Efficacy of Platelet-Rich Plasma as an Adjuvant Therapy to Endoscopic Sinus Surgery in Anosmia Patients with Sinonasal Polyposis: A Randomized Controlled Clinical Trial.

Background: Treatment of patients with anosmia is a major therapeutic challenge. The present study evaluated the efficacy of platelet-rich plasma (PRP) in the treatment of anosmia in patients with sinonasal polyposis. Methods:In the present clinical trial, atotal of 48 patients with sinonasal polyposis with theIran Smell Identification Test (I-SIT) score of <6 who completed the medical treatment and were observed 3 months after the sinus surgery were included and randomly divided in to 2groups. After endoscopic sinus surgery, the intranasal injection of 1 mL PRP and normal saline was performed in the olfactory region in the intervention and control groups, respectively. Odor function was assessed using the I-SIT at the baseline and at the end of the studyby an independent samples ttest. Results: Based on the findings of the present study, the I-SIT improved in both groups during the follow-up, as it reached from 2.63 ± 2.63 to 5.85 ± 2.46 after oral steroid administration and 18.93 ± 1.14 after surgery in the intervention group and from the baseline of 2.10 ± 2.83 to 5.62 ± 2.99 after receiving standard medical treatment and 18.43 ± 1.36in the control groupafter surgery. Although this improvement was significant in both groups in either time interval (all with p<0.001), there was no significant difference between the 2groups in terms of changes in the I-SIT score (p=0.802). Conclusion: According to the current study, PRP injection showed no short-term effect on the recovery of olfactory function in patients with sinonasal polyposis.