Читать книгу Anterior Skull Base Tumors - Группа авторов - Страница 99

The resulting skull base defect is reconstructed by the endoscopic endonasal multilayer technique, which is preferably performed using autologous materials. In our experience, fascia lata and/or the iliotibial tract possess the best characteristics in terms of thickness, pliability, and strength. For the first intradural layer of duraplasty, the graft has to be at least 30% larger than the dural defect and split anteriorly on the midline to adjust to the falx cerebri in case of bilateral resection. The second layer, intracranial and extradural, needs to be precisely sized and tacked between the previously undermined dura and the residual bone of the skull base. Fragments of fatty tissue are placed to eliminate the dead space between the second and third layers and to flatten the residual denuded skull base. The third extracranial layer must cover all of the exposed anterior skull base, but must not overlap the frontal sinusotomies. The borders of the second and third layers are properly fixed with small amounts of fibrin glue. No bone or cartilage grafts are used to repair the skull base to avoid radionecrosis, infection, and extrusion after postoperative radiotherapy. In the case of a tumor not involving the nasal septum and without multifocal localizations, the third layer of the skull base reconstruction can be harvested using mucoperiosteal/mucoperichondrial pedicled flaps based on the nasal branches of the sphenopalatine artery (Hadad-Bassagasteguy flap) [14] or vascularized by the septal branches of ethmoidal arteries (septal flip flap) [15, 16]. The use of local pedicled flaps facilitates rapid healing of the surgical cavity and reduces postoperative nasal crusting, which is particularly helpful in patients who require adjuvant irradiation. At the end of the procedure, in selected cases, the frontal sinusotomies can be stented with rolled polymeric silicone sheaths to allow subsequent frontal sinus debridement with no risks for duraplasty. The surgical cavity is packed for about 48 h.

Fig. 3. Complications after endoscopic endonasal surgery. a, b Left frontal lobe abscess after skull base reconstruction; coronal and sagittal views, respectively. c, d Brain herniation after endoscopic skull base reconstruction; coronal and sagittal views, respectively.