Mastoid Reconstruction in Lateral Suboccipital Craniotomy: Autologous Bone Paste Enhances Sealing and Promotes Air-cell Osteogenesis.

Lateral suboccipital craniotomy is frequently used for cerebellopontine angle lesions, during which the mastoid air cells may be opened. This study evaluated whether the autologous bone paste technique prevents postoperative cerebrospinal fluid leakage and anatomically reconstructs the mastoid air cells. Eighty-six patients who underwent lateral suboccipital craniotomy with opened mastoid air cells were included in this study. The opened cells were sealed with various methods, including the autologous bone paste technique, in which bone dust harvested during the craniotomy was mixed with fibrinogen solution and stabilized with thrombin solution. We compared the postoperative incidence of cerebrospinal fluid leakage and infectious complications between patients who underwent reconstruction using autologous bone paste and those treated with alternative materials. Furthermore, in cases with over 1 year of postoperative follow-up using computed tomography, we evaluated the degree of mastoid air-cell reconstruction and longitudinal changes in computed tomography values. Histological analyses were also performed on the reconstructed areas from 2 reoperation cases. Postoperative cerebrospinal fluid leakage and infectious complications were comparable between the groups. However, the degree of mastoid air-cell reconstruction was significantly better in the bone paste group than in the non-bone paste group. Histological analyses revealed that the reconstructed sites contained osteoblasts, osteocytes, and osteophytes without an inflammatory response, and osseous lamellae around the Haversian canal were observed. In conclusion, autologous bone paste is a simple osteogenic sealant that effectively seals the opened mastoid air cells in lateral suboccipital craniotomy.