RU2465875C1 - Method of preventing internal ear vibrotrauma during removal of atresia of external auditory meatus - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, namely to otorhinolaryngology. Essence of method lies in performing parotid cut, expanded antromastoidotomy, complete ablation of atretic plate, restoration of incudostapedial articulation by means of glass-ionomeric cement, tympanoplasty. Ablation of atretic plate is performed with preliminary disconnection of the chain of auditory ossicles in the place of incus and stapes connection before starting work on elimination of bone obliteration. Malleus and incus are preserved. Access to incudostapedial articulation is performed by application of posterior tympanotomy without involvement of atretic plate. Recovery of chain of auditory bones is performed during ossiculoplasty.

EFFECT: application of claimed invention makes it possible to realise prevention of labyrinth vibrotrauma by preventing transmission of fluctuation onto internal ear structures via the chain of auditory ossicles in case of atretic plate ablation.

5 dwg, 1 ex

Description

The invention relates to medicine, namely to otorhinolaryngology, and can find application in performing hearing-improving operations in patients suffering from persistent hearing loss as a result of an anomaly in the development of the ear.

According to various authors, sensorineural hearing loss (hereinafter - SNT) can develop in 11-17% in patients with an abnormality of the middle ear after removal of atresia of the external auditory canal.

Congenital malformation of the outer and middle ear continues to be a difficult task for the surgeon of the otorhinolaryngologist. Atypical arrangement of nerves and structures of the tympanic cavity leads to the risk of intraoperative and postoperative complications, including the development of SNT in the postoperative period.

With a significant anomaly of the auditory ossicles, when there is no possibility for their normal functioning, they undergo complete or partial removal with subsequent ossiculoplasty with prostheses.

When the auditory ossicles function well after being released from the atretic plate and the risk of their involvement with possible repeated atresia is low, these structures are retained to form the sound conduction system.

The thickness of the bone obliteration of the auditory meatus creates additional difficulties with surgical intervention. There are known cases when the removal of bone obliteration with boron subsequently led to SNT caused by vibrations transmitted to the labyrinth from the atretic plate through the chain of auditory ossicles.

A known method of eliminating atresia of the external auditory canal (see Jahrsdoerfer RA, Aguilar EA. Surgical management of congenital malformations. In, Jahrsdoerfer RA, Helms J, eds. Head and Neck Surgery, vol. 2, Ear. Stuttgart, Thieme, 1996, p .35-66).

When using this method, a Z-shaped skin incision is made at the site of the planned canal of the external auditory canal, the bone canal is formed by the bore to the tympanum, focusing on the front wall of the maxillary joint, while the mastoid cells are not affected or are not involved significantly.

The atretic plate is removed from above to visualize the auditory ossicles and other landmarks, then the removal of the atretic plate is continued in full according to the atomic landmarks. If it is impossible to keep the chain of auditory ossicles functional, after their removal, ossiculoplasty is performed with prostheses and tympanoplasty, after which the bone canal is lined with free skin grafts taken from the inner surface of the shoulder or thigh.

The disadvantage of this method is that the auditory canal is quite narrow. This limits the possibilities of the surgeon, the visualization of the structures of the middle ear, increases the risk of developing repeated atresias.

Aggressive work with boron on an atretic plate promotes significant transmission of vibrations directly to the inner ear along the auditory ossicles chain, increasing the risk of undesirable effects in the postoperative period from the side of the inner ear, including the development of sensorineural hearing loss.

The narrow auditory meatus and the need for preliminary visualization of anatomical landmarks do not immediately allow the separation of the auditory ossicle chain to reduce undesirable effects on the structures of the inner ear.

There is also a method of eliminating atresia of the external auditory meatus (see DENECKE H.J. On the surgery of ear abnormalities with reference to the facial nerve Laryngol Rhinol Oto, 1960, Jul, 39, p. 425-8).

When using this method, a wide incision is made, capturing the apex of the mastoid process. In this case, the facial nerve is detected and isolated at its exit from the bone canal - the styloid opening. Then the bony part of the mastoid process is carefully removed with burs, focusing on the bone channel of the facial nerve, while gradually rising upward along it, the surgeon will find the tympanic cavity.

The performed interventions in the tympanic cavity depend on the found developmental abnormalities. The auditory ossicle chain can be removed with insufficient functionality and replaced with a titanium prosthesis. Then the canal of the external auditory canal is formed finally posterior to the condyle of the upper jaw, and the resulting defect in the bone tissue of the mastoid can be eliminated with a muscle flap if necessary. The neotympanic membrane is formed by a fascial flap. The bone walls of the external auditory meatus are covered with free displaced split skin grafts.

