Pneumolabyrinth: a systematic review

Purpose: The aim of this study is to provide a systematic review of the literature about the etiology, clinical and radiological presentation, surgical management, and outcomes of pneumolabyrinth (PNL). Methods: A systematic review of the literature was performed including studies published up to September 2020 in electronic databases (PubMed/MEDLINE, EMBASE, Cochrane Library, and Scopus). The PRISMA standard was applied to identify English, Italian, or French-language studies mentioning PNL. Full texts lacking information on the etiology were excluded. Data concerning the cause, site of air bubbles/fistula, clinical presentation, treatment, and outcome were collected. A qualitative synthesis of the results was performed. Results: Seventy-eight articles were eventually included; 132 patients were involved in the qualitative synthesis. The most common causes were: stapes surgery (24/132, 18.2%), temporal bone fracture (42/132, 31.8%), head trauma without temporal bone fracture (19/132, 14.4%), penetrating trauma (21/132, 15.9%), and barotrauma (15/132, 11.4%). The site most commonly involved was the vestibule (102/107, 95.3%), followed by cochlea (43/107, 40.2%) and semicircular canals (25/107, 23.4%). Conclusion: The etiopathogenesis of PNL can be summarized in traumatic, iatrogenic, or inflammatory/infective. Its management consists in exploratory tympanotomy and sealing the fistula, but also conservative treatments can be attempted. Vestibular symptoms disappear in the majority of cases. Instead, the prognosis of hearing function is widely variable, and complete recovery is less probable. The certainty of evidence is still too low to make it useful for clinical decision-making.