Assessment of mucosal changes associated with nasal splint in a rabbit model

Numerical Analysis of Nasal Flow Characteristics with Microparticles

This study was to investigate the airflow characteristics in nasal cavity under different conditions and analyze the effects of different respiratory intensity, particle diameter, and particle density on the deposition of particles carried by airflow in the nasal cavity, respectively. The three-dimensional geometric model of the nasal cavity was established based on typical medical images. The SST k-ω turbulence model in the computational fluid dynamics (CFD) was used to simulate the airflow in the nasal cavity, and the deposition of particles in the airflow was analyzed with the Lagrange discrete phase model. The results showed that the air in the nasal cavity flows in the left and right nasal passages through the perforation in front of the nasal septum and forms a vortex structure at the perforation site, and the particle deposition efficiencies (DE) under perforation nasal cavity are higher than that under normal nasal cavity. Different parameters had different effects on the particle DE. The results showed that the DE of particles with smaller size (≤2.5 μm) is lower; the higher the respiration intensity, the greater the influence on the DE of the larger particle size; and the larger particle density (>1550 kg·m⁻³) has little effect on the DE of larger particle size (DP = 10 μm). The results agree well with the corresponding research data.

Porcine Tracheal Mucosa-Derived Decellularized Patch to Prevent Septal Perforation in a Rabbit Model

BACKGROUND

Nasal septal perforation is caused by bilateral septal mucosal injuries resulting from nasal trauma and septal surgeries. Previous studies have reported that biocompatible materials may be effective for repairing nasal septal perforations. However, they were primarily used for treatment; no study has investigated their use for prevention of nasal septal perforation.

OBJECTIVE

To determine whether porcine tracheal mucosa-derived decellularized patch can prevent the progression of nasal mucosa injuries to septal perforations.

METHODS

Bilateral nasal septal mucosal defects were surgically induced in 36 rabbits. Silastic sheets were applied bilaterally in all rabbits, and decellularized mucosal patch was applied unilaterally (n = 12) or bilaterally (n = 12) at the defect site in the respective experimental groups. Between 1 and 8 weeks postoperatively, the animals were sacrificed, and their nasal septa were completely removed. The excised septa were examined macroscopically and microscopically (histopathological examinations). Moreover, glycosaminoglycan (GAG) estimations of the septa were performed to evaluate mucosal regeneration and mechanical properties.

RESULTS

Septal perforations occurred in 5 animals in the control group (5/12; 42%), 1 in the unilateral group (1/12; 9%), and in none in the bilateral group. Compared with the control group, the experimental groups showed significantly different mucosal and cartilage regeneration.

CONCLUSION

Decellularized porcine tracheal mucosa can prevent mucosal defects from progressing to septal perforation, promote the repair of mucosal defects, and protect the nasal cartilage.

The Effect of Dexpanthenol-Vitamin A (Nazalnem) on Silastic Splints After Nasal Septal Surgery

OBJECTIVE

To investigate the effect of dexpanthenol-vitamin A (Nazalnem) ointment applied to the surface of silastic splints with an airway immediately after nasal septal surgery on postoperative complaints and nasal mucosa function.

MATERIALS AND METHODS

The study enrolled 60 patients undergoing nasal septoplasty surgery. Group 1 (n = 30) received silastic splints with ointment containing dexpanthenol-vitamin A (Nazalnem), and Group 2 (n = 30), the control group, received silastic splints with vaseline. Of these patients, 2 patients from the Group 1 and 9 from the Group 2 were excluded.A thin layer of ointment was applied to the flat side of a silastic splint with an airway. The splints were removed on the second postoperative day. Patients were evaluated preoperatively and 1 and 2 weeks postoperatively using a visual analog scale and the Sino-Nasal Outcome test (SNOT-22). Mucociliary clearance (MCC) tests were performed at the same times.

RESULTS

Visual analog scale for nasal crusting, nasal congestion, and foul odor was better in Group 1 than in Group 2 both at 1 week and at 2 weeks postoperatively (P < 0.05).The SNOT scores were significantly lower in Group 1 than in Group 2 at 1 week (P < 0.01), but did not differ at 2 weeks postoperatively (P > 0.05).Postoperatively, the MCC were insignificant between the groups and within the groups at 1 and 2 weeks (P > 0.05).

CONCLUSION

Although Dexpanthenol-Vitamin A ointment had no direct effect on wound healing, it had significant effects on crusting, obstruction, and foul smell. However, silastic splints with dexpanthenol did not improve the MCC of the nose.

Effects of polymer-based, silver nanoparticle-coated silicone splints on the nasal mucosa of rats

Infection is a serious complication after nasal packing that otolaryngologists seek to avoid. The aim of this study is to investigate the use of silver (Ag) nanoparticle, which serves as antimicrobial agents, with nasal tampons. The study design is an experimental animal model and the setting is tertiary referral center. Twenty-four rats were randomized into the following four groups: (1) control group (n = 6); (2) silicone nasal splint (SNS) group (n  =  6); (3) polypropylene-grafted polyethylene glycol (PP-g-PEG) amphiphilic graft copolymer-coated SNS group (n  =  6); and (4) Ag nanoparticle-embedded PP-g-PEG (Ag-PP-g-PEG) amphiphilic graft copolymer-coated SNS group (n  =  6). These tampons were applied to rats for 48 h, after which they were removed in a sterile manner, and the rats were sacrificed. The nasal septa of the rats were excised, and assessments of tissue changes in the nasal mucosa were compared among the groups. The removed tampons were microbiologically examined, and quantitative analyses were made. When the groups were compared microbiologically, there were no significant differences in bacterial colonization rates of coagulase-negative Staphylococcus spp. among the three groups (p = 0.519), but there was a statistically significant difference among bacterial colonization rates of Heamophilus parainfluenzae and Corynebacterium spp. (p = 0.018, p = 0.004). We found that H. parainfluenzae grew less robustly in the Ag-PP-g-PEG than the PP-g-PEG group (p = 0.017). However, we found no significant difference between the Ag-PP-g-PEG and SNS groups, or between the SNS and PP-g-PEG groups. The growth of Corynebacterium spp. did not differ significantly between the Ag-PP-g-PEG and SNS groups (p = 1.000). When Group 4 was compared with Group 2, the former showed less inflammation. Compared with other tampons, Ag-PP-g-PEG amphiphilic graft copolymer-coated silicone nasal tampons caused less microbiological colonization and inflammation. Therefore, the use of these tampons may prevent secondary infections and reduce the risk of developing complications by minimizing tissue damage.