动物造模,实验兔黏膜损伤模型 z-bio 2021-10-09 586

　　Introduction: The mucosa of the nasal septum may be damaged by many nasal cavity surgeries. With the development of nasal endoscopic skull base surgery and the reconstruction of the septal valve, the number and extent of iatrogenic septal mucosal injuries are increasing. However, a comprehensive understanding of the healing process of the septal mucosa is still unclear, and it is necessary to clarify the factors that affect its regeneration. The wound repair process has been extensively studied in tissues such as gums and skin. Although various animal models have been used to study the healing process of the nasal mucosa, there are currently no studies evaluating the damage to the septal mucosa after wound healing. Silicone rubber sheets are usually used to promote mucosal healing after nasal surgery. It is believed that the mucosal healing process can be promoted by moisturizing the wound. Although the clinical results of the silicone rubber sheet after diaphragm formation have been reported, the effect of the material on the diaphragm mucosa has not been clearly documented. Moreover, relatively few studies have explained this effect at the histological level. Hyaluronic acid has a short epithelialization time in sinus surgery, but it has not been shown to promote the healing of septal mucosa. The purpose of this study is to investigate the regeneration process of rabbit nasal mucosa with traumatic septal defect, and to evaluate the effectiveness of various interventions in promoting the healing of mucosal injuries. Materials: Establishment of a wound healing model of rabbit nasal septum mucosa: 40 New Zealand white rabbits with an average weight of 3700 grams (3000-4200 grams) were used as experimental animals. It is randomly divided into four groups: control group, silicone rubber sheet group (SS), hyaluronic acid group (HA), silicone rubber sheet and hyaluronic acid group (SS + HA). Before the operation, each animal was injected intramuscularly and took 10mg/kg Zoirel (125mg/ml tribylamide, 125mg/ml Zolaxi) and Lumpun (2 % Thiazide) for general anesthesia. Shave nose hair and disinfect with povidone-iodine solution. After mixing 1% lidocaine with 1:100,000 epinephrine, a 5 cm long median dorsal skin incision was made through the periosteum with a 10 μm blade. The periosteal flaps on both sides are lifted to fully expose the nasal bone. For nasal osteotomy, use a 4mm rectangular straight bone knife to access the septum. Separate the upper cartilage from the nasal septum, and perform a bilateral partial resection of the inferior turbinate to completely expose the nasal septum. Use our circular punch to make a circular mucosal incision with a diameter of 7 mm. The mucosa of the round lesion rises and peels off the perichondrium, exposing the cartilage of the lower nasal septum. The bleeding was stopped with gauze, the left septum was on the intervention side of 16 rabbits, and the right 24 rabbits were on the intervention side. In the control group, after the mucous membrane was removed, the nasal bone was lifted and reset, and the skin was closed. For the SS group, a 1 cm x 1 cm piece of silicone rubber was placed on the defective septum and fixed on the septum with 5-0 Vicryl. In the HA group, according to the manufacturer's instructions, Melgel was cut into 1 cm x 1 cm squares, placed in the damaged septum, and hydrated with 1 ml of sterile saline. Finally, in the case of the SS + HA group, paste a silicone rubber sheet on top of the HA. Procaine penicillin (40,000 IU) was injected intramuscularly and fentanyl (0.02 mg/kg) was injected subcutaneously for analgesia for 3 consecutive days. All operations are performed by researchers. Two animals in each group were sacrificed at 1, 2, 3, 4, and 5 weeks to evaluate the healing process of the mucosa. Obtain an assessment of the entire cartilage spacing. Mucosal regeneration analysis: The collected diaphragm was rinsed with phosphate buffered saline 3 times to obtain a digital photo of the wound site. Use mild suction and flushing fluid to remove residual clots, foreign bodies and granulation tissue on the diaphragm. Use a micrometer with an optical microscope to measure the shortest distance on the sample