Sagittal computerized tomography reconstruction of the lateral nasal wall for functional endoscopic sinus surgery.

Coronal computerized tomography (CT) scanning is imperative in the preoperative work-up for functional endoscopic sinus surgery (FESS). This study describes additional information provided by lateral CT reconstruction with special attention to the (naso-) frontal recess. Thin axial scans were taken from 10 patients suffering from chronic rhinosinusitis. This procedure avoided artefacts from dental fillings on the computerized reconstructions. The common landmarks of the lateral nasal wall as described in the surgical anatomy of FESS were easily identified on sagittal views. The average angulation of the sagittal plane from the midline required to obtain optimal images of the frontal recess was antero-posteriorly 8.7 degrees (SD, 2.4), cranio-caudally 7.7 degrees (SD, 2.6). Size and condition of the frontal recess could be demonstrated. Variations of the angle between frontal sinus and ethmoid infundibulum appeared to depend on the anterior projection of the frontal sinus and may give an indication as to the optimal endoscopic angle for visualization of the frontal ostium. Sagittal reconstructions provide information for better spatial orientation particularly in the plane of the surgical approach and may help to diagnose underlying functional changes of chronic frontal sinusitis.