SPLIT CALVARIAL GRAFT CRANIOPLASTY FOR THE PREVENTION OF HEADACHE AFTER RETROSIGMOID RESECTION OF ACOUSTIC NEUROMAS

Objective: This study describes the technique and efficacy of split ca lvarial graft cranioplasty for the reconstruction of retrosigmoid/subo ccipital defects following surgery for acoustic neuromas. Study Design : A prospective study of the technique of split calvarial graft cranio plasty, its postoperative healing, and incidence of postoperative head ache. Methods: The technique requires splitting of the craniotomy bone flap into outer and inner table bone grafts, The combination of both bony grafts allows the coverage of a wider area of posterior fossa dur a. This technique was used in 18 patients. All patients were followed for a minimum of 6 months. Eleven of 18 patients were followed for 1 y ear or longer. Four patients had three-dimensional computed tomography of their skull and area of split calvarial bone graft. Results: One o f 18 patients had a persistent disabling headache at 1 year postoperat ively. A natural contour of the retrosigmoid area was achieved in all patients. Three-dimensional computed tomography scan, obtained 6 month s postoperatively, showed total coverage of the retrosigmoid area and fusion of the bone flap to the surrounding skull. Conclusion: The tech nique of split calvarial grafting of posterior fossa defects is a feas ible, safe, and effective way of separating the nuchal musculature and posterior fossa dura. The technique also allows the restoration of th e contour and bony covering of the retrosigmoid area. The technique is a simple alternative to other types of cranioplasties aimed at reduci ng the incidence of postoperative headache in patients with acoustic n euromas.