Seishi Hasebe

Gas Exchange Function Through the Mastoid Mucosa in Ears After Surgery

Gas exchange function through the mastoid mucosa was investigated in ears after surgery using nitrous oxide. Increase in the mastoid pressure was assessed by a micropressure sensor placed in the mastoid cavity during the second‐stage revision operation performed under general anesthesia using 67% nitrous oxide, 33% oxygen, and sevoflurane on 14 ears with chronic adhesive otitis media or cholesteatoma as well as on seven ears without inflammation as controls. All seven control ears showed pressure increase in the mastoid in various degrees. In the 14 postoperative ears, nine of the 10 ears on which the mastoid mucosa had previously been able to be preserved in various degrees showed pressure increase in the mastoid, but none of the remaining four ears, which had previously had mastoidectomy, showed any pressure increase. The presence or absence of the mastoid pressure increase of those ears was also found to be correlated well with the presence or absence of mastoid aeration on computed tomography examined just before the second‐stage operation. These results appear to indicate that, in ears after surgery, recovery of both the gas exchange function and aeration in the mastoid is expected only when the mastoid mucosa can be preserved even partially.

Influence of the Gas Exchange Function Through the Middle Ear Mucosa on the Development of Sniff‐Induced Middle Ear Diseases

To investigate the influence of gas exchange function through the middle ear mucosa on the development of sniff‐induced middle ear diseases, the authors examined the mastoid pneumatization among patients with sniffing habit using computed tomography, and also examined the change of negative middle ear pressure induced by sniffing using tympanogram. In 20 ears with cholesteatoma or adhesive otitis media, the areas of mastoid cavity measured at the level of the lateral semicircular canal were significantly smaller than those in 26 ears with otitis media with effusion (OME) or attic retraction and in eight normal ears with sniffing habit (P < .01 and P < .0001, respectively). In 26 ears with OME or attic retraction, the areas of mastoid cavity were significantly smaller than those in eight normal ears with sniffing habit (P < .0001). By contrast, in the four ears with sniff‐induced middle ear disease, the recovery of negative middle ear pressure in 5 minutes without swallowing was less than 10 mm H2O, whereas in all seven ears with normal eardrum, negative middle ear pressure recovered by more than 20 mm H2O in 5 minutes. These findings suggested that impairment of gas exchange function through the middle ear mucosa, as well as eustachian tube dysfunction, might be closely related to the development of sniff‐induced middle ear diseases.

Gas exchange function of the middle ear in patients with otitis media with effusion

Gas exchange function through the middle ear mucosa was assessed using nitrous oxide (N2O) in patients with otitis media with effusion (OME), as well as in normal ears during elective surgery for unrelated disorders. In all normal ears except one (n = 43), an increase in pressure was observed after N2O inhalation. In 42 of 84 ears with OME, a pressure increase was observed, but not in the remaining 42 ears (50%), indicating that the gas exchange function in these latter ears was impaired. In 21 of the 42 ears showing no middle ear pressure increase following N2O inhalation, the middle ear pressure was again monitored after myringotomy and aspiration of the effusion A pressure increase was found in 16 ears, indicating that the impairment in gas exchange function in ears with OME may be reversible in most cases. Computed tomography of the mastoid was examined preoperatively in 66 ears, with the presence or absence of a middle ear pressure change well correlated in 57 ears with the presence or absence of mastoid aeration.

Factors affecting recovery of mastoid aeration after ear surgery.

Abstract Fifty-six patients after tympanomastoid surgery were examined to determine recovery of mastoid aeration and various pre- and intraoperative factors such as eustachian tube (ET) function, how the mastoid mucosa had been treated during surgery and whether or not a large silastic sheet had been placed in the middle ear or a ventilation tube used. Mastoid aeration recovery was confirmed by computed tomography in 27 of the 57 cases (47%) within 12 months of surgery. Among the factors examined, preservation of the epitympanic mucosa was found to be most important in mastoid aeration recovery. Use of a large silastic sheet to cover the area from the bony ET and tympanic cavity to epitympanum, aditus ad antrum or antrum was found to be of some help in recovery mastoid aeration after complete resection of the mucosa and mastoid air cells. Preoperative ET function, anterior tympanotomy and use of a ventilation tube did not influence recovery.

Influence of the Upper Respiratory Tract Infection on Tubal Compliance in Children with Otitis Media with Effusion

To clarify the influence of inflammation on tubal compliance in children with otitis media with effusion (OME), we investigated the change of compliance of the ET by upper respiratory tract infection (URTI) in 18 children (23 ears) with OME using the forced response test. The tubal compliance index (TCI), the ratio of passive tubal resistances at two different airflow rates, significantly increased during URTI represented by acute rhinitis or paranasal sinusitis in comparison with non-URTI periods (paired t-test: t = 4.14, p < 0.001). In nine ears, the TCI could be followed for some months after that, during which the children had had URTI several times. A clear reproducible correlation was found between the presence or absence of URTI and the TCI values; the TCI values increased again during URTI and decreased after the URTI periods. These results seemed to support our hypothesis that compliance of the ET may depend not only on the property of the cartilaginous framework of the ET but also upon the mucosal condition.

