Pneumolabyrinth as an Early Computed Tomographic Finding After Cochlear Implantation and its Clinical Significance

Acute pneumolabyrinth: a rare complication after cochlear implantation in a patient with obstructive sleep apnoea on CPAP therapy

Pneumolabyrinth is a condition characterised by the presence of air within the inner ear and is a rare complication after cochlear implant surgery. One of the causes of pneumolabyrinth may be the increase in pressure in the middle ear. The use of continuous positive airway pressure (CPAP) is an effective treatment strategy for obstructive sleep apnoea. According to a recent study, the use of CPAP should be delayed by 1 or 2 weeks in subjects undergoing middle ear surgery; however, there is currently no indication to delay the CPAP in subjects undergoing cochlear implant surgery. We report the case of a patient on CPAP who underwent left cochlear implantation and, in the early postoperative period, reported severe vertigo and tinnitus. Cone-beam CT of the temporal bone revealed the presence of pneumolabyrynth. We believe that the use of CPAP should be delayed in subjects undergoing cochlear implantation to avoid the development of acute pneumolabyrinth.

Postoperative Pneumolabyrinth Following the Middle Cranial Fossa Approach for Superior Semicircular Canal Dehiscence Repair, 2014-2020

OBJECTIVE

The present study investigates risk factors and clinical outcomes of postoperative pneumolabyrinth following the middle cranial fossa approach for superior semicircular canal dehiscence repair, a complication that has not been documented previously.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary/quaternary care referral center.

METHODS

We conducted a retrospective review of 332 middle cranial fossa procedures from 2014 to 2020 at a tertiary/quaternary care institution. Upon identifying pneumolabyrinth cases from postoperative computed tomography temporal bone scans, we conducted multivariable logistic regression analysis to explore demographic and clinical factors that were independently linked to this complication. We also compared the rates of postoperative symptoms among patients with different grades of pneumolabyrinth.

RESULTS

We identified 41 (12.3%) pneumolabyrinth cases. Patients with older age, higher preoperative pure tone average, and frank dehiscence were at higher risk for pneumolabyrinth. Furthermore, patients with pneumolabyrinth reported significantly higher rates of postoperative dizziness and exhibited significantly greater pure tone average and air-bone gap postoperatively as compared with patients without pneumolabyrinth. Finally, higher-grade pneumolabyrinth was associated with increased rates of postoperative hearing loss, and grade III pneumolabyrinth was associated with higher rates of postoperative tinnitus vs grade I and II cases.

CONCLUSION

Pneumolabyrinth following the middle cranial fossa approach was associated with poor clinical outcomes, including dizziness and auditory impairment. Old age, high preoperative pure tone average, and frank dehiscence were risk factors for this complication. The highlighted parameters may be important to note when considering this approach as a treatment option and while monitoring postoperative recovery.

[Emphysema after cochlear implantation - risk factors and therapeutic options]

OBJECTIVE

In case of cochlear implantation seroma, hematoma, local wound infections or vertigo are rare but typical complications. In contrast, emphysema is seldom reported. They can occur after cochlear implantation both in the postoperative healing phase and years later. A therapeutic algorithm does not yet exist.

METHODS

We report on 3 patients with subcutaneous emphysema in the area of the receiver-stimulator. An unsystematic review of the literature of cases with emphysema after cochlear implantation highlights possible risk factors and the therapeutic options.

RESULTS

The 3 cases developed subcutaneous emphysema 2-11 month after cochlear implantation due to nose blowing or CPAP therapy in obstructive sleep apnea. The current literature reports another 35 cases of emphysema after cochlear implantation. Air insufflation via the Eustachian tube is the most frequently described cause. Diseases of the nose and sinuses, tube dysfunction and obstructive sleep apnea are potential risk factors. Pressure bandage, puncture, tympanic tubes, and surgical revision are common treatments.

CONCLUSIONS

Most emphysema can be controlled by conservative methods such as pressure bandaging and behavioral instruction. Punctures should be avoided due to the risk of upcoming infections. The prophylactic use of antibiotics seems dispensable. Surgical revision should be considered especially in cases of pneumocephalus with suspected leakage in the dura. The coverage of the mastoidectomy by a bony cap can be precautious and beneficial in cases with risk factors.