Long-term results using a piezoelectric semi-implantable middle ear hearing device: the Rion Device E-type.

The Rion Device E-type (RDE) has been applied to 39 patients with severe mixed deafness that could not be rehabilitated by surgical means or the conventional hearing aid. Careful follow-up studies have been conducted on all of them to assess clinical and audiologic results. The device could function more than 10 years, affording natural quality of hearing without howling and wearing discomforts. Functional principles of the device, indications, and surgical methods of implantation are described. The failures and delayed problems were also presented together with the preventive measures.

[Laterofixation of the vocal cord by Ejnell's operation for bilateral vocal cord paralysis].

In patients with bilateral vocal cord paralysis, several therapeutic techniques have been proposed to improve laryngeal obstruction. Since 1990, we have performed Ejnell's operation on six patients, one male and five females, suffering from bilateral vocal cord paralysis. Tracheostomy had been performed in four patients prior to their consultation. Five patients underwent a breathing capacity examination before and after the operation. Four of the patients showed improvement in breathing capacity and the tracheostoma was closed in those four patients. There was little aspiration problem during the postoperative follow-up period. Our experience suggests that Ejnell's operation is technically simple and should be useful in the treatment of bilateral vocal cord paralysis.

[Radiotherapy combined with daily administration of low-dose cisplatin for squamous cell carcinomas of the head and neck].

The effects of radiotherapy combined with daily administration of low-dose cisplatin (CD DP) and radiotherapy alone for squamous cell carcinomas of the head and neck were compared clinically and histologically. There was no difference in the response rate between two groups with and without CDDP for pre-operative irradiation (30-40 Gy). However, the complete response rate in the radical irradiation group (60-70 Gy) with CDDP was significantly higher than without CDDP. In the histologic effect assessed by the classification of Shimozato in 9 of 19 patients undergoing radical irradiation with CDDP, 3 patients in this group showed a grade III effect, and the other 6 a grade IV effect. Only 5 of 11 patients having irradiation alone showed grade III or IV effect. In conclusion, full-dose radiotherapy combined with CDDP provided a high level of organ preservation and local control because of the high clinical and histological complete response rate at the primary site.

Staged intact canal wall tympanoplasty for treatment of middle ear cholesteatoma.

Results of surgery for middle ear cholesteatoma were investigated in 202 ears of 197 patients who had undergone surgery by the staged intact canal wall technique. Surgical procedures used in the second stage for prevention of a retraction pocket were classified into three types: Type S1, no scutumplasty; Type S2, scutumplasty; Type S3, scutumplasty plus mastoid obliteration. Recurrent cholesteatoma was found in 9 ears (4%) and retraction pocket in 47 ears (23%). They occurred between 2 and 120 months (average: 26 months) after the second stage, most frequently at 1 to 3 years. The incidence was higher after Type S3 surgery than after the other types, probably because the middle ear was severely involved in patients who were indicated Type S3 surgery. For prevention of a retraction pocket, bone putty and cartilage were proved to be appropriate materials for scutumplasty, and hydroxyapatite for mastoid obliteration. As the retraction pocket tended to recur in patients with the pocket at the second stage, these patients needed obliteration of the mastoid cavity to prevent a retraction pocket. Postoperative hearing was evaluated according to the criteria proposed by the Japan Society of Clinical Otology. Of 145 ears of the 142 patients who were followed for more than 1 year, 118 ears (81%) the surgery was judged successful. The success rate in hearing was in good accordance with the condition of the tympanic membrane.

Effects of mastoid cavity obliteration on the growth of experimentally produced residual cholesteatoma.

The effects of obliteration of the mastoid cavity on the growth of residual cholesteatoma were histologically studied in an animal model. A dermal cyst was produced by grafting a piece of autologous auricular skin in the otic bulla of 11 guinea-pigs. Three weeks after grafting, part of the cyst wall facing the cavity was removed and the debris accumulated inside was inserted into the surrounding granulation using a micropick. This procedure simulates the growth mechanism of cholesteatoma residue which sometimes occurs after middle ear surgery in human subjects. In six animals, the bulla was then obliterated with plaster of Paris. The remaining five animals were used as controls. Animals were killed for histological study at 2, 4 or 8 weeks postoperatively. Microscopic examinations revealed that in the obliteration group, severe inflammatory reactions were induced in the otic bulla, although the graft epithelium survived there; dermal cyst reformed in only one of six animals. In the controls, cyst reformation was recognized in all animals. This indicated that severe inflammation induced by plaster prevented growth of the graft epithelium in the otic bulla.

