The Nasopharyngo-Septal Butterfly Flap: A Novel Salvage Option for Reconstruction of Clival and Craniocervical Junction Defects

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Background: Extended endoscopic endonasal approaches have revolutionized skull base surgery by providing a less-disruptive route to access and resect lesions in the region. However, the resulting skull base defects can be challenging to reconstruct, especially those that affect the clival and craniovertebral junction (CVJ) regions as they are often large and require a sturdy repair matrix.

The nasoseptal flap (NSF) is a pedicled vascularized flap which has proven reliable and remains a widely used option for skull base reconstruction. However, the NSF can be compromised if the pedicle containing the sphenopalatine artery is damaged by tumor invasion, previous surgery, or revision surgery. In these cases, other vascularized flaps may be a necessary option. These include the temporalis fascia flap or the pericranial flap. These flaps are more complex to harvest and position, in addition to requiring a longer recovery time.

Objective: The goal of this cadaveric study is to describe a novel nasopharyngo-septal butterfly flap for clival and CVJ reconstruction.

Methods: Endoscopic endonasal dissection was carried out in 15 cadaveric heads. A modification in the lower incision of the classic NSF was carried out. The lower incision was performed at a higher level sparing the mucosa covering the sphenoid rostrum instead of passing along the choanal mucosal fold. Two lateral longitudinal incisions were carried out starting at the pterygo-sphenoidal junction and extending posteriorly across the petroclival junction, freeing the nasopharyngeal mucosa. A third incision was performed inferiorly separating the previously preserved rostral mucosa from the nasal floor mucosa. The designed flap was reverted postero-superiorly to cover the clivus and CVJ.

Results: An inferiorly based butterfly-shaped nasopharyngo-septal flap, consisting of nasopharyngeal and rostral mucosa and receiving blood supply from the superior branch of the ascending pharyngeal artery, was formulated. The two lower wings are formed by nasopharyngeal mucosa while the rostral mucosa bilaterally represents the two upper wings. The mean surface area of the flap was 9.66 ± 1.04 cm² which was sufficient to cover the whole clivus with CVJ in all the 15 cadavers.

Conclusion: The nasopharyngo-septal flap is a novel vascularized flap that is well-suited for reconstructing middle, lower clivus and CVJ defects. It is particularly advantageous when the NSF is harvested with the modification suggested. The nasopharyngo-septal flap can provide adequate mucosal coverage for clival and CVJ reconstruction in cases where the NSF is deficient.

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Artikel online veröffentlicht:
05. Februar 2024