Midori Nagai

Pathogenesis of Cholesteatoma Based on Clinical Results of Anterior Tympanotomy

A new conception of the pathogenesis of cholesteatoma is proposed based on clinical results of anterior tympanotomy, a procedure developed in order to prevent recurrence of cholesteatoma following retraction pocket formation after canal-up operation. In the cholesteatomatous ear, there is always a long, thick bony septum between the epitympanum and the supratubal recess. This septum is called the anterior attic bony plate, forming the tympanic diaphragm together with the tensor tympani mucosal fold. In anterior tympanotomy, this bony plate is removed finishing intact canal wall mastoidectomy, making a new ventilating route to the eustachian tube. With this technique, the rate of recurrence was reduced from 17 to 5%. Based on these results it is proposed that the real pathogenesis of cholesteatoma is not tubal dysfunction, but the osseous tympanic diaphragm.

The effects of anesthesia of the tympanic membrane on eustachian tube function

SummaryIn our previous histological studies of the tympanic membrane, we reported the presence of encapsulated nerve corpuscles that are capable of detecting middle ear pressure. Based on these findings, the relation between sensory receptors in the tympanic membrane and tubal function was examined in a clinical study. Tubal function was tested during Valsalva maneuvers and its active equilibration. Function was recorded as a change of the static compliance of the tympanic membrane on an otoadmittance meter. To paralyze the sensory receptors in the tympanic membrane, iontophoresis was used to induce anesthesia of the drum. Forty ears of 20 subjects were tested. All ears were able to equalize positive middle ear pressure without or with a single swallowing. After anesthesia, 13 ears needed more than two swallows and 4 ears failed to equalize middle ear pressure in spite of repeated swallowings. As eustachian tube function changed following anesthesia of the tympanic membranes, a neural connection between sensory receptors in the tympanic membrane and tubual muscles is suggested.

Scanning electron microscopy of arteriovenous anastomosis in nasal respiratory mucosa

SummaryArteriovenous anastomosis (AVA) in nasal respiratory mucosa of humans and guinea pigs were studied with scanning electron microscopy (SEM) after removal of extracellular connective tissues by tryptic digestion and HCl hydrolysis. The shape of AVA in humans is different from that in guinea pigs. In guinea pigs, it is simple with no specific structure observed on the vessels. In humans, it is characterized by a spherical swelling at the intermediate segment. The Tunica media of the spherical body is formed by the aggregation of spindle-shaped cells and receives a rich nerve supply. These findings suggest powerful contractility of human AVA compared with guinea pigs. Arteriovenous anastomosis in human nasal respiratory mucosa may strongly influence arterial blood flow into the cavernosus sinusoid and determine the characteristic microcirculatory pattern in human nasal mucosa.

The Ultrastructure of Lymphatic Vessels in the Human Middle Ear with Cholesteatoma

Lymphatic vessels were few in the edematous portion of the cholesteatoma perimatrix of the human middle ear. But the lymphatic vessels contained mucus and consisted of degenerated endothelial cells. Edema of the perimatrix was considered to be caused by the degeneration of lymphatic vessels. Normal lymphatic vessels were found in the fibrous perimatrix, while macrophages infiltrated and phagocytosed cell debris. In addition, regenerating blood vessels were observed. Degeneration of connective tissue due to lymphatic edema and its repair were both present in the perimatrix. The degeneration of perimatrix was hypothesized to be caused by confined mucous epithelium behind the cholesteatoma matrix.

Scanning electron microscopy of the human submandibular gland.

SummaryWe examined human submandibular gland parenchyma by scanning electron microscopy after removal of connective tissue components by HCl hydrolysis. Stellate-shaped myoepithelial cells and basal infoldings were clearly seen, indicating active function of the gland.

