RU2354344C1 - Method of cohlear implant fixation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to otolaryngology. Essence of method lies in the following: retroauricular incision of skin 4-5 mm long is made on parotid fold. Then incision of periosteum backward from skin incision is made at distance in upper wound corner twice longer than distance in lower corner. Bed is formed under periosteum from upper corner of parotid wound in oblique direction backward and downward at angle 35-40° from periosteum incision line. Upper bed border is located higher than conventional line going to malar curve. Implant is installed into formed subperiostal recess, then fixed with muscle-periostal tissue layer.

EFFECT: reduction of traumaticity of performed operation and simultaneous increase of implant fixation reliability.

2 ex, 3 cl, 1 dwg

Description

The invention relates to medicine, namely to otorhinolaryngology, and may find application in the surgical stage of cochlear implantation.

Cochlear implantation or electrode hearing prosthetics is one of the most promising areas for the rehabilitation of people with high hearing loss and deafness, especially children with congenital hearing loss of an early (up to 3 years) age.

During cochlear implantation, an operation is performed, during which an electrode system is introduced into the patient’s inner ear, which ensures the perception of sound information by electrical stimulation of the preserved fibers of the auditory nerve. In this case, a bone bed is usually formed under the implant body in the temporal-parietal region and is additionally fixed with various materials.

A known method of fixation of a cochlear implant with acrylic immersion joints [1].

With this method, an extensive (10-12 cm) endaural incision is made and the skin flap along with the auricle is mobilized downward. Then, a section of the fascial-muscular layer is performed near the apex of the mastoid process and a muscular-periosteal flap is formed with the base at the top. The bone bed under the implant is drilled using a special template. Then, the implant is fixed with acrylic immersion seams through the side openings superimposed on the edges of the bone bed.

There is also known a method of fixing a cochlear implant with titanium screws with a wide head or propylene loops [2].

With this method, an S-shaped retro-aural incision is made and a muscular-periosteal flap is formed, which is retracted posteriorly and downward. The bone bed under the implant is drilled using cutting and diamond milling cutters. The implant is fixed with titanium screws with a wide cap, which are screwed into the bone around the periphery of the device. Fixation with propylene loops is also possible.

A disadvantage of the known methods is their high invasiveness. Cochlear implantation is performed mainly in young children, that is, during the period of intensive growth and development of the bones of the skull, so the formation of a bone bed can adversely affect the development of the temporal bone. In addition, the bones of the skull in children during this period are quite thin and in order to form a bone bed under an implant of a sufficient size, it is necessary to partially or completely expose the dura mater, while its likelihood of fibrosis is quite high.

The disadvantage is that the formation of the bone bed and fixation of the implant requires large skin incisions with the formation of extensive muscle-periosteal flaps, wide mobilization of tissues inevitably increases the risk of infection, tissue atrophy over the implant body and its extrusion, as the area of flap ischemia increases, venous changes and lymphatic outflow.

It should also be noted significant bleeding from bone vein graduates, the duration of the operation and, accordingly, the duration of anesthesia, which creates an additional drug load on the child's body.

The closest in technical essence to the claimed solution is a method of fixation of a cochlear implant with soft tissues [3].

This method is less traumatic, it allows you to operate on children under the age of 18 months, while making a small behind-the-ear incision. The implant is installed in the prepared bone bed flush with the cortical layer of the bones of the cranial vault and is fixed from above with soft tissues (muscle-periosteal flap and skin, after layer-by-layer wound closure).

The disadvantages of this method are the passive mobility of the implant, a narrow field of view during the formation of the bone bed under the implant, which creates a risk of bleeding, hematoma, the possibility of damage to the dura mater with subsequent cerebrospinal fluid. In addition, with such contact of the implant with the dura mater, a pressure sore of the latter and the development of a cicatricial process in it are possible. All of the above can adversely affect the result of cochlear implantation.

The technical result of the invention is to reduce the morbidity of the operation when installing a cochlear implant while increasing the reliability of its fixation.

To achieve the specified technical result in the method of fixation of the cochlear implant with soft tissues when it is installed in the bed, made through a behind-the-ear incision. According to the proposal, a retroauricular skin incision is performed at a length of 4-5 cm along the ear fold, then the periosteum is cut posterior to the skin incision at a distance in the upper corner of the wound twice as much as the distance in the lower corner, the bed is formed under the periosteum from the upper corner of the ear wound in an oblique direction back and downward at an angle of 35-40 ° from the cut line of the periosteum, the upper border of the bed being located above the conditional line going to the zygomatic arch, and the cochlear implant is installed in the formed subperiosteal pocket and fix ruyut musculo-periosteal tissue formation. In this case, the periosteum incision is made at a distance of not less than 1.0 cm from the skin incision in the lower corner of the wound, and not more than 0.5 cm from the implant body, and the bed width exceeds the implant width by no more than 0.5-0.7 cm .

