PubMed Health⌕ Search

Biomedical subjects

G D Smyth

Publications and source records attributed to G D Smyth.

At least 37 records · Page 2Linked to original sources
PubMed1987

Preservation of cochlear function in the surgery of cholesteatomatous labyrinthine fistulas and oval window tympanosclerosis.

Anakusis is reported as a not uncommon complication of the surgical treatment of cholesteatomatous fistula of the labyrinth. Likewise, although published results on the surgical treatment of tympanosclerotic ears are infrequent, most otologists are aware of greater than usual risks of severe sensorineural impairment from ossiculoplasty in this type of middle ear disease. Because of recent developments in implanted aids-to-hearing, in tympanoplasty operations, when they fail to adequately improve hearing, preservation of eighth nerve function becomes ever-increasingly important. This article concerns two types of middle ear disease in which surgical treatment threatens hair cells and neurons, to the extent that surgical complications might prejudice the eventual possible benefits of a standard hearing aid or any implanted device, if either was indicated.

Adolescent↗
PubMed1986

Long-term viability of transplanted ossicles.

Doubt has been raised about the long-term suitability of ossicular implants in tympanoplasty. Twenty-three ossicular implants that had been in the middle ear for a mean duration of 9.6 years were examined histologically by light microscopy. Although there were only two specimens showing subtotal replacement of the dead ossicular implant by new bone, the structural integrity of all implants was maintained and there was no evidence of overt osteoclastic bone resorption. Therefore our findings support the concept of prolonged survival of ossicular implants in the middle ear and we do not see any good reason for abandoning their use in reconstructive tympanoplasty.

Ear Ossicles↗
PubMed1986

Vestibular nerve section and saccus decompression: an evaluation of long-term results.

The 1972 AAOO committee (Alford, 1972) guidelines brought some uniformity into the evaluation of therapy for Menière's Disease. We have adhered to its recommendations in this long-term follow-up report of 21 saccus decompressions and 29 vestibular nerve sections performed on 46 patients between 1968 and 1977. Comparisons between these and other groups have been possible with regard to: control of vertigo; hearing; tinnitus; and development of hydrops in the contralateral ear. All the vestibular nerve section group have enjoyed sustained relief from vertigo. Class D results (recurrent vertigo) account for 14 per cent of the saccus decompression group at one year and 29 per cent at eight to 10-year follow-up. Hearing levels in both groups deteriorated in parallel as time progressed but tinnitus became less noticeable. Nineteen per cent of the long-term review patients showed evidence of developing cochlear hydrops in the contralateral ear. Conservative surgical procedures should be employed whilst any useful hearing exists, though the emphasis remains on controlling vertigo. Saccus decompression, despite its controversial therapeutic basis, will remain the first-line surgical procedure for many otologists. However, in the fit young Menière's cripple or saccus decompression failure with serviceable hearing, vestibular nerve section remains the treatment of choice.

Adult↗
PubMed1986

Operations on the saccus endolymphaticus and vestibular nerve: have they fulfilled their promise?

The rationale for operations on the saccus and vestibular nerve in patients incapacitated by Meniere's disease as a replacement for total labyrinthectomy, has been the expectancy that less radical procedures will protect these patients from total auditory incapacity. Aware of postoperative hearing losses in some patients after 3 years, we have studied the results in 21 Shambaugh saccus decompression (SD) and 29 middle fossa vestibular nerve section (VNS) operations, in order to assess the claims made for these procedures. We found that while control of vertigo was similar to that reported elsewhere, worse hearing (AAOO criteria) developed in many cases. With SD this increased from 14% at 1 year to 58% at 10 years, and with VNS it increased from 17% at 1 year to 48% at 10 years, when the worse preoperative audiogram was used. Only 17% of SD and 11% VNS ears with serviceable best preoperative hearing had retained this at 10 years. Nineteen percent developed audiometric evidence of contralateral disease during the first 10 postoperative years. It is concluded that although, regrettably, neither of these surgical therapies appears to have the capability of preventing the progress of hearing loss, the reality of bilateral disease justifies the continued use of SD or VNS by adequately trained surgeons.

Ear, Inner↗
PubMed1986

Hearing aids poststapedectomy: incidence and timing.

Ninety-four percent of 508 patients operated on between 1960 and 1975 have been followed-up at yearly intervals. Their status as of 1977 was assessed in order to determine their mean duration of socially adequate hearing levels and to relate the type of surgical procedure to the interval between operation and hearing aid requirement. Postoperative hearing losses due to conduction and sensorineural deficits resulted in preoperative bone/postoperative air gaps greater than 10 dB in up to 40% of large fenestra operations and in 15% of small fenestra operations at 5 years. On average, a large fenestra ear would require amplification at 13 years and a small fenestra ear at 21 years postoperatively.