The disadvantages of this method are its high complexity and duration. Significant work with boron can lead to concussion of the facial nerve and, through the chain of auditory ossicles, the structures of the labyrinth, including the development of sensorineural hearing loss. A large amount of damage lengthens the recovery period.

Closest to the technical nature of the claimed solution is a method of eliminating atresia of the external auditory canal (see Tos M. Manual of middle ear surgery. Vol.3, Surgery of the external auditory canal. Georg Thieme Verlang Stuttgart New York, 1997, p. 251 -64).

When using this method, a behind-the-ear incision is made behind the rudiment of the auricle, while the surface of the mastoid process is exposed. Then the cartilage that makes up the skeleton of the rudiment is removed, and the cartilage is saved for later use in tympanoplasty and the formation of the ear canal.

By marking the site of the mastoid process according to computed tomography with a cutting boron, the external auditory meatus is formed in a transmastoid way, initially focusing on the cells of the mast process and projection of the antrum.

After opening the latter, orientation is carried out on the protrusion of the lateral semicircular canal and a horizontal portion of the facial nerve canal, auditory ossicles. The expansion of the tympanic part of the cavity is performed before the opening of the mouth of the auditory tube anteriorly, downward to the hypothympanum, posteriorly to the vertical portion of the facial nerve canal.

To prevent trauma to the inner ear and the development of SNT, the auditory ossicles are first disconnected and the anvil and malleus are removed before the removal of the main mass of the atretic plate begins.

Reconstruction of the ossicular apparatus is performed with prostheses. The tympanal flap is formed from the cartilaginous tissue of the rudiment of the auricle. Then, the formed channel and the non-tympanic membrane are lined with free skin grafts taken from the ear region or from the shoulder. Soft tissues in the projection of the proposed auditory meatus are dissected by a z-shaped incision and sutured to preformed milling holes.

The disadvantage of this method is the removal of the chain of auditory ossicles (malleus and anvil), as a result of which the hearing-improving effect requires ossiculoplasty with prostheses, which can lead to a decrease in the functional result.

The technical result of the proposed solution is to prevent vibrotrauma of the labyrinth by preventing transmission of vibrations to the structures of the inner ear through the chain of auditory ossicles when removing the atretic plate.

To achieve the specified technical result in the method of preventing vibroinjury of the inner ear when removing atresia of the external auditory meatus, including a behind-the-ear incision, extended anthromastoidotomy, complete removal of the atretic lamina, restoration of the anvil-stirrup articulation with glass ionomer cement, tympanoplasty, according to the proposal, the removal of the atretic lamina is performed by previously disconnecting the chain auditory ossicles at the junction of the anvil and stapes, prior to the removal of tnoj obliteration retain the hammer and the anvil, wherein the access incudostapedial articulation carried by the rear overlay tympanotomy without locking atresial plate and vosstanavleniju ossicular chain is carried out during ossikuloplastiki.

The method is illustrated by drawings, where figure 1 schematically shows the anomaly of the development of the outer and middle ear - the absence of an external auditory canal; figure 2 shows the formation of the auditory meatus by transmastoid access; figure 3 shows the separation of the anvil-stirrup joint; figure 4 shows the removal of the main array of atretic plate, the formation of the external auditory canal; figure 5 shows the stage of tympanoplasty, the connection of the anvil-stirrup articulation with glass ionomer cement.

The following positions were used in the drawings: 1 - the bone mass of the temporal bone with an atretic plate, 2 - the lower jaw, 3 - the tympanic cavity, 4 - the lateral (horizontal) semicircular canal, 5 - the channel of the facial nerve (horizontal part), 6 - the anvil, 7 - anvil-stirrup articulation, 8 - malleus, 9 - external auditory meatus formed by boron; 10 - glass ionomer cement; 11 - non-tympanic membrane.

The method is as follows.

Surgical intervention is carried out under endotracheal anesthesia. An incision is made behind the rudiment of the auricle. Soft tissues are separated and a fascial flap is prepared to form a non-tympanic membrane.

Boron through the bone mass 1, focusing on the projection of the joint of the lower jaw 2, transmastoid access to the tympanic cavity 3. Search for anatomical landmarks - the projection of the passage of the sigmoid sinus, synodural angle, horizontal semicircular canal 4 and horizontal projection and the second knee of the facial nerve canal 5. With the preservation of the auditory ossicles, they are also guided by the short process of the anvil 6 to construct the projection of the descending portion of the canal of the facial nerve 5. The back is carefully removed with the boron part of the atretic plate to a good visualization of the anvil-stirrup joint 7. Then the anvil-stirrup articulation 7. is then disarticulated. This avoids or significantly reduces the transmission of microvibrations caused by boron to the window during the subsequent removal of the atretic plate and the release of the malleus 8, further formation of the bone part external auditory meatus 9.