and analyze the diameter of the remaining defects. Diameters less than 0.01 mm are considered to be fully healed. The samples were then fixed in 10% formaldehyde buffer for 24 hours. Then embed it in paraffin along the coronal direction. Four 4μm thick nasal septal defects were collected and stained with HE. The sections were evaluated under an optical microscope, and the regenerated septal mucosa was histologically analyzed. Measure the thickness of the mucosa from the cartilage defect to the cartilage transition zone. Mucosal Thickness Index (MTI) is the ratio of regenerated mucosa to intact mucosa on the opposite side. The epithelial thickness index (ETI) of the regenerated mucosa is the same as the thickness of the basement membrane (magnification 400 times). Ciliary Cell Index (CCI) is calculated as the ratio of the number of newly formed ciliated cells on the regenerating side to the number of ciliated cells on the opposite side. Conclusion: The size of the ventricular septal mucosal defect: no animal died during the perioperative period, and all 40 rabbits were specimens. Melgill? Rabbit's nasal septum healed 1-3 weeks after surgery, regardless of the presence of silicone rubber sheet. The average size of the septal mucosal defect was recorded. The average wound size of the control group at 1, 2, 3, 4, and 5 weeks after surgery was 5.1, 3.65, 1.2, 0.75, and 0.05 mm, respectively. Five weeks after the operation (0.1 mm and 0 mm), the defect healed completely. At 1, 2, 3, 4, and 5 weeks postoperatively, the average defect sizes in the SS group were 4.35, 2.1, 0.35, 0.15, and 0 mm, respectively, while those in the HA group were 5.1, 3.8, 2.05, 0.85, and 0 mm. 0.05 mm, 4.05, 3.15, 1.75, 0.65, and 0 mm in the SS + HA group, respectively. Complete mucosal healing was observed in each group after 5 weeks. The wounds in the SS group healed one week earlier than the control group. Within 2 weeks after surgery, the average size of SS defects was also significantly reduced. In the remaining groups, there was no significant difference in defect size. Mucosal and epithelial thickness: The loss of normal airway cilia and subcutaneous epithelium was observed early postoperatively. The thickness of the entire mucosa and epithelium increases with time. The average contralateral mucosal thickness and epithelial thickness of the control group were 167 μm and 29 μm, respectively. At 1, 2, 3, 4, and 5 weeks after surgery, the average MTI of the control group was 0.95, 1.45, 1.95, 1.4, and 1.1, and the SS group was 1.05, 1.6, 1.25, 1.3, and 1.15. The HA group were 1.2, 1.25, 1.35, 1.25, and 0.95, while the SS + HA group were 0.75, 1.2, 1.2, 0.75, and 0.95, respectively. There was no statistically significant difference in MTI in the intervention group. One week after surgery, the average ETI of the four groups of animals was 0.5, 0.45, 0.55, and 0.6, 0.6, 0.7, 0.8, 0.6 at 2 weeks after surgery, 0.7, 0.85, 0.65, 0.6 at 3 weeks after surgery, and 0.75, 0.8 at 4 weeks after surgery , 0.55, 0.6, 0.65, 0.55, 0.6 and 0.45, 5 weeks after the operation, the thickness of the mucosal epithelium in each group did not fully recover. At any given time, there were no significant differences in ETI between the intervention groups. Ciliary cell index: As time goes by, the number of regenerated mucociliary epithelial cells increases, CCI reaches 1, 1, 2, 3, 4 and 5 weeks after surgery, and the average CCI of the control group is 0.2 , 0.45, 0.68, 0.89, and 0.97 mm, while the average CCI of the SS group was 0.3, 0.7, 0.83, 0.85, and 0.98 mm. The HA group was 0.45, 0.63, 0.67, 0.83, 0.93mm; the SS + HA group was 0.35, 0.47, 0.63, 0.75, 0.9mm, respectively. In the early postoperative period, the silicone rubber sheet and hyaluronic acid were compared with the control group. The duration (1-2 weeks after surgery) CCI increased, but the difference was not statistically significant. Late postoperative CCI is similar to intervention. Conclusion: A new rabbit nasal septum model has been proposed to effectively evaluate the healing of the nasal mucosa. Silicone rubber sheets applied to mucosal defects of the nasal septum can significantly enhance mucosal regeneration in the early stages of injury, and ultimately lead to faster healing.