Better late than never: initial experience of intra-arterial pulsed-urokinase-injection as a salvage therapy for refractory sudden sensorineural hearing loss

Background and purpose: Cochlear vascular micro-thrombosis has been hypothesized as one of the pathogenic mechanisms for sudden sensorineural hearing loss (SSNHL) refractory to regular management. This study aimed to evaluate the feasibility and safety of intra-arterial pulsed-injection urokinase (IAPU) as a salvage therapy for SSNHL after the failure of conventional therapy.

Methods: We retrospectively reviewed our patient database to identify refractory SSNHL patients between November 2017 and July 2020. Study outcomes before and after the IAPU therapy were compared between IAPU and conventional therapy groups.

Results: Sixty-seven moderate-profound SSNHL patients (29 in IAUP group, 38 in control group) were included in this study. Compared to the control group, patients in the IAPU group showed more significant improvement in pure tone average (PTA) (34.2 ± 23.5 vs. 10.7 ± 13.1, p < 0.001) and degree of hearing recovery (total: 20.7% vs. 5.3%, partial: 24.1% vs. 10.5%, mild: 27.6% vs. 13.2% and non: 27.6% vs. 71.1%) 2 weeks after admission. In the IAPU group, a significant improvement of PTA (86.6 ± 11.5 vs. 54.6 ± 20.1 dB, p < 0.005) was observed on the first day after IAPU treatment.

Conclusion: In carefully selected SSNHL cases with a highly suspected vascular origin, IAPU is a safe and effective therapy when conventional treatments have failed. Despite the encouraging findings of our work, large studies are needed to better investigate the strengths and limitations of this salvage therapy.