Rapid post-mortem human temporal bone retrieval and cochlear preservation: a standardised protocol with systematic comparison of published methodologies

Human temporal bone specimens are essential for studying inner ear pathology, age-related hearing loss, and cochlear implantation. However, limited availability and rapid postmortem degeneration of neurosensory structures remain major challenges.

To describe a standardised protocol for rapid postmortem human temporal bone retrieval and cochlear chemical fixation and to compare it with previously published methods.

PubMed/MEDLINE and Web of Science were searched for protocols published between January 2000 and October 2026, supplemented by Google Scholar and the Cochrane Library. Postmortem interval, retrieval technique, fixation, decalcification, embedding and downstream applications were compared with a standardised workflow of the Inner Ear Laboratory, Medical University of Innsbruck: bilateral en block retrieval, targeted within 12hours postmortem; perfusion through the oval and round windows; fixation with freshly prepared 4% formaldehyde; neutral-pH EDTA decalcification; embedding and serial sectioning. The protocol was validated in 40 donors (aged 61-97 years).

Of 599 records identified, 19 studies were included, showing considerable variability in preservation methods and reporting standards. In our series, bilateral retrieval took a mean of 35.7 ± 7.2min (median 32.5; range 25-50min; n = 32 timed donors), and postmortem interval was below 24hours in 37 of 40 donors. The tissue was well preserved and suitable for histological and immunohistochemical analyses in most specimens evaluated.

We present an optimised workflow, compare it with the literature, and demonstrate that it yields tissue of sufficient quality for histological and immunohistochemical analyses.