Vibrant Soundbridge middle ear implant in mixed hearing loss. Indications, techniques, results

OBJECTIVES

The aim of this article is to illustrate the aetiologies of mixed hearing loss that can benefit from a Vibrant Soundbridge (VSB) middle ear implant, the techniques performed and the first results.

MATERIALS AND METHOD

The authors report their experience of 13 implantations in mixed hearing loss due to otosclerosis, sequelae of chronic otitis media and congenital aural atresia. The VSB implant was implanted alone or in association with another middle ear surgical procedure, on the ossicular chain or on the round window membrane.

RESULTS

The average auditory gain for all patients is 32 dB for pure tone thresholds, and 25 dB for speech recognition. It results from the addition of a gain on the conductive hearing loss by direct stimulation of the inner ear, to a gain on the sensorineural hearing loss by amplification.

CONCLUSION

Middle ear implants are the only hearing aids affording a gain in both the conductive and sensorineural components of mixed hearing losses.

[Middle ear cholesteatoma]

Cholesteatoma is a serious form of chronic otitis media. The aim of this paper is to present the state of the art of disease management, including recent data from the literature and the authors' derived from their Mentors' teaching, Professor Pierre Roulleau (Paris, France) and Professor Robert Charachon (Grenoble, France). The main recent advances concern the use of cartilage grafts to reconstruct the canal wall and/or tympanic membrane (allowing a significant reduction in residual cholesteatoma) and progress in medical imaging allowing more acute preoperative determination of extension of the cholesteatoma (in order to propose an optimally designed surgical technique) and a less invasive postoperative follow-up.

Use of the subgaleal fascia to construct the auditory canal in microtia associated with aural atresia. A preliminary report

In this paper we introduce the use of a subgaleal flap to construct the auditory canal in cases of microtia associated with aural atresia. The anatomy, the vascularisation, and the nomenclature of the different planes that constitute the temporal region are wellknown. The subgaleal fascia, also referred to as the loose areolar fascia has been until now the less surgically exploited of these planes. Nevertheless, it has a structure and a vascularisation that enables it to be dissected and used surgically. The subgaleal flap used to line the neoauditory canal drilled into the bone provides a vascular bed that greatly improves the quality of the skin graft and supports the tympanoplasty. The procedure is done while the ear is being raised, which constitutes the second stage of the two-stage ear reconstruction. This new approach has been used on 22 ears. A preliminary analysis of the results shows that construction of the auditory canal has been improved.

Argon Laser and Gherini-Causse Endo-Otoprobe™ in Otologic Surgery

The authors describe the various surgical indications and techniques of the argon laser and Gherini-Causse Endo-Otoprobe™ in otologic surgery, from otosclerosis to chronic otitis. The advantages are numerous, permitting the surgeon to vaporize or coagulate tissue with optimal effect, avoiding excessive mobilization of the ossicular chain and diminishing the risk of damage to the facial nerve and inner ear structures.

Argon laser and Gherini-Causse Endo-Otoprobe in otologic surgery

The authors describe the various surgical indications and techniques of the argon laser and Gherini-Causse Endo-Otoprobe in otologic surgery, from otosclerosis to chronic otitis. The advantages are numerous, permitting the surgeon to vaporize or coagulate tissue with optimal effect, avoiding excessive mobilization of the ossicular chain and diminishing the risk of damage to the facial nerve and inner ear structures.

Ossiculoplasty with composite prostheses. Overview and analysis

Aeration of a mucosa-lined tympanic cavity is essential for a functioning middle ear. Extrusions of even the best-designed prostheses occur from abnormal middle ear conditions such as atelectasis, middle ear fibrosis, recurrent cholesteatoma, tympanic membrane perforation, and otitis media. Various polymers have been developed in an attempt to maximize prosthetic biocompatibility and ease of use while minimizing the chance of extrusion. One such polymer is a composite of hydroxyapatite and Silastic, known as Flex H/A. This material has been incorporated into two ossicular prostheses, the Universal Plus and the Causse Flex H/A prostheses. Certainly, refinements will continue to be made in the chemical makeup of the bioceramics in order to achieve optimal biocompatibility. In addition to biocompatibility, cost containment issues have influenced the development of ossicular prostheses. A universal prosthesis eliminates the need to stock multiple designs, thereby reducing the cost to institutions. One of the greatest challenges in the future will be to define the appropriate prosthetic design for optimal sound transmission. Consideration of prosthesis weight, head size, and footplate attachment are future research questions that need to be addressed in a scientific biologic model.

