Comparison of argon and CO2 laser stapedotomy in primary otosclerosis surgery.

PURPOSE: The primary use for the laser in otosclerosis surgery is to create a stapes footplate fenestration that obviates the need for mechanical footplate removal. Experimental studies that evaluate the potential safety of visible (argon and potassium-titanyl-phosphate [KTP]) and invisible (CO2) light laser systems in stapes surgery report conflicting results. The purpose of this study is to compare the clinical safety and efficacy of the CO2 and argon laser systems when used for primary laser stapedotomy. MATERIALS AND METHODS: A retrospective case review of 124 primary laser stapedotomies using either the argon (n = 59) or CO2 (n = 65) laser was performed. Data consisted of pre- and postoperative air and bone conduction audiometry, speech discrimination scores (SDS), intraoperative findings, and postoperative complications. Between group differences (argon v CO2) were sought using standard statistical methodology. RESULTS: The argon and CO2 laser groups were comparable with regards to age, sex, preoperative air-bone gap, and laterality. Mean preoperative air and bone conduction pure-tone average (PTA) and SDS were somewhat higher in the CO2 laser group (P < .05). Postoperatively, both groups showed similar results in mean change in air conduction PTA, air-bone gap, and SDS, as well as in the frequency of complications. There were no anacoustic ears in either group. CONCLUSIONS: The results suggest that the argon and CO2 laser systems are comparable with regards to safety and efficacy when used by experienced surgeons for stapedotomy.

Acoustic tumor growth: implications for treatment choices.

BACKGROUND: Knowledge of acoustic neuroma (AN) growth is essential for treatment planning. METHODS: A retrospective analysis of 119 patients with AN (mean age, 65 years; range, 37-84 years) followed with interval magnetic resonance imagings (MRIs) was performed. Change in maximum tumor dimension as a function of follow-up period was analyzed. RESULTS: Overall, maximum tumor dimension increased >2 mm in only 30% of patients. Of those that grew, the mean growth rate was 3.8 mm/year (maximum, 25 mm/year). Age, gender, and laterality did not predict growth. Most tumors that grew (86.1 %) were <20 mm at presentation. However, tumors >20 mm were statistically more likely to grow (71%, p =0.028). CONCLUSIONS: Most ANs followed with periodic MRIs do not grow. Available clinical information usually cannot predict growth. Serial MRIs are advocated for all patients treated with observation.

Cochlear implants in the geriatric population: benefits outweigh risks.

Cochlear implantation has become widely accepted as an effective means of hearing rehabilitation in severely and profoundly deaf individuals. In the elderly, cochlear implantation involves a number of unique issues that can affect patient outcomes. These factors include age-related changes in the auditory system, prolonged durations of deafness, diminished communication abilities, and coexisting medical and psychosocial problems. In general, the results of cochlear implantation in the elderly have been comparable with those of younger adults. Perioperative attention to medical and surgical details allows for safe insertion and a minimum of postoperative complications. Patients older than 65 have obtained excellent results by both audiologic and quality-of-life measures.

Intraoperative corticosteroids in acoustic tumor surgery.

BACKGROUND: Corticosteroids are frequently used for the prevention and treatment of neural edema. Although perioperative steroid therapy has been used in patients undergoing acoustic neuroma removal, the efficacy of such therapy has not been previously documented. METHODS: A retrospective review of 169 patients who underwent acoustic neuroma surgery with (n = 75) or without (n = 94) a single dose of intraoperative corticosteroids was performed. Tumor size ranged from 0.4 cm to 6 cm (mean, 2.1; SD, 1.0) The translabyrinthine approach was used in 85% of the patients, and the middle cranial fossa approach was used in 13%. Data were analyzed for differences in postoperative facial function and complication rates. RESULTS: After controlling for differences in tumor size, no significant effects of steroid therapy were found for any of the outcome variables. CONCLUSIONS: This retrospective study showed no apparent benefit from intraoperative steroid use in acoustic neuroma surgery. A prospective, randomized, placebo-controlled trial should be performed to confirm these findings.

Beta-2 transferrin assay in the identification of perilymph.

HYPOTHESIS: Western blot assay for beta-2 transferrin protein is a clinically useful method for the detection of human perilymph and should be used for the diagnosis of perilymph fistulas (PLFs). BACKGROUND: Considerable controversy exists regarding the diagnosis of PLF. Recent studies suggest that the detection of beta-2 transferrin protein may be useful in the identification of perilymph. METHODS: To evaluate the usefulness of the beta-2 transferrin assay for identifying human perilymph, paired perilymph samples and negative controls were collected on Gelfoam pledgets from 20 patients who had surgery that opened the inner ear. Blinded immunoelectrophoretic assay (Western blot) for beta-2 transferrin was performed on each specimen. RESULTS: Only one (5%) of the known perilymph samples and none of the control specimens were definitely positive for beta-2 transferrin. Combined with historical data, this assay has 29% sensitivity, 100% specificity, 100% positive predictive value, and 31% negative predictive value. CONCLUSIONS: These findings suggest that the beta-2 transferrin protein assay may not be a reliable method for detecting human perilymph when performed using this technique.

