2025 Poster Presentations
P043: THE ROLE OF ANTERIOR ETHMOIDAL ARTERY DURING ENDONASAL ENDOSCOPIC ACCESS TO THE LATERAL FRONTAL SINUS AND SKULL BASE
Cem Meco1; Suha Beton2; Hazan Basak, PhD2; Nihal Apaydin3; 1Ankara University Medical School and Salzburg Paracelsus Medical University Departments of ORL-HNS; 2Ankara University Medical School Department of ORL-HNS; 3Ankara University Medical School, Department of Anatomy
Introduction: During the endonasal endoscopic surgeries of the frontal sinus, transnasal visualization and visualized reach and manipulation at the lateral part of the frontal sinus and skull base poses a great challenge and most of the times is not possible due to inadequate reach. Especially in well pneumatized frontal sinus development this difficulty poses a greater challenge and even makes endonasal endoscopic approach (EEA) impossible which necessitates external approaches that require skin incisions and integrate osteoplastic techniques to access the same anatomical region. Even though advanced endoscopic surgery techniques were developed to overcome these difficulties, numerous anatomical studies have demonstrated that access to the lateral portion of the frontal sinus is not possible through an EEA. However, the periorbital suspension technique as earlier described by us overcomes the difficulty accessing these areas. As anterior ethmoidal artery (AEA) seems to play a role in this technique, we planned an anatomical study to assess its role in reaching far lateral frontal sinus and skull base through EEA.
Method: In this study we used 10 cadaver heads with 20 sides that has computed tomography (CT) done before dissections. CT scans were evaluated to assess pneumatization levels of frontal sinus and supraorbital recesses. Measurements for visualized reach to the far lateral aspect of the frontal sinus, skull base and supraorbital recess area through EEA were done and documented after gradual dissections in the order of Draf Type I, IIA, IIB, III procedures to determine the extent of access on every occasion. Then, the same measurements were done after dissection and transection of the AEA were done and periorbital suspension was added to the Draf procedures to further widen the access.
Results: Medial orbital wall posed the main limitation to the lateral access through EEA even if Draf procedures were utilized in well pneumatized sinuses. However, as the only medial attachment of periorbita, dissection and transection of the AEA enabled adequate lateralization of periorbita while performing periorbital suspension which enabled full access to the lateral frontal sinus, skull base and supraorbital recesses in all cadavers.
Conclusion: Our dissection findings revealed that the AEA plays a key role as an anatomical structure in performing periorbital suspension procedure. Its transection enables adequate lateralization of periorbita after sufficient bone removal that eliminates the main limitation during endonasal endoscopic access to the lateral frontal sinus, skull base and supraorbital recess.