Stellate Ganglion Block Combined with Hyperbaric Oxygen Therapy for Sudden Sensorineural Hearing Loss: A Retrospective Three-Arm Study

Sudden sensorineural hearing loss (SSNHL) carries unpredictable recovery, and adjunctive therapies beyond systemic corticosteroids are limited. Stellate ganglion block (SGB) and hyperbaric oxygen therapy (HBOT) have each been proposed as adjuncts, yet their combined effect remains poorly characterized. A retrospective three-arm cohort study (IRB No. 202401644B0) enrolled 75 SSNHL patients: Control (standard corticosteroid, n = 39), SGB (n = 21), and SGB+HBOT (n = 15). PTA4 improvement and Siegel recovery categories were assessed at two weeks, one month, and two months. Subgroup analyses stratified patients by baseline PTA4 < 70 dB and ≥70 dB. Groups differed significantly in overall baseline PTA4 (Kruskal–Wallis p = 0.044; SGB group worst at 80.4 ± 17.3 dB) and in diabetes mellitus (DM) prevalence (Control 44% vs. 7% in SGB+HBOT; p = 0.018). Within the ≥70 dB subgroup, baseline PTA4 was balanced across groups (Control 86.5 ± 13.0 dB, SGB 88.2 ± 14.2 dB, SGB+HBOT 90.9 ± 15.3 dB; p = 0.748). In this balanced stratum, SGB+HBOT achieved the greatest two-month PTA4 improvement (+23.6 ± 27.2 dB) and the highest complete recovery rate (43%, 3/7), versus 27% (3/11) in Control and 9% (1/11) in SGB. No statistically significant between-group differences were identified. However, SGB+HBOT demonstrated the numerically greatest audiometric improvement and the highest complete recovery rate in the severe–profound subgroup despite baseline disadvantages, suggesting a possible therapeutic benefit for this population. These exploratory findings support prospective evaluation in an adequately powered randomized controlled trial.