Follow-Up Studies↗
PubMed1985

Cholesteatoma surgery: the influence of the canal wall.

Although there is an increasing awareness of the risks of complications following intact canal wall tympanoplasty (ICWT) for cholesteatoma, long-term evidence to support a preference for alternative techniques in which the canal wall having been removed, the resultant cavity is obliterated, is comparatively scarce. In order to clarify this uncertainty, long-term results with both operations have been analyzed to determine incidence rates for postoperative complications and functional results. Recurrent cholesteatoma (retraction pocket) has occurred in 14% of ICWT ears and 1% of ears with mastoid obliteration and tympanic reconstruction. The incidence of clinically detected residual disease with both operations has been extremely low so far, in spite of greater than 20% incidence of epithelial pearls at the second stage of separate planned two-stage procedures with each technique. It is concluded that reduction to the greatest degree possible of cholesteatomatous complications from tympanoplasty necessitates removal of the canal wall.

Cholesteatoma↗
PubMed1985

Results of middle ear reconstruction: do patients and surgeons agree?

The usual methods of measuring the therapeutic effects of middle ear reconstruction in tympanoplasty and stapedectomy take into account only changes occurring in the operated ear. These do not necessarily reflect the final state of the patient's auditory capacity, because normal speech perception is a bilateral function. Minor temporary interaural differences due, for example, to ear canal occlusion by cerumen can cause considerable distress. To determine what might be the final audiometric situations that would be worthwhile for patients having unilateral operations aimed only at improving auditory status, 203 patients' personal assessments of their final hearing ability were correlated with the audiometric data from both ears. The results indicated that the most relevant factor in predicting assessment was the postoperative hearing level.

Adolescent↗
PubMed1984

Porous prostheses: an electron microscopic study.

Proplast and Plastipore prostheses, removed at revision surgery, have been examined under the electron microscope. Foreign material in the multinucleated foreign body giant cells, previously reported under the light microscope, has been confirmed. The appearances were consistent with the conclusion that the giant cells were breaking down the prostheses by two different modes of action. X-ray elemental analysis is of limited value in this investigation because of the low atomic number of the elements involved. However, such analysis of this foreign material was consistent with the conclusion that it arose from the prosthesis.

Biocompatible Materials↗
PubMed1984

Etiologic aspects and pathogenesis of persistent middle ear effusion.

For generations malfunction of the eustachian tube has been considered the primary cause of middle ear disease. Although the role of such malfunction in the initiation of the disorder is well proven, in the light of immunologic research, its contribution to persistence is less certain. Recent developments in immunology and the comparative possible roles of tubal malfunction and an immune complex disorder in persistent middle ear effusion are reviewed with a view to providing an explanation for treatment failures with current therapies.

Acoustic Impedance Tests↗
PubMed1984

Management of otitis media with effusion: a review.

The majority of ears affected by otitis media with effusion recover, but whether these recoveries are assisted by noninvasive therapies is not yet established. What is known is that some middle ears affected by otitis media with effusion will eventually develop permanent structural and functional defects in spite of surgical intervention. The role of medications and the arguments for and against adenoidectomy and tympanostomy are reviewed in relation to the author's findings from short- and long-term studies of ears treated surgically.

Adenoidectomy↗
PubMed1983

Congenital syphilitic deafness--a further review.

Initial optimism about the successful outcome of treatment of congenital syphilitic deafness with ampicillin and steroids has always been tempered with an awareness of the uncertain long-term results. This paper is a review of 16 patients treated with various combinations of ampicillin and steroid; these have been followed up for periods of five to 14 years. Ampicillin alone does not prevent progressive hearing loss in the majority of patients. Ampicillin combined with prednisone, or with prednisone and ACTH, has preserved the hearing in all but two ears which had useful hearing before treatment. The fact that the hearing in many of these ears, although maintained, continues to fluctuate still gives cause for concern.

Adrenocorticotropic Hormone↗
PubMed1982

Recent and future trends in the management of otosclerotic conductive hearing loss.

The protection of cochlear function following stapedectomy has emerged as the major problem in the surgical treatment of otosclerosis. Both immediate and delayed sensorineural losses continue to occur in spite of refinements of technique. The frequency and extent of these complications has been investigated by prospective and retrospective studies of the author's patients. It has been concluded that the size of the footplate fenestration plays a major role in the outcome, both immediately, and in the long term. Revision operations are necessary when initially good results rapidly deteriorate, both to resolve complications such as perilymphatic fistulae and also to restore function. Although second ear operations are usually worthwhile, they should be performed only when certain specific criteria have been met. The expected duration of unaided hearing gain, although often adequate when a standard large fenestra operation is performed, is considerably prolonged by restricting the size of the footplate to less than half its total area. For reasons unknown, bone conduction thresholds appear to be better, eventually, in operated as compared to unoperated ears.

Bone Conduction↗