Clinical information
The patient, a 75-year-old male, had bilateral progressive hearing loss with tinnitus for 15 years. The patient began to experience bilateral hearing loss 15 years ago, with progressive aggravation and persistent low-pitched “buzzing” tinnitus, and early on he felt that his hearing was better in a noisy environment, without middle ear discharge, vertigo and stuffy feeling. He started to wear hearing aids 3 years ago, but now he came to our hospital for further diagnosis and treatment because of the obvious limitation of communication, especially in the left ear.
He was admitted to our hospital for further diagnosis and treatment. Physical examination: bilateral Rinne(-) Weber deviation to the right, clear tympanic membrane markings, no invagination, perforation, pus flow, consistent with conductive deafness.
Pure tone audiometry: bilateral severe conductive deafness A-B gap 60dB, presence of Kahar cut (2KHz), Gelle’s Test (-); ABR 100dB bilaterally without any waveform; acoustic conduction resistance: bilateral type As, stapedius muscle emission disappeared.
CT of temporal bone: thickening at the stapes pedicle bilaterally, with a large number of obvious bony hyperdense shadows in the mastoid process.
Artificial stapes replacement in the left ear
Intraauricular incision was made → chiseled away part of the anterior wall of the superior tympanic chamber and the posterior wall of the external auditory canal → exposed the stapes, saw the stapes fixed, and the sclerotic foci were located around the pedicle and at the bone capsule → a small hole (0.6 cm in diameter) was drilled in the center of the pedicle with a fine needle manually → the anterior and posterior arches of the stapes were broken → the distance between the anvil and the pedicle was measured and the length of the artificial stapes was determined → the artificial stapes was placed (one end in the small hole and the other end over the anvil) → the vestibular window was covered with fat.
Discussion.
Otosclerosis is an autosomal dominant disorder that occurs in 20-40 years of age, is more common in women, and can be exacerbated in pregnant women. The etiology is related to vitamins, genetic factors, and metabolic disorders leading to nutritional disorders in the bone vagus, and its typical pathological histological changes are primary focal spongy degeneration of the bone vagus, followed by bone resorption or sclerosis.
Clinical manifestations: progressive hearing loss in both ears; tinnitus; hypoacusis; Willis mishearing; vertigo.
Family history
Examination: wide external auditory canal, thin tympanic membrane, Schwartze’s sign (marked congestion and reddening of the tympanic membrane in the posterior upper quadrant of the bone capsule).
Typing.
By site of lesion involvement
1. Stapedial otosclerosis: the lesion is located in the vestibular window, and the lesion is located in the anterior area of the vestibular window and the edge of the round window.
2. Cochlear otosclerosis: The lesions are located in the vestibule or internal auditory conduction, causing auditory receptor or auditory nerve lesions.
According to the extent of lesion involvement: Portmann 4 types
Type 1: early otosclerosis with sclerosis of the anterior stapes ligament only.
Type 2: anterior region of the vestibular window.
Type 3: other areas of the vestibular window.
Type 4: total sclerotic lesion of the floor plate or obstructive type.
According to whether clinical symptoms appear or not
1. Clinical otosclerosis: clinical symptoms due to stapes fixation.
2. Histological otosclerosis: lifelong absence of conscious symptoms, seen only on autopsy pathology, 8-10% of whites, and clinical otosclerosis accounts for only 12% of them
Presentation by imaging (CT).
1. window type: involving the oval and round windows, CT shows disappearance of the oval window and replacement by sclerotic bone.
2. posterior window type: involving the bony vagus including the cochlea, vestibule and semicircular canal, CT shows a low density halo around the cochlea.
Drug treatment
Sodium fluoride inhibits hydrolase and protease activity in the spongiotic lesion, reduces osteoclast resorption, promotes osteoblast formation, and slows or terminates progressive hearing loss in otosclerosis. Studies have shown that sodium fluoride 45 mg/d or less does not increase bone formation, but only involves enzyme activity. It is believed that moderate amounts of sodium fluoride (15-45 mg/d) can prevent cochlear degeneration without aggravating stapes fixation.
1. In adults with severe cochlear pattern or proven positive Schwartze’s sign, sodium fluoride 45mg/d, 5d/w, for 6-8m.
2.Sodium fluoride for those who have been operated and have progressive cochlear symptoms.
Surgical treatment
1.Simple open-heart surgery
In 1897, a window was opened on the head of Passow bone and the tympanic membrane was covered, and in 1899, a window was opened on the Floderus horizontal semicircular canal. However, if the footplate is active, the ectolymphatic vibration waves will cancel each other out, and it is very unlikely that the window will improve hearing.
2.Stapedius shaking operation
In 1952, Rosens first proposed to restore the movement of the sclerotic footplate, with a success rate of 30~35%. The reasons for failure were anvil joint interruption, stirrup foot fracture or stirrup refixation.
3.Stirrup elevation surgery
The key point of the operation is to shake the stirrup with uniform strength and apply force gradually to avoid sudden fracture or dislocation of the footplate and injury to the inner ear, and to keep the mucosa intact after shaking, and to make the original fracture surface of the footplate a certain distance away to prevent the footplate from re-adhesion.
4.Large hole windowing of the stapes footplate (LFT) is a total stapedectomy: the footplate is completely cut or the excision range is greater than 1/2 of the footplate, which is mostly used for Portmann type 1 and 4. Type 1 is the early stage of otosclerosis and only the ligament in front of the stapes is sclerotic, so it is easy to excise the stapes together with the bottom plate at the same time, resulting in a large hole in the bottom plate. Therefore, a small hole must be drilled first, and then the window hole must be enlarged by picking the sclerotic foci outward with a small crochet, which may also result in a large hole in the floor.
Portmann 2 and 3 types have moderate sclerosis, and the floor plate is not easily ruptured when drilling, so it is easy to maintain the small hole status.
(1) Manual fine needle for drilling
(2) The diameter of the small hole of the window opening is 0.1mm larger than the diameter of the piston
(3) Piston diameter: Smyth – 0.3mm, Fish – 0.4mm, McGee – 0.6mm, Farrior – 0.8mm.
(4) Bailey that the small hole opening diameter 0.8 ~ 1mm
(5) Marquet’s small-aperture technique was used to treat 4000 cases of otosclerosis, and the A-B Gap closure rate was 95% after surgery.
Both small-hole windowing and large-hole windowing are better than LFT in terms of postoperative hearing and SFT is also significantly better than LFT in terms of vertigo and tinnitus, and the postoperative complications are also lighter.
6.Laser pedicle resection
Working substances: gas (CO2, Ni-YAG , argon laser), liquid, solid, semiconductor.
Wavelength: ultraviolet, infrared, visible.
output mode: continuous, repetitive pulse, single pulse laser.
Advantages: precise localization, less trauma, fewer complications.
Disadvantages: thermal effect, pressure effect on the inner ear damage.
7.Minimally invasive stapedioplasty without pseudo-replica
Using endoscopy and laser, only the anterior foot of the stapes is removed and the foot plate is transected posterior to the sclerotic foci, preserving the stirrup tendon, allowing the stapes to move again, and various complications are further reduced.