Early computed tomography findings of the inner ear after stapes surgery and its clinical correlations

Clinical Phenotypic Variability and Significance of Pneumolabyrinth After Tympanum-Penetrating Injury

OBJECTIVES

This study aimed to investigate the clinical manifestations, treatment, and prognosis of traumatic pneumolabyrinth caused by tympanic membrane (TM) perforation.

METHODS

Clinical data were collected from 3 cases of traumatic pneumolabyrinth occurring between 2015 and 2021 and 22 cases were identified from 20 articles in PubMed database that reported pneumolabyrinth due to tympanum-penetrating injury.

INTERVENTION

Nonoperative treatment was performed in Cases 1 and 3. Middle ear inspection was performed 1 year after the injury due to worsening vertigo upon head movement in Case 2.

MAIN OUTCOME MEASURES

Hearing outcomes and vestibular evaluations were presented for the 3 cases, and all comparable cases in the literature were reviewed.

RESULTS

All 25 patients had a history of traumatic TM perforation, with perforations mostly located in the posterior or posterior superior quadrant (16 cases). Air signs were observed in the vestibule in all 25 patients, 15 of whom revealed stapes luxation into the vestibule. Conservative treatments were performed in 8 cases, and exploratory surgery in 17 cases. Most patients were free of vertigo (23/25). There were no significant hearing improvements in 15 cases, while hearing recovery or improvement was observed in 9 cases.

CONCLUSIONS

The clinical manifestations of pneumolabyrinth due to tympanum-penetrating injuries vary widely. Importantly, the degree of hearing loss is not directly related to the subjectively perceived vertigo but to the location and extent of pneumolabyrinth.

Traumatic Stapes Luxation into the Vestibule

We report a rare case of traumatic stapes luxation into the vestibule. A 31-year-old female visited an emergency room with sudden onset of vertigo and conductive hearing loss after accidental penetrating injury to the right ear. Temporal bone computed tomography detected pneumolabyrinth, with a shade of whole intact stapes in the vestibule. Under exploratory tympanotomy, we observed a separated incudostapedial joint, and the stapes was depressed into the vestibule. The stapes was pulled out to the middle ear, and stapedectomy was performed; the crus were cut, the suprastructure was removed, and the fractured footplate and the long process of the incus were connected with a piston wire. The stapes footplate was sealed with soft tissue and surgical glue. Vertigo rapidly subsided after surgery, and hearing was improved to normal range. However, hearing loss at high frequencies was not recovered, probably because of inner ear damage due to the stapes depressed into the vestibule or surgical manipulation within the vestibule. Traumatic ossicular dislocation is not an uncommon occurrence in otolaryngologic practice, but stapes luxation is rare. Here, we report a rare case with successful repair. This report could serve as a basis for proper treatment in similar cases in the future.

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

OBJECTIVE

To determine the incidence and volume of pneumolabyrinth using early temporal bone computed tomography (TBCT) findings and evaluate the correlation between pneumolabyrinth and various clinical variables.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary academic center.

PATIENTS

Fifty-three consecutive adult cochlear implantation (CI) recipients (53 ears) with normal inner ears who underwent high-resolution TBCT within 3 days after CI were included.

INTERVENTION

Axial TBCT images were used for detection and measurement of pneumolabyrinth.

MAIN OUTCOME MEASURES

Incidence and volume of pneumolabyrinth were evaluated. In addition, the following clinical variables were analyzed to evaluate the correlation with pneumolabyrinth volume: demographics, implant type, surgical approach, postoperative dizziness, and preservation of functional residual hearing.

RESULTS

Pneumolabyrinth was present in all patients, and the average volume was 8.496 mm3. Pneumolabyrinth was confined to the cochlea (pneumocochlea) in all patients except for one who also had pneumovestibule. The pneumolabyrinth volume in patients with postoperative dizziness was significantly larger than that in patients without postoperative dizziness (10.435 mm3 vs. 8.016 mm3; p = 0.029). Multivariate analysis showed that a larger volume of pneumolabyrinth was significantly associated with postoperative dizziness (odds ratio, 1.420; 95% confidence interval, 1.114-1.808; p = 0.005).

CONCLUSION

A certain volume of pneumolabyrinth was always present in the early stage after CI, and the volume of pneumolabyrinth measured using early TBCT findings was significantly associated with the occurrence of postoperative dizziness.

