Risk assessment for divers with a history of middle ear surgery.

Objective: Risk assessment is worked out for diving after surgery on middle ears with differentiation on different interventions such as Myringoplasty, Tympanoplasty, Mastoidectomy, Stapes surgery, and implantable hearing systems.

Methods: Data research was carried out via the National Library of Medicine (pubmed.ncbi.nlm.gov) and ResearchGate (researchgate.net). In the literature, no evidence-based studies were found on barotraumatic injuries after ear surgery nor on non-operated ears. Therefore, Risk assessments are based on interpreting anatomical, physiological, and physical facts, the results of pressure-exposed cadaver tests, and the studies concerning follow-up observations on post-op ears after pressure exposition.

Results: Critical conditions after tympanoplasty type I, temporal fascia, cartilage, perichondrium, transposition of auto-ossicles, titanium TORP and PORP, omega connector, stapes surgery, malleovestibulopexy, canal wall down (CWD) and canal wall up (CWU) after cholesteatoma, obliteration of CWD, active hearing implants CI and soundbridge are presented. Immersion depth values are represented by the pressure difference between the auditory canal and the middle ear.

Discussion: Tympanoplasty type I: after the complete healing process and regular tympanometry type A, the risk is not higher than in non-operated ears. Minimal burst pressure is 35 kPa (11,71 ft or 3,57 msw) when diving without Valsalva and regular tympanic membrane (TM), 30 kPa (9,84 ft or 3,0 msw) in TM with atrophic scars. PORP: same risk as type I. TORP: risk is higher than type I: burst pressure 25 kPa (8,2 ft (2,5 msw). When the stapes footplate has contact with the matrix of the cholesteatoma, diving is contraindicated. CWU: same risk as type I. CWD: contraindication for diving. Stapes surgery: same risk as for non-operated ears with regular vestibular function (verified by tympanometry).