Stapedectomy in military aircrew

Brazilian Society of Otology task force - Otosclerosis: evaluation and treatment

OBJECTIVES

To review and provide evidence-based recommendations for the diagnosis and treatment of otosclerosis.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on otosclerosis were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: 1) Diagnosis - audiologic and radiologic; 2) Treatment - hearing AIDS, pharmacological therapy, stapes surgery, and implantable devices - bone-anchored devices, active middle ear implants, and Cochlear Implants (CI).

CONCLUSIONS

The pathophysiology of otosclerosis has not yet been fully elucidated, but environmental factors and unidentified genes are likely to play a significant role in it. Women with otosclerosis are not at increased risk of worsening clinical condition due to the use of contraceptives or during pregnancy. Drug treatment has shown little benefit. If the patient does not want to undergo stapedotomy, the use of hearing aids is well indicated. Implantable systems should be indicated only in rare cases, and the CI should be indicated in cases of profound deafness.

Flight After Stapes Surgery: An Evidence-Based Recommendation

Objective

Recommendations for air travel after stapes surgery, specifically stapes surgery, vary, with no standard recommendation to guide patients and surgeons. According to our search, no previous article has explored the physics of middle ear changes during flight and its effects on poststapedectomy patients in a systematic way. The aim of this study is to bring together 2 arms of expertise, otology, and aviation, to produce an evidence-based recommendation for flight after stapes surgery.

Data Sources

The database MEDLINE was searched during August 2022. The search strategy had the goal of identifying studies that discovered the effects of flying on stapes surgery patients and the effects of atmospheric pressure on middle ear structures.

Review Methods

The articles yielded from the search strategy were transferred to the online citation manager Rayyan. Included in the review were those studies reporting patient outcomes after flying following ear surgery; additional studies included those reporting pressure changes in the middle ear and ossicular chain displacement whether in experimental or animal conditions.

Conclusion

Modern-day commercial air travel is safe for patients who have undergone stapedotomy surgery, even very shortly after hospital discharge if they have to.

Implications for Practice

If stapedotomy patients wish to fly after hospital discharge, otologists are to reassure them that it is safe to do so. Patients are to be reminded to perform a gentle Valsava maneuver about every 4 minutes during airplane descent.

[Modern ideas about the professional suitability of employees of regulated professions with middle ear pathology and the possibility of their return to work (analytical review of the literature)]

Fitness for work in persons with middle ear disease who are exposed to harmful work environment and their possible return to work was analyzed. Fitness for work expertise procedure in the Russian Federation is disclosed in detail. A list of medical contraindications to work in harmful and/or dangerous work environment according to hearing condition is given. Clinical aspects of middle ear diseases in the industry workers are presented and modern ideas about middle ear surgical treatment, it's functional results, documenting technique and outcome calculation are described in detail. Possibility of returning the employee to work is discussed based on all the analyzed materials.

Influence of ambient air pressure changes on vestibular symptoms after stapes surgery

OBJECTIVE

To examine if vestibular irritation after stapes surgery may be provoked by pressure changes across the tympanic membrane, which consecutively results in displacements of the ossicular chain and the piston prosthesis suspended to it.

METHODS

In this prospective study 15 patients (13 female, 2 male) received unilateral stapes surgery (4 left, 11 right ear) with stapedotomy (n=14) or stapedectomy (n=1) at an academic tertiary referral center. Surgery was performed under local anesthesia via a transmeatal approach with a piston prosthesis 0.4×4.5mm. The fixation of the stapes, the exclusion of a malleus head fixation, and the gliding capacity of the malleus-incus joint were examined intraoperatively. A pure tone audiogram at four frequencies, a tympanometry with simultaneous video-oculography (VOG), caloric testing, and posturography with and without simultaneous tympanometry were performed six days before surgery, six weeks and three months after surgery, respectively.

RESULTS

The mean air bone gap improved significantly from 25 (±8) dB preoperatively to 10 (±6) dB after surgery. In the tympanometry with simultaneous VOG only two patients showed nystagmus beats into the operated ears during only one of the two follow-up appointments. All other patients did not show any vestibular symptoms or nystagmus during any of the follow-up appointments. In the combined testing of posturography and tympanometry no patient showed any pathological findings.

CONCLUSION

In patients who underwent stapes surgery with a piston prosthesis no vestibular symptoms can be provoked by pressure changes in the external auditory canal.

Controversies in the Evaluation and Management of Otosclerosis

Controversies have been associated with the etiology, diagnosis, evaluation, and management of otosclerosis since Valsalva first described stapes fixation as a cause of hearing loss. Although the exact mechanism of the bone remodeling associated with otosclerosis remains uncertain, stapedotomy has been accepted as the surgical treatment of most patients with stapedial otosclerosis. There remains a disparity of opinion, however, regarding the role of preoperative imaging, surgical technique, implant selection, and medical therapy for cochlear otosclerosis. In addition, opinions vary regarding the optimal postoperative care of patients undergoing stapedotomy and a patient's ability to participate in activities that may result in barotrauma.