Scanning electron microscopy of the nasal glands and vessels

ZusammenfassungDie Tripsin-HCl Methode von Uehara wurde an der respiratorischen Nasenschleimhaut der Ratte und des Meerschweinchens angewendet und das oberflächliche Aussehen der Drüsen, der Gefäße und der begleitenden Nervenfasern wurde rasterelektronenmikroskopisch betrachtet. Der terminale Abschnitt der Drüsen besteht aus Drüsen- und Myoepithelialzellen. Die letzteren sind sternförmig und bedecken mit dünnen zytoplasmatischen Fortsätzen den terminalen Drüsenabschnitt. Die Arteriolen und Venolen lassen sich auf Grund des charakteristischen Aussehens der Zellen der glatten Muskulatur und des Innervationsmusters leicht unterscheiden. Die Arteriolen sind gelegentlich mit Arteriolen besonderer Struktur verbunden. Dies scheint eine wichtige Rolle bei der Regulation der peripheren Blutversorgung zu spielen.SummaryThe trypsin-HCl method of Uehara was applied to the respiratory nasal mucosa of rats and guinea pigs, and the stereoscopic surface view of the nasal glands, vessels, and associated nerve fibers were observed under the scanning electron microscope (SEM).The terminal portion of the glands was composed of glandular cells and myoepithelial cells, the latter were starfishlike features and extended thin cytoplasmic processes which covered the small area of the terminal portion. The arterioles and venules could be clearly distinguished by their adventitial aspects and innervation pattern. Arterioles were occasionally connected to small arterioles with a characteristic structure, which seemed to play a role in the regulation of peripheral blood supply.

Laryngoplasty Using Suprahyoid Muscles—Hyoid Transposition Laryngoplasty—

A new technique of laryngoplasty using the function of the suprahyoid muscles (hyoid transposition laryngoplasty) was reported. Total laryngectomy is carried out as usual and the tracheal stump is anastomosed directly to the hypopharynx. The hyoid bone is cut medially, then transpositioned and sutured to the posterolateral margins of the tracheal stump. With this procedure, the new glottis is pressed strongly to the tongue base during swallowing and aspiration is avoided. Postoperative swallowing and speech in the cases operated on with this method were satisfactory, and even nasal respiration was possible in some cases.

Scanning Electron Microscopy of Nasal Arterioles Effected by Vasoactive Agents

SummaryMorphological changes in nasal blood vessels induced by α- and β-adrenergic and cholinergic agonists were studied under a scanning electron microscope after removal of extracellular connective tissue and the basal lamina. Arterioles were constricted and dilatated following topical application of α-adrenergic and cholinergic agonists. Distinctive morphological changes were observed on their smooth muscle cells. Smooth muscle cells of constricted arterioles had a rugged surface with numerous fine invaginations. However, in dilatated arterioles the cells had a smooth surface and intercellular spaces were clearly revealed. No remarkable changes were produced in smooth muscle cells by the β-adrenergic agonist. It is concluded that nasal arterioles are sensitive to α-adrenergic and cholinergic stimulation but not to β-adrenergic stimulation.

Surface view of strial vessel, prominence vessel, and external sulcus cells as revealed by scanning electron microscopy

ZusammenfassungBetrachtung der Stria vascularis und der Prominentia spiralis im Rasterelektronenmikroskop und die Darstellung der strukturellen Besonderheiten sowohl der Zellen als auch der Gefäße.SummaryThe stria vascularis and the spiral prominence in the lateral cochlear wall were observed with scanning electron microscopy (SEM) after dissolving out the epithelial layer and the basement membrane by tryptic digestion and HCl hydrolysis. The external sulcus cells have regularly arranged pegs and a fine basal interdigitation on the cell surface. The strial vessel and the spiral prominence vessel could be visualized well and the characteristic surface view of their periendothelial cells presented. The former has cytoplasmic processes with a fine branching appearance similar to red coral and the latter has bulged popcorn like processes. Their functional significance is discussed.

Myringoplasty in Children

Our 11 years of experience of myringoplasty in 87 children aged 3 to 14 years were retrospectively studied. The children were followed up over a period of 3 years. Children in the 3-to-12-year-old age group had a success rate of 57.7%. Graft-take rate was 100% in children operated on at the age of 13 and 14 years. Revision surgery was needed in 33 ears, and ultimate success was achieved in 88.9%. Within the same period, 38 ears were conservatively treated and 20 perforations of them were spontaneously closed. The state of the opposite ear and the perforation size were not a decisive factor in the results of myringoplasty. Children between 7 and 10 years old with small mastoid pneumatization had a statistically lower graft-take rate. We concluded that myringoplasty is warranted for children 13 years of age and older or children aged 7 to 12 years with large mastoid pneumatization.