Minimally invasive endoscopic pericranial flap: a new method for endonasal skull base reconstruction.

OBJECTIVES One of the major challenges of cranial base surgery is reconstruction of the dural defect. Following a craniofacial resection, the standard reconstructive technique is direct suture repair of the dural defect with a fascial graft and rotation of an anteriorly based pericranial scalp flap to cover the dura. The introduction of endoscopic techniques and an endonasal approach to the ventral skull base has created new challenges for reconstruction. The nasoseptal flap has become the workhorse for vascularized endoscopic skull base reconstruction; however at times, the septal mucosal flap may be unavailable for reconstruction. This can be due to prior surgical resection or involvement of the nasal septum by sinonasal cancer. We have developed a minimally invasive endoscopic pericranial flap for endoscopic skull base reconstruction. The use of a pericranial scalp flap for reconstruction during endonasal skull base surgery using minimally invasive techniques has not been previously reported. METHODS We performed cadaveric studies to illustrate feasibility of an endoscopic pericranial flap for endonasal skull base reconstruction, then applied this novel technique to an elderly patient after endonasal skull base and dural resection of an esthesioneuroblastoma. RESULTS The technical report of the minimally invasive pericranial flap is outlined and the advantages and limitations during endonasal skull base reconstruction are discussed. The patient had excellent healing of her skull base and had no evidence of any postoperative cerebrospinal fluid leak. CONCLUSIONS The minimally invasive endoscopic pericranial flap provides another option for endonasal reconstruction of cranial base defects. There is minimal donor site morbidity, and it provides a large flap that can cover the entire ventral skull base. The issues of intranasal tissue tumor involvement and the need for radiotherapy make the endoscopic pericranial flap an ideal reconstruction for anterior cranial base defects resulting from endonasal sinonasal and skull base cancer resections.