Mastoid Condition and Clinical Course of Cholesteatoma

This study was carried out to establish which type of cholesteatoma is controllable by conservative treatment from the viewpoint of mastoid ventilation. We examined the area of the air cell system and airspace (aeration) in the mastoid cavity by computed tomography and eustachian tube (ET) function by inflation-deflation test in 20 ears (20 patients) with severe attic retraction for over 12 months (retraction pocket group), 16 ears (16 patients) with cholesteatoma which could be controlled only by conservative treatment for over 12 months (nonsurgical group) and 43 ears (43 patients) which required surgery within a year in spite of similar conservative treatment (surgical group). The size of the mastoid air cell system in the retraction pocket group, nonsurgical group and surgical group was 2.9 ± 1.3, 1.9 ± 0.7 and 1.5 ± 0.9 cm2 on average, respectively, with no significant difference between both cholesteatoma groups (nonsurgical and surgical group). While aeration was observed in the mastoid in 17 of 20 ears (85.%) in the retraction pocket group and in 12 of 16 ears (75.0%) in the nonsurgical group, aeration was present only in 9 of 43 ears (26.5%) in the surgical group, being significantly less in the surgical group than in the nonsurgical group and the retraction pocket group. In all ears in the retraction pocket and nonsurgical groups, and 19 of 30 ears in the surgical group, ET function was poor, there being no significant difference among the three groups. The present clinical observations suggest that progressiveness of cholesteatoma could be related to the ventilatory conditions in the mastoid rather than ET function, and that conservative treatment may be effective when ears with cholesteatoma have aeration in the mastoid.

The diagnostic and prognostic value of eardrum mobility in otitis media with effusion.

Abstract Diagnostic and prognostic values of eardrum mobility were determined by pneumatic otoscopy in 37 patients (56 ears) having otitis media with effusion (OME). Eardrum mobility was impaired or lost in less than half of the ears (46.4%), while a tympanogram detected 77.8% of OME. In 27 of the 37 patients (42 of the 56 ears), aeration of the middle ear space was examined by CT and demonstrated that the presence or absence of aeration was significantly correlated with the presence or absence of eardrum mobility. In another 38 children (62 ears with OME), effect of antibiotics was correlated with eardrum mobility before treatment, and the improvement rate was found to be significantly higher in ears with positive mobility of eardrum (34.3%) than in ears without eardrum mobility (10.0%). These results indicate that eardrum mobility is a good prognostic indicator of OME rather than its diagnostic indicator alone.

Cerebellar arteriovenous malformation with facial paralysis, hearing loss, and tinnitus: A Case report

Objective To describe cerebellar arteriovenous malformation in a 21-year-old man with symptoms resembling those of ear disease and to discuss the relationship between the findings of neurotologic examination and magnetic resonance imaging. Study Design Case report. Setting Department of Otolaryngology, Head-and-Neck Surgery of the Kyoto University Hospital, which is a tertiary care center, in Kyoto, Japan. Patient A 21-year-old man had cerebellar arteriovenous malformation and symptoms resembling those of ear disease: recurrent left facial paralysis, left retrocochlear hearing loss, and tinnitus. Auditory brainstem responses showed only waves I and II on his left side. Downbeat nystagmus was seen by anteflexion and retroflexion of his neck. He also experienced a slight sensory disturbance on the left side of his face and right lower extremity. Magnetic resonance imaging and vertebral angiography revealed a cerebellar arteriovenous malformation and a varix functioning as a drainer of the arteriovenous malformation surrounded by an edematous region probably induced by a small hemorrhage in the brainstem. Intervention Conservative treatment, including intravenous prednisolone, vitamin B12, and oral adenosine triphosphate was performed followed by total extirpation of the arteriovenous malformation. Conclusion In examining patients with peripheral facial paralysis (sometimes recurrent with a short interval) and other symptoms resembling those of ear disease, especially those suggesting certain central disorders, it is important to take intracranial arteriovenous malformation into consideration because the condition may be sometimes life threatening if overlooked.

Postnatal changes in the connective tissue in the region lateral to the eustachian tube: possible relationship to tube function.

In order to delineate the possible role of connective tissue (CT) in the region lateral to the eustachian tube (ET) between the ET lumen and the tensor veli palatini muscle (TVPM), we studied the postnatal changes in the CT in histologic sections of human ET. In fetuses and neonates, the lateral region was filled with mesenchyme. Loose collagenous CT appeared first at 2 weeks of age, and in subjects older than 4 years of age, the collagen formed dense, meshlike structures attaching to both the subepithelial CT layer of the ET and the tendonlike membrane of the TVPM. Along the long axis of the ET, those attachments were distributed mainly in the region at the posterior part of the cartilaginous portion of the ET. Attachments to the subepithelial CT layer of the ET were distributed mainly in the upper half of the region. The dense, meshlike collagenous CT might help the ET to be opened by drawing the lateral wall of the ET lumen through inferolateral movement of the tendonlike membrane of the TVPM when the TVPM contracts. It may work to open mainly the parts that include the narrowest portion of the ET, and also the upper aspect of the ET lumen. Incomplete development of this structure in infants may be one of the factors associated with dysfunction in ET opening.

Organic change of effusion in the mastoid in otitis media with effusion and its relation to attic retraction

To try to solve the pathogenesis of severe attic retraction viewed from mastoid condition, we examined the residual soft tissue density (RSTD) in the mastoid by computed tomography (CT) in 85 patients (107 ears) with otitis media with effusion (OME) 3 months after tympanostomy tube insertion or later. The incidence of RSTD in the mastoid was significantly higher in OME of adults (52.6%) than in children (24.1%). Ears with severe attic retraction had RSTD significantly more frequently (80%) than those with no or mild attic retraction, and many of the mastoids with severe attic retraction were occupied totally by RSTD. The area of the mastoid (mastoid pneumatization) was significantly smaller, and CT density of the mastoid (sclerotic tendency) was significantly higher in ears with RSTD than in those without. RSTD after tympanostomy tube insertion in the mastoid indicating organic change of effusion was considered one of the important factors relating to the pathogenesis of severe attic retraction.