Sneeze-induced pneumolabyrinth 15 years after stapedotomy

Pneumolabyrinth refers to the presence of air within the inner ear and is a fairly common occurrence immediately after stapes surgery, but rarely occurs in a delayed manner years after the initial operation. We present a case of a patient with a history of left stapedotomy 15 years prior, who presented with acute onset vertigo, tinnitus and hearing loss in her operated ear. Her symptoms were preceded by an upper respiratory tract infection associated with bouts of sneezing. Examination revealed a spontaneous right beating nystagmus and positive head thrust to the left. Pure tone audiometry demonstrated a left mixed hearing loss which subsequently deteriorated to a profound sensorineural hearing loss. CT showed the presence of air within the left vestibule and semicircular canals. The patient underwent an exploratory tympanotomy and repair of perilymphatic leak with resolution of vestibular symptoms but no improvement in sensorineural hearing thresholds.

Pneumolabyrinth: a systematic review

PURPOSE

The aim of this study is to provide a systematic review of the literature about the etiology, clinical and radiological presentation, surgical management, and outcomes of pneumolabyrinth (PNL).

METHODS

A systematic review of the literature was performed including studies published up to September 2020 in electronic databases (PubMed/MEDLINE, EMBASE, Cochrane Library, and Scopus). The PRISMA standard was applied to identify English, Italian, or French-language studies mentioning PNL. Full texts lacking information on the etiology were excluded. Data concerning the cause, site of air bubbles/fistula, clinical presentation, treatment, and outcome were collected. A qualitative synthesis of the results was performed.

RESULTS

Seventy-eight articles were eventually included; 132 patients were involved in the qualitative synthesis. The most common causes were: stapes surgery (24/132, 18.2%), temporal bone fracture (42/132, 31.8%), head trauma without temporal bone fracture (19/132, 14.4%), penetrating trauma (21/132, 15.9%), and barotrauma (15/132, 11.4%). The site most commonly involved was the vestibule (102/107, 95.3%), followed by cochlea (43/107, 40.2%) and semicircular canals (25/107, 23.4%).

CONCLUSION

The etiopathogenesis of PNL can be summarized in traumatic, iatrogenic, or inflammatory/infective. Its management consists in exploratory tympanotomy and sealing the fistula, but also conservative treatments can be attempted. Vestibular symptoms disappear in the majority of cases. Instead, the prognosis of hearing function is widely variable, and complete recovery is less probable. The certainty of evidence is still too low to make it useful for clinical decision-making.

Hearing Recovery After Ejection of Air in a Case of Traumatic Pneumolabyrinth: Mechanism and Management Options

OBJECTIVE

To describe a case of traumatic pneumolabyrinth and subsequent hearing recovery after ejection of air with transcanal endoscopic surgical exploration.

PATIENTS

A 38-year-old man was struck by his child while cleaning his ear with an ear pick made of bamboo, which penetrated deep into the left ear canal. Severe vertigo with vomiting and left hearing impairment ensued. In addition, high-resolution computed tomography demonstrated an air density within the vestibule.

INTERVENTIONS

Exploratory tympanotomy was performed endoscopically a day after the injury and air was ejected from the oval window surgically.

MAIN OUTCOME MEASURES

High-resolution computed tomography, audiologic testing.

RESULTS

Several hours after surgery, the patient's subjective vestibular symptoms lessened and 7 days after surgery, the patient felt slight dizziness when moving his head and no apparent spontaneous nystagmus was observed with an infrared charge-coupled device camera and was discharged from the hospital. Two years later, there are no subjective vestibular symptoms at all and the pure-tone average of his left ear improved to 16.7 dB.

CONCLUSION

We presented a case of traumatic pneumolabyrinth and the subsequent hearing recovery after ejection of air following endoscopic exploratory tympanotomy. We propose that initial management for traumatic pneumolabyrinth should be ejection of the air bubble if it is located solely in the vestibule and sparing the cochlea.

The Potential for Preserved Cochleovestibular Function in the Setting of Prolonged Pneumolabyrinth

OBJECTIVE

To discuss the natural history and management of pneumolabyrinth, with particular attention to illustrative cases where hearing improved after a fluid-filled vestibule was restored.