Trypanosoma cruzi in a low- to moderate-risk blood donor population: seroprevalence and possible congenital transmission.

BACKGROUND: Several recent studies documented the seroprevalence of Trypanosoma cruzi in blood donors at high risk for infection, but little information is available regarding donors with lower levels of risk. Thus, the present study was designed to measure the seroprevalence of T. cruzi in a donor population with a low to moderate risk for infection. STUDY DESIGN AND METHODS: During a 10-month period, donations from all allogeneic blood donors in the American Red Cross Southwest Region were tested for T. cruzi antibodies by enzyme immunoassay, and results were confirmed by radioimmunoprecipitation. Confirmed-seropositive donors were counseled and lookback investigations were initiated for those who were repeat donors. RESULTS: A total of 100,089 donations were tested: 150 were repeatably reactive, and 3 (0.003%) were confirmed as positive for T. cruziantibodies. All three seropositive donors were from the Waco, TX, area, where the estimated seroprevalence rate was 1 in 7700. Two of these three donors reported no risk factors; both were born in the United States and had not traveled to an endemic area. Both had extensive familial histories of cardiac disease and complications. CONCLUSION: Blood donors seropositive for T. cruzi are present in populations with low to moderate risk, albeit at lower rates. The presence of seropositive blood donors without the usual identifiable risk factors argues against the use of a geographic screening question and also suggests that other routes of transmission, including the congenital route, should be considered in efforts to increase blood safety.

Prosthesis size in stapedectomy.

Primary stapedectomies were performed on 60 patients with bilateral otosclerosis. Every patient had a 4 mm long Robinson prosthesis with a 0.4 mm wide shaft placed in one ear and a 4 mm long Robinson prosthesis with 0.6 mm wide shaft placed in the opposite ear. With the 0.4 mm wide prosthesis, 54 patients overclosed the air bone gap and 6 were within 10 dB of closing. With the 0.6 mm wide prosthesis, which was placed in the opposite ear, 51 patients overclosed their air-bone gap and 8 were within 10 dB of closing. We conclude that there is no statistical difference in hearing results between the 0.4 mm and the 0.6 mm wide Robinson prosthesis when they are used in a partial stapedectomy with a vein graft covering the oval window.

p53 mutations and chromosome instability in basal cell carcinomas developed at an early or late age.

Tumor DNA from 45 primary basal cell carcinoma (BCC) biopsies was screened for p53 gene mutations, chromosome 9 allele loss, and microsatellite instability. p53 mutation frequency increased significantly as a function of the age at BCC onset ranging from 6% (1/16) in early BCC (before age 40 years) to 35% (10/29) in late BCC. All p53 mutations found implicated sunlight as the mutagen. Chromosome 9 instability (allele loss or microsatellite instability) was detected at high frequency (38%) independently of age at tumor onset. Allelic loss was confined to chromosome 9q, whereas microsatellite instability was observed prevalently on chromosome 9p often in association with a replication error (RER+) phenotype. Most of our late BCC patients reported occupational sun exposure, while early BCC patients recalled childhood (0-20 years) recreational sun exposure. These data suggest that chronic exposure to sunlight is responsible for accumulation of p53 mutations and thus for late BCC appearance, whereas acute UV exposure in childhood and adolescence leads to early skin cancer development in genetically susceptible individuals via a p53-independent pathway.

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.

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.

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.

Interobserver variability on the histopathologic diagnosis of cutaneous melanoma and other pigmented skin lesions.

PURPOSE: To assess the interobserver agreement on the diagnosis and classification of cutaneous melanoma. MATERIALS AND METHODS: A set of 140 slides of cutaneous melanoma, including a small subset of benign pigmented skin lesions, were circulated to four experienced histopathologists. The kappa statistic for multiple ratings per subject was calculated using the method described by Fleiss. RESULTS: The kappa value on the diagnosis of cutaneous melanoma versus benign lesions was 0.61. There was some discordance on the diagnosis in 37 of 140 cases (26%). For the histopathologic classification of cutaneous melanoma, the highest kappa values were attained for Breslow thickness (kappa = 0.76) and presence of ulceration (kappa = 0.87). The agreement was generally poor for other histologic features, such as level of dermal invasion (kappa = 0.38), presence of regression (kappa = 0.27), and lymphocytic infiltration (kappa = 0.27). CONCLUSION: Our study suggests considerable disagreement among pathologists on the diagnosis of melanoma versus other pigmented lesions. Tumor thickness and presence of ulceration are the most reproducible histologic features of cutaneous melanoma.

