The purpose of the present study was to observe the influence of speaking valve (SV) on aspiration, oral secretions, olfaction, and the phonation in perioperative tracheostomised patients with fibular flap reconstruction of mandibular defects based on fluid dynamics analysis.

Eight tracheotomised patients with fibular flap reconstruction of mandibular defects were divided into two groups, the SV group and control group. The SV group were asked to wear SV two days after the tracheostomy while the control group weren′t treated with SV. And the differences were compared between the two groups on aspiration, oral secretion, olfaction and phonation. Dye test was used to assess deglutition functions; visual analog scale (VAS) was adopted to measure oral secretions; patients can correctly answer the odor of volatile molecules were positive function of olfaction; patients can conduct language exchange were positive function of phonation. Two groups were scanned by CBCT before and after the surgery respectively and three-dimensional models were reconstructed with CBCT data by Mimics. The internal flow of upper respiratory tract was simulated by Gambit and Fluent software, and the differences between two groups on the pressure of pharyngeal cavity and infraglottic cavity were compared by SPSS 23.0 software, and the data results are demonstrated with the median (25%, 75%) .

There were significant differences between two groups, four patients of SV group had improvement in deglutition, oral secretion, olfaction and phonation (P<0.05) . The preoperative and postoperative pressures of infraglottic cavity in control group were 101 327.00 Pa (101 326.25, 101 327.75) and 101 270.00 Pa (101 269.25, 101 270.75) respectively, while the preoperative and postoperative pressure of infraglottic cavity in SV group were both 101 327.00 Pa (101 326.25, 101 327.75) , with no statistical significance (P>0.05) .

The application of SV can significantly decrease aspiration and oral secretion, improve olfactory function, and restore the communication ability for the perioperative tracheostomised patients underwent fibular flap reconstruction of mandibular defects, which helps patients safely go through the perioperative period. Therefore, SV is suitable to be applied in perioperative tracheotomised patients with fibular flap reconstruction of madibular defects.