[Thermoradiotherapy combined with daily administration of low dose cisplatin for locally advanced laryngeal carcinoma].

We applied thermoradiotherapy combined with daily administration of low dose cisplatin (CDDP) to five patients with locally advanced laryngeal carcinoma. The total response rate (CR + PR) was 100% after irradiation of 30 or 40 Gy. One case showed CR, and the larynx could be preserved by adding a full dose of irradiation. CDDP administration was discontinued in two cases due to renal dysfunction or thrombopenia, but other cases tolerated the therapy without severe side effects. Total laryngectomy and bilateral neck dissection was carried out in four cases after irradiation of 30 or 40 Gy. Removed larynxes were prepared for light microscopic observations of the serial sections. One of the four specimens revealed a CR histologically. The combination of thermoradiotherapy with low dose CDDP showed a remarkable effect on reduction of tumor size and cytotoxicity of tumor cells. This might contribute to saving the larynx of patients with locally advanced laryngeal carcinoma.

Effects of ionomer cement on guinea pig cochleas.

The inner ear toxicity of ionomeric cement (Ionocem) when used as a reconstructive material in ear surgery was evaluated in 47 guinea pigs used in a morphological study. The cement was implanted on either the promontory, the round window membrane or the stapes. There was no significant hair cell loss compared with the control ear at three weeks, two months or three months after implantation. Using electrocochleography, the hearing thresholds before, and three weeks, two and three months after the implantation were compared in an additional seven animals. No evident hearing loss was observed in any animal during the study period. No morphological or functional evidence for an ototoxic effect of the ionomeric cement was found in this study.

Surgical rehabilitation of deafness with partially implantable hearing aid using piezoelectric ceramic bimorpli ossicular vibrator.

We developed two types of implantable hearing aids, a totally implantable hearing aid (TIHA) and a partially implantable hearing aid (PIHA) in 1983. In both types a piezoelectric ceramic bimorph was used as an ossicular vibrator which was coupled to the stapes to transmit sound signals to the inner ear efficiently. Due to technological immaturities, clinical application of the TIHA has not yet been realized. But the PIHA is available for clinical use at present. In the PIHA only the ossicular vibrator is implanted with inner link coil. The rest of components such as microphone, amplifier, battery, and outer link coil remain in their usual location behind the auricle. Since 1984, we have applied the PIHA to 37 patients with mixed deafness. Careful follow-up studies have been conducted on all of them to assess clinical and audiological results. We have confirmed that the device could function safely for more than 10 years affording natural quality of hearing without howling and wearing discomforts. Our studies suggest that the PIHA can be a choice of rehabilitation for mixed deafness due to middle ear diseases which cannot be rehabilitated satisfactorily by either surgical means or a conventional hearing aid. Functional principle of device, indications and surgical methods of implantation were described. Failures and delayed problems we experienced were also presented together with the preventive measures. We believe that an implantable hearing aid of this type will be an otologic breakthrough if substantial technological difficulties are cleared.

Residue of middle ear cholesteatoma after intact canal wall tympanoplasty: surgical findings at one year.

The rate of residual disease after surgery for acquired middle ear cholesteatoma was investigated in 167 ears of 164 patients who had undergone planned second-look tympanoplasty by the intact canal wall technique. Overall, operative findings at the second stage revealed 65 cases of residual disease in 48 ears (29%). These consisted of 50 squamous pearls, 11 cases of the flat, open type, and 4 cases of the extensive type. The configuration of residual disease is closely related to the technical difficulty of eradication, since en bloc removal is much easier in the squamous pearl than in the open or extensive type, mainly because of the unclear margin with the surrounding tissues. The proportion of cases of the open type was greater in children than in adults, in pars tensa cholesteatoma than in pars flaccida cholesteatoma, and in severe primary middle ear disease than in moderate or mild disease, although these differences were not statistically significant. The extensive type occurred in 4 ears with severe primary disease, 3 of which were in children. These results support the value and importance of the staged procedure for middle ear cholesteatoma, particularly when operated on by the intact canal wall technique.

Configuration of experimentally produced cholesteatoma by transplantation of a free skin graft.

Residual cholesteatoma was experimentally produced in guinea pigs by transplanting a free skin graft into the middle ear bulla. In group A, the graft was placed on the mucosa after scratching the surface with a pick, while in group B, it was placed on the bone surface following removal of the mucosa and drilling with a diamond burr. The group A procedure was conducted on the left ear and the group B procedure on the right ear in 12 guinea pigs. The animals were sacrificed at two, four and eight weeks after transplantation. In all 12 ears of group A, the graft kept its original flat shape, resembling an open type residue. In eight of 12 ears of group B, the graft grew forming a squamous pearl, while in the remaining four ears it retained a flat shape. The difference in configuration is thought to be due to the amount of granulation around the graft.

