Reconstructive options for periocular defects.

Reconstruction of the periorbital area following skin cancer excision requires a thorough knowledge of orbital anatomy and eyelid function. Reconstructive procedures should maintain the function of periorbital structures while attempting to achieve optimal cosmesis. Generally, eyelid reconstruction can be considered in terms of the thickness and overall size of the defect. Both the anterior and posterior lamella should be restored, and at least one of these layers needs to be vascularized. The integrity of the canthal tendons should also be addressed. If severed, the tendons should be attached to bony landmarks in order to recreate the proper curvature of the eyelid against the globe. Finally, defects involving the lacrimal system should be assessed and properly reconstituted.

An animal model for the study of genetic predisposition in the pathogenesis of middle ear inflammation.

OBJECTIVES: Chronic otitis media with effusion (COME) is the most prevalent inflammatory disease in children and is associated with numerous adverse long-term sequelae. Many factors have been associated with an increased risk of developing COME, one of which may be a genetic predisposition to the disease. To study the role that genetics play in the pathogenesis of COME, we used an animal model to compare the middle ear inflammatory responses in two different strains of rats (Lewis and Fisher). METHODS: In earlier studies, we demonstrated that exposure of the middle ear to endotoxin caused early extensive exudation and, later, goblet cell hyperplasia and mucin hypersecretion. In the present study, the animals were divided into six groups. In each group the animals were given transtympanic injection with gram-positive bacterial cell wall product (peptidoglycan-polysaccharide [PG-PS]). The middle ear bullae were studied at 1 week and 3 weeks after infection, and after systemic reinfection. Comparisons were made of the quantity of mucin exudate by enzyme-linked immunosorbent assay and by histological evaluation of the middle ear epithelial thickness. RESULTS: Our data demonstrate a statistically significant difference in middle ear inflammation and effusion formation between the two genetically different strains of rats. CONCLUSIONS: These data support the hypothesis that the middle ear response to PG-PS may be genetically determined and therefore suggest that genetic predisposition may play a role in the pathogenesis of COME.

CT evaluation of prosthetic ossicular reconstruction procedures: what the otologist needs to know.

Postoperative otologic evaluation of patients who have undergone ossicular reconstruction is often difficult. However, thin-section computed tomography (CT) can help determine the type of prosthesis used for reconstruction and adequately assess for complications that may be causing postoperative conductive hearing loss. A variety of prostheses may be used in ossicular reconstruction (eg, stapes prosthesis, incus interposition graft, Applebaum prosthesis, Black oval-top prosthesis, Richards centered prosthesis, Goldenberg prosthesis) and can usually be identified at CT by their shapes and locations. Several causes of prosthetic failure are readily demonstrated at CT, including recurrent cholesteatoma and otitis media, formation of granulation tissue or adhesions, and various mechanical problems (eg, subluxation, dislocation, extrusion, fracture, bending). Perilymphatic fistula can be difficult to identify at CT but may be suggested by the presence of pneumolabyrinth, unexplained middle ear effusion, or fluid accumulation within the mastoid air cells. The presence of soft tissue within the oval window niche 4-6 weeks following surgery may indicate poststapedectomy granuloma or fibrosis. Familiarity with the normal and abnormal CT appearances of ossicular prostheses will enable the radiologist to assist the otologist in identifying patients in whom revision surgery is most appropriate.

Effect of stenting after laryngotracheal reconstruction in a subglottic stenosis model.

OBJECTIVES: This study addresses the impact of stenting on early wound healing after laryngotracheal reconstruction (LTR) in a rabbit model with established subglottic stenosis. METHODS: Subglottic stenosis was created in 42 New Zealand white rabbits through a transoral, endoscopic technique. Three weeks later, endoscopy and axial CT were performed to document and grade the degree of stenosis. Subsequently, LTR was performed in all animals, with half of the animals receiving an intraluminal stent. Four rabbits from each group were euthanized on postoperative days 6, 9, 14, 21, and 28. Measurements of graft vascularization were obtained with a computerized image measurement program, and a comparison was made regarding the rate of vascularization. RESULTS: There was a statistically significant increase in the rate of vascularization in the stented group (mean 75% +/- 5% vs 56% +/- 3% at day 14; P < 0. 05). However, clinical and radiographic comparisons of the stented and nonstented specimens revealed a trend toward increased mucosal edema and granulation tissue in the stented group at later time intervals (days 21 and 28). CONCLUSION: This analysis suggests that stenting does not inhibit graft vascularization in the early postoperative period after LTR; however, complications were seen in the stented group at longer time intervals.

