed abnormal respiratory function (135±6.2% and 148±13% in respiratory elastance and resistance, respectively; p<0.001). Improvement in the airway properties was observed immediately after surgery (-15.2±3.4%; p<0.005) and lasted for the study period (-19±4.1%; p<0.001). Respiratory tissue elastance, which correlated preoperatively to the diastolic pulmonary arterial pressure, decreased only 5 days postoperatively (-20.6±4.1%; p<0.005). However, there was no evidence of a clear, immediate effect of surgery on the tissue mechanical parameters measured intraoperatively despite a decrease in diastolic pulmonary pressure.
  
  
  CONCLUSIONS
  Mitral valve disease in children leads to abnormal airway and respiratory tissue mechanics. Even though surgical repair of mitral insufficiency alleviates abnormal airway function, residual lung tissue stiffening may persist even weeks after the surgery, contributing to a sustained impairment in lung function.
authors: Pediatric Anesthesia Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland; †Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology and Intensive Care, University of Geneva, Geneva, Switzerland; ‡Pediatric Cardiology Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland.
authors: Iliona
authors: I
authors: Malaspinas
authors: §Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
authors: Ferenc
authors: F
authors: Petak
authors: Pediatric Anesthesia Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland.
authors: Lionel
authors: L
authors: Chok
authors: Pediatric Anesthesia Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland.
authors: Anne
authors: A
authors: Perrin
authors: ‡Pediatric Cardiology Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland.
authors: Anne-Laure
authors: AL
authors: Martin
authors: ‡Pediatric Cardiology Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland.
authors: Maurice
authors: M
authors: Beghetti
authors: Pediatric Anesthesia Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland; †Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology and Intensive Care, University of Geneva, Geneva, Switzerland. Electronic address: walid.habre@hcuge.ch.
authors: Walid
authors: W
authors: Habre
mesh_terms: D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung; D008297:Male; D008943:Mitral Valve / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*; D059035:Perioperative Period; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000502:physiology*
keywords: children; mitral valve surgery; pulmonary hypertension; respiratory mechanics