Biomechanics of stapesplasty: a review

OBJECTIVE

The replacement of an otosclerotic fixed stapes by a prosthesis significantly modifies the function of the normal ossicular chain. Because the ear works as a pressure receptor, a piston prosthesis will both modify the sound pressure transmission and respond to the ambient air pressure changes in a different way than the normal stapes. Both aspects, the acoustic transmission and the displacements of the prosthesis with variations of atmospheric pressures, are reviewed.

CONCLUSION

The diameter of a piston should not be smaller than 0.4 mm and it should be inserted into a significantly larger perforation of the footplate. A low mass is advantageous for transmission of higher frequencies. Firm attachment at the processus lenticularis is necessary for effective energy transmission. This is of paramount importance in a malleovestibulopexy because of the oblique position of the piston. A piston can be displaced up to 0.5 mm in the vestibule at ambient air pressure changes, as it is not attached to the annular ligament. These large movements explain why a short piston can be lifted out of the footplate fenestration (i.e., after sneezing) and why a piston with excessive length can impale the structures of the membranous labyrinth, causing vertigo (i.e., in a retraction of the tympanic membrane). However, flying or diving should be allowed generally, provided that a test with tympanometry, applying variable pressures of +/- 400 mm H(2)O, is tolerated without evoking vertigo.

Diving after stapedectomy: clinical experience and recommendations

OBJECTIVES

Much controversy exists concerning the risk of inner ear barotrauma after stapes surgery in scuba and sky divers. Uniform consensus has not been established regarding poststapedectomy barorestrictions. The purpose of this study was (1) to determine the prevalence of adverse auditory and/or vestibular sequelae in patients after stapedectomy related to scuba and sky diving, and (2) to offer recommendations on barometric exposure after stapes surgery.

STUDY DESIGN

Survey questionnaires were mailed to 2222 patients who had undergone stapedectomies at a single tertiary otologic referral center between 1987 and 1998. Two hundred eight of the initial 917 respondents (22.7%) had snorkeled, scuba, or sky dived after stapes surgery, and 140 of these responded to a second questionnaire detailing dive protocols, otologic symptoms, and their relationship to the diving activities. Of the 140, 28 had scuba or sky dived. Their survey data were analyzed and their medical records were reviewed.

RESULTS

Four of the 22 scuba divers (18.1%) experienced otologic symptoms at the time of diving. These included otalgia on descent (3/22; 13.6%), tinnitus (1/22; 4.5%), and transient vertigo on initial submersion (1/22; 4.5%). One patient had sudden sensorineural hearing loss and vertigo develop 3 months after scuba diving, which he related to noise exposure. He was subsequently found to have a perilymph fistula, which was successfully repaired. Of the 9 patients who sky dived, 2 patients (22.2%) reported otologic symptoms during the dive. No significant diving-related long-term effects indicative of labyrinthine injury were seen in any of the 28 patients.

CONCLUSIONS

Stapedectomy does not appear to increase the risk of inner ear barotrauma in scuba and sky divers. These activities may be pursued with relative safety after stapes surgery, provided adequate eustachian tube function has been established.

Inner ear barotrauma after stapedectomy in the guinea pig

OBJECTIVE

The safety of scuba diving after stapedectomy is controversial. Stapedectomy is thought to predispose to inner ear barotrauma (e.g., perilymph fistula); however, many individuals continue to scuba dive following stapedectomy without ill effects. The purpose of this study was to evaluate the cochlear effects of barotrauma, similar to that experienced with scuba diving, on inner ears previously treated with stapedectomy.

STUDY DESIGN

Prospective, controlled.

METHODS

Sixteen Hartley albino guinea pigs underwent unilateral total stapedectomy followed by hyperbaric dives on 5 consecutive days, beginning 3 weeks after stapedectomy. Cochlear effects were determined using click and tone-pip evoked electrocochleographic thresholds and cochlear hair cell counts.

RESULTS

Mean auditory thresholds increased by 29 dB after stapedectomy (P < .001), then remained stable thereafter. Mean thresholds in both the operated and control ears did not change with hyperbaric dives. Evidence of middle ear barotrauma (e.g., hemorrhage or tympanic membrane perforation) was observed in eight poststapedectomy ears and five control ears, but none demonstrated significant threshold elevation greater than or equal to 10 dB. Hair cell counts were not different between operated and control ears.

CONCLUSIONS

Stapedectomy does not appear to predispose to cochlear sequelae in the guinea pig model of diving-related barotrauma.