title: Increased hemoglobin levels in patients with early onset scoliosis: prevalence and effect of a treatment with Vertical Expandable Prosthetic Titanium Rib (VEPTR).
abstract: METHODS
  The medical records of 138 subjects with Early Onset Scoliosis (EOS) from 5 US institutions were reviewed to analyze their hemoglobin levels before and after surgery. Eighty-five subjects were operated with the Vertical Expandable Prosthetic Titanium Rib (VEPTR) and 53 with growing rods.
  
  
  OBJECTIVE
  To estimate the prevalence of hypoxia and thoracic insufficiency using hemoglobin as a surrogate marker for pulmonary function, and to measure the effect of spine surgery with expandable devices.
  
  
  BACKGROUND
  An early intervention with expandable devices might improve pulmonary function. This hypothesis is difficult to test in young subjects because the standard pulmonary function tests require that the patient be at least 7-year old. Previous studies demonstrated that hemoglobin levels are correlated with chronic hypoxemia.
  
  
  METHODS
  Blood data were collected before and 6 to 24 months after surgery. The hemoglobin and hematocrit levels were converted into Z-scores, using age-adjusted references to perform t test paired comparisons.
  
  
  RESULTS
  The prevalence of elevated hemoglobin and hematocrit levels in EOS was 23.2% and 22.5%, respectively. The mean hemoglobin Z-score decreased from 1.26 to 0.92 (P = 0.03) after surgery and the hematocrit Z-score changed from 0.90 to 0.88 (P = 0.90). In the VEPTR group, the mean hemoglobin Z-score decreased from 0.98 to 0.69 (P = 0.20) and in the subgroup of subjects who had an expansion thoracostomy, it decreased from 0.82 to 0.24 (P = 0.04). In the subjects operated with growing rods, the hemoglobin Z-score decreased from 1.75 to 1.32 (P = 0.83).
  
  
  CONCLUSIONS
  Twenty-three percent of the patients with EOS showed signs of chronic hypoxia. The hemoglobin levels decreased significantly 6 to 24 months after surgery. The greatest effect was observed in subjects with congenital scoliosis and rib fusion and who had an expansion thoracostomy with implantation of VEPTR.
authors.affiliation: Children's Hospital, Boston, MA 02115, USA.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Caubet
authors.forename: John B
authors.initials: JB
authors.lastname: Emans
authors.forename: John T
authors.initials: JT
authors.lastname: Smith
authors.forename: Harold
authors.initials: H
authors.lastname: Vanbosse
authors.forename: Norman
authors.initials: N
authors.lastname: Ramirez
authors.forename: John
authors.initials: J
authors.lastname: Flynn
authors.forename: Michael
authors.initials: M
authors.lastname: Vitale
authors.forename: Melissa
authors.initials: M
authors.lastname: Smith
authors.forename: Tricia
authors.initials: T
authors.lastname: St Hilaire
authors.forename: Steve
authors.initials: S
authors.lastname: Klinge
mesh_terms: D017668:Age of Onset; D015415:Biomarkers / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008499:Medical Records; D018579:Patient Selection; D015995:Prevalence; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012129:Respiratory Function Tests; D012131:Respiratory Insufficiency / Q000453:epidemiology* / Q000378:metabolism / Q000601:surgery*; D012272:Ribs / Q000601:surgery*; D012600:Scoliosis / Q000453:epidemiology / Q000378:metabolism / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000601:surgery; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D014025:Titanium