2025 Proffered Presentations
S366: EXPANDED ENDOSCOPIC ENDONASAL APPROACHES TO THE MAXILLARY SINUS AND MEDIAL MIDDLE CRANIAL FOSSA
Yun-Kai Chan, MD1; Kai-Chun Lin, MD1; Po-Kai Huang, MD2; Chia-Hsing Lin, MD2; Ying-Piao Wang, MD, PhD2; 1Department of Neurosurgery, MacKay Memorial Hospital, Taipei, Taiwan; 2Department of Otolaryngology-Head and Neck Surgery, MacKay Memorial Hospital, Taipei, Taiwan
Introduction: Lesions in the posterolateral wall of the maxillary sinus or medial middle cranial fossa can be accessed using various approaches. The Endoscopic Endonasal Approach (EEA) offers benefits such as minimal invasiveness, reduced brain manipulation, and decreased retraction. This study aims to make the comparison between EEA with medial maxillectomy (MM), the prelacrimal approach (PL), the modified Denker’s approach (MD), and the Caldwell-Luc transmaxillary approach (CLTM).
Materials and Methods: Using CT registration, three cadavers (six sides) were dissected. For the posterolateral wall of the maxillary sinus, the medial superior point, medial inferior point, lateral superior point, most lateral point, and lateral inferior point were measured to calculate the area of exposure. For the medial middle cranial fossa, the Meckel’s cave, superior orbital fissure, and foramen rotundum were used for the anteromedial triangle. The Meckel’s cave, foramen rotundum, and foramen ovale were used for the anterolateral triangle. Attack angles to the Meckel’s cave in axial and sagittal planes were analyzed for each approach.
Results: The CLTM approach provided a significantly larger exposure area of the posterolateral wall of the maxillary sinus (811.42 ± 87.56 mm²) compared to EEA with MM (304.82 ± 29.18 mm²), PL (412.27 ± 31.82 mm²), and MD (598.2 ± 49.36 mm²) (p < 0.001). CLTM also offered greater lateral and inferior access. For the anteromedial triangle, the exposure area was larger with CLTM (185.07 ± 21.8 mm²) compared to EEA with MM (94.47 ± 4.94 mm²), PL (103.9 ± 4.8 mm²), and MD (117.21 ± 2.8 mm²) (p < 0.001). The anterolateral triangle's exposure areas were nearly identical across approaches. EEA with MM could not access the lateral aspect of Meckel’s cave. The CLTM approach provided the largest axial and sagittal attack angles.
Discussion and Conclusions: Two patients with trigeminal schwannoma were presented. One, with involvement of the middle cranial fossa and infratemporal fossa, underwent EEA combined with MM and CLTM, achieving complete tumor removal without complications. The other, with involvement of the pterygopalatine fossa, middle cranial fossa, and posterior cranial fossa, was treated using EEA combined with MM, PL, and MD, also achieving complete tumor removal without complications.
EEA combined with MM, PL, MD, and CLTM offers different trajectories for accessing the posterolateral wall of the maxillary sinus and medial middle cranial fossa, enabling safe access to skull base lesions depending on the unique features of each approach.
Fig. 1: Points used to measure the area of exposure of the right posterolateral wall of the maxillary sinus
Fig. 2: Points used to measure the area of exposure of the right anteromedial and anterolateral triangles
Fig. 3: Area of the left posterolateral wall of the maxillary sinus exposed by different approaches (Blue: EEA with medial maxillectomy; Yellow: Prelacrimal approach; Orange: Modified Denker’s approach; Pink: Caldwell-Luc transmaxillary approach)
Fig. 4: Area of the left anteromedial and anterolateral triangles exposed by different approaches (Pink: Prelacrimal approach; Green: Modified Denker’s approach; Orange: Caldwell-Luc transmaxillary approach)