Abstract
Introduction:
Minimal access endoscopic transmaxillary approaches have shown utility in the resection of lesions within the retromaxillary space and pterygopalatine fossa. The ipsilateral endonasal exposure may be enhanced by several maneuvers, including a contralateral transseptal approach, endoscopic Denker’s procedure, and endoscopic Caldwell-Luc approach. In this anatomic study, we compare the exposure and surgical freedom of these three different transmaxillary approaches. This information may be helpful for preoperative approach selection.
Methods:
Four silicon-injected cadaveric heads were dissected bilaterally (eight sides) using three endoscopic transmaxillary approaches: contralateral transseptal, endoscopic Denker’s, and Caldwell-Luc approaches. Prior to dissection, stereotactic CT scans were obtained on each head to obtain anatomic measurements. Using stereotactic guidance, surgical freedom was measured by calculating 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. Area of exposure was calculated with the extent of the orbital floor, maxillary sinus floor, nasal floor, and mandibular ramus exposed through each approach.
Results:
The mean area of exposure was similar between the three approaches, including an area of 9.9 cm
2
± 2.5 cm
2
for the Caldwell-Luc, 10.4 cm
2
± 2.6 cm
2
for the Denker’s, and 10.1 cm
2
± 2.1 cm
2
for the transseptal approach (
P
> 0.05). However, there were significant differences in surgical freedom. The surgical freedom of the Caldwell-Luc approach (113 cm
2
± 7 cm
2
) was greater than for either the Denker’s (76 cm
2
± 15 cm
2
,
P
= 0.000) or the transseptal approach (83 cm
2
± 15 cm
2
,
P
= 0.003). There was no significant difference in the surgical freedom between the latter two approaches (
P
= 0.2).
Conclusions:
Our work demonstrates that the endoscopic Caldwell-Luc approach offers greater surgical freedom than either the endoscopic Denker’s approach or contralateral transseptal approach to targets in anterolateral skull base, but offers a similar area of exposure. Knowledge of surgical freedom and area of exposure may help with surgical planning.