Impact of partial mastoid obliteration on caloric vestibular function in canal wall down mastoidectomy.

OBJECTIVE: To evaluate the influence of our technique of partial mastoid obliteration with autologous bone pâté covered by cartilage plates on vestibular stimulation. METHODS: Twenty-six patients who were treated for recurrent chronic otitis media by revision canal wall down tympanomastoidectomy and subsequent partial obliteration were invited for follow-up; 18 patients agreed to a complete follow-up including vestibular testing. Patients received questionnaires for evaluating preoperative and postoperative symptoms associated with vertigo. Examination comprised otomicroscopy, pure-tone audiometry, and caloric testing. RESULTS: Mean follow-up was 6 years. Before surgery, 54% of the patients reported vertigo on caloric stimuli such as wind, water, or suction cleaning of the tympanomastoid cavity. In all patients, these symptoms were suspended after partial mastoid obliteration. The postoperative obliterated cavity volume averaged 3.1 ml. All cavities after surgery appeared completely epithelialized and dry. The postoperative caloric vestibular tests revealed an average nystagmus count of 46 beats per minute compared with 72 beats before surgery. Thus, the partial mastoid cavity obliteration led to a mean nystagmus reduction of 36% in our study group. CONCLUSION: Our technique of partially obliterating tympanomastoid cavities with autologous bone pâté being covered by cartilage plates results in small cavities with complete epithelialization of all surfaces. Furthermore, obliteration of mastoid cavities confers protection to the labyrinthine organ, thereby reducing postoperative vertigo on caloric stimulation.

Cartilage plate tympanoplasty.

OBJECTIVES: The purpose of this work was to report our modified cartilage plate tympanoplasty technique ("tulip leaves") and to analyze its clinical outcome in primary and recurrent cases of chronic otitis media with and without cholesteatoma. STUDY DESIGN: Clinical retrospective study. METHODS: Patients being operated on with this technique at the University Department of Otorhinolaryngology, Dresden, Germany, between 1993 and 2001 were invited for survey, otomicroscopy, and pure-tone audiometry in 2003. Patients' charts were used to draw necessary conclusions. RESULTS: A total of 39 patients who were treated with this technique after canal wall down tympanomastoidectomy and cavity obliteration were included in this long-term analysis after a median follow-up of 6 years. Seventeen patients (44%) experienced chronic otitis media with cholesteatoma, whereas 22 (56%) of them had a diagnosis of chronic otitis media without cholesteatoma. At the time of examination, all patients displayed a closed tympanic membrane. However, retractions were observed in 19 patients (48%). One patient required (3%) revision surgery for recurrent cholesteatoma due to prosthesis extrusion during the study period. CONCLUSION: On the basis of this study, we recommend the tuliplike arrangement of thin but large auricular cartilage slices for the reconstruction of tympanic membrane defects in high-risk ears. This combination proved its high stability and long-lasting vitality in our long-term study. These characteristics are crucial for permanent disease removal and for reducing the risk of recurrent pathologic abnormality.

The application of latent class analysis for diagnostic test validation of chronic Trypanosoma cruzi infection in blood donors.

The main strategy to prevent transfusion-associated Chagas disease is the identification of T. cruzi-infected blood donors by serological screening tests, however there is no perfect serological gold standard. We evaluated an enzyme immunoassay (EIA), an indirect hemaglutination (IHA), and an indirect immunofluorescence (IIF) test for detecting T. cruzi antibodies in Brazilian blood donors. The results were submitted to latent class analysis, and a radioimmunopreciptation (RIPA) test was performed on repeatedly positive samples. Among 1951 donors, 11 (0.56%) were positive by EIA, 6 (0.31%) by IHA and 16 (0.82%) by IIF. Six samples were positive with all tests, while 4 reacted with EIA and IIF. The RIPA was positive in 6 (75.0%), 7 (66.6%), and 4 (54.0%) samples reacting by the EIA, IHA and IIF tests, respectively. The latent class model detected a high sensitivity rate (100%) for the EIA and IIF, and a specificity rate of 99.95% and 99.69% for the EIA and IIF tests, respectively. The probability of being case according to the model was 99.92% when both EIA and IIF were positive, and 100% for the association of EIA, IIF, and IHA.

