The Frontal Sinus Drainage in Relation to Frontal Sinus Surgery.

Abstract

In order to perform a successful endoscopic frontal sinus surgery, prevent complications, and lower the recurrence risk, it is essential to understand the anatomy of the frontal sinus (FS) and frontal recess cells with many variations in frontal sinus drainage (FSD). Preoperative assessment of the FSD in three levels in order to find prognostic factors in the decision process regarding the kind and the extent of surgery when required. Three FSD levels were assessed by computed tomography in two dimensions; antero-posteriorly and laterally in 100 consecutive patients with chronic sinusitis symptoms. The first level represents the proper drainage of FS. The second level is the drainage of FS without the effect of the frontoethmoidal cells. The third level is the maximum drainage that can be achieved in a single FS. The relation of FSD levels to FS and frontoethmoidal cells pathology were assisted. Within 100 patients (200 sides, 186 FSs), for the proper FSD, antero-posterior (AP) length was 5.94 ± 3.42mm in opaque FS and 5.32 ± 2.87mm in clear FS and its lateral length was 3.04 ± 1.6mm in opaque FS and 2.30 ± 1.25mm in clear FS. For the functional FSD, AP length was 8.97 ± 2.7mm in opaque FS and 8.05 ± 2.7mm in clear FS and its lateral length was 7.51 ± 1.69mm in opaque FS and 7.58 ± 1.75mm in clear FS. In the anatomical FSD, AP length was 11.25 ± 3.07mm in opaque FS and 10.01 ± 2.87mm in clear FS and its lateral length was 11.1 ± 2.6mm in opaque FS and 10.95 ± 1.7mm in clear FS. This study offers essential data for preoperative assessment in order to improve surgeons' awareness of the frontoethmoidal region for optimal safe EFSS with lower incidence of complications and recurrences.