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Biomedical subjects

J Stahle

Publications and source records attributed to J Stahle.

At least 37 records · Page 2Linked to original sources

Endolymphatic sac valve implant surgery. I: The technique.

A resurgence of interest in surgery on the endolymphatic sac (ELS), not only for relief of vertigo but also for stabilization or improvement of hearing, has emerged. With the concept of operating early in the course of the disease after the diagnosis is well established, various modifications of existing procedures on the ELS have been utilized in an attempt to improve the overall results. One such major modification is the unidirectional inner ear valve implant modified from the eye valve for glaucoma. This valve implant has produced impressive one-year results for both hearing improvements and relief of vertigo in patients who were scheduled for labyrinthectomy. Subsequent preliminary reports by several investigators show good to excellent results for the hearing (AAOO--Class B or A) as well as the vertigo without consideration for the stage of the disease. This study presents primarily the step by step technique with drawings and a color atlas to facilitate the correct performance of this surgery.

Ear, Inner↗

Endolymphatic sac valve implant surgery. II: The unidirectional inner ear valve implant.

A unidirectional inner ear valve implant was developed to direct excess endolymph out of the inner ear in the hydropic state (Ménière's disease) into the mastoid cavity. A detailed technical description of the valve implant is presented as well as some technical aspects of the valve implant based on the surgical anatomy of the endolymphatic sac.

Ear, Inner↗

Lymphocyte-macrophage activity in the endolymphatic sac. An ultrastructural study of the rugose endolymphatic sac in the guinea pig.

The irregular epithelial layer which delimits the intermediate part of the endolymphatic sac, and the surrounding perisaccular tissue, were examined morphologically in the guinea pig by transmission electron microscopy. Specialized areas of the epithelium which have previously been designated as "non-vascularized epithelial processes" (NVP) were constantly observed. These proliferative areas showed a close topographical relation to the free luminal cells and contained an abundance of lymphoid cells. Lymphocytes and macrophages were intimately associated with each other in a manner similar to that seen in these two types of cells in antigen-stimulated lymphoid tissues. There was a marked degeneration and phagocytosis of cells. The richly vascularized perisaccular tissue was rich in plasma cells, monocytes, mast cells and lymphocytes. The latter could be seen to migrate through the endothelial cells in the thin post-capillary venules into the sac tissue. The authors consider that the endolymphatic sac plays a role as an immunological defence organ for the internal ear. A hypothetical model concerning circulation and turnover of certain of the free intraluminal cells in presented.

Animals↗

Extracranial meningioma presenting as a nasal polyp.

The extracranial occurrence of meningiomas is summarized. A patient suffering from repeated episodes of epistaxis presented with a lobulated nasal polyp which was found to be a meningioma. At subsequent radical removal, the extracranial location in the nose, ethmoidal region and cribriform area was verified.

Diagnosis, Differential↗

Accumulation of substances with melanin affinity to the internal ear. Therapeutic or ototoxic mechanism?

The capacity of the melanin in the internal ear to accumulate and retain labelled lidocaine, bupivacaine and chlorpromazine after intravenous and intraperitoneal injection was examined by whole-body autoradiography. Both young pigmented hooded rats and albino rats were studied. In the pigmented rats chlorpromazine showed the greatest accumulation, which was more pronounced in the cochlea than in the vestibular portion. The other two substances were evenly distributed in the internal ear. After a single injection of chlorpromazine and of bupivacaine these substances were still bound to the melanin of the internal ear after 14 days, which was the longest survival time. Lidocaine, on the other hand, had disappeared after only 4 days. In albino animals there was very weak, transient uptake of chlorpromazine and bupivacaine, but not of lidocaine, in the internal ear. In studies in vitro on isolated bovine eye melanin there was considerably greater adsorption of chlorpromazine than of lidocaine and bupivacaine.

Animals↗

Melanin capacity to accumulate drugs in the internal ear. A study on lidocaine, bupivacaine and chlorpromazine.