Herpes simplex virus ICP0 and ICP4 immediate early proteins strongly enhance expression of a retrovirus harboured by a leptomeningeal cell line from a patient with multiple sclerosis

A leptomeningeal cell line (LM7) harbouring an unknown retrovirus was recently isolated from the cerebrospinal fluid of a patient with multiple sclerosis. However, spontaneous expression of the LM7 retrovirus in this primary culture is quite low. We present results showing that in vitro infection of LM7 cells with herpes simplex virus type 1 (HSV-1), but not that of control cells, results in (i) potent stimulation of the specific reverse transcriptase (RT) activity detected in the culture supernatant and (ii) co-expression of both typical HSV-1 virions and abundant retrovirus-like particles. Transfection of LM7 cells with plasmids expressing HSV-1 immediate early (IE) ICP0 and ICP4 proteins produced a similar enhancement of RT activity in culture supernatants with retrovirus-like particles being identifiable by electron microscopy. These effects were not observed with a plasmid expressing ICP27 or with the parental plasmid in LM7 cells, nor with any of these four plasmids in control cells. These results show that HSV IE trans-activating proteins strongly enhance the expression of the latent retrovirus present in LM7 cells. The possible role in vivo of herpesviruses as 'triggering' cofactors in the retrovirus hypothesis for multiple sclerosis aetiology is also discussed.

In vitro transmission and antigenicity of a retrovirus isolated from a multiple sclerosis patient

We have recently isolated an apparently novel retrovirus (LM7) from a patient with multiple sclerosis (MS). We present here results showing that (1) LM7 retrovirus can be transmitted in vitro to a normal human leptomeningeal cell culture and that (2) specific antibody against this retroviral strain can be detected in MS cases. Our results suggest that, if this virus is an endogenous retrovirus, it is different from human endogenous elements already described.

Chondrosarcomas of the petrous apex

From 1974 to 1988, four patients with chondrosarcomas of the petrous apex were followed. Average age was 46 years (range, 30 to 61), one man and three women. The mean delay between the first patient's symptoms and the visit was 18 months (range, 15 to 24). The surgical treatment consisted of two infratemporal approaches (type A), one transcochlear approach, and one partial excision by retrofacial route. For the four patients, the surgery was followed by cobalt therapy. Three of four patients are alive and one patient died 5 years later of a cerebrovascular lesion and bilateral acute parotiditis. None presented with a recurrent disease.

[Congenital cholesteatoma of the middle ear in children]

In a series of 16 middle ear cholesteatomas of a congenital type are reported in children; the youngest (18 months) presented with a bilateral case. Whereas a simple tympanoplasty could cure a localized pearl, typically anterosuperior in the mesotympanum, the stapes is fast eroded (7 cases) if progression goes on. Intact canal wall technique in 2 stages was the typical procedure. Good hearing results were generally achieved (except in one case of fixed footplate): 9 cases/14 with an ABG within 20 dB and an AC level within 30 dB.

[Meningo-encephalomyelitis in Lyme disease]

A case of isolated central nervous system involvement in Lyme disease is described. A 13 year-old boy developed progressive spastic quadraparesis, chronic lymphocytic meningitis with a low CSF glucose concentration and demyelinating lesions of the white matter on MRI. The diagnosis was proved serologically by high antibody titers against Borrelia burgdorferi (BB) in the serum (1:5, 120) and CSF (1:1,280). There was evidence of specific intrathecal immune response against the BB antigen. The patient was treated with penicillin G and then ceftriaxone. The CSF abnormalities quickly improved but improvement of the neurologic symptoms was gradual and to date still incomplete.