[Quantitative analysis of color of the nasal mucosa].

The color of the nasal mucosa was quantitatively studied. Chromaticity of the nasal mucosa was indicated by two parameters, x (red component in RGB) and y (green in RGB) values, measured with a chromameter (MINOLTA Co., CS-100). According to preliminary studies in normal subjects, the following conditions were thought to make the method suitable for measuring the color of the nasal mucosa. 1) The chromameter can be held in the hand. 2) Brightness of the nasal mucosa should be kept as constant as possible. 3) The inferior turbinate mucosa is easier to measure than the septal one. In the preliminary study there was no significant difference in chromaticity measurements among the examiners. Chromaticity of the inferior turbinate was compared among patients with perennial nasal allergy (PNA, n = 19), with cedar pollinosis (CP, n = 11), and normal subjects serving as a control (n = 15). The x values in the PNA and CP groups were significantly lower than those in the control group (p < 0.01), and the y values were significantly higher (p < 0.02). The results agreed with the macroscopic observations made by trained rhinologists. The x values increased when azelastin was administered in five of the PNA group. This increase was related to improvement of their subjective symptoms. Quantitative analysis of the nasal mucosal color could be useful for objective evaluation of the clinical course of allergic rhinitis.

[Radiotherapy combined with daily administration of low dose cisplatin for head and neck cancer].

Radiotherapy combined with daily administration of low-dose cisplatin (CDDP) was applied to 12 cases with head and neck cancer. They consisted of 12 carcinomas, occurring in the epipharynx (3 cases), mesopharynx (3), oral cavity (1), larynx (3) and parasinuses (2). The total response rate (CR + PR) was 83.3%. There was a remarkable effect in reducing tumor size, particularly on patients with laryngeal or epipharyngeal carcinoma. Severe mucositis with ulcers as a side effect was seen in eight cases after the irradiation of 20 to 30 Gy. Six of them tolerated a full dose of irradiation, but CDDP administration was stopped except in one case. To continue the CDDP administration in cases having irradiation of over 40 Gy, it is necessary to reduce the frequency of CDDP administration and/or to give post-irradiative hydration with 500 ml saline. When this combination therapy is used as a preoperative treatment, daily administration should be continued. Incidence of nausea or vomiting was not so frequent and they could be easily controlled by a serotonin-antagonist. Leukopenia was not severe.

[Fates of bone defects in the mastoid cavity studied from the findings of two-stage tympanoplasty].

The incidence and prognosis of bone defects occurring in the mastoid cavity were investigated in 205 ears of 197 patients who underwent planned two-stage tympanoplasty by the intact canal wall technique. Bone defects found at the first stage had spontaneously closed by the second stage in 43 of 62 ears at the mastoid tegmen, in 13 of 15 ears at the posterior wall of the mastoid cavity and in 2 of 17 ears at the posterior wall of the external ear canal. Twenty two ears developed bone defects at the ear canal between the first and second operations, despite the canal wall having been primarily preserved. Of the 6 ears with closure of the labyrinthine fistula using temporalis fascia at the first stage, the defects were obliterated with regenerated bone in 5 ears at the second stage. Bone defects at the facial canal were recognized in 67 ears at the first stage, 21 of which were no longer seen at the second stage.

[Revision endoscopic sinus surgery--long-term follow up and operative findings].

Among 170 cases (301 sides) with chronic sinusitis who underwent endoscopic sinus surgery, 15 cases (25 sides) were reoperated on because of unsatisfactory results. We examined 12 such cases, periodically, with an endoscope following the first operation. Postoperative endoscopic management, including removal of polyps in the middle nasal meatus and irrigation of the maxillary sinus with sterilized saline water through the enlarged opening, had been done if necessary. However, stenosis of the middle nasal meatus had gradually progressed and mucous or purulent discharge had increased despite postoperative endoscopic treatment. The middle nasal meatus in 17 of the 25 sides had been closed by polyps or/and adhesion at the time of reoperation. The adhesion occurred between the lateral wall of the anterior ethmoid cavity and the middle turbinate. As a result, the opening of the frontal sinus became narrow or even closed, and pus retention was noted in 14 frontal sinuses during revision surgery. In contrast, only seven maxillary sinuses had pus retention. We concluded that adhesion in the middle nasal meatus holds the key to control of inflammatory changes in the paranasal sinuses.

Partially implantable hearing aid using piezoelectric ceramic ossicular vibrator. Results of the implant operation and assessment of the hearing afforded by the device.

