Glenn W. Knox

Y modification of the Fisch meatoplasty

A universally held axiom in otologic surgery is that a widely patent external auditory canal is essential for the postoperative success of canal wall down mastoid surgery. A sufficiently large meatus facilitates postoperative office evaluation and debridement of the mastoid cavity. A large meatoplasty supports the rapid epithelialization and overall exteriorization of mastoid bowl size. Failure to perform an adequate meatoplasty may lead to cholesteatoma formation, chronic secretion, and postoperative canal stenosis.

Hemangioma of the intratemporal vestibular nerve.

Hemangiomas that occur in bone are uncommon, but the skull is the site most frequently involved. Hemangiomas within the temporal bone usually occur along the facial nerve at the geniculate ganglion in the internal auditory canal (IAC) or in the middle ear. The predilection for these tumors to occur at the geniculate ganglion or in the IAC may be related to the capillary plexus surrounding the geniculate ganglion and Scarpa’s ganglion. Because of their association with the facial nerve, they often present with facial paralysis or hemifacial spasm with weakness. Those lesions limited to the IAC most frequently present with marked unilateral sensorineural hearing loss or aural fullness, tinnitus, or unsteadiness, all of which are more common than facial nerve dysfunction. These intracanalicular lesions show calcium stippling by CT and high signal intensity on both T 1and T2-weighted MRIs. 1

Metallurgical Considerations in Shape-Memory Nitinol Middle Ear Prosthetics

Objectives: At the conclusion of this presentation, the participants should be able to 1) describe how the metallurgical phenomenon of creep may be involved in the failure of nitinol middle ear devices, and 2) describe how other metallurgical phenomena such as microfractures can also be involved. Methods: Retrospective literature review of nitinol middle ear device failure; retrospective literature review of known metallurgical properties of nitinol such as creep and microfractures; and prospective survey of otologic surgeons. Study period: January 2001 to present (literature review), and 2011 to present (survey). Condition studied: Delayed conductive hearing loss after stapes surgery. Subjects studied: Patients with otosclerosis described in previous studies who underwent surgery with nitinol shape-memory devices. Surgeons who implanted such devices. Interventions: Analysis of known metallurgical properties of nitinol applied to results obtained with such devices. Results: A comprehensive literature review revealed many instances of delayed conductive hearing loss after middle ear surgery with nitinol shape-memory devices. A survey of otologic surgeons by the author revealed 50% of surgeons reporting “loose-wire” syndrome as a delayed complication of such surgeries, signifcant to P < 0.05 confidence level (94 surgeons). Conclusions: 1) “Loose-wire” syndrome is a frequent complication encountered by surgeons performing middle-ear surgery with nitinol shape-memory devices. 2) Metallurgical properties of nitinol such as creep (deformation over time as a result of stress) and microfractures may theoretically be responsible. 3) Additional metallurgical laboratory analysis of nitinol is indicated in order to explain and prevent such complications.

Motion Sickness Treatment Analysis with OVAR

Objective: Evaluation of transdermal scopolamine for motion sickness prophylaxis. Method: Randomized, prospective double blind. 2010-11. Twelve patients, 7 male, 5 female, ages 21 to 57. Intervention(s): Off-vertical axis rotation 20° in the dark after administration of transdermal scopolamine or placebo. Outcome measures: Duration of tolerated off-vertical rotation; subjective symptom reporting at 1-minute intervals on a 0 to 4 scale. Results: Patients treated with transdermal scopolamine had statistically significant improved tolerance time to off-vertical axis rotation. Reported symptomatology on the 0-3 subjective symptom scale was significantly improved as compared to placebo and was dose-dependent. These results were significant to the .05 confidence level. Conclusion: Off-vertical axis rotation is a useful modality for the evaluation of motion sickness medications. Transdermal scopolamine showed statistically significant dose-dependent effects in mitigating OVAR-induced motion sickness symptomatology and was well tolerated.