The presence of distinctive features indicates the conformity of the claimed technical solution to the patentability criterion of "novelty."

The inventive method allows the formation of a tight pocket, the stability of which is ensured on three sides by non-mobilized tissues, the integrity of the temporal muscle and aponeurosis are not violated at all, and the natural tone of these tissues holds the implant from above after layer-by-layer suturing of the ear wound. In this case, the implementation of the bed inclined at an angle of 35-40 ° from the cut line of the periosteum allows not to mobilize the periosteum in the upper corner of the wound, provide access to the auditory meatus and prevent the implant from slipping or shifting towards the auricle. Reliable fixation of the implant is provided by the muscular-periosteal tissue array.

Since the bone bed in the temporoparietal region of the skull is not drilled, this method is less traumatic compared to known methods.

From the foregoing, it follows that the technical result of the invention is achieved by a new set of essential features, both newly introduced and known, therefore, the claimed method meets the patentability criterion of "inventive step".

The method is illustrated in the drawing, which shows a diagram of the formation of a bed under a cochlear implant (right ear).

The following positions are used in the drawing: 1 - behind-the-ear skin incision; 2 - incision of the periosteum; 3 - bed under the implant (subperiosteal pocket).

The method is as follows.

General anesthesia is used. Antiseptic treatment of the skin of the ear region, auricle and external auditory meatus is performed.

A retroauricular skin incision is performed, 4-5 cm long along the behind-the-ear fold. Then, the periosteum is incised posterior to the skin incision at a distance in the upper corner of the wound twice as much as the distance in the lower corner. After that, the periosteum in the middle and lower wound area is exfoliated towards the ear canal, a transverse incision is made of the skin of the posterior wall of the external auditory canal. Then perform tympanotomy, revision of the tympanic cavity and form a cochleostomy in the region of the anteroposterior edge of the round window above the tympanal cochlea with an angular bore. The bed under the implant is formed by a bone raspator under the periosteum from the upper corner of the ear wound, above the conditional line leading to the zygomatic arch, obliquely back and down, located at an angle of 35-40 ° from the cut line of the periosteum.

In this case, take into account that the width of the bed should exceed the width of the implant, but not more than 5-7 mm, since the height of the implant is 5 mm. Thus, a tight pocket is formed, the stability of which is ensured on three sides by non-mobilized tissues. In the front, the periosteum is sutured by stepping back 0.5 cm from the implant body, while approaching the periosteum incision to the implant body ensures its most stable fixation. The integrity of the temporal muscle and aponeurosis is not violated, and the natural tone of these tissues holds the implant from above, after suturing the skin in the behind-the-ear fold.

The method is illustrated by the following examples. The method is intended for an implant with a flat body.

Example 1. Patient K., born on August 29, 2004 (at the time of the operation, age 1 year and 4 months), case history No. 6624, was admitted to the III clinic of the State Institution "St. Petersburg Research Institute of Ear, Throat, Nose and Speech" 19.12. 05 with a diagnosis of chronic bilateral sensorineural hearing loss, IV degree, of unknown etiology. Secondary disorder of receptive and expressive speech.

Upon admission, the patient's parents complained of a lack of hearing in both ears, a lack of speech development, and the inefficiency of binaural prosthetics with heavy-duty digital hearing aids. From the anamnesis it is known that pregnancy and childbirth proceeded without pathology, up to 8 months the child developed in accordance with age, at 1.5 months the patient began to walk, babble appeared at 8 months. After which the parents began to notice the regression of speech development. For the first time, an audiological office was contacted in July 2005, the child underwent a clinical and audiological examination. The Department of Health of the Krasnodar Territory sent the child to our institution to address the issue of the possibility of cochlear implantation.

On admission: the nasal mucosa is pink. The septum of the nose is in the midline. The nasal passages are free. The nasopharynx is free. Nasal breathing is satisfactory. The mucous membrane of the pharynx is pink. AD, AS - the external auditory canals are free, the eardrum is gray, the light reflex is preserved. Speech does not perceive.

According to CSWP, perception by the left and right ear is more than 103 dB. Game audiometry and a promontorial test are not shown for the child's age. According to computed tomography, the spiral channels of both snails are passable, but the gaps of the basal curls of both snails with a tendency to ossification are narrowed to 0.6 mm on the right and 0.8 mm on the left.

