Increased hemoglobin levels in patients with early onset scoliosis: prevalence and effect of a treatment with Vertical Expandable Prosthetic Titanium Rib (VEPTR).
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.
Caubet
Jean-Francois
JF
Children's Hospital, Boston, MA 02115, USA.
Emans
John B
JB
Smith
John T
JT
Vanbosse
Harold
H
Ramirez
Norman
N
Flynn
John
J
Vitale
Michael
M
Smith
Melissa
M
St Hilaire
Tricia
T
Klinge
Steve
S
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
D015415:Biomarkers; D006454:Hemoglobins; D014025:Titanium