PATIENTS

Adults at two academic medical centers with documented pneumolabyrinth on computed tomography (CT) imaging.

INTERVENTION

Middle ear surgery or observation.

MAIN OUTCOME MEASURES

Cochlear and vestibular symptoms are reported. Inner ear function was documented with audiometry and vestibular testing. Resolution of pneumolabyrinth was documented on imaging for a subset of patients.

RESULTS

All patients presented with severe hearing loss following temporal bone fracture (three cases), penetrating trauma (one case), or stapedectomy (three cases). The radiographic finding was typically seen when imaging was obtained in the first few days after the injury. In two cases, vestibular symptoms resolved and partial recovery of hearing was seen despite a relatively long time interval between the inciting event and repair.

CONCLUSION

Management of pneumolabyrinth is individualized based on the mechanism of injury, severity of symptoms, and timing of the imaging study. In most cases, the barrier between the middle ear and inner ear is expected to heal with rapid resolution of pneumolabyrinth. Late repair is demonstrated to result in favorable recovery in selected cases. The presence of air in the vestibule cannot be assumed to be indicative of irreversible inner ear damage.

Postoperative Imaging of the Temporal Bone

The anatomy of the temporal bone is complex, and postoperative imaging evaluation of this bone can be challenging. Surgical approaches to the temporal bone can be categorized didactically into tympanoplasty and ossicular reconstruction, mastoidectomy, and approaches to the cerebellopontine angle and internal auditory canal (IAC). In clinical practice, different approaches can be combined for greater surgical exposure. Postoperative imaging may be required for follow-up of neoplastic lesions and to evaluate unexpected outcomes or complications of surgery. CT is the preferred modality for assessing the continuity of the reconstructed conductive mechanism, from the tympanic membrane to the oval window, with use of grafts or prostheses. It is also used to evaluate aeration of the tympanic and mastoid surgical cavities, as well as the integrity of the labyrinth, ossicular chain, and tegmen. MRI is excellent for evaluation of soft tissue. Use of a contrast-enhanced fat-suppressed MRI sequence is optimal for follow-up after IAC procedures. Non-echo-planar diffusion-weighted imaging is optimal for detection of residual or recurrent cholesteatoma. The expected imaging findings and complications of the most commonly performed surgeries involving the temporal bone are summarized in this review. Online supplemental material is available for this article. ^©RSNA, 2021.

Imaging Studies in Otosclerosis: An Up-to-date Comprehensive Review

Introduction  Otosclerosis is a primary osteodystrophy of the otic capsule, frequently responsible for acquired hearing loss in adults. Although the diagnostic value of imaging investigations in otosclerosis is debatable, they might still be employed with different goals within the context of the disease.

Objectives  The present paper aims to review the most recent literature on the use of imaging studies in otosclerosis for the most varied purposes, from routine application and differential diagnosis to prognostic prediction and investigation of surgical failure.

Data Synthesis  The diagnosis of otosclerosis is usually clinical, but computed tomography (CT) is paramount in particular cases for the differential diagnosis. The routine use, however, is not supported by strong evidence. Even so, there is growing evidence of the role of this method in surgical planning and prediction of postoperative prognosis. In specific scenarios, for example when superior semicircular canal dehiscence (SSCD) syndrome is suspected or in surgical failure, CT is crucial indeed. Magnetic resonance imaging (MRI), however, has limited – although important – indications in the management of individuals with otosclerosis, especially in the evaluation of postoperative complications and in the follow-up of medical treatment in active ostosclerosis.

Conclusion  Imaging studies have a broad range of well-established indications in otosclerosis. Besides, although the routine use of CT remains controversial, the most recent papers have shed light into new potential benefits of imaging prior to surgery.

Post-traumatic pneumolabyrinth: a rare cause of hearing loss

Pneumolabyrinth (PL) is the presence of air within the vestibule, semicircular canals, or cochlea. It represents an abnormal connection between the inner ear and middle ear spaces. PL most commonly occurs after blunt head trauma, followed by penetrating injuries. Temporal fractures may or may not accompany. Prognosis of hearing loss is poor, while prognosis of vestibular symptoms is good. Herein we present a 45-year-old female with unilateral pneumolabyrinth, who presented with significant dizziness and unilateral total hearing loss after a car accident.

