Radiographic Variants Associated With Allergic Fungal Rhinosinusitis: Key Differences for Pre-Operative Planning

Allergic fungal rhinosinusitis (AFRS) often results in expansion of disease beyond the paranasal sinuses, which may put important structures, such as the anterior ethmoid artery (AEA) or lateral lamella of the cribiform, at risk of injury during endoscopic sinus surgery (ESS). This study aims to compare the AEA to skull base (AEA-SB) length in patients with AFRS versus chronic rhinosinusitis with nasal polyps (CRSwNP), as well as additional anatomic variants.

A single institutional retrospective chart review of patients undergoing ESS for AFRS and CRSwNP was performed. AEA-SB length were compared between the 2 groups. Other anatomic variants, including Keros measurement and presence of supraorbital ethmoid air cells (SOEC), concha bullosa (CB), sphenoethmoidal, and infraorbital ethmoid cells were measured and compared between the 2 groups.

Twenty-one patients were included in each cohort. The AFRS group was younger in age (P = .015) and had a significantly longer AEA-SB length (P = .014) compared to the CRSwNP group. No significant differences were observed between the 2 groups regarding Keros measurement, presence of concha bullosa, infraorbital ethmoid, sphenoethmoidal, or SOEC. No association was seen between AEA-SB length and Keros class in either group.

AFRS harbors anatomical differences when compared to CRSwNP, with the former associated with a longer AEA-SB length. This key difference should be considered in preoperative planning to prevent injury to the AEA in patients undergoing ESS for AFRS.