Attachment variations of Koerner Septum in patients with anterolateral sigmoid sinus: Surgical implications and limitations

This study aims to examine in detail the attachment variations, integrity, and fenestration characteristics of the Koerner Septum (KS) in patients with an anterolateral sigmoid sinus (ALSS) who undergo temporal region tomography for any reason, to reveal the relationship of these anatomical variations with lateral displacement and Chronic Otitis Media (COM), to evaluate their effects on surgical approach, and to identify potential surgical risks. The study included 210 individuals aged 18-85 years who did not have any pathology that could disrupt the structure of the temporal region. The attachment patterns of the KS, the presence of ALSS, COM, and KS, and their relationships with each other were evaluated across sides and genders. Of the patients, 57% (n=120) were female and 43% (n=90) were male, with an average age of 45.16 ± 14.83 years. 71.9% (n=151) of the patients had right-sided KS and 76.2% (n=160) had left-sided KS. KS was incomplete in 98.7% and fenestrated in 98.8%. Right-sided ALSS was observed in 59.5% of cases, while left-sided ALSS was observed in 46.2%. The presence of right-sided ALSS was found in 46.7% (n=42) of men and 69.2% (n=83) of women and was statistically significant (p=0.001). No statistically significant differences were found in KS parameters based on the presence of ALSS and COM (p>0.05). ALSS and KS were detected bilaterally more frequently in women (35.8%) than in men (17.8%), and this was statistically significant (p=0.04). In mastoid surgeries, ALSS was found to be significantly higher on the right side in women (p=0.001). Furthermore, the rate of both ALSS and KS being bilateral was significantly higher in women (p=0.04). Keywords: Koerner septum, Sigmoid sinus variation, Temporal bone surgery