Boron prepare a bone bed. When the auditory ossicles are preserved and their mobility is satisfactory, the disconnected anvil-stirrup joint 7 is freed from soft tissues and connected using glass ionomer cement 10. After exposure for 10 minutes, the material hardens, while the continuity and rigidity of the auditory ossicles chain and their ability to conduct sound are restored. Fascial flap is placed on the bone bed, the handle of the malleus 8, forming a non-tympanic membrane 11.

Then, a displaced thinned free skin flap is taken from the behind-the-ear region along the edge of the incision or from the extremity (the inner surface of the shoulder, thigh), laid on a non-otimal membrane 11 and the bone walls of the formed external auditory canal 9. The skin at the exit site of the proposed external auditory canal 9 is dissected with a lingual forming a skin flap.

After that, milling holes are formed along the edges of bone perforation, the edges of skin flaps are sutured to them with non-absorbable suture material. The behind-the-ear incision is sutured in layers.

The formed external auditory meatus 9 is plugged with non-absorbable aseptic materials with the addition of an antiseptic. An aseptic dressing is then applied. For the prevention of bacterial infections, antibiotic therapy is prescribed for 7 days.

The method is illustrated by the following example.

Patient V., born in 1984, was admitted to the clinic of the Department of Ear Pathophysiology of the Federal State Institution “St. Petersburg Research Institute of Ear, Throat, Nose and Speech of the Ministry of Health and Social Development of the Russian Federation” with a diagnosis of congenital malformation of the left ear with complete atresia of the external auditory canal, conductive hearing loss III degrees to the left.

Upon admission, the patient complained of hearing loss in the left ear, the absence of an external auditory canal on the left. From the anamnesis it is known that the patient was born with an abnormality of the left ear.

On examination: The mucous membrane of the nose is pink, wet. Nasal septum - slightly curved to the right. The nasal passages are free. The nasopharynx is free. Nasal breathing is satisfactory. The mucous membrane of the pharynx is pink, dry. The laryngeal mucosa is pink, moist. The vocal folds are white, their movement in full. The glottis is wide.

AD - the external auditory meatus is free. The eardrum is gray, the contours are clear. Whispering speech of 6 m, colloquial speech of more than 6 m. Samples of Lewis-Federichi and Jelle - positive.

AS - complete fusion of the external auditory canal, microtia. Whispering speech is at the auricle, conversational speech is 0.5 m. The symptom of Lewis-Federici is negative, the lateralization in the Weber test is to the left.

Results of tonal threshold audiometry: left-side conductive hearing loss with sound conduction thresholds in the area of speech frequencies of 60-70 dB in the presence of a bone-air interval of 50-60 dB.

On the computer tomogram of the temporal bones on the right, it is clear that the external auditory canal is free, the mastoid cells are pneumatized, the tympanic cavity is free, the auditory ossicles are partially visualized, without pathology, the cochlear lumen is free. On the left, the external auditory meatus is absent in the bone and soft tissue sections, the mastoid has a sclerotic type of structure, and its cells are pneumatized. The tympanic cavity is slightly reduced in volume compared with the right tympanic cavity, the auditory ossicles are visualized, the malleus grows to the lateral bone wall of the tympanic cavity, the lumen of the cochlear canal is free.

The patient underwent surgery on his left ear.

In conditions of endotracheal anesthesia, an arcuate incision was made in the skin and soft tissues to the bone in the behind-the-ear region with a length of about 5 cm along the transitional fold. Separation of soft tissues anteriorly along the temporal bone was performed; the bony section of the external auditory meatus is absent. In the upper corner of the wound, a fragment of autofascia of the temporal muscle with a diameter of 2 cm is highlighted.

Then, the site of the mastoid process was marked taking into account the data obtained by computed tomography. The cutting part of the bone formed the external auditory meatus and the tympanic cavity as follows.

An antromastoidotomy was performed. Focusing on the protrusion of the horizontal (lateral) semicircular canal and the channel wall of the horizontal portion of the facial nerve, as well as on the short process of the anvil, the necks carefully removed the posterior part of the atretic plate until the visualization of the anvil-stapes junction was well visualized.