Pneumolabyrinth: a rare complication of stapes surgery

Pneumolabyrinth is the entrapment of air within the inner ear and is a rare complication of stapes surgery. We report the case of a patient submitted to stapedectomy who, 4 weeks later, suddenly developed right hearing loss, ipsilateral tinnitus and vertigo. On the physical examination, the patient showed no signs of vestibular deficits. Audiometry was compatible with right profound mixed hearing loss and high-resolution CT of the temporal bone revealed the presence of pneumolabyrinth. During exploratory tympanotomy, the prosthesis was found dislodged; the communication between the middle and inner ear was closed with vein graft and a new prosthesis was placed. Following surgery, vestibular symptoms was abolished and the patient experienced great improvement of the hearing thresholds.

Impact of Imaging in Management of Otosclerosis

The use of imaging in otosclerosis for diagnosis, preoperative assessment, and follow-up has the potential to give the clinician an additional tier of patient evaluation and validation of diagnosis. Before stapes surgery, imaging may help avoid unnecessary middle ear explorations in nonotosclerotic cases, prevent potential complications, and assist in appropriate patient counseling regarding management expectations. Postoperatively, following unsuccessful air-bone gap closure in stapes surgery or conductive hearing deterioration following initial successful closure of the air bone gap, imaging can be used to determine the prosthesis position in the middle ear.

Early Postoperative Imaging of the Labyrinth by Cone Beam CT After Stapes Surgery for Otosclerosis With Correlation to Audiovestibular Outcome

BACKGROUND

Sensorineural complications of stapes surgery are rare but potentially serious. Imaging is usually performed to identify an underlying cause, such as excessive intravestibular penetration of the prosthesis or pneumolabyrinth suggesting perilymphatic fistula. Unfortunately, there is very little data in an unselected series of uneventful patients.The aim of this study was to analyze the depth of prosthesis penetration within the vestibule and the rate of pneumolabyrinth the day or the day after the procedure by performing a cone beam computed tomography of the temporal bone in a cohort of unselected patients, and to correlate imaging findings to clinical outcome.

METHODS

A prospective monocentric study was conducted in a tertiary referral medical center. A cone beam computed tomography was performed in 80 consecutive patients having undergone stapes surgery for otosclerosis, the day or the day after the procedure. Penetration length and location of the prosthesis within the vestibule, as well as presence or absence of a pneumolabyrinth, were recorded, and compared with clinical data (vertigo, nystagmus, hearing measurement).

RESULTS

Pneumolabyrinth was found in 15% of the patients. The mean penetration length of the prosthesis within the vestibule was 1 mm (0-1.9 mm). No serious complication occurred during the study period. No correlations were found when comparing imaging findings to clinical outcome.

CONCLUSION

Our results do not support empirically insights into detrimental effects of postoperative pneumolabyrinth or too long prosthesis after stapes surgery. Further studies are needed to better understand the causes of postoperative complications of stapes surgery.

Late pneumolabyrinth after stapedectomy

INTRODUCTION

Pneumolabyrinth is defined as the presence of air within the inner ear causing cochleovestibular signs and symptoms. Twenty-seven cases of pneumolabyrinth are published in the literature of which only two were described as delayed pneumolabyrinth as a complication of stapes surgery.

CASE REPORT

A 45-year-old male patient presented with vertigo after Valsalva maneuver 12 years after stapedectomy. He was diagnosed with delayed pneumolabyrinth on high resolution computed tomography and underwent an exploratory tympanotomy with surgical repair.

DISCUSSION

Delayed pneumolabyrinth is a rare complication of stapes surgery and should be considered in patients presenting with vestibulocochlear symptoms even many years later. An exploratory tympanotomy is recommended for patients diagnosed with pneumolabyrinth and having a sensorineural hearing loss and/or persistent vertigo.

The Rates and Clinical Characteristics of Pneumolabyrinth in Temporal Bone Fracture

BACKGROUND

Pneumolabyrinth is a rare inner ear clinical manifestation. To date, only about 50 cases have been reported—all as case reports. Consequently, the rate and clinical characteristics of pneumolabyrinth have not been evaluated.

