The nasoseptal flap for reconstruction of the medial and inferior orbit.

BACKGROUND: Endoscopic endonasal orbital surgery may result in large orbital defects that mandate reconstruction to minimize the risk of diplopia and enophthalmos. The purpose of this study is to determine whether the nasoseptal flap can provide adequate coverage of maximal orbital defects.

METHODS: This was an anatomic cadaveric study. Morphometric measurements were completed in 5 cadaveric orbits to determine the dimensions of an orbital defect comprising the entire lamina papyracea and the orbital floor. The dimensions of a planned nasoseptal flap were then calculated and an appropriately sized flap was harvested to verify complete coverage of the defect.

RESULTS: The mean ± standard deviation (SD) medial orbital defect was a depth of 47.3 mm ± 2.52, height of 13.67 mm ± 2.73, and width of 13.33 mm ± 1.03 for the orbital floor. The mean flap dimensions were a width of 55 ± 6.16 mm, height of 48 ± 4.47 mm, and depth of 70 ± 3.54 mm. In all cases, the harvested flap adequately covered the orbital defect. These dimensions correlated with flap incisions subtending the mucocutaneous junction anteriorly, the inferior meatus laterally, the attachment of the middle turbinate superiorly, and the choanal arch posteriorly.

CONCLUSION: Endoscopic orbital approaches may result in large orbital defects with significant orbital fat herniation and extraocular muscle exposure. Immediate vascularized flap reconstruction of the orbit may help to limit the attendant morbidity including diplopia and enophthalmos. This study is the first to demonstrate the feasibility of the nasoseptal flap for the reconstruction of maximal orbital defects.