Surgical technique for anterior skull base reconstruction using hydroxyapatite cement and titanium mesh

Abstract

Dear Sirs: We have previously reported a surgical technique for anterior skull base reconstruction using an overlapping free bone graft with galea–pericranium [1]. This method prevented CSF leakage and sequestrum formation. However, in patients with tumour infiltration into the inner table of skull, it is difficult to use this method for skull base repair. A 52-year-old man was admitted because of small cell carcinoma. Magnetic resonance images (MRI) revealed the extension of a tumour to the medial orbits, frontal sinus and frontal lobe (Fig. 1a). Computed tomography (CT) demonstrated the presence of a skull base defect and the destruction of the inner table of the frontal sinus. After the total removal of the tumour, a 6×5-cm bone defect was observed. The reconstruction of the skull base was performed as follows: the skull base defect was covered with 0.3-mm-thick titanium mesh (Stryker, Tokyo, Japan) (Fig. 1d) and hydroxyapatite cement (HAC; Kobayashi Medical, Osaka, Japan) (Fig. 1e); then, both were covered with a vascularised galeal–pericranial flap. The dural laceration of the frontal base was repaired with a galea, and thereafter the edge of the galeal–pericranial flap was sutured to the normal dural margin. All layers and dual flaps were fixed with fibrin glue. The free frontal bone flap, in which tumour invasion was observed, was autoclaved and used for cranioplasty. The patient did not show any surgical complications, such as CSF leakage or meningitis. Postoperative MRI demonstrated complete remission and skull base repair (Fig. 1b). Sagittal reconstruction of a CTshowed skull base reconstruction and more than 60% of the skull base was covered with titanium mesh and HAC (Fig. 1c). Since its introduction in 1996, injectable HAC has been used successfully in many fields. Durham et al. [2] demonstrated a technique in which they use HAC, reinforced with tantalum mesh and titanium miniplates, for the repair of large (>25 cm) cranial defects. On the other hand, Kitano and Taneda [3] showed a technique of HAC for cranial base reconstruction after transsphenoidal surgery. However, they used it for relatively small bone defects. It is difficult to use this method for large cranial base reconstruction. Therefore, we used thin transformable titanium mesh, as a supporting and reinforcing material for HAC. Although the number of patients on whom we have performed this technique is low, none of the patients had any complications related to the surgery. This skull base reconstruction procedure is therefore considered to be a simple and useful technique to prevent CSF leakage and infection. Further experiments are therefore required to determine whether this procedure does indeed help to reduce the risk of complications. Acta Neurochir (2009) 151:1337–1338 DOI 10.1007/s00701-009-0392-4