CRANIOPLASTY WITH AUTOGENOUS AUTOCLAVED CALVARIAL BONE FLAP IN THE CASES OF TUMORAL INVASION

When a bone flap is raised in the course of a craniotomy, the ideal is to replace it at the end of the procedure. When it is invaded by tumo ural cells, it cannot be replaced due to the risk of tumoural recurren ce. In these cases we have autoclaved the bone flap to be able to repl ace it with no fear of tumoural recurrence. Between October 1989 and O ctober 1995 sixty-two patients required autoclaving of the bone flap i n the course of a craniotomy due to tumoural invasion (thirty-five men ingiomas, sixteen bone tumours, five metastases, and eight scalp rumou rs). The infiltrated bone flaps were removed, cleaned, autoclaved for 20 minutes at 134 degrees C and 1 kg/cm(2) and re-implanted. Patients were followed-up for 10 to 58 months (average 41 months). At every fol low-up visit skull x-ray studies, clinical examination, and photograph s were done. When needed a CT scan was performed to assess the thickne ss of the bone flap. On follow-up roentgenograms partial resorption wa s observed in twelve cases (19.3%). CT scan studies showed loss of thi ckness in another thirty-five cases (56.4%). Meanwhile the external as pect remained unchanged. In six cases (3.2%) biopsies of the bone flap s were taken at a second surgical procedure. They showed newly formed bone partly re-populated by osteocytes but retaining areas of sequeste red bone. We conclude that autoclaved bone, if replaced with direct co ntact with living bone, it is gradually repopulated with osteocytes. C ranial vault autoclaved autologous bone flap is a good alternative whe n the original bone flap is invaded but not destroyed by tumoural cell s.