The conclusion of the commission: cochlear implantation is indicated, auditory-speech rehabilitation is promising. Given the data of computed tomography, the decision was made not to postpone cochlear implantation, due to the threat of contraction of the gaps of the cochlea

12/22/2005. the operation was performed - cochlear implantation on the right ear using the Combi 40+ implant.

In conditions of endotracheal anesthesia, a skin incision was made along the behind-the-ear fold, a periosteum incision was made posterior to the skin incision, in an oblique direction, 2 cm in the upper corner of the wound, and 1 cm in the lower corner. The periosteum in the middle and lower wound region is exfoliated towards auditory meatus. A transverse incision was made of the skin of the posterior wall of the external auditory meatus, the skin of the posterior wall of the auditory meatus was peeled off, the eardrum was highlighted and, together with the skin flap, pushed forward, after revision of the tympanic cavity with an angular bore, a cochleostomy was formed in the region of the anterior upper edge of the round window above the tympanal cochlear staircase.

The bed under the implant body, namely, under its transducer, is formed by a bone raspator under the aponeurosis from the upper corner of the ear wound, obliquely back and down, at an angle of 35 ° from the cut line of the periosteum. In this case, the bed width was 3 cm, the length was 4 cm. A narrow tunnel 3 cm long and 5 mm wide was formed under the temporal muscle upwards for laying the passive cochlear implant electrode, which is usually performed after laying the transducer body in the prepared bed. The active electrode is passed through the bone groove, a recess for excess electrode, the bone tunnel under the cortical layer of the posterior wall of the external auditory meatus and through the cochleostomy is inserted into the tympanic cochlea.

When reflexes of the stirrup muscle were obtained after telemetry of the implant, the meato-tympanal flap was placed in place with additional fixation with a strip of sterile latex and a hemostatic sponge. Further, sutures were placed on the periosteum (0.5 cm anterior to the edge of the implant transducer casing), a continuous suture was made on the behind-the-ear wound with silk. The wound is closed with an aseptic cotton-gauze dressing.

On the 7th day, the sutures were removed and the tamponade was removed from the ear canal, healing took place by primary intention.

The postoperative period was uneventful. When discharged on the 12th day after surgery: AD - the external auditory meatus is free, there is no discharge. The eardrum is pink, somewhat swollen.

Control examination one month after the operation 01/23/2006:

AD - the external auditory meatus is free, there is no discharge. The eardrum is normal, without defects. Allowed to connect the implant.

The girl underwent an initial course of auditory-speech rehabilitation with implant adjustment in our institution, then - classes with a sound educator individually at home. One year after the operation, according to the results of testing by the specialists of the speech clinic of the St. Petersburg Research Institute of Ear, Throat, Nose and Speech, the rehabilitation result was rated as "excellent".

Example 2. Patient Z., born in 1999 (at the time of the operation, age 6 years), medical history No. 7584, was admitted to the III clinic of the State Institution "St. Petersburg Research Institute of Ear, Throat, Nose and Speech" 04.04.06 with a diagnosis of chronic bilateral sensorineural hearing loss, IV degree, post-infectious etiology. Secondary disorder of receptive and expressive speech.

From the anamnesis, it is known that a patient aged 1.5 years suffered a severe form of influenza and rubella after 1 month, after which progressive bilateral sensorineural hearing loss developed. For the first time, the patient came to our institution in December 2005, she was examined by the cochlear implantation program. The conclusion of the commission: cochlear implantation is indicated, auditory-speech rehabilitation is promising. As budgetary funds arrived, the child was called for an operation.

On examination: The mucous membrane of the nose is pink. The septum of the nose is in the midline. The nasal passages are free. The nasopharynx is free. Nasal breathing is satisfactory. The mucous membrane of the pharynx is pink, Tonsils - I degree. The laryngeal mucosa is pink, moist. Vocal folds are mobile - in full. The glottis is regular in shape. AD, AS - the external auditory canals are clear. Speech does not perceive.

The results of tonal threshold audiometry testified to a high degree of bilateral hearing loss with thresholds of sound conduction on the right 70-110 dB, in the range from 125 to 2000 Hz, the patient does not perceive tones with his left ear. According to CSWP, perception by the left and right ear is 103 dB. Tympanogram of type A. According to the results of a promonterial test, the electroexcitability of the auditory nerve is preserved on the right and absent on the left. According to computed tomography, the spiral channels of both snails are passable.

04/10/2006. the operation was performed - cochlear implantation on the right ear, using the Combi 40+ implant.

Under endotracheal anesthesia, a skin incision was performed along the behind-the-ear fold. The periosteum was incised posterior to the skin incision in an oblique direction in the upper corner of the wound by 3 cm, and in the lower by 1.5 cm.

