J Neurol Surg B Skull Base 2013; 74(06): 369-385
DOI: 10.1055/s-0033-1347368
Original Article
Georg Thieme Verlag KG Stuttgart · New York

The Extended Nasoseptal Flap for Skull Base Reconstruction of the Clival Region: An Anatomical and Radiological Study

Maria Peris-Celda
1  Department of Neurological Surgery, University of Florida, Gainesville, Florida, United States
,
Carlos Diogenes Pinheiro-Neto
2  Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
,
Takeshi Funaki
1  Department of Neurological Surgery, University of Florida, Gainesville, Florida, United States
,
Juan C. Fernandez-Miranda
3  Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
,
Paul Gardner
3  Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
,
Carl Snyderman
2  Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
,
Albert L. Rhoton
1  Department of Neurological Surgery, University of Florida, Gainesville, Florida, United States
› Author Affiliations
Further Information

Publication History

18 May 2012

25 May 2012

Publication Date:
17 June 2013 (online)

Abstract

Objective Reconstruction of large clival defects after an endoscopic endonasal procedure is challenging. The objective is to analyze the morphology, indications, and limitations of the extended nasoseptal flap, which adds the nasal floor and inferior meatus mucosa, compared with the standard nasoseptal flap, for clival reconstruction.

Design Twenty-seven sides of formalin-fixed anatomical specimens and 13 computed tomography (CT) scans were used. Under 0-degree endoscopic visualization, a standard flap on one side and an extended flap on the other side were performed, as well as exposure of the sella, cavernous sinus, and clival dura mater. Coverage of both flaps was assessed, and they were incised and extracted for measurements.

Results The extended flap has two parts: septal and inferior meatal. The extended flaps are 20 mm longer and add 774 mm2 of mucosal area. They cover a clival defect from tuberculum to foramen magnum in 66.6% cases and from below the sella in 91.6%. They cover both parasellar and paraclival segments of the internal carotid arteries. The lateral inferior limits are the medial aspect of the hypoglossal canals and Eustachian tubes. CT scans can predict the need or limitation of an extended nasoseptal flap.

Conclusions The nasal floor and inferior meatus mucosa adds a significant area for reconstruction of the clivus. A defect laterally beyond the hypoglossal canals is not likely covered with this variation of the flap. Preoperative CT scans are useful to guide the reconstruction techniques.