Comparison of surgical freedom and area of exposure in three endoscopic transmaxillary approaches to the anterolateral cranial base.

Objective Endoscopic ipsilateral endonasal transmaxillary, contralateral endonasal transseptal transmaxillary, and Caldwell-Luc approaches can access lesions within the retromaxillary space and pterygopalatine fossa. We compared the exposure and surgical freedom of these transmaxillary approaches to assist with surgical decision making. Design Four cadaveric heads were dissected bilaterally using the three approaches just described. Prior to dissection, stereotactic computed tomography (CT) scans were obtained on each head to obtain anatomical measurements. Surgical freedom and area of exposure were determined by stereotaxis. Main Outcome Measures Area of exposure was calculated as the extent of the orbital floor, maxillary sinus floor, nasal floor, and mandibular ramus exposed through each approach. Surgical freedom was the area through which the proximal end of the endoscope could be freely moved while moving the tip of the endoscope to the edges of the exposed area. Results The mean exposed area was similar: 9.9 ± 2.5 cm(2) (Caldwell-Luc), 10.4 ± 2.6 cm(2) (ipsilateral endonasal), and 10.1 ± 2.1 cm(2) (contralateral transseptal) (p > 0.05). The surgical freedom of the Caldwell-Luc approach (113 ± 7 cm(2)) was greater than for either endonasal approach, 76 cm(2 )± 15 (p = 0.001) (ipsilateral endonasal) and 83 cm(2) ± 15 (p = 0.003) contralateral transseptal. Conclusions Our work demonstrates that the Caldwell-Luc endonasal approach offers greater surgical freedom than either approach for anterolateral skull base targets, although these approaches offer similar exposure.