The application of latent class analysis for diagnostic test validation of chronic Trypanosoma cruzi infection in blood donors

The main strategy to prevent transfusion-associated Chagas disease is the identification of T. cruzi-infected blood donors by serological screening tests, however there is no perfect serological gold standard. We evaluated an enzyme immunoassay (EIA), an indirect hemaglutination (IHA), and an indirect immunofluorescence (IIF) test for detecting T. cruzi antibodies in Brazilian blood donors. The results were submitted to latent class analysis, and a radioimmunopreciptation (RIPA) test was performed on repeatedly positive samples. Among 1951 donors, 11 (0.56) were positive by EIA, 6 (0.31) by IHA and 16 (0.82) by IIF. Six samples were positive with all tests, while 4 reacted with EIA and IIF. The RIPA was positive in 6 (75.0), 7 (66.6), and 4 (54.0) samples reacting by the EIA, IHA and IIF tests, respectively. The latent class model detected a high sensitivity rate (100) for the EIA and IIF, and a specificity rate of 99.95 and 99.69 for the EIA and IIF tests, respectively. The probability of being case according to the model was 99.92 when both EIA and IIF were positive, and 100 for the association of EIA, IIF, and IHA.

Trypanosoma cruzi in Los Angeles and Miami blood donors: impact of evolving donor demographics on seroprevalence and implications for transfusion transmission.

BACKGROUND: Trypanosoma cruzi, the agent of Chagas' disease, continues to be a concern for blood safety, as demonstrated by recent transfusion-transmitted cases in the United States and Canada. The chronic nature of Chagas', coupled with increasing numbers of immigrants from T. cruzi-endemic countries, suggests that Chagas' is a long-term public health problem. Herein, we report on a multiyear epidemiologic study of T. cruzi in Los Angeles and Miami blood donors. STUDY DESIGN AND METHODS: From May 1994 to September 1998, blood donors in Los Angeles and Miami were queried regarding birth or time spent in an endemic country. Donations of "yes" respondents were tested by EIA, confirmed by radioimmunoprecipitation assay, and if confirmed as seropositive, enrolled in look-back investigations. RESULTS: A total of 1,104,030 Los Angeles and 181,139 Miami donors were queried regarding risk; 7.3 and 14.3 percent, respectively, responded yes. Seropositive rates were 1 in 7,500 Los Angeles and 1 in 9,000 Miami donors. In Los Angeles, seroprevalence rates increased significantly from 1996 to 1998 and were significantly higher for directed donors than nondirected donors. Look back identified 18 recipients, all of whom were seronegative for T. cruzi. CONCLUSION: Significant numbers of T. cruzi-seropositive donors contribute to the U.S. blood supply. The incidence of seropositivity is enhanced by minority recruitment efforts necessitated by donor demographic shifts. Similarly, high rates among directed donations in Los Angeles are attributable to a disproportionate number of at-risk directed donors. Current look-back data likely underestimate the frequency of transfusion- transmitted T. cruzi. These results indicate that continued evaluation of transfusion as a mode of T. cruzi transmission in the United States is needed.

DPOAEs and vestibular function in different types of autosomal-dominant non-syndromal hearing impairment.

BACKGROUND/OBJECTIVE: The application of distortion-product otoacoustic emissions (DPOAE) could be advantageous in the early diagnostic of descendants of families with autosomal-dominant non-syndromal hearing impairment (ADNSHI). PATIENTS/METHODS: DP-grams of 58 affected persons of 21 families with ADNSHI were measured (f(2)/f(1)=1.22; L(1)=70 dB SPL; L(2)=65 dB SPL; four points per octave). The mode of transmission was determined by pedigree. The phenotype was determined by pure tone audiometry (PTA) and caloric vestibular test (CVT). RESULTS: We could find 12 families with mild to severe mid-frequency U-shaped ADNSHI, three families with steeply sloping high tone ADNSHI, two families with moderate to severe gently sloping high tone ADNSHI, three families with profound ADNSHI and one family with variable ADNSHI. One family showed an additional vestibular lesion. Fifty-six of 58 affected persons showed pathological DP-grams. In 48 persons (83%) these DP-grams showed distinct similarity within the families, that they could be classified as "ADNSHI-typical" within an affected family. CONCLUSIONS: Affected persons of a family with ADNSHI show similar DP-grams. These DP-grams are useful in the early routine-diagnostics of newborns within such families.