Anatomical identification of supraseptal posterior ethmoid cells and its significance for endoscopic sinus surgery.

ABSTRACT

BACKGROUND: To investigate the anatomical imaging characteristics of supraseptal posterior ethmoid cells (SPEC). MATERIALS AND METHODS: Paranasal sinus computed tomography scans of 153 inpatients from February 2019 to September 2021 were reviewed, and the anatomical characteristics of SPEC in the scans were collected. RESULTS: Supraseptal posterior ethmoid cells are posterior ethmoid (PE) cells extending medially and superiorly to the posterior superior of the nasal septum and into the sphenoid body but not close to the optic canal. The SPEC, Onodi cell, and sphenoidal sinus (SS) may appear in the posterior superior of the nasal septum, but the occurrence rate of the SPEC (5.88%; 9/153 cases) was significantly lower than that of the SS (22.88%) and Onodi cell (21.57%). The anterior SPEC is adjacent to the cribriform plate, the perpendicular plate of the ethmoid bone and the posterior ethmoidal artery (PEA). The posterior SPEC is adjacent to the SS and PE (6/9 cases), the SS and Onodi cell (2/9 cases) or the PE only (1/9 cases). CONCLUSIONS: The SPEC is a rare pneumatization that occurs in the posterior superior area of the nasal septum. Care should be taken to protect the skull base, cribriform plate and PEA when opening the SPEC during endoscopic sinus surgery.