Prognostic value of anesthesia type for patients treated for cutaneous melanoma.

BACKGROUND: General anesthesia has been reported to compromise several cell-mediated immune functions. Hence it is plausible that anesthesia could affect the postoperative outcome of cancer patients. OBJECTIVE: To study the influence of the type of anesthesia on survival of 459 patients with localized cutaneous melanoma observed between 1980 and 1991. METHODS: Crude survival proportions were calculated by the methods of Kaplan and Meier. Cox proportional hazards regression analysis was used to estimate the effect on death rates of the type of anesthesia. RESULTS: The 5-year survival proportions were 81% for patients treated under local anesthesia, 71.9% for patients receiving halothane isoflurane or enflurane, and 88.4% for neuroleptanalgesia (P < .05). After multiple adjustment for other prognostic variables (tumor thickness, presence of ulceration, age, sex, cross-sectional profile), using patients treated under local anesthesia as a reference group, the relative risk for general anesthesia with volatile agents was 1.3 (95% CI, 0.84-2.10). CONCLUSION: The type of anesthesia does not seem to affect the survival of patients with cutaneous melanoma, when other prognostic factors are considered.

Vestibular nerve section.

INTRODUCTION: Vestibular nerve section is considered to be the most effective surgical procedure for control of intractable symptoms secondary to labyrinthine and eighth nerve function. This study was developed to retrospectively evaluate the efficacy of vestibular nerve section in patients treated for disabling labyrinthine dysfunction. METHODS: A retrospective review of hospital and office records was carried out on 39 patients who underwent vestibular nerve section. All patients received a comprehensive questionnaire to subjectively evaluate efficacy. RESULTS: Questionnaires were returned from 36 of 39 patients. Follow-up averaged 51 months. A decrease in vertiginous attacks was reported by 94% of patients. An improvement in activity tolerance was reported by 30% of patients. Preoperative tinnitus and ear fullness reportedly improved after surgery in 53% and 65% or patients respectively. Complications encountered included cerebrospinal fluid (CSF) leak (six patients), meningitis (two patients), and intracranial fluid collection (one patient). CONCLUSION: Vestibular nerve section is a relatively safe and effective method of treatment for intractable vertigo.

Survival and prognostic factors in patients with localised cutaneous melanoma observed between 1980 and 1991 at the Istituto Dermopatico dell'Immacolata in Rome, Italy.

530 patients with localised cutaneous melanoma consecutively observed between 1980 and 1991 at a hospital for skin diseases in Rome, Italy, were studied. Crude survival proportions were calculated with the method of Kaplan and Meier. Cox proportional hazards regression analysis was used to estimate the effect of prognostic factors on death rates. Females and younger patients had better 5- and 10-year survival rates, while increasing tumour thickness was associated with a decrease in survival time. In the multivariate analysis, an independent association with survival was found for tumour thickness, presence of ulceration, age, sex and cross-sectional profile of neoplasia. Our study confirms that females and young patients with thin melanomas have a better prognosis, while the importance of cross-sectional profile needs further study.

Superior sagittal sinus thrombosis after radical neck dissection.

Dural sinus thrombosis is a rare, potentially fatal complication of a radical neck dissection. The prognosis can vary from complete recovery to rapid death. Magnetic resonance venography provides an effective, noninvasive diagnosis. The goals of therapy are to decrease intracranial pressure and to lyse the thrombus. Systemic anticoagulation and systemic thrombolytics are controversial therapies. The direct intrasinus infusion of thrombolytic agents is under investigation.

Endoscopic management of a giant cholesterol cyst of the petrous apex.

Giant cholesterol cyst (GCC) of the petrous apex is a rare clinical entity. This benign cystic lesion can cause neurologic deficits and vascular compromise by persistent growth and progressive bone destruction. Magnetic resonance imaging studies of GCC show the lesions to be hyperintense on T(1)-weighted sequences with progressively lower signal intensities on the first and second echoes of T(2)-weighted sequences. These findings are relatively specific for GCC, permitting a narrow differential diagnosis. The goal of surgery is to provide adequate drainage with the creation of a permanent fistula. The classic approaches to these lesions are the posterior fossa craniotomy and the middle fossa extradural craniotomy. The translabyrinthine approach provides wide exposure at the expense of cochlear and vestibular function. The transsphenoidal approach provides adequate drainage with hearing preservation and no craniotomy. The endoscopic, endonasal transsphenoidal approach to a 2.5 cm GCC of the petrous apex accomplished complete drainage with the creation of a fistula. Advances in endoscopic technique and instrumentation facilitated the addition of the approach to the surgeon's armamentarium. In selected cases, this approach provides adequate surgical exposure with minimal morbidity.