The aim of designing an implantable hearing aid (IHA) is to compensate for some of the disadvantages of conventional hearing aids. The IHA described in this article is a direct oscillation type in which the piezoelectric ceramic ossicular vibrator coupled directly to the stapes transmits sound signals to the perilymph effectively. This type of IHA can give a better fidelity of sound perception than a conventional hearing aid.

Experimental cholesteatomas arising from autologous free skin grafting in the middle ear cavity.

An autologous free skin graft taken from the upper or the lower external ear canal or the auricle was implanted in the otic bulla of 28 guinea pigs. An epidermal cyst simulating middle ear cholesteatoma was successfully produced in 25 (89.3%) animals 8 weeks after grafting. Using this model, the histological reaction of middle ear granulation tissue to the debris was studied. Cysts originated from the auricular skin showed the strongest activity with regard to growth rate, amount of debris produced, and inflammatory reaction to the exposed debris. We conclude that the exposed debris plays an important role in chronic granulomatous inflammation in association with cholesteatoma.

Prevention of recurrence of cholesteatoma in intact canal wall tympanoplasty.

In the treatment of cholesteatoma employing intact canal wall tympanoplasty, staging the operation and re-establishment of aeration of the tympanic cavity are required to eradicate possible causes of recurrence, cholesteatoma residue, and retraction pocket. The planned staged tympanoplasty with preventive measures for recurrence has evolved. At the second-stage operation, one of the following three types of operations was performed according to the grade of aeration and healing of tympanic cavity: type S1, only ossiculoplasty; type S2, ossiculoplasty and scutumplasty; and type S3, ossiculoplasty, scutumplasty, and mastoid obliteration. The surgical concept, indication, and technique are described in detail. The recurrence rate in the 134 patients without previous surgery, 95 adults and 39 children, operated on between 1987 and 1991 was 2.2 percent (7.6% in the children and 0% in the adult). Although the rate of the recidivism was significantly reduced, deep retraction pocket developed in 15 percent of adults and in 23 percent of children. The incidence of deep retraction pocket formation was lowest in the adults with type S1 operation and highest in the children with type S3 operation.

Incidence of attic retraction after staged intact canal wall tympanoplasty for middle ear cholesteatoma.

Incidence of retraction pocket and recurrent cholesteatoma in the attic after surgery for middle ear cholesteatoma using the staged intact canal wall technique were investigated in 95 ears of 91 patients, all of which had various degrees of bone defect in the tympanic scutum. Surgical procedures employed in the second stage for prevention of attic retraction were classified into three types: Type I, no scutumplasty; Type II, scutumplasty; Type III, scutumplasty plus mastoid obliteration. In 83 ears followed up for more than 1 year after the second stage, such retraction troubles occurred in 2 of 13 ears (15%) in Type I, 8 of 20 ears (40%) in Type II, and 24 of 50 ears (48%) in Type III. Incidence of retraction troubles was higher in Types II and III, probably because these procedures were indicated in ears with large scutum defects. Dislocation and atrophy of the graft materials, together with bone resorption around the bone defect were the main reasons for failure in scutumplasty. Dysfunction of the eustachian tube and traction of the eardrum by the scar tissue behind it may have also contributed to attic retraction. Mastoid obliteration with small blocks of hydroxyapatite was more effective in prevention of retraction troubles than that with pedicled temporalis muscle flap.

[Experimental middle ear cholesteatoma originated from free skin graft of the external ear].

The pathogenesis of middle ear cholesteatoma has been thought to be invasion of squamous epithelium originated from the external ear skin including the tympanic membrane. There is no evidence, however, that the external ear skin has more potential to form cholesteatoma than that of other sites. In this report experimental middle ear cholesteatoma of guinea pigs originated from the external ear skin was histologically compared with that originated from the auricular skin. Cholesteatoma as dermal cyst was seen in the middle ear of almost all animals (25/28 = 89.3%), using a free skin graft (3 x 3 mm), regardless of the skin taken from superior (group A) or inferior (group B) part of the external ear, or the auricle (group C) eight weeks after skin implantation. The activity of epithelium such as keratinization was evident in group C. There is, however, no obvious difference in surrounding granulation tissues among group A, B, and C. In a half of this series, cyst wall was broken and its contents (debris) mainly consisted of keratin were put on surrounding granulation tissues three weeks after skin implantation. Striking keratinized epithelium and subepithelial inflammations in relation to the amount of debris were observed at the eighth week. These findings suggest that the external ear skin does not have specific potential to form cholesteatoma and keratin plays some roles in growth of cholesteatoma.