Allergy increases susceptibility to otitis media with effusion in a rat model. Second place--Resident Clinical Science Award 1998.

To investigate the possible relationship between allergy and otitis media with effusion (OME), we investigated the hypothesis that allergen presentation to the middle ear causes functional disruption of the eustachian tube predisposing to the development of OME. Thirteen of 19 Brown-Norway rats were sensitized to ovalbumin, and the remaining 6 served as nonallergic controls. To mimic subclinical exposure to allergen, we transtympanically injected ovalbumin at a dose (0.01 mg) that produced no changes detectable by otologic examination. Next, both allergic and nonallergic rats were exposed to transtympanic injection of either low-dose (10 microg/mL) or high-dose (100 microg/mL) lipopolysaccharide to simulate bacterial exposure. The allergic rats were found to have larger middle ear effusions when exposed to high-dose lipopolysaccharide as compared with the nonallergic controls. This response could be inhibited by diphenhydramine. We conclude that allergen presentation to the middle ear of allergic rats causes eustachian tube dysfunction predisposing to OME.

Subglottic stenosis: correlation between computed tomography and bronchoscopy.

The evaluation of subglottic stenosis has been limited by the lack of standardized methods for determining the cross-sectional area and length of the stenotic segment. A rabbit model was used to prospectively evaluate the correlation between computed tomography (CT) and bronchoscopy in the evaluation of this disease. Subglottic stenosis was produced in 39 New Zealand White rabbits by a transoral endoscopic technique. The animals were evaluated 3 weeks later with spiral CT, rigid bronchoscopy, and open laryngotracheal exploration. Spiral CT was performed with the location, degree, and length of subglottic stenosis being determined by a blinded observer. Each animal then underwent rigid bronchoscopy and open laryngotracheal exploration for determination of the same measurements. Data were analyzed to determine the correlation between the radiographic and surgical techniques in evaluating the airway stenosis. With regard to the degree of stenosis, 94% of the rabbits were determined to have CT and bronchoscopic measurements that were within 15% (Pearson correlation .94, p < .05). With regard to the length of stenosis, 94% of animals had a measurement on CT that was within 2 mm of that observed upon open exploration (Pearson correlation .81, p < .05). The CT evaluation of subglottic stenosis correlated well with the currently used method of visual inspection at bronchoscopy in evaluating tracheal stenosis in this animal model. These data suggest that CT could serve as a useful adjunct in the evaluation of tracheal stenosis, especially when serial examinations are required.

External laryngeal trauma analysis of 392 patients.

BACKGROUND: External laryngeal trauma (ELT) is a rare but clinically important injury. OBJECTIVE: To perform the first population-based, time series analysis of the epidemiology, management, and outcomes of ELT using an 11-state, inpatient sample database containing more than 54 million patients. PATIENTS: Three hundred ninety-two patients with a primary or secondary diagnosis of ELT were identified. Over a 5-year period, the incidence of ELT in this series was 1/137,000. The mean (+/-SD) age was 37 (+/-7) years, and the overall mortality rate was 2.04%. Two hundred forty-eight patients required surgical intervention. RESULTS: The average length of stay for 67 patients not requiring surgical intervention for any injury was 3 (+/-2) days, with no mortality. One hundred eighty patients underwent endoscopy, with 14 requiring tracheotomy alone and 57 requiring tracheotomy plus laryngeal repair. The average length of stay and the mortality rate were higher in these latter groups. Overall, 139 patients underwent tracheotomy, with a mortality rate of 5%, while 96 patients underwent laryngeal repair, with a mortality rate of 1%. Surgical treatment was performed in 140 patients with ELT within 24 hours after presentation, while another 60 received treatment within 48 hours. Associated injuries included skull base or intracranial injury (13%), open neck injury (9%), cervical spine injury (8%), and esophageal or pharyngeal injury (3%). CONCLUSION: External laryngeal trauma is a rare injury, with most patients requiring surgical intervention.

Systemic reactivation of otitis media with effusion in a rat model.

