A protocol for a network meta-analysis of interventions to treat patients with sudden sensorineural hearing loss

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.

Exploratory tympanotomy in sudden sensorineural hearing loss for the identification of a perilymphatic fistula - retrospective analysis and review of the literature

OBJECTIVE

The diagnostic value of exploratory tympanotomy in sudden sensorineural hearing loss remains controversial. This study and review were performed to identify the incidence of perilymphatic fistula in patients with sudden sensorineural hearing loss. The effectiveness of tympanotomy for sealing of the cochlear windows in cases with perilymphatic fistula was evaluated.

METHODS

A search in common databases was performed. Overall, 5034 studies were retrieved. Further, a retrospective analysis on 90 patients was performed.

RESULTS

Eight publications dealing with tympanotomy in patients with sudden sensorineural hearing loss were identified. In 90 patients diagnosed with sudden sensorineural hearing loss and undergoing exploratory tympanotomy, 10 patients (11 per cent) were identified with a perilymphatic fistula, and this corresponds to the results obtained from our review (13.6 per cent).

CONCLUSION

There was no significant improvement after exploratory tympanotomy and sealing of the membranes for patients with a definite perilymphatic fistula.

A systematic review and network meta-analysis of existing pharmacologic therapies in patients with idiopathic sudden sensorineural hearing loss

BACKGROUND

Hearing loss is one of the leading causes of disability worldwide. Patients with hearing loss experience impaired quality of life, as well as emotional and financial consequences that affect both themselves and their families. Idiopathic sudden sensorineural hearing loss (ISSNHL) is a common but difficult to treat condition that has a sudden onset of ≤ 72 hour associated with various etiologies, with the majority of cases being idiopathic. There exists a wide range of therapeutic options, however, the uncertainty surrounding their comparative efficacy and safety makes selection of treatment difficult. This systematic review and network meta-analysis (NMA) assessed the relative effects of competing treatments for management of ISSNHL.

METHODS

A protocol for this review was registered with PROSPERO (CRD42017073756). A detailed search of MEDLINE, Embase and the Cochrane Library from inception to February 8th, 2018 was carried out by an experienced information specialist. Grey literature was also searched. Screening full-text records, and risk of bias assessment were carried out independently by two reviewers, and disagreements were resolved through consensus or third party adjudication, while data was collected by one reviewer and verified by a second reviewer. Bayesian network meta-analyses (NMA) were performed to inform comparisons between interventions for a priori specified outcomes that included pure tone average (PTA) improvement and hearing recovery.

RESULTS

The search identified a total of 1,138 citations, of which 613 remained for review after removal of duplicates. Of these, 23 publications describing 19 unique studies (total sample size of 1,527) met our a priori eligibility criteria, that were assessed to be at unclear or high risk of bias on several domains. We identified data on several interventions for ISSNHL therapy and were able to construct treatment networks consisting of six intervention groups that included placebo; intratympanic (IT) steroid; IT plus systemic steroid; per oral (PO) steroid; intravenous (IV) steroid; and IV plus PO steroid for our NMAs. IT plus systemic steroids demonstrated the largest difference in PTA improvement compared to placebo (25.85 dB, 95% CrI 7.18-40.58), followed by IV plus PO steroids (22.06 dB, 95% CrI 1.24-39.17), IT steroids (18.24 dB, 95% CrI 3.00-29.81). We observed that the difference of PTA improvement between each intervention and placebo diminished over time, attributed to spontaneous recovery. The binary outcomes of hearing recovery demonstrated similar relative ordering of interventions but were less sensitive than PTA improvement to capture the significant differences between interventions and placebo.

CONCLUSION

Unclear to high risk of bias trials rated IT plus systemic steroid treatment as the best among the six interventions compared, and all active treatments were better than placebo in improving PTA. However, it should be noted that certain comparisons were based on indirect evidence only or few studies of small sample size, and analyses were unable to control for steroid type and dosage. Given these limitations, further data originating from methodologically sound and rigorous trials with adequate reporting are needed to confirm our findings.

Determining the Sample Size for Future Trials of Hearing Instruments for Unilaterally Deaf Adults: An Application of Network Meta-analysis

OBJECTIVE

Previous trials have compared the efficacy of hearing instruments to no intervention in adults with single-sided deafness (SSD) or the relative efficacy of different instruments. Network meta-analysis (NMA) was used to refine estimates of effect sizes to determine required sample sizes for further trials.

DATA SOURCES

PubMed, EMBASE, MEDLINE, Cochrane, CINAHL, and DARE databases were searched with no restrictions on language, with studies to February 2015 included.

STUDY SELECTION

Studies were included that 1) assessed hearing instruments in adults with SSD; 2) compared instruments with other instruments, placebo, or no intervention; 3) measured speech perception in quiet/noise and listening ability; 4) were prospective controlled or observational studies.

DATA EXTRACTION

The following data were extracted: sample size in each group, type of intervention and comparator, type of outcomes, mean outcome scores and their 95% confidence intervals.

DATA SYNTHESIS

Random-effects meta-analysis was conducted to determine pooled effects for each outcome based on direct evidence alone. NMA used graph-theoretical method to determine pooled effects based on indirect evidence. Sample size calculations were conducted for each outcome for each class of evidence.

CONCLUSIONS

The incorporation of indirect evidence had substantial impacts on some effect sizes but negligible impacts on other effects. The most notable impacts were on self-reported listening ability and measures of speech perception in noise. Changes in effect size estimates and required sample sizes resulting from the incorporation of indirect evidence highlight areas of uncertainty where trials may be feasible to conduct.