Morphometry of the middle turbinate as a preparatory stage for surgical intervention on the middle meatus structures

Middle turbinate (MT) is a key structure in the nasal cavity, anatomical changes of which can impede access to the middle meatus and contribute to the development of synechias in the postoperative period. However, criteria allowing to determine the need for surgical intervention on the MT during endoscopic sinus surgery are absent in the literature. Objective. Comparative morphometric assessment of different variants of the MT structure using computed tomography data and anatomically based planning of surgical correction of the turbinate as a stage of endoscopic rhinosurgery. Material and methods. CT scans of 40 patients who underwent endoscopic interventions on the paranasal sinuses were analyzed. Among them, 20 (50%) had anatomically abnormal MT (paradoxical flexure, double, accessory and hypertrophied MT) and 20 (50%) had typical MT. Using a computer thermogram viewing program (RadiAnt DICOM Viewer (64-bit)), measurements of the MT were performed in two segments (points): in the area of the anterior attachment of the uncinate process to the lateral wall of the nasal cavity and in the projection of its free edge. The obtained indicators were compared with intraoperative data on the method of influence on the MT. Results. Horizontal dimension of the MT at the first point was significantly larger in patients with atypical anatomy and averaged 6.98±1.58 mm compared to 4.51±1.69 mm in the group with typical anatomy (p<0.001), horizontal dimension at the second point was significantly higher in the group with atypical anatomy — 7.21±1.16 mm versus 5.71±1.23 mm in the group with typical anatomy (p<0.001). Vertical dimension at the first and second points did not demonstrate significant differences between the groups (p=0.133 and p=0.860, respectively). Comparison of data from patients who underwent surgical correction of the MT and patients who underwent limited medialization of the turbinate showed significant differences in the horizontal and vertical dimensions of the MT at the first measurement point. The vertical dimension of the MT at the first point was significantly greater in the surgical correction group — 27.7±4.0 mm versus 24.5±4.1 mm (p=0.042). The horizontal dimension at the same point was also significantly higher in the surgical group — 7.25±1.55 mm versus 5.24±1.96 mm (p=0.006). The horizontal dimension of the MT at the second point had a tendency to differ between the groups (p=0.055) amounting to 7.19±1.07 and 6.21±1.43 mm, respectively, with a mean difference of 0.98 mm. The vertical dimension at the second point did not show statistically significant differences between the groups (p=0.473). Conclusions. The horizontal dimensions of the MT in both anatomical segments are significant morphometric indicators of anatomically abnormal anatomy as well as predictors of the need for surgical intervention on this structure. In patients with atypical anatomy of the MT, significantly larger horizontal dimensions compared to the group with typical anatomy were found, which allows to differentiate them objectively.