[Study on the influence of buried thread nasal augmentation on dorsal soft tissue of nose and revision rhinoplasty].

[OBJECTIVE] To investigate the influence of buried thread nasal augmentation on dorsal soft tissue of nose and revision rhinoplasty.

[METHODS] A clinical data of 29 patients requesting revision rhinoplasty after buried thread nasal augmentation, who were admitted between July 2017 and July 2019 and met the selection criteria, was retrospectively analyzed. All patients were female with an average age of 26.8 years (range, 18-43 years). The patiens were admitted to the hospital at 3-48 months after buried thread nasal augmentation (median, 15 months). Among them, there were 18 cases of insufficient nasal tip projection, 22 cases of insufficient nasal root projection, 7 cases of threads ectasia, 5 cases of threads exposure, 3 cases of infection, and 10 cases with two or more conditions. There were 9 cases of combined short nose deformity, 1 case of spherical hypertrophy of the nasal tip, 3 cases of deviation of the nasal columella, 3 cases of excessive width of the nasal base, and 1 case of nasal hump. Three infected patients only underwent threads removal and debridement. The rest patients underwent revision rhinoplasty, and the dorsum of the nose was made with polytetrafluoroethylene expansion; the tip of the nose was reshaped by taking autologous rib cartilage and alar cartilage in 16 cases, and by taking autologous septal cartilage and alar cartilage in another 10 cases. The threads and surrounding tissue specimens removed during operation were subjected to histologic observation. Nasal length and nasal tip projection were measured after revision rhinoplasty and the ratio was calculated to evaluate the nasal morphology; patient satisfaction was evaluated using the Likert 5-grade scale.

[RESULTS] Patients were followed up 12-48 months (mean, 18 months). Inflammation was controlled in 3 patients with infections caused by buried thread nasal augmentation. The remaining 26 patients had satisfactory results immediately after revision rhinoplasty. Before revision rhinoplasty and at 7 days and 6 months after revision rhinoplasty, the nasal length was (4.11±0.34), (4.36±0.25), and (4.33±0.22) cm, respectively; the nasal tip projection was (2.34±0.25), (2.81±0.18), and (2.76±0.15) cm, respectively; and the nasal tip projection/nasal length ratio was 0.57±0.08, 0.65±0.05, and 0.64±0.04, respectively. There were significant differences in the nasal length and the nasal tip projection between time points ( <0.05). There was a significant difference in the nasal tip projection/nasal length ratio between pre- and post-operation ( <0.05), but there was no significant difference between 7 days and 6 months after operation ( >0.05). The Likert score for satisfaction ranged from 1.5 to 5.0 (mean, 4.05). During follow-up period of 26 patients, no nasal prosthesis was exposed, and the shape of the nose was stable, and the nasal skin of 5 patients with exposed threads could be seen with different degrees of scarring; there was no infection, cartilage resorption, and no cartilage deformation, displacement, or exposure. Histological observation showed that absorbable threads were not only absorbed after implantation, but also with the prolongation of time, the inflammatory changes in the surrounding tissues caused by decomposition and absorption of the threads showed a gradual aggravation of the first, the heaviest inflammatory reaction in 6 to 12 months, and then gradually reduce the trend.

[CONCLUSION] After implantation of the absorbable thread into the subcutaneous tissue of the nasal dorsum, the nature of the thread is different from the body's own tissue, which will affect the soft tissue compliance of the nasal dorsum. The degradation and absorption of the thread will stimulate the infiltration of inflammatory cells and the proliferation of fibroblasts in the surrounding tissue and then form scar tissue, which will affect the design and effect of revision rhinoplasty.