Pneumocoele after cochlear implantation

Scalp pneumocoele is a rare complication of cochlear implantation surgery. We present the largest case series to date; consisting of four cases over 8 years from one centre. The presentation, diagnosis, and management of each case are reviewed. Previously unreported complications of pneumocoeles are highlighted.

Three of our four cases, consisting of two adults (aged 53 and 81 years) and one child (aged 26 months), developed scalp pneumocoeles within the first 3 months of implantation. Another child (aged 10) developed pneumocoele 7 years after surgery. The common diagnostic features include a soft, non-tender, fluctuant swelling over the receiver/stimulator package. In all cases, pneumocoeles were triggered by Valsalva's or Toynbee's manoeuvres. Complications include infection (case one) and reduction in cochlear implant (CI) function (cases three and four), secondary to displacement of the receiver/stimulator package or electrode displacement.

Diagnosis is made from clinical history and examination. Aspiration results in reduction of pneumocoeles. This is not necessary for smaller pneumocoeles as they may resolve spontaneously. Additional investigations may reveal complications of pneumocoeles, such as X-rays for implant displacement, and inflammatory marker to detect signs of infection. To prevent the recurrence of pneumocoeles, patients are advised to avoid Valsalva's or Toynbee's manoeuvres. There were no recurrences of pneumocoeles.

Post-cochlear implantation pneumocoeles can be associated with harmful complications such as infection and CI dysfunction. The mechanism of pneumocoele formation is discussed, and strategies for its prevention are examined.