The periosteum in the middle and lower wound area was detached towards the auditory meatus. Then, a transverse incision was made of the skin of the posterior wall of the external auditory meatus, the skin of the posterior wall of the auditory meatus was peeled off, the eardrum was selected, and, together with the skin graft, was folded anteriorly. After that, a revision of the tympanic cavity was made and a cochleostomy was formed in a typical place with an angular boron, departing 1 mm from the edge of the niche of the cochlea window above the tympanic membrane.

The bed for the implant transducer was formed by a bone raspator under the aponeurosis from the upper corner of the ear wound, obliquely back and down, located at an angle of 40 ° from the cut line of the periosteum, the upper edge of the bed corresponding to the conditional line going to the zygomatic arch. The width of the bed was 3 cm, the length was 4 cm. A narrow tunnel was formed upward under the temporal muscle, 3 cm long and 5 mm wide, for laying the passive electrode, which was performed after laying the transducer case in the prepared bed.

The active electrode was passed through the osseous groove, a notch for excess electrode, the bone tunnel under the cortical layer of the posterior wall of the external auditory canal and through the cochleostomy was inserted into the tympanic cochlea. After telemetry of the implant, visual reflectionometry of the stirrup muscle was performed, after which the meato-tympanal flap was put in place and fixed with a strip of sterile latex and a hemostatic sponge. Sutures were placed on the periosteum (0.5 cm anterior to the edge of the implant transducer body), a continuous suture was applied to the behind-the-ear wound. An aseptic cotton-gauze dressing was applied.

On the 7th day, the sutures were removed and the tamponade was removed from the ear canal, healing by primary intention. The postoperative period was uneventful. At discharge on the 9th day after surgery: AD - the external auditory meatus is free. The eardrum is pink, the light reflex is preserved.

Control examination 3 weeks after surgery 02.05.2006: AD - the external auditory meatus is free, there is no discharge. The eardrum is gray, shiny; no defects. Allowed to connect the implant. The girl twice passed a course of auditory-speech rehabilitation in our institution, one year after the operation according to the results of testing by specialists of a speech clinic, the outcome of the rehabilitation was rated as "excellent".

The inventive method was tested in a children's clinic and the department of pathophysiology of the ear of the Federal State Institution "St. Petersburg Research Institute of Ear, Throat, Nose and Speech" from 2005 to 2006, 54 operations were performed. All patients achieved excellent functional results; these patients did not require repeated surgical intervention associated with the displacement of the implant transducer, its extrusion and other complications of the operation.

The inventive method also allows to reduce the duration of the operation and, accordingly, the duration of anesthesia, and the low invasiveness of the operation allows you to accelerate the healing of tissues and reduce the duration of hospital stay.

It follows from the foregoing that the proposed method provides a technical result, does not cause difficulties, involves the use of developed materials and standard equipment, which indicates the compliance of the claimed technical solution with the patentability criterion of "industrial applicability".

Information sources:

1. T. Kiratzidis, W. Arnold, T. Iliades, “Veria Operation Updated”, ORL, 2002, v 64, p. 404-412;

2. B. Davis, R. Labadie, S. Mc Memong, D. Haynes, “Cohlear Implant fixation using propulene mesh and titanium screws”, Laryngoscope, 2004, No. 114, v12, p.2116-2118;

3. J. Roberson, L. Kunda, K. Stidham, M. Inserra, W. Chehoe, L. Tonokawa, “Modifications of standard cochlear implantation techniques for children under 18 months of age”, Cochlear implants international, 2006, vol. 7, N 4, p.207-213.

Claims (3)

1. The method of fixation of the cochlear implant with soft tissues when it is installed in the bed, made through a behind-the-ear incision, characterized in that the retroauricular skin incision is 4-5 cm long along the behind-the-ear fold, then the periosteum is cut posterior to the skin incision at a distance in the upper corner the wounds are twice the distance in the lower corner, the bed is formed under the periosteum from the upper angle of the ear wound in an oblique direction back and down at an angle of 35-40 ° from the cut line of the periosteum, with the upper border of the bed located above the conditional inii extending to the zygomatic arch, and a cochlear implant placed in subperiosteal pocket formed and fixed musculo-periosteal tissue formation. 2. The method according to claim 1, characterized in that the periosteum is produced at a distance of not less than 1.0 cm from the skin incision in the lower corner of the wound, and not more than 0.5 cm from the implant body. 3. The method according to claim 1, characterized in that the width of the bed exceeds the width of the implant by no more than 0.5-0.7 cm.