Guiliang Huang1, Xihui Chen, Hongyan Jiang. 1. Otorhinolaryngology Hospital, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
Abstract
OBJECTIVE: To evaluate the effects of NasoPore after packing of the middle ear in guinea pigs. STUDY DESIGN: A randomized, prospective, controlled animal study. SETTING: University laboratory. SUBJECTS AND METHODS: Forty-one guinea pigs were divided into 3 groups. In group 1(n=12), the middle ears of animals were unilaterally implanted with NasoPore, leaving the contralateral middle ears packed with absorbable gelatin sponge soaked in a solution containing kanamycin and furosemide as an ototoxicity-positive control; group 2 (n = 17) underwent the same experimental protocol as group 1, except the gelatin sponge was unsoaked; in group 3 (n = 12), NasoPore was inserted unilaterally and no packing material was placed into the contralateral ear. Auditory brainstem responses (ABRs) were performed preoperatively and 3 months after the procedure. The surface preparation and scanning electron microscopy (SEM) were assessed 3 months postoperatively, whereas pathology of middle ear was analyzed in 5 samples of group 2. RESULTS: ABR thresholds of the contralateral ear significantly increased in group 1 and were slightly shifted in group 2 compared with the NasoPore-packed and nonpacked ears 3 months postoperatively. The NasoPore-packed middle ears were found to have less fibrosis and inflammation and less thickened bone and tympanic membranes than Gelfoam-packed ears. Surface preparations and SEM showed no ototoxicity in the inner ear of NasoPore-packed ears. CONCLUSION: NasoPore appears to be effective for use in otosurgery. It caused less fibrosis in the middle ear than conventional packing agents and no ototoxicity to the inner ear.
OBJECTIVE: To evaluate the effects of NasoPore after packing of the middle ear in guinea pigs. STUDY DESIGN: A randomized, prospective, controlled animal study. SETTING: University laboratory. SUBJECTS AND METHODS: Forty-one guinea pigs were divided into 3 groups. In group 1(n=12), the middle ears of animals were unilaterally implanted with NasoPore, leaving the contralateral middle ears packed with absorbable gelatin sponge soaked in a solution containing kanamycin and furosemide as an ototoxicity-positive control; group 2 (n = 17) underwent the same experimental protocol as group 1, except the gelatin sponge was unsoaked; in group 3 (n = 12), NasoPore was inserted unilaterally and no packing material was placed into the contralateral ear. Auditory brainstem responses (ABRs) were performed preoperatively and 3 months after the procedure. The surface preparation and scanning electron microscopy (SEM) were assessed 3 months postoperatively, whereas pathology of middle ear was analyzed in 5 samples of group 2. RESULTS: ABR thresholds of the contralateral ear significantly increased in group 1 and were slightly shifted in group 2 compared with the NasoPore-packed and nonpacked ears 3 months postoperatively. The NasoPore-packed middle ears were found to have less fibrosis and inflammation and less thickened bone and tympanic membranes than Gelfoam-packed ears. Surface preparations and SEM showed no ototoxicity in the inner ear of NasoPore-packed ears. CONCLUSION: NasoPore appears to be effective for use in otosurgery. It caused less fibrosis in the middle ear than conventional packing agents and no ototoxicity to the inner ear.