The Endoscopic-Assisted Pericranial Flap: An Update on Technique and Clinical Outcomes

Background: The superiority of vascularized flaps in skull base reconstruction has been well established. There are instances where the nasoseptal flap may not be readily available during endoscopic endonasal resection of skull base tumor pathology, and alternative techniques for reconstruction must be employed. Since its original description, the endoscopic-assisted pericranial flap has become an integral component in skull base reconstructive techniques.

Objective: The aims of this study are to assess clinical outcomes of patients undergoing endoscopic-assisted pericranial flap for reconstruction of the anterior cranial base. In addition, we look at the variations in the endoscopic-assisted technique that have developed at our institution with time.

Methods: A retrospective chart review was performed to identify all patients undergoing endoscopic-assisted pericranial flap over a 5-year period. Data recorded include operative indications, prior radiotherapy or adjuvant radiotherapy, postoperative follow-up intervals, and any postoperative complications. The changes in endoscopic harvest techniques are also described.

Results: A total of 19 patients were identified who underwent endoscopic-assisted pericranial flap for reconstruction for a variety of indications (skull base malignancy, encephalocele, CSF leak, and septal perforation). The mean follow-up interval was 22.3 months, and a total of 13 patients (68.4%) had prior radiotherapy or underwent adjuvant radiotherapy. There were no cases of flap loss during the follow-up intervals, and there were no injuries to the frontal branch of the facial nerve. There was one case of tension pneumocephalus that required revision, and one patient developed a frontal sinus mucocele that required operative intervention. The technique developed over time to incorporate a small trichophytic incision along with a glabellar incision, different from the previously described three port techniques with incisions at a designed coronal incision line. This adaptation still provided for adequate flap length, but more direct access to the nasion for delivery of the flap into the sinonasal cavity.

Conclusion: The pericranial flap remains a robust reconstructive option for the anterior cranial base, particularly following tumor resection in which there is a high likelihood for adjuvant therapy. The endoscopic-assisted technique for flap harvest can be accomplished through two small incisions, avoiding a coronal incision altogether. Morbidity remains low and outcomes are comparable to other reconstructive techniques incorporating vascularized flaps.