Iatrogenic Inner Ear Dehiscence after Skull Base Surgery: Treatment Quandary

A complication of lateral skull base surgery not well characterized in the literature is iatrogenic inner ear dehiscence. Dehiscence of the otic capsule, the classic example being superior semicircular canal dehiscence (SCCD), or Minor’s syndrome, can disrupt the physiologic transmittance of vibroacoustic energy within the inner ear. This results in hearing loss (pseudo-) and third-window phenomena including autophony, pulsatile tinnitus, oscillopsia, bone conductive hyperacusis, and sound- and pressure-induced vertigos. This case-series study describes three patients with inner ear dehiscence following lateral skull base surgery at a tertiary medical center. We describe a management algorithm for iatrogenic inner ear dehiscence including intraoperative identification and repair, as well as minimally invasive transcanal round window reinforcement for patients with delayed dehiscence recognition. Two patients in our series had inner ear dehiscence from skull base surgery identified only after presentation to neuro-otology clinic for third-window symptoms. These patients subsequently underwent transcanal round window reinforcement resulting in improvement of their symptoms and reported quality of life. For one patient in our series, inner ear dehiscence was successfully identified, and subsequently repaired, intraoperatively during a multidisciplinary surgery of the lateral skull base. This patient experienced expected postoperative hearing deficit but was spared third-window symptoms. Should intraoperative repair not be possible, due either to technical considerations or failure to identify the dehiscence, transcanal round window reinforcement is a minimally invasive intervention which can improve quality of life for patients suffering from third-window symptoms.