Introduction: Reconstruction of large anterior skull base (ASB) defects after endoscopic removal of cranial base tumors via the transcribriform corridor remains a challenge despite the advent of the vascularized pedicled nasoseptal flap (PNSF). These defects often extend from orbit to orbit in the coronal plane, and from the posterior table of the frontal sinus to the planum sphenoidale in the sagittal plane. In some cases, the PNSF may be under tension and not have enough anterior reach to cover the posterior table of the frontal sinus. In addition, tension across the sphenoidal portion of the PNSF prevents the flap from covering the posterior extent of the ASB defect. We describe a relaxing slit incision that is made in the sphenoidal portion of the PNSF that extends the anterior and posterior reach of the flap in order to maximize tensionless coverage of transcribriform defects.
Methods: A retrospective chart review was conducted on all cases (n=15) of endoscopic skull base reconstruction of transcribriform defects that utilized a relaxing slit incision of the PNSF. A variety of tumors were treated including olfactory groove meningioma (6), schwannoma (1), esthesioneuroblastoma (2), and other sinonasal ASB malignancies (6).
Results: No patients developed postoperative CSF leaks (0%). The ASB repair was monitored via postoperative outpatient nasal endoscopy at various time points, which demonstrated excellent mucosalization of the ASB. Mean postoperative follow-up was 12.2 months (range 0.8-24.3 months).
Conclusions: Our simple relaxing slit incision in the sphenoidal portion of the PNSF allows for maximal anterior reach of the flap to cover the posterior table of the frontal sinus. Posterior rotation of the sphenoidal portion of the PNSF allows for increased posterior reach of the flap to cover the planum sphenoidale. Tensionless coverage of extensive transcribriform ASB defects can be accomplished to facilitate successful endoscopic skull base reconstruction.
Patient Care: This technique can potentially reduce postoperative complications commonly associated with EEA-TC procedures.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the importance of proper repair after EEA-TC procedures.
2) Discuss, in small groups how the simple relaxing slit can expand coverage area.
3) Identify an effective repair options after EEA-TC