Abstract
In this study, we suggest a new classification for skull base defects that is in accordance with the following flap selection and reconstructive procedures. We define the new classification as outlined below.
For the anterior skull base, the cribriform plate is defined as the center of the defect, and for the middle skull base, the infratemporal fossa is defined as the center of the defect. The defects are classified as localized in the defect's center (Ia, IIa) or extended horizontally (Ib, IIb) or vertically (Ic, IIc) from the defect's center. The accompanying defects of the orbital contents and skin are indicated by “+O” and “+S,” respectively. Ia , IIa, Ic and IIc are reconstructed with locoregional flaps, and Ib, IIb, “O”, “S” and patients with combined defects are reconstructed with free flaps.
Between July 2000 and January 2012, 127 skull base reconstructions were performed in our institute. The patients were 73 males and 54 females, ranging in age from 2 to 79 years (median 43 years). Of the cases, 76 were malignant and 51 were benign tumors. All defects were re-sorted according to the new classification without omission. The correlation rate ranged from 92 to 100% between the flaps indicated by the new classification and the flaps that had actually been used. The rate of postoperative complications tended to be higher with Ic defects.
As a result, the concept of our new classification will not only adequately classify skull base defects but also has the possibility of deciphering the appropriate flap to apply and the reconstructive procedure to perform. Moreover, this new classification will provide information about the trend of postoperative complications, which will improve reconstructive procedures of skull base.
