Investigation of the relationship of sphenoidal sinus and carotid canal with neurovascular structures by DynaCT method for endoscopic endonasal surgery, anatomy dissertation thesis

Purpose: Endoscopic endonasal transsphenoidal surgery is considered the gold standard treatment for resection of pituitary adenomas and other lesions of the sellar region. Preoperative imaging, detailed examination of the anatomy of the sphenoidal sinus and adjacent neurovascular structures is important in surgical planning. The aim of the present study was to to evaluate the anatomical relations of the sphenoidal sinus and adjacent structures with the flat-panel DynaCT method, which has been used more frequently in recent years. Methods: The DynaCT images of 278 patients (556 sides) [164 females (%59) and 114 males (%41)] were analyzed in this study. The type of sphenoidal sinus pneumatization, prevalence of internal carotid artery (ICA) and optic nerve (ON) protrusion and dehiscence, septation of sphenoidal sinus, pneumatization of anterior clinoid proces (ACP) and the presence of onodi cell were assessed bilaterally. Results: There was no conchal type pneumatization. The percentages of presellar, sellar types of pneumatization were %15,8 (n=44) and %84,2 (n=234). The more pneumatized the sinus sphenoidalis was, the greater the frequency of ON and ICA protrusion of their wall to the sinus (p=0,001). There was a strong correlation between NO and ACI protrusion on the sides and the pneumatization of the ipsilateral PCA (p<0,001). In the same, a significant relationship was found between the parties (right-left) in all parameters examined bilaterally (p<0,001). Onodi cell in 20.1% of the right side (n=56); it was seen in 24.1% (n=67) of the left side. No significant association was found between NO protrusion or dehiscence and the presence of onodi cells. Conclusion: The present study may be useful in reducing the risk of iatrogenic damage by providing anatomical information about the sphenoidal sinus and surrounding structures, which are necessary to avoid intraoperative complications.