Melanin in the inner ear. An experimental study with control and kanamycin-intoxicated colored guinea-pigs

Following several studies on the effects of kanamycin toxicity on the inner ears of guinea pigs, we have studied the importance of melanin in this phenomenon. Transmission electron microscopy showed that, under the influence of kanamycin, the intermediate strial cells developed a secretory aspect similar to that seen in skin melanocytes. This aspect as yet has never been described for the inner ear cells. A planimetric, morphometric method was also used to determine the strial cell melanin status in control animals. Additional findings in the study confirmed an increase in the number of melanosomes during kanamycin poisoning. Statistical data are discussed.

Anatomical and functional reconstruction of old radical mastoidectomy cavities by obliteration tympanoplasty

One hundred and seventeen patients who had previous radical mastoidectomies, atticotomies or Bondy operations were operated on between 1973 and 1984. An open technique with obliteration and traction meatoplasty was used in one stage in 19 ears (normal mucosa in mesotympanum) and in 2 stages in 98 ears (poor mesotympanum which needed to be dissected and covered with silastic sheeting). The second stage was performed 12 to 18 months later. Closure of the tympanic membrane was achieved in 93% of ears at the first stage. In 6 ears out of 81 second stages, residual cholesteatoma was found in the mesotympanum. No residual cholesteatoma was subsequently observed behind the flap but only 4 ears were checked behind the flap at the second stage. An air-bone gap within 20 dB was achieved in 85% of ears if the stapes was intact and surgery was performed in one stage, and in 55% of ears of the stapes was intact and surgery performed in 2 stages. If the crura were missing, an air-bone gap within 20 dB was achieved in 57% of ears in 2 stages.

[Maternal-child transmission of Chlamydia trachomatis. A prospective inquiry in 168 pregnant women]

A prospective study was performed in 168 pregnant women in order to evaluate the frequency of perinatal transmission of Chlamydia trachomatis and to measure its effects on the child's health during his first 3 months of life. The micro-organism was detected by an immunoenzymatic method specific to Chlamydia antigens, and microimmunofluorescence was used for serological testing. Cervical smears taken at the end of pregnancy were positive in 3 women (1.7 per cent), while the sera of 37 women were positive for Chlamydia trachomatis. Altogether, 26.8 per cent of the women explored had had a contact with the micro-organism. Conjunctival smears taken from 1 month old infants were all negative, but 4 infants (out of 126) had positive nasal smears. The mothers of 2 of these had been exposed to the bacterium, but all 4 mothers had negative cervical smears. Antibody titres in 3-month old infants were 1.2 dilution on average below those found in the mothers. Women exposed to Chlamydia trachomatis are frequently unmarried; their pregnancies tend to shorter than normally, and their infants have more frequent episodes of rhinitis. These peculiarities are insufficiently pronounced to single out a population at risk that might benefit from detection of the bacterium.

Closed versus obliteration technique in cholesteatoma surgery

In 533 surgical procedures for cholesteatoma, a closed technique was used in 60%, an obliteration technique with Palva flap was used in 35%, and an open technique was used in 5%. The closed technique has been done in stages in the authors' institution since 1973. The obliteration technique was only staged if the mesotympanum was dissected. In some cases, the Palva flap was partially lifted from the bone to check posterior cavities. A closed technique in one stage provided intact tympanic membrane in 97% of cases, but retraction pocket occurred in 25%; ABG was within 20 dB in 68% of ears if the stapes was intact and in 40% if crura were missing. Obliteration technique in one stage (if the mesotympanum was normal) provided intact tympanic membrane in 100% of cases, but one late residual cholesteatoma under the flap eroded the semicircular canal after 5 years. ABG within 20 dB was achieved in 68% of the ears if the stapes was intact and in 40% if crura were missing. Closed technique in two stages with Silastic sheeting achieved intact tympanic membrane in 97% of the ears. Residual cholesteatoma was removed at the second stage in 24% of the ears. ABG within 20 dB was achieved in 57% of the ears if stapes was intact and in 52% if crura were missing. Ten percent of the ears underwent an obliteration transformation at the second stage because of large mesotympanum cholesteatoma or retraction pocket. Late retraction pockets were observed in 10% of cases. Obliteration technique in two stages provided an intact tympanic membrane in 96.8% of the ears.(ABSTRACT TRUNCATED AT 250 WORDS)

