Septal dislocation for endoscopic access of the anterolateral maxillary sinus and infratemporal fossa

Background: Transnasal approaches to the anterolateral maxillary sinus and infratemporal fossa are challenging with traditional endoscopic techniques and instrumentation. Additional access in the anterior and lateral direction can be obtained with modified endoscopic medial maxillectomy (MEMM) or total endoscopic medial maxillectomy (TEMM) or via a transseptal approach. Alternatively, we have used a septal dislocation technique to help access these areas. Access to these areas may be necessary for treatment of inverted papilloma, schwannoma, and juvenile nasopharyngeal angiofibromas. The aim of this study is to examine the effectiveness of septal dislocation for anterolateral reach in extended endoscopic sinus surgery. Methods: Cadaver dissection was performed on eight sides. MEMM, TEMM, and septal dislocation were sequentially performed according to standard techniques. Image-guided axial screenshots were used to identify the extent of anterolateral reach in each stage by measuring the angle of access from the midline. Results: TEMM adds 12° of anterolateral reach when compared with MEMM. With septal dislocation, an average of 20 additional degrees is provided over TEMM. The anterior maxillary sinus is routinely accessed with straight instruments after septal dislocation. Conclusion: The anterolateral maxillary sinus and infratemporal fossa are difficult areas to access with standard endoscopic techniques. Septal dislocation is a straightforward technique to achieve additional visualization and access when combined with TEMM.