RESUMO
BACKGROUND: Distraction osteogenesis has been used to treat diminished skull space caused by craniosynostosis. Our report investigated the relationship between space volume change by computer technology and the intracranial pressure change. Cerebrospinal fluid (CSF) regular test and CSF biochemistry test were also performed to ensure the safety of distraction process. METHODS: Seven minipigs, weighing 15 to 20 kilograms, were chosen; 4 × 3 cm bone flap was lifted in the left parietal bone. The dura was carefully protected. The distractor and assisted apparatus were implanted. Distraction was started with 10-day latency, 1 mm/d distraction rates for 10 days. Twelve weeks after distraction, the distraction device and the assist apparatus were removed. All pigs underwent 3-dimensional computerized scans of the craniofacial skeleton, CSF pressure measurement, CSF regular test, and CSF biochemistry test before operation, after 7 days' operation, immediately after distraction was finished, 4 weeks after distraction, 8 weeks after distraction, and 12 weeks after distraction. The 3-dimensional datum was collected, and volume change of skull was measured by 3-dimensional medicine surface rendering software. RESULTS: All pigs tolerated the procedure. The mean volume 12 weeks after distraction was 87.93 ± 3.11 cm, which was also significantly higher than 79.46 ± 3.15 cm that of before operation (P < 0.001). The CSF pressure becomes maxim after 7 days' operation. The CSF pressure went down immediately after distraction was finished. Then, the CSF pressure kept stable but lower than the CSF pressure before the operation except 1 pig whose CSF pressure after operation was higher than the CSF pressure before the operation. Cerebrospinal fluid regular test and CSF biochemistry test show stable results, and the WBC does not rise during the whole process. CONCLUSIONS: The distraction osteogenesis is an efficient and safe method to enlarge the intracranial volume. The assisted apparatus of distraction is useful for rotating distraction. Three-dimensional DICOM datum and 3-dimensional medicine surface rendering are efficient for measurement of skull volume.