METHODS

Of the 38, 568 patients who visited our emergency department for head trauma, 466 underwent temporal bone computed tomography (CT). One hundred seventy-five patients had temporal bone fracture (13 bilateral temporal bone fractures; 188 ears with temporal bone fractures), and 14 patients had pneumolabyrinth (15 ears with pneumolabyrinth; 1 bilateral case). A retrospective review of their medical records and radiologic findings was performed. Temporal bone fractures were classified by two different systems: the traditional classification and an otic capsule-based classification.

RESULTS

Pneumolabyrinth occurred in 8.0% of all temporal bone fractures, 4.0% of longitudinal temporal bone fractures, 16.1% of transverse or mixed temporal bone fractures, and 48.4% of otic capsule-violating temporal bone fractures. In all cases, pneumolabyrinth was found on CT, which was performed within 3 days, but not on follow-up CT performed 5 days or longer after head trauma. All patients complained of hearing loss and dizziness. Hearing in most patients (83.3%) did not improve, whereas dizziness improved in 91.7% of patients. Air was located only in the vestibule or semicircular canal in 53.3% and in the vestibular or semicircular canal and cochlea in 46.6% of ears with pneumolabyrinth. The initial hearing threshold and recovery rate using pure-tone audiometry were not different according to the air location in the inner ear.

CONCLUSION

Pneumolabyrinth was more common than expected; we believe that the timing of evaluation affects its rarity. Pneumolabyrinth was detected in nearly 50% of patients with otic capsule-violating temporal bone fractures when CT scanning was performed early after trauma.

Otologic disorders causing dizziness, including surgery for vestibular disorders

This chapter will focus on vertigo/dizziness due to inner-ear malformations, labyrinthine fistula, otosclerosis, infectious processes, and autoimmune inner-ear disorders. Inner-ear malformation due to dehiscence of the superior semicircular canal is the most recently described inner-ear malformation. Vertigo/dizziness is typically induced by sound and pressure stimuli and can be associated with auditory symptoms (conductive or mixed hearing loss). Labyrinthine fistula, except after surgery for otosclerosis, in the context of trauma or chronic otitis media with cholesteatoma, still remains a challenging disorder due to multiple uncertainties regarding diagnostic and management strategies. Otosclerosis typically manifests with auditory symptoms and conductive or mixed hearing loss on audiometry. Vertigo/dizziness is rare in nonoperated otosclerosis and should draw clinical attention to an inner-ear malformation. Computed tomography scan confirms otosclerosis in most cases and should rule out an inner-ear malformation, avoiding needless middle-ear surgical exploration. Labyrinth involvement after an infectious process is unilateral when it complicates a middle-ear infection but can be bilateral after meningitis. Labyrinth involvement due to an inflammatory disease is a challenging issue, particularly when restricted to the inner ear. The diagnosis relies on the bilateral and rapid aggravation of audiovestibular symptoms that will not respond to conventional therapy but to immunosuppressive drugs.

Magnetic resonance imaging in a guinea pig model of inner ear decompression sickness and barotrauma

OBJECTIVES/HYPOTHESIS

Scuba diving may cause severe hearing loss and vertigo due to inner ear barotrauma and decompression sickness. These may be difficult to differentiate clinically. Decompression sickness requires costly and potentially dangerous hyperbaric therapy, whereas such treatment may worsen barotrauma. The objective of this study was to assess the potential utility of magnetic resonance imaging to identify and distinguish blood from air in the inner ear, manifestations of barotrauma and decompression sickness, using a guinea pig model.

STUDY DESIGN

Prospective animal trial.

METHODS

Magnetic resonance of the head was performed at 3 Tesla, pre- and postinjection of 2, 4, or 10 μL of air or blood through the round window into the perilymph. With this model, 2 μL has been shown to cause hearing loss. Images were reviewed by a neuroradiologist blinded to the treatment.

RESULTS

All 14 normal ears, five of seven blood- and five of seven air-injected ears, were correctly interpreted. Two blood- and one air-injected ear were interpreted as indeterminate. One air-injected ear was incorrectly interpreted as blood.

CONCLUSIONS

Magnetic resonance reliably distinguishes small volumes of air and blood in the guinea pig inner ear. Magnetic resonance should be evaluated for its utility in the diagnosis of inner ear barotrauma and decompression sickness in scuba divers.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:2106-2109, 2016.