15From Diagnosis to Decision: Putting It All Together
The whole chapter resolves into one pathway: three branch points sort every malformed ear into one of four destinations. Around that skeleton sit the team, the parent conversation and the honest prognosis.
TThree branch points
Branch 1 - Is there a stimulable cochlea? A useful cochlear lumen with surviving neural tissue is the prerequisite for any inner-ear electrode. Branch 2 - Is there a cochlear nerve? A present nerve (even hypoplastic) keeps the implant in play; an absent nerve moves the child toward ABI regardless of how good the cochlea looks. Branch 3 - What are the surgical risks? Gusher likelihood (IP-III 100%, IP-I 50%, EVA always, IP-II <10%) and facial-nerve aberrancy must be anticipated and pre-armed. These three questions, in order, are what the prognosis-oriented algorithm formalises - they convert imaging and audiology into a decision.[2024][2016][2017]
TFour destinations
Medical / hearing aid or stapedotomy: a conductive malformed ear with a useful lumen and normal aperture/nerve may be managed without an implant. Cochlear implant: a nerve-bearing cochlea (including malformed-but-stimulable ears) with severe-to-profound SNHL, matched to a suitable array. Auditory brainstem implant: when the cochlear nerve is absent (aplasia) or no useful lumen exists - common cavity with no neural substrate, severe hypoplasia, CV aplasia, rudimentary otocyst, cochlear aplasia, IP-I, CH-I. Watch / defer: fluctuating or progressive EVA hearing is monitored until it crosses into CI candidacy, rather than implanting prematurely.[2024][2005][2020]
CThe team and the conversation
Decisions are made by a multidisciplinary team - otologist, neuroradiologist, audiologist, speech-language therapist, paediatrician and the family - not by any one specialty in isolation. The parent counselling conversation translates the branch into plain language: what the child has, what the operation involves, what gusher/facial-nerve risks mean, and what the realistic range of hearing is. Expectation-setting is explicitly tied to anomaly and nerve status: optimistic for IP-II/EVA, guarded and individualised for common cavity/severe hypoplasia, and framed as an attempt-with-fallback where the nerve is borderline. The plan is documented and revisited after activation, so families experience a continuum rather than a single irreversible verdict.[2024][2016][2009]
FWhere this connects in the atlas
Imaging supplies branches 1-3: CT defines the lumen, modiolus and BCNC; MRI confirms the cochlear nerve - revisit the Preoperative Imaging chapter for the protocols. Candidacy and the audiological battery establish that the loss is severe-to-profound and aided benefit insufficient before any malformation pathway begins. Surgery covers the operative execution - array selection, gusher control and facial-nerve management flagged here are carried out there. Special Populations and the ABI material extend this pathway: cochlear nerve deficiency, common cavity and the ABI candidate are developed in depth in those chapters.[2024][2017][2005]
Which destination on the pathway best fits her today?
Which branch point most decisively separates a cochlear-implant candidate from an ABI candidate?
A conductive malformed ear with a useful lumen and a normal cochlear aperture and nerve maps to which destination?
Which atlas chapters supply the inputs this decision pathway depends on?