Biomedical subjects
A G Schuring
Publications and source records attributed to A G Schuring.
Cholesteatoma and imaging.
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Otologist versus otologist.
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Staging for cholesteatoma in the child, adolescent, and adult.
A closed tympanomastoidectomy with subsequent staged surgical procedures leading to the excision of cholesteatoma was validated as described. All elements of staging with a 10-year experience of 354 patients are covered according to categories of child (0 to 9 years), adolescent (10 to 15 years), and adult. The child differed from the adolescent and adult in the following manner: more recurring cholesteatomas, greater ossicular necrosis, poorer hearing results, less aggressive residual cholesteatoma, and significantly poorer results with pars flaccida cholesteatoma than pars tensa cholesteatoma. After the end stage, 90% of the cases remained closed, with acceptable hearing in 60% of the patients.
Contracting for otologic surgery.
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Claims and suits against otology.
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Validating the excision of cholesteatoma.
Use of a closed tympanomastoidectomy with subsequent staged surgical procedures until the excision of cholesteatoma is validated is described. All elements of staging in the author's 10-year experience with 354 patients is covered. After the final stage of the procedure, 90 per cent of the cases remained closed; 60 per cent of the patients had acceptable hearing.
A postoperative audiometric evaluation of cochlear implant patients.
As the benefits of the cochlear implantation become more defined, many investigators hope that these devices can be offered to patients with a lesser degree of hearing loss. Accordingly, it is necessary to investigate the audiometric thresholds in the implanted ear after surgery. Preservation of the residual hearing after implantation would support the claims that surgery and the presence of a cochlear implant do not adversely affect the implanted ear.
An otologic informed consent.
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Iatrogenic facial nerve injury.
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Reconstructing the absent lenticular process.
When a surgeon encounters an absent lenticular process of the incus, he must either reposition the incus or attempt to bridge the small gap between the remaining incus long process and the stapes capitulum. Our solution to this problem is to place a Lippy modified Robinson stapes prosthesis on the stapes footplate and attach it to the remaining long process, thus bypassing the stapes superstructure. This modified Robinson prosthesis has a portion of the well removed allowing the eroded long process to enter from the side. The hearing results of 63 cases at 6 months (two-thirds of which had a concurrent tympanoplasty) are 67% within 10 dB and 91% within 20 dB of the preoperative bone hearing level. The use of an existing and proven prosthesis provides both stability and, to date, the most successful hearing results for reconstructing the absent lenticular process.
The ossicle-cup prosthesis: five years later.
The ossicle-cup prosthesis is a semibiologic prosthesis that incorporates a synthetic portion into the remaining (or transplant) ossicle. This assembly is positioned on the stapes capitulum, with the synthetic cup forming a dynamic joint. During 1978, 114 patients underwent surgical procedures in which an ossicle cup prosthesis was used. After 1 year 84% of these patients were within 20 dB of their preoperative bone hearing levels. Patients with a concurrent mastoidectomy did worse than those who underwent only a tympanoossiculoplasty. Five years later, 74% of the successful cases were still within 20 dB of the preoperative hearing levels. Eighteen patients underwent a revision surgical procedure to regain hearing. The postoperative hearing results at 1 year were 50% within 20 dB. The causes of failure included further ossicle necrosis (28%), a laterally healed tympanic membrane (39%), and fixation of the prosthesis (33%). Extrusion of the prosthesis during the 5-year period was between 1% and 2%. Overall, the ossicle cup prosthesis has proved to be a stable assembly, easy to revise, and longlasting. Once successful, three of four cases will retain successful hearing for more than 5 years.
Validating the excision of cholesteatoma.
In lieu of a radical mastoidectomy, 138 patients underwent a closed tympanomastoidectomy with subsequent staged surgical procedures until the excision of cholesteatoma could be validated. All the patients underwent two surgical procedures, 29% underwent three procedures, and 4% underwent four procedures. The surgical findings at the second procedure were: negative, 41.5%; retraction pockets, 7%; squamous pearls, 14%; recurrent cholesteatoma, 12%; and residual cholesteatoma, 25.5%. At each stage the likelihood of finding any form of cholesteatoma lessens. A conversion from a closed to an open mastoidectomy was necessary for 9% of the patients, and 4% were lost to follow-up. The opportunity to adjust the reconstructed ossicular assembly exists at each stage. With the use of semibiologic prostheses (ossicle cup and columella), the hearing results were: first stage, 67% within 20 dB, 84% within 30 dB; second stage, 77% and 90%; third stage, 77% and 96%.
Stapedectomy for otosclerosis with malleus fixation.
Malleus fixation, in addition to stapes fixation, presents a perplexing surgical problem. Should the incus replacement prosthesis procedure be performed or only a stapedectomy? The hearing results of a stapedectomy alone in 45 cases with both stapes and malleus fixation are 70% within 10 dB and 84% within 20 dB of the preoperative bone conduction hearing level.
An incus replacement prosthesis. The ossicle cup.
To achieve better hearing after incus replacement surgery, the ossicle-cup prosthesis is introduced. This prosthesis incorporates part of a Teflon Robinson's stapes prosthesis into the body of an incus. The ossicle-cup prosthesis has a dynamic joint with the stapes capitulum, as well as a variable height above the stapes. Preliminary hearing results of 45 cases show air-bone gap closure of 67% within 10 dB and 98% within 20 dB.