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

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. 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. 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). According to the current study, PRP injection showed no short-term effect on the recovery of olfactory function in patients with sinonasal polyposis.