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Biomedical subjects

W H Lippy

Publications and source records attributed to W H Lippy.

At least 19 recordsLinked to original sources

Acoustic reflexes, auditory brainstem response, and MRI in the evaluation of acoustic neuromas.

Patient records were reviewed to determine whether persons with absent acoustic reflexes have a higher incidence of abnormal auditory brainstem response (ABR) results in the absence of a cerebellopontine angle (CPA) tumor than those with normal acoustic reflexes. Results showed patients with absent reflexes to have borderline or abnormal ABR results in 45.2% of the cases. Patients with normal reflexes had borderline or abnormal ABR results in 14.2% of the cases. Results indicate that magnetic resonance imaging is a more appropriate test for patients with absent reflexes, since ABR was often nondiagnostic for a CPA tumor in this group.

Evoked Potentials, Auditory, Brain Stem

Prosthesis on a mobilized stapes footplate.

Managing a mobilized footplate in stapedectomy surgery can be challenging. Between 1963 and 1992, 145 footplates were inadvertently mobilized during otosclerosis surgery. After a vein graft, a 4.0-mm Robinson prosthesis was placed on all footplates, making no attempt to remove the footplate. There were 73 thin, blue footplates and 72 thick, white footplates. Hearing results in the thin, blue footplate group was 97% successful and 100% satisfactory at 3 years. No footplate refixed. In the thick, white group, hearing was 60% successful and 72% satisfactory at 6 months. Footplate refixation was found at revision in all but one unsuccessful case. After revision, the thick, white group had 79% successful and 89% satisfactory hearing results at 3 years. No patient in either group was worse. We conclude that placing a vein graft and a Robinson prosthesis is a safe and effective technique for a mobilized footplate. If the footplate is thin and blue, there is little or no risk of refixation. If the footplate is thick and white, approximately 30% will require revision.

Follow-Up Studies

Stapedectomy in the elderly.

Clinical records were reviewed to examine the effectiveness of stapedectomy in patients 70 years and older. A total of 154 patients was studied, including 11 with profound hearing loss with long-standing otosclerosis. Ages at the time of surgery ranged from 70 to 92 years (mean, 76.3 years). The mean pure-tone average (500, 1,000, 2,000, and 4,000 Hz) improved 30.6 dB after surgery for the 143 patients in the main otosclerotic group and 26.8 dB for the patients in the profound-hearing-loss group. The rate of successful stapedectomies for the 70(+)-year-old patients (90.9%) and the younger comparison group (90.0%) were similar. These findings extend the documented range of stapedectomy as a safe and effective procedure through the eighth decade of life.

Aged

Stapedectomy in combat pilots.

Between 1977 and 1995, nine stapedectomies using the Robinson-vein graft technique were performed in six high-performance airplane pilots diagnosed with otosclerosis. All of them returned to full active duty after stapedectomy without any vestibular symptoms. These cases illustrate that it can be safe for fighter or test pilots to return to full flight status after stapedectomy. These cases also suggest that full flight status can be reinstated as soon as 3 months after stapedectomy without endangering flight safety.

Aviation

Far-advanced otosclerosis.

Far-advanced otosclerosis (FAO) is an uncommon diagnosis. Hearing levels in patients with FAO may range from profound loss, by air conduction and fragmentary bone conduction thresholds, to no measurable air or bone conduction thresholds. Thus, FAO may be difficult to distinguish from a sensorineural hearing loss. This report presents the results of surgery in 73 ears with FAO, 77 percent of which had improvement in air conduction thresholds of greater than 20 dB. Discrimination was improved by more than 15 percent in 54 percent of cases, and 75 percent realized improvement in use of a hearing aid. There was no evidence that success was related to preoperative hearing. The surgical results of a subgroup of 14 patients having bilateral FAO were also analyzed. For all 14, similar surgical outcomes were achieved in both the initial and the contralateral ear, with six successes bilaterally and eight failures bilaterally. Although far advanced otosclerosis is uncommon and difficult to diagnose, surgery is worthwhile.

Acoustic Stimulation

Simultaneous presentation of facial nerve neuroma and otosclerosis.

Otosclerosis often occurs as a unilateral mixed or conductive hearing loss. In the absence of retrocochlear findings, otologists usually do not pursue further diagnostic testing. A patient who presented to the Warren Otologic Group with a unilateral mixed hearing loss is discussed. He was followed for 1 year with the intent of scheduling a stapedectomy. Two weeks prior to the surgical date, the patient developed a sudden hearing loss and was admitted to the hospital for treatment. Magnetic resonance imaging demonstrated a tiny, enhancing mass in the lateral internal auditory canal, measuring 7 mm in diameter. At surgery, the tumor was found to originate at the union of the nervus intermedius and the facial nerve. The simultaneous occurrence of facial nerve neuroma and otosclerosis is discussed, with emphasis on a thorough evaluation of all unilateral mixed hearing losses, including those attributable to otosclerosis.

Adult

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.

Adolescent

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.

Audiometry

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.

Ear Ossicles

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.

Adolescent

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%.

Cholesteatoma

Stapedectomy revision following sensorineural hearing loss.

This study analyzes 71 stapedectomies that resulted in a sensorineural hearing loss, followed by a revision stapedectomy on the suspicion of an oval window fistula. The cases were divided between two primary stapedectomy techniques: a stainless steel Robinson prosthesis on a vein graft and a wire prosthesis with Gelfoam. The major differences between the surgical findings of the two groups were the fistula rate with the wire prosthesis was 10 times that with the Robinson prosthesis; the wire prosthesis was longer than necessary in 21% of the cases in which it was used; there was no finding of excess length with the Robinson prosthesis; and after revision stapedectomy, dizziness was lessened in 20% of the patients in the Robinson prosthesis group, in 60% of those in the wire prosthesis group, and in 75% of those with fistula. Surgical directions are given for revision stapedectomy following a sensorineural hearing loss.

Cochlear Implants

Solving ossicular problems in stapedectomy.

Three unusual ossicular problems encountered in stapedectomy are: floating stapes footplate, partial absence of the incus long process, and otosclerosis combined with a fixed malleus. The surgical techniques advocated in solving these problems are: placing a Robinson prosthesis on the floating footplate, utilizing the Lippy modification of the Robinson prosthesis for the problem incus, and performing only a stapedectomy for malleus fixation and otosclerosis. The hearing results in 242 cases were quite satisfactory and no patient had a further sensorineural loss.

Ear Ossicles

Solving ossicular problems in tympanoplasty.

Four troublesome problems encountered in ossicular reconstruction are: low profile stapes, lateral tympanic membrane, remaining stapes crura, and absent stapes capitulum. The design advantages and modifications of the semibiological ossicle cup and ossicle columella prostheses are given to solve these problems. The hearing results are completely satisfactory.

Ear Ossicles

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.

Bone Conduction