Laser stapedotomy minus prosthesis (laser STAMP): absence of refixation.

OBJECTIVE: To determine what percentage of patients with otosclerosis could successfully undergo a laser stapedotomy minus prosthesis over a 5-year period, and to determine the percentage of patients in whom refixation develops during follow-up. STUDY DESIGN: Retrospective case review of 136 patients (137 ears) who underwent primary surgery for otosclerosis. SETTING: An otology/neurotology tertiary referral center. PATIENTS: Patients were chosen if they had clinical evidence of otosclerosis without a history of otologic surgery. INTERVENTIONS: A standard stapes approach was used for all patients. For the laser stapedotomy minus prosthesis, a hand-held laser probe was used to vaporize the anterior crus of the stapes and perform a linear stapedotomy across the anterior one third of the footplate. If otosclerosis was confined to the fissula ante fenestram, the stapes became completely mobile. The stapedotomy opening was sealed with an adipose tissue graft from the ear lobe. MAIN OUTCOME MEASURES: Pure-tone audiometry with appropriate masking and auditory discrimination testing was performed before surgery, 6 weeks after surgery, and every year thereafter. RESULTS: Of the 137 cases, favorable anatomy and minimal otosclerosis allowed 46 (33.6%) of these patients to undergo laser stapedotomy minus prosthesis. Fifty-seven patients (41.6%) could not undergo the procedure because of extensive otosclerosis. The remaining 34 patients (24.8%) did not receive laser stapedotomy minus prosthesis because of other anatomic or technical difficulties. Of the 34 patients in the laser stapedotomy minus prosthesis group with more than 4 months follow-up, the average air-bone gap was closed from a mean of 22 dB (SD 10 dB) to 6 dB (SD 4 dB) 6 weeks postoperatively. Follow-up periods ranged from 5 months to 53 months (mean 767 days, SD 437 days). The long-term air-bone gap improved slightly to an average of 5 dB (SD 6 dB) in comparison with the sixth postoperative week value. CONCLUSION: Laser stapedotomy minus prosthesis is a minimally invasive procedure, which over the follow-up period has a very low incidence of refixation, as evidenced by a lack of progressive conductive hearing loss. The success of this procedure depends on the correct selection of cases. This procedure has been successfully performed on 33.6% of patients undergoing primary stapes surgery. Laser stapedotomy minus prosthesis seems to be a viable alternative to conventional stapedotomy that yields good results without evidence of refixation over an extended time.

Use of the malleus handle as a landmark for localizing the round window membrane.

Localization of the round window membrane is desirable in order to allow a more direct application of medication to the inner ear. A new procedure has been developed to deliver direct, near-continuous inner ear perfusion to the round window with the Silverstein MicroWick. In this office procedure, the wick is inserted through a tympanostomy tube into the round window niche. Accurate localization of the round window is a necessary component of this procedure. In an effort to ascertain the precise location of the round window, we examined 25 cadaveric human temporal bones and measured the distance from the umbo to the round window in each sample. We found that the round window was an average of 3.44 mm (+/- 0.68) from the umbo and was situated at an average angle of 113.2 degrees (+/- 9.8) from the long process of the malleus. Our simple and reliable determination of the relationship between the malleus handle and the round window niche allows for the accurate placement of the Silverstein MicroWick and other devices.

Pediatric laser-assisted tympanostomy.

OBJECTIVE: To evaluate effectiveness of laser-assisted tympanostomy in treatment of pediatric patients with chronic otitis media with effusion. STUDY DESIGN: Retrospective review of 23 pediatric patients who received office laser-assisted tympanostomy. METHODS: A CO2 laser attached to an operating microscope with a microscope laser adaptor device or the handheld Oto-LAM (Needham, MA) was used to perform all of the tympanostomies. The average diameter of tympanostomy was 2 mm; on average, 13.6 W was applied for 0.13 seconds. RESULTS: Laser-assisted tympanostomy was performed on 37 pediatric ears (patient age range, 2-16 y) for the diagnosis of chronic otitis media with effusion. Average follow-up time was 4.7 weeks. At the time of the follow-up examination, 46% of the ears had no evidence of fluid and required no further intervention. Forty-nine percent of the ears required placement of pressure equalization tubes. The average SRT improved from 30.8 dB preoperatively to 21.03 dB postoperatively. CONCLUSIONS: Laser-assisted tympanostomy appears to be an effective treatment for chronic otitis media with effusion in pediatric patients.

Phenotypic and genotypic heterogeneity in familial Milroy lymphedema.

Familial Milroy lymphedema (ML) is classified as an autosomal dominant disorder characterized by peripheral edema of the lower extremities at birth or in early childhood. The variety of phenotypes are not well described, and the genomic location and functional expression of the gene or genes underlying this and related familial lymphedema syndromes remain largely unknown. In this collaborative study between the University of Arizona and the University of São Paulo, we collected clinical pedigrees on 6 ML families, carried out clinical examination of affected and unaffected individuals, and, in representative affected members of two of the families performed dynamic lymphangioscintigraphy (LAS) of the lower and upper limbs to delineate further the ML lymphangiodysplastic phenotype. To localize the gene for ML, we conducted a genome-wide search in 4 of the families using 387 polymorphic dinucleotide-repeat markers at approximate 10 cM spacing in 54 subjects (affected, unaffected bloodline relatives, and spouses). In all 6 families (86 subjects), we specifically examined the suggested linkage to the vascular endothelial growth factor (VEGF)-C receptor (Flt4) gene localized to the chromosome region 5q34-q35. The findings provide evidence for a spectrum of ML clinical and LAS phenotypes and also suggest ML locus heterogeneity.

Genomic DNA-based hMSH2 and hMLH1 mutation screening in 32 Eastern United States hereditary nonpolyposis colorectal cancer pedigrees.

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant cancer syndrome characterized by early age of onset colorectal cancer (mean 45 years) as well as endometrial, urinary tract, and upper gastrointestinal adenocarcinomas. The HNPCC phenotype has been shown to segregate with germline mutations in the human homologues of the DNA mismatch repair genes MSH2, MLH1, PMS1, and PMS2. However, the majority of published DNA mismatch repair gene mutation surveys associated with HNPCC kindreds report multiple levels of preselection, including 2p and 3p chromosomal linkage analysis and the evaluation of microsatellite instability of proband colorectal cancers prior to mutation analysis. For this reason, the concise contribution of each of the known DNA mismatch repair genes to the HNPCC phenotype remains unknown. We report the results of a genomic DNA-based analysis of hMSH2 and hMLH1 germline mutations in 32 unrelated Eastern United States HNPCC kindreds. These families were selected for study on the basis of phenotype only. We identified three hMSH2 and six hMLH1 mutations in eight families, for a positive mutation rate of 25%. Two mutations were identified in one of the families. Four of the mutations detected have not been reported in the literature previously. One of the mutation-positive families is African American; the others were of European-American ancestry. These results provide a clarification of the contribution of hMSH2 and hMLH1 to the HNPCC phenotype and suggest that in the majority of Eastern United States HNPCC kindreds selected by phenotype alone, the molecular genetic basis for the disease remains unknown.