R057: Inhibition of Influenza Neuraminidase by Elderberry Lectin:

gus can represent a diagnostic and therapeutic challenge. Failure to identify a perforation can result in neck abscess, mediastinitis, and death. Iatrogenic injury of the pharyngoesophagus is rare; however when it occurs, prompt diagnosis and management is essential to ensure a favorable outcome. The purpose of this study is to review the diagnosis and management of acute iatrogenic pharyngoesophageal injury at a single institution. METHODS: Between July 1998 and January 2006, 15 patients with iatrogentic cervical esophageal injury were available for review. Patient charts were reviewed for the initial cause of injury, clinical presentation, management, and outcome. The data were then reviewed for factors associated with a favorable outcome. RESULTS: Patients ranged in age from 22 to 78 years (mean 49.1). Four injuries occurred at MSH and 11 occurred at outside institutions and were transferred to MSH for care. Time to diagnosis, presence of fever or elevated WBC, and presentation (i.e. abscess, fistula, subcutaneous air) were not correlated with an adverse outcome. However, a delay in diagnosis was associated with increased hospital length of stay and complications including deep venous thrombosis and pneumonia. Patients initially managed conservatively with antibiotics and observation demonstrated a higher rate of failure (57%) requiring reoperation when compared to those managed with a staged pharyngoesophageal reconstruction (12%). Late cervical esophageal stenosis was more common in patients undergoing conservative management or primary closure (42%) than in those managed with a controlled fistula and staged reconstruction (12%). CONCLUSION: Primary closure and conservative management of iatrogenic cervical esophageal injuries have a higher rate of failure and delayed stenosis, while the creation of a diverting esophagastome and a staged reconstruction have an improved outcome. SIGNIFICANCE: The presenters offer a reconstructive guideline that minimizes future complications.

Adaptation of otolith responses assessed by off-vertical axis rotation

Abstract Objectives: During rotation in darkness at constant velocity about an axis tilted relative to gravity (OVAR) the otolith organs are stimulated by the change in head orientation relative to gravity. The frequency of the linear acceleration stimulus during OVAR is determined by the speed of rotation. The magnitude of the linear acceleration stimulus during OVAR is demonstrated by how far the axis of rotation is tilted (20 degrees = 0.34 g). Methods: Tilt angles used were 10 degrees and 20 degrees. Rotational frequencies were 0.125 Hz and 0.5 Hz. Directions were clockwise and counterclockwise. The subjects were normative controls (n = 14), unilateral vestibular deficient patients (n = 3) and astronauts pre- and postflight (n = 14). Results: In normal subjects during OVAR, there is a clear correspondence between eye movements and motion perception data. In patients with unilateral vestibular loss, OVAR responses were not substantially different than healthy control subjects (compensation from the intact side and/or proprioceptive inputs). Astronauts returning from spaceflight experienced a larger sense of both tilt and translation during OVAR at low and high frequency, respectively. Torsion at 0.125 Hz and modulation of horizontal SPV at 0.5 Hz appear similar to preflight values. Conclusion: The overestimation of tilt and translation during OVAR in returning astronauts is in agreement with previous results. It is due to a decrease in the weight of the inertial body vertical after adaptation to microgravity. We have isolated the otolith inputs from the semicircular canals, proprioceptive, and visual inputs. Eye movements from otolith stimulation were not altered after spaceflight.

12: The “Y” Modification of the Fisch Meatoplasty

Otolaryngologists are frequently presented with traumatic or surgical defects that require replacement of missing tissues to achieve optimal functional results. Although autologous or allogeneic tissue, aUoplasts, and metals have been used in various combinations successfully, each of these materials has drawbacks. In an effort to improve and expand our armamentarium, several researchers have demonstrated reproducible results growing cartilage or bone for host tissue replacement using tissue-engineered cell-polymer constructs. Studies have demonstrated that chondrocytes and osteoblasts implanted onto a synthetic mesh can produce mature cartilage or bone when grown subcutaneously in the nude mouse. Tissue produced in this fashion may require additional shaping to be suitable for use in specific defects. To determine whether mature cartilage and bone grown using a standardized cell-polymer construct will reliably retain their shape and tissue integrity after harvesting, shaping and reimplantation, the following study was designed. Using standard tissue-engineering techniques, 25 nude mice were implanted with a 1 cm 2 of synthetic mesh seeded with chondrocytes. Similarly, 25 nude mice were implanted with osteoblast-seeded mesh. After 6 weeks the tissue blocks were removed and carved into a two-dimensional seven-sided figure, similar to an incus. The tissue was photographed for digital analysis and reimplanted in nude mice, for a total incubation time of 20 weeks. At 20 weeks the tissue was again removed. Analysis with digital photography was performed for gross retention of size and shape, with 20% change considered significant. The tissue was also examined histologically for confirmation of mature cartilage and bone in each respective group. In this manner a custom bony or cartilaginous prosthesis could be tissue-engineered. The results of this study will be presented in detail, along with implications for future direction of tissue-engineering studies.

The Treatment of Intractable Vertigo

Educational objectives: To understand and use methods of differential diagnosis of intractable vertigo and to understand the diagnostic and treatment modalities for the intractably vertiginous patient.