Anvil-stirrup articulation was performed to prevent transmission of vibrations from the atretic plate to the labyrinth through the auditory ossicle chain. The removal of the atretic plate with boron continued. The tympanic part of the tympanic cavity is dilated anteriorly until the opening of the mouth of the auditory tube, downward to the hypothympanum, posteriorly to the vertical portion of the facial nerve canal. The upper part of the external auditory meatus is expanded upward to the dura mater of the middle cranial fossa, anteriorly - to the temporomandibular joint. The fixed bones (malleus and anvil body) are freed from the atretically altered walls of the tympanic cavity with a diamond bur.

The atretic plate is completely removed, a bone drum ring is formed, and a gap of 1 mm is left between it and the auditory ossicles. In the cortical plate along the periphery of the created bone section of the external auditory meatus, several holes are made for subsequent fixation of the skin flap.

A check of the structures of the tympanic cavity showed that the niches of the vestibule window and the cochlear window are free, the stirrup is movable, the symptom of the transmission of vibrations from the base plate to the cochlea window (Khilov's symptom) is positive, the anvil and hammer are movable. The continuity of the auditory ossicle chain was restored by fixing the anvil-stirrup joint with glass ionomer cement, after an exposure of 10 minutes, the rigidity of the auditory ossicle chain was checked - good, Khilov's symptom was positive.

A fragment of the fascia of the temporal muscle was used as a neotympanic flap. The flap is laid on the restored ossicular structure - the handle and the heads of the malleus and partially on the body of the anvil. Next, a tongue-like skin incision was made parallel to the curl with the formation of a skin flap on the front leg. Cartilage and fibrous tissue from the base of the auricle have been completely removed, the skin has been mobilized and hemmed to the edges of the bony section of the external auditory canal through the previously formed openings.

A split free skin flap, taken by the dermatome from the inner surface of the shoulder, is laid around the circumference on the inner surface of the created trepan cavity, while the outer edge of the flap is also fixed with sutures (Vicryl 4-0) to the edge of the external auditory meatus through the above openings. The tongue-like flap is relegated to the trepanation cavity, while covering its front wall, and also on the sides it is fixed to the bone walls of the newly created external auditory meatus.

A thin skin flap is firmly pressed against the walls of the external auditory meatus, taking into account the location of the tongue-like skin flap on the front wall. At the final stage, the fascial flap (formed non-tympanic membrane) was also covered with a split free skin flap.

A gauze swab soaked in iodoform and liquid paraffin is introduced into the external auditory meatus. The primary incision in the ear region was sutured in layers.

The postoperative period was uneventful. Sutures were removed on the 10th day. Tampons from the external auditory canal were removed on day 11, while the external auditory canal was tamped weekly for a month with a hemostatic sponge soaked in iodoform and 4% Na-CMC gel (sodium salt of carboxymethyl cellulose).

At the control examination on the 30th day after the operation: AS - the external auditory meatus is wide, free, no discharge. The skin flap and non-tympanic membrane are pink, somewhat swollen, no defects.

Results of control tonal threshold audiometry: AS - sound conduction thresholds in the area of speech frequencies from 10 dB to 15 dB in the presence of a bone-air interval of up to 10 dB.

At the control examination 5 months after the operation: AS - the external auditory meatus is wide, free, no discharge. The non-tympanic membrane is gray, there are no defects.

Results of control tonal threshold audiometry: AS - sound conduction thresholds in the area of speech frequencies from 15 dB to 20 dB in the presence of a bone-air interval from 10 dB to 15 dB.

As a result of the application of the proposed method, good functional results were obtained, the bone-air interval in the postoperative period was, on average, from 10 to 15 dB.

Thus, the separation of the anvil-stirrup joint with the removal of atresia of the external auditory canal with its subsequent fixation using glass ionomer cement avoids vibration trauma of the structures of the inner ear and prevents the development of sensorineural hearing loss caused by boron vibration in the postoperative period, as well as obtaining good functional results.

Claims (1)

A method for the prevention of vibroinjury of the inner ear when removing atresia of the external auditory canal, including a behind-the-ear incision, extended anthromastoidotomy, complete removal of the atretic lamina, restoration of the anvil-stirrup articulation with glass ionomer cement, tympanoplasty, characterized in that the removal of the atretic lamina is performed by first separating the auditory lamina from the site to the auditory anvil and stapes compounds, before the start of work to eliminate bone obliteration, retain the hammer and the anvil, and this access incudostapedial articulation carried by the rear overlay tympanotomy without locking atresial plate and restoring the ossicular chain is carried out during ossikuloplastiki.

Images