Effectiveness of Multiple Platelet-Rich Plasma Injections for Olfactory Dysfunction
Jerome R. Lechien, Sven SaussezImportance
The injections of platelet-rich plasma (PRP) in the olfactory clefts of patients with olfactory dysfunction (OD) is an emerging treatment. To date, no study investigated the effectiveness of multiple PRP injections.
Objective
To evaluate the effectiveness and usefulness of multiple injections of PRP in the olfactory clefts of patients with OD.
Design
Prospective controlled study.
Setting
Monocentric medical center.
Participants
Patients with long-lasting OD treated with PRP injections and controls who underwent olfactory training with multiple psychophysical olfactory assessments.
Intervention
Two PRP injections into the olfactory clefts at 4- to 6-month intervals.
Main Outcomes
Outcomes included adverse events, dose-effect relationships, and olfactory function changes measured by threshold, discrimination, and identification (TDI) testing with minimal clinically important difference (MCID).
Results
Eighty-three subjects completed the evaluations. Patients had anosmia (n = 39), hyposmia (n = 27), and parosmia (n = 17). The mean duration of OD was 49.1 ± 46.9 months. Seventy-seven patients received 2 injections. Transient epistaxis was the primary adverse event (46.2%). The mean injected PRP volume ranged from 1.4 to 1.7 mL. TDI significantly increased after both first and second injections across all OD subgroups. MCID was achieved in 49.4% after a first injection and 28.9% after a second. MCID was reached in 63 cases (75.9%) from baseline to final evaluation. Baseline TDI strongly predicted post-second injection TDI (
Conclusion and Relevance
Two injections of PRP demonstrate significant improvement in psychophysical olfactory evaluations. Future studies are needed to determine the optimal number of injections and identify predictors of therapeutic effectiveness.