OBJECTIVE: This study addresses the interaction of bacterial antigens, specifically peptidoglycan-polysaccharide (PG-PS) and lipopolysaccharide (LPS), in the induction and reactivation of mucoid middle ear effusions. METHODS: Twenty-seven rats underwent eustachian tube obstruction before inoculation of the middle ear bulla with PG-PS. Three weeks later, after resolution of all middle ear effusions, 6 rats were randomly selected and euthanized as the first control group (control I). The remaining 21 animals were randomly assigned to 3 groups that received intravenous injections of Krebs Ringer (control II), PG-PS, and LPS, respectively. These rats were euthanized 2 days after intravenous injection. Middle ear mucin production and histologic changes were measured in all animals. RESULTS: The mean concentrations of mucin were 0.94 +/- 0.52 mg/mL, 0.41 +/- 0.87 mg/mL, 16.33 +/- 3.67 mg/mL, and 1.15 +/- 0.41 mg/mL in the control I, control II, PG-PS, and LPS groups, respectively. Thus the mean concentration of mucin in the middle ear lavage samples was significantly greater in rats that were injected intravenously with PG-PS than in rats in other groups (P < 0.05). Histologic analyses demonstrated a greater degree of goblet cell hyperplasia in the PG-PS group than in other groups. CONCLUSIONS: This is the first animal model of recurring otitis media with effusion in which a systemic injection of PG-PS was used to reactivate a middle ear effusion in rats previously primed with a transtympanic injection of PG-PS. This study suggests that after otitis media with effusion has resolved, it may be reactivated by the presence of bacterial antigens and/or cytokines in the systemic circulation.

Mucin production in the middle ear in response to lipopolysaccharides.

OBJECTIVE: This study examined the response of middle ear tissue to establish the lowest dose of lipopolysaccharide to induce mucin production in a rat otitis media model. METHODS: Twenty-six male Sprague-Dawley rats' eustachian tubes were obstructed before transtympanic inoculation of the bulla tympanica with 35 microL of Krebs Ringer or 1, 10, 100, or 1000 microgram/mL lipopolysaccharide. After 7 days the effusion and a lavage were collected for mucin ELISA measurement, and tissue was collected for histologic evaluation. RESULTS: Mucin secretion was significantly increased in the 100 microgram/mL 51.20 +/- 13.6 microgram/mL (SE) and 1000 microgram/mL 69.42 +/- 8.57 microgram/mL groups when compared with the Krebs Ringer control group 1.84 +/- 0.28 microgram/mL (P < 0.05). Histologic evaluation shows goblet cell metaplasia and hyperplasia in the middle ear epithelium in the 1000 and 100 microgram/mL groups. CONCLUSIONS: The histology and ELISA results suggest that a middle ear effusion is generated with a dose of lipopolysaccharide as low as 100 microgram/mL.

Computer-based physician education.

Physicians are turning to computers with increasing frequency to access patients' records and laboratory values, to communicate with colleagues, and to keep current with the developments in their field. This article reviews the impact of the computers on the education of medical students and on continuing education for residents and practicing physicians. Furthermore, it emphasizes the importance and need for educating physicians about computers and the basic principles behind their development.

Long-term follow-up of recurrent laryngeal nerve avulsion for the treatment of spastic dysphonia.

Long-term follow-up of 3 to 7 years is reported on 18 patients who had undergone recurrent laryngeal nerve avulsion (RLNA) for the treatment of adductor spastic dysphonia (SD). Data on neural regrowth after previous recurrent laryngeal nerve section (RLNS) are presented in 2 of these 18 patients. We introduced RLNA as a modification of standard RLNS to prevent neural regrowth to the hemiparalyzed larynx and subsequent recurrence of SD. We have treated a total of 22 patients with RLNA, and now report a 3- to 7-year follow-up on 18 of these 22 patients. Resolution of symptoms was determined by routine follow-up assessment, perceptual voice analysis, and patient self-assessment. Sixteen of 18, or 89%, had no recurrence of spasms at 3 years after RLNA as determined at routine follow-up. Two of the 16 later developed spasms after medialization laryngoplasty for treatment of weak voice persistent after the avulsion. This yielded a total of 14 of 18, or 78%, who were unanimously judged by four speech pathologists to have no recurrence of SD at the longer follow-up period of 3 to 7 years. Two of these 4 patients were judged by all four analysts to have frequent, short spasms. The other 2 were judged by two of four analysts to have seldom, short spasms. Three of 18 patients presented with recurrent SD after previous RLNS. At the time of subsequent RLNA, each patient had evidence of neural regrowth at the distal nerve stump as demonstrated by intraoperative electromyography and histologic evaluation of the distal nerve stump. One remained free of SD following RLNA, 1 was free of spasms at 4 years after revision avulsion but developed spasms after medialization laryngoplasty, and the final patient developed spasms 3.75 years after revision RLNA. Medialization laryngoplasty with Silastic silicone rubber was performed in 6 of 18, with correction of postoperative breathiness in all 6, but with recurrence of spasm in 3. Spasms resolved in 1 of these with downsizing of the implant. We conclude that RLNA represents a useful treatment in the management of SD in patients not tolerant of botulinum toxin injections.