Melanine value in the stria vascularis of pigmented guinea-pigs treated by kanamycin

In a previous report, kanamycin (400 mg/kg/d) seemed to increase the number of melanine granulations in intermediate cells of the stria vascularis, especially in the second and third turns. To precise these data, melanine was studied in those turns by ultrastructural morphometry in a control group with 12 animals. We observed a large intra-individual and inter-individual variation before intoxication. Thus, the meaning of melanine modifications by kanamycin must be carefully evaluated.

The surgical treatment of cholesteatoma in children

Between 1966 and 1981, 141 cholesteatomas were operated upon in children who were 3-15 years old. Radical mastoidectomy was performed in 5 cases. Open cavity tympanoplasty was done in 3 cases. Intact canal wall technique was performed in 99 cases, with a planned second stage in 83 cases (all cholesteatoma cases since 1973). ICWT avoids a large cavity in a well pneumatized mastoid and the second stage controls residual cholesteatomas which were more frequent in children (50%) than in adults (22%). Because of multiple or large residual cholesteatomas, a third stage was performed in 3 cases. Because of a large mesotympanum and/or attic residual cholesteatoma, a transformation of ICWT to an obliteration technique was performed in 4 cases. Retraction pockets were found after the first stage in 12 cases and a transformation of ICWT to an obliteration technique was done in 8 cases at the second stage. Late retraction pockets were found after 5 years in 20% after 2 stages and in 25% after one stage. If a retraction pocket is observed at the second stage, transformation of ICWT to an obliteration technique must be performed. Obliteration technique was performed in 34 cases. A second stage was planned in 26 cases only if the mesotympanum was to be dissected raw. Hearing results were better with an intact stapes (56% of air-bone gap less than or equal to 20 dB).

Classification and surgical treatment of fibroadhesive otitis

Surgical treatment for fibroadhesive otitis was performed in thirty-seven ears: eight were classified grade 1, with fibrogranulomatous tissue and mucous effusion; twenty-seven were stage 2, with thick fibrogranulomatous tissue without effusion but with cholesterol granuloma. Fifteen ears had small or middle size cholesteatomas, four had posterior retraction pockets. Results obtained were as follow. One stage procedures were usually functional failures in spite of Silastic sheeting, including one tympanoplasty using closed technique with posterior tympanotomy, three dissections of mesotympanum combined with antroatticotomy, and four obliteration procedures in one stage. Better results were obtained with two stage procedures with Silastic sheeting placed at the first stage and removed at the second. Five closed techniques yielded only one good functional result, but seventeen obliteration procedures with Palva flaps yielded the best results: healthy and thin mucosa in fifteen cases, with the mucosa remaining thick in only two cases. Good functional results (air-bone gap less than or equal to 20 dB) were obtained in ten cases, and among them very good functional results (air-bone gap less than or equal to 10 dB) in seven cases. Seven second stages have not yet been done.

Results of an ultrastructural study comparing stria vascularis with organ of Corti in guinea pigs treated with kanamycin

Ultrastructural study of ototoxicity is well documented with two points of interest: organ of Corti for aminoglycosides and stria vascularis for loop diuretics. As a previous study suggested initial lesions of stria vascularis, an attempt of comparison and of chronological study was made between the organ of Corti and stria vascularis lesions by kanamycin intoxication. The method was devised by J. M. ARAN, with electrophysiological control. We failed to find in the stria vascularis a radial or longitudinal pattern of lesions. We could not discern a chronological injury between the organ of Corti and stria vascularis because both were damaged even in the less deafened animals. Nevertheless, two facts were clarified: hair cell lesions are lysosomial as for the kidney lesions, while stria vascularis lesions are mitochondrial, melanine granulations play a part in drug metabolism (increased number, secretory aspect) and deserve further study.