Introduction: Endoscopic endonasal transcribriform resection of anterior skull base tumors results in large skull base defects that may extend the entirety of the cribriform plate, from the posterior wall of the frontal sinuses to the tuberculum sellae sagitally, and from one medial orbital wall to the other coronally. Endoscopic repair of these large cribriform defects can often be challenging. We describe our reconstruction technique for large anterior skull base defects after endoscopic endonasal transcribriform resection of anterior skull base tumors. This triple-layer technique is comprised of autolgous fascia lata, acellular dermal allograft, and a vascularized pedicled nasoseptal flap (PNSF). The technique is described and postoperative cerebrospinal fluid (CSF) leak rate is evaluated.
Methods: Retrospective review of a prospective database over a two-year period identified 10 patients who underwent a purely endoscopic endonasal transcribriform approach for resection of anterior skull base tumors. Lesions included 2 olfactory groove meningiomas, 2 esthesioneuroblastomas, 1 olfactory schwannoma, 1 sinonasal small cell neuroendocrine carcinoma, 1 sinonasal melanoma, 1 adenoid cystic carcinoma, 1 sinonasal/anterior skull base inflammatory pseudotumor, and 1 recurrent osteoblastoma. After tumor resection, all patients underwent triple-layer reconstruction using autologous fascia lata inlay, acellular dermal allograft inlay/overlay, followed by a vascularized PNSF to reconstruct a large cribriform SBD.
Results: The average cribriform defect size was 9.1 cm2 (range, 5.0 – 13.8 cm2). All 10 patients underwent successful reconstruction with a postoperative CSF leak rate of 0% without the use of postoperative lumbar drainage. The mean follow-up period was 7.4 months (range, 2 to 17 months). The mean age was 45.8 years (range, 15-81 years) with 30 percent of the patients being females.
Conclusions: The triple-layer reconstruction technique using autologous fascia lata, acellular dermal allograft and a vascularized PNSF is effective in reconstructing large anterior skull base defects after endoscopic resection of the cribriform plate.
Patient Care: The triple-layer reconstruction technique using autologous fascia lata, acellular dermal allograft and a vascularized PNSF has, in our experience, been effective in reconstructing large anterior skull base defects after endoscopic resection of the cribriform plate. This may be a useful technique which other neurosurgeons and otolaryngologists can effectively apply to reconstruct large skull base defects after endoscopic skull base surgery.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of robust cribiform defect reconstruction after endoscopic skull base surgery 2) Discuss the literature on various methods of cribiform defect reconstruction and their advantages and disadvantages 3)Discuss the triple layer reconstruction technique and how it can be applied to repairing cribiofrm defects after skull base surgery