The distribution and retention of labelled lidocaine, bupivacaine, and chlorpromazine to melanin in the internal ear after intravenous and intraperitoneal injection were examined by whole-body autoradiography. Both young pigmented hooded rats and albino rats were studied. In the pigmented rats chlorpromazine showed the greatest accumulation, which was more pronounced in the cochlea than in the vestibular portion. The other two substances were evenly distributed in the internal ear. After a single injection of chlorpromazine and of bupivacaine these substances were still bound to the melanin of the internal ear after 14 days, which was the longest survival time. Lidocaine, on the other hand, had disappeared after only 4 days. Strong uptake and retention of the three substances were observed in the eyes of pigmented animals. In albino animals there was very weak, transient uptake in the internal ear of chlorpromazine and bupivacaine, but not of lidocaine. In studies in vitro on isolated bovine eye melanin there was considerably greater adsorption of chlorpromazine than of lidocaine and bupivacaine. An uptake was noted in the human eye in experiments in vitro. Clinical tests revealed no acute or late damage to hearing or sight after large doses of lidocaine. The participation of melanin in different basal labyrinthine functions such as the energy transfer mechanism and the sound protective mechanism is discussed in the light of the results obtained. Further, the theory is put forward that the melanin affinity of certain substances can be of both therapeutic and ototoxic importance.

Animals↗

Unidirectional inner ear valve implant for endolymphatic sac surgery in Meniere's disease.

In five patients with long-standing Meniere's disease, a unidirectional inner ear valve was implanted into the endolymphatic sac (ELS) to facilitate removal of excess endolymph in the hydropic state. These patients were all candidates for ablative surgery. They all had intractable vertigo and severe hearing losses. Four out of five patients had positive preoperative glycerol tests. In the patients with positive glycerol tests, the group averages before surgery were as follows: pure-tone average (PTA), 63 dB; speech reception threshold (SRT), 79 dB; and discrimination score, 27%. All of the patients, except a patient with a negative glycerol test, benefited from the surgery, including exceptional hearing improvements, averages of 21 dB in PTA, 30.5 dB in SRT, and 48% in discrimination, which remained so for at least a one-year minimum follow-up. All patients with preoperative positive glycerol tests had a class A result according to the criteria set forth by the American Academy of Ophthalmology and Otolaryngology. The cumulative follow-up exceeded the minimal requirements by a factor of 39 times. The only failure was in a patient with a negative glycerol test, which was predictable. Results of tomography confirmed the correct position of the valve without evidence of migration or extrusion even in the failure. This new valve appears to be a safe and more effective implant than Silastic sheeting alone or any other ELS implant in patients with a positive glycerol test.

Adult↗

Regression of a prolactin-secreting pituitary tumor during long-term treatment with bromocriptine.

A nulliparous woman with 12 years of amenorrhea, galactorrhea, and hyperprolactinemia and radiologic evidence of a pituitary macroadenoma was treated with large doses of bromocriptine. During treatment the greatly increased prolactin levels normalized and ovulatory menstrual cycles were regained after 48 weeks of treatment. A transsphenoidal surgical exploration of the pituitary fossa was performed after 27 months of treatment. The findings at surgery suggested that regression of the pituitary adenoma had occurred during the prolonged treatment with bromocriptine. After discontinuation of the therapy, the patient continued to ovulate and subsequently conceived.

Adenoma↗

Incidence of Ménière's disease.

The incidence of Ménière's disease in Sweden for the year 1973 has been calculated as one case in a population of 2,163. This gives an overall incidence of 46/100,000. Extrapolating the Swedish incidence data to the population of the United States, there should have been 97,000 cases of Ménière's disease treated as inpatients or outpatients during the year 1973. The incidence in the United States of Ménière's disease, cochlear type, is considered to be even higher. In addition, the Swedish statistic for some other disorders, including otosclerosis, are reported. For otosclerosis, the yearly incidence in Sweden is 12/100,000 or one case in a population of 8,414. This could be extrapolated to 25,000 patients with clinical otosclerosis in the United States for the year 1973. By comparison, Ménière's disease, by stringent diagnostic criteria, is approximately four times as common as clinical otosclerosis. It is also more common than all laryngeal carcinomas, all salivary gland tumors, both benign and malignant, as well as acute epiglottitis and acute nephritis.

Adolescent↗

The surgical anatomy of the endolymphatic sac.

The endolymphatic sac (ELS) and vestibular aqueduct (VA), which play a notable role in the pathogenesis of endolymphatic hydrops and Meniere disease, were identified in all anatomic and tomographic materials. More than 100 temporal bones were used for microdissection, tomography, and plastic molds. Normal subjects and Meniere disease patients were studied tomographically (N = 63) and observed during ELS surgery (N=49). In Meniere disease there is, with increassing duration of diseases, a decrease in the periaqueductal and opercular air cell pneumatization, with a concomitant shorter and straighter VA. This correlates with a decreased ELS luminal patency, and a more inferiorly positioned ELS. These factors help to explain both the difficulties of visualizing the VA by tomography in Meniere disease as well as the occasional difficulties reported by others in satisfactorily identifying the ELS at sac surgery. All observations are made from the surgeon's viewpoint to enhance clinical identification of the ELS.

Adult↗