Computed tomographic assessment of risk of anterior skull base injury of adult patients in tertiary care centre: a cross-sectional study

Abstract

Background and objectives: Functional endoscopic sinus surgery (FESS) carries the risk of anterior skull base injury. Understanding computed tomography of the paranasal sinuses (CT PNS) and anatomical variations is crucial before surgery. Several classifications, including Kero’s, Gera’s, and Thailand-Malaysia-Singapore (TMS), assess the risk of skull base injury. The objective was to determine the risk of anterior skull base injury using CT PNS in adult patients. Methods: A study of 188 patients with head and paranasal sinus pathologies used CT scans to measure olfactory fossa depth, the angle between lamina papyracea and horizontal plane, and the distance from the orbital rim to the cribriform plate. Variations were classified using Kero’s, Gera’s, and TMS classifications. Results: The study involved 188 individuals aged 18–85, with OF depths ranging from 0.1 to 0.52 cm. Kero’s Class I was observed in 82.44% and 81.38% of individuals, while distances from orbital floor to cribriform plate and ethmoidal roof ranged from 1.37 to 2.93 cm. TMS Type I was observed in all individuals, and the angle between lateral lamella of the cribriform plate and cribriform plate ranged from 34° to 85°. Gera’s Class II was observed in 77.12% and 84.57% of individuals. Conclusion: CT PNS provides important anatomical information for assessing the risk of skull base injury during FESS. Kero’s, Gera’s, and TMS classifications can be utilized to evaluate this risk. The study findings provide insights into the variations in olfactory fossa depth, distance measurements, and angle, which can aid in preoperative planning and reducing complications during FESS in Nepalese populations.