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Biomedical subjects

P Ashley Wackym

Publications and source records attributed to P Ashley Wackym.

18 recordsLinked to original sources
PubMed2006

Direct detection of bacterial biofilms on the middle-ear mucosa of children with chronic otitis media.

CONTEXT: Chronic otitis media (OM) is a common pediatric infectious disease. Previous studies demonstrating that metabolically active bacteria exist in culture-negative pediatric middle-ear effusions and that experimental infection with Haemophilus influenzae in the chinchilla model of otitis media results in the formation of adherent mucosal biofilms suggest that chronic OM may result from a mucosal biofilm infection. OBJECTIVE: To test the hypothesis that chronic OM in humans is biofilm-related. DESIGN, SETTING, AND PATIENTS: Middle-ear mucosa (MEM) biopsy specimens were obtained from 26 children (mean age, 2.5 [range, 0.5-14] years) undergoing tympanostomy tube placement for treatment of otitis media with effusion (OME) and recurrent OM and were analyzed using microbiological culture, polymerase chain reaction (PCR)-based diagnostics, direct microscopic examination, fluorescence in situ hybridization, and immunostaining. Uninfected (control) MEM specimens were obtained from 3 children and 5 adults undergoing cochlear implantation. Patients were enrolled between February 2004 and April 2005 from a single US tertiary referral otolaryngology practice. MAIN OUTCOME MEASURES: Confocal laser scanning microscopic (CLSM) images were obtained from MEM biopsy specimens and were evaluated for biofilm morphology using generic stains and species-specific probes for H influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis. Effusions, when present, were evaluated by PCR and culture for evidence of pathogen-specific nucleic acid sequences and bacterial growth, respectively. RESULTS: Of the 26 children undergoing tympanostomy tube placement, 13 (50%) had OME, 20 (77%) had recurrent OM, and 7 (27%) had both diagnoses; 27 of 52 (52%) of the ears had effusions, 24 of 24 effusions were PCR-positive for at least 1 OM pathogen, and 6 (22%) of 27 effusions were culture-positive for any pathogen. Mucosal biofilms were visualized by CLSM on 46 (92%) of 50 MEM specimens from children with OME and recurrent OM using generic and pathogen-specific probes. Biofilms were not observed on 8 control MEM specimens obtained from the patients undergoing cochlear implantation. CONCLUSION: Direct detection of biofilms on MEM biopsy specimens from children with OME and recurrent OM supports the hypothesis that these chronic middle-ear disorders are biofilm-related.

Adolescent↗
PubMed2006

Biomechanical strength of reconstruction plates when used for medial support of MED-El cochlear implants: implications for diagnostic MRI.

PURPOSE: It is hypothesized that a mesh reconstruction plate designed to fit a cochlear implant (CI) internal device will provide immediate structural support to the site of the implant and that this strength far exceeds the forces induced by a 1.5-tesla MRI. PROCEDURES: Human calvarial specimens were drilled and plated with reconstruction mesh. Force was applied until failure was reached. RESULTS: Mean maximum force, mean force to first failure and mean displacement measures for group 1 (resorbable mesh, n = 10) were 302.9 N, 283.0 N and 3.05 mm, respectively. The mean maximum force for group 2 (0.4-mm titanium mesh, n = 10) and group 3 (0.6-mm titanium mesh, n = 8), were 121.3 and 234.0 N, respectively. Mean force of first failure was 92.0 N for group 2 and 164.8 N for group 3. CONCLUSIONS: The force required for failure of the mesh is significantly greater than the 0.17 N exerted on a CI magnet by a 1.5-tesla MRI scan.

Absorbable Implants↗
PubMed2005

In silico analysis of 2085 clones from a normalized rat vestibular periphery 3' cDNA library.

The inserts from 2400 cDNA clones isolated from a normalized Rattus norvegicus vestibular periphery cDNA library were sequenced and characterized. The Wackym-Soares vestibular 3' cDNA library was constructed from the saccular and utricular maculae, the ampullae of all three semicircular canals and Scarpa's ganglia containing the somata of the primary afferent neurons, microdissected from 104 male and female rats. The inserts from 2400 randomly selected clones were sequenced from the 5' end. Each sequence was analyzed using the BLAST algorithm compared to the Genbank nonredundant, rat genome, mouse genome and human genome databases to search for high homology alignments. Of the initial 2400 clones, 315 (13%) were found to be of poor quality and did not yield useful information, and therefore were eliminated from the analysis. Of the remaining 2085 sequences, 918 (44%) were found to represent 758 unique genes having useful annotations that were identified in databases within the public domain or in the published literature; these sequences were designated as known characterized sequences. 1141 sequences (55%) aligned with 1011 unique sequences had no useful annotations and were designated as known but uncharacterized sequences. Of the remaining 26 sequences (1%), 24 aligned with rat genomic sequences, but none matched previously described rat expressed sequence tags or mRNAs. No significant alignment to the rat or human genomic sequences could be found for the remaining 2 sequences. Of the 2085 sequences analyzed, 86% were singletons. The known, characterized sequences were analyzed with the FatiGO online data-mining tool (http://fatigo.bioinfo.cnio.es/) to identify level 5 biological process gene ontology (GO) terms for each alignment and to group alignments with similar or identical GO terms. Numerous genes were identified that have not been previously shown to be expressed in the vestibular system. Further characterization of the novel cDNA sequences may lead to the identification of genes with vestibular-specific functions. Continued analysis of the rat vestibular periphery transcriptome should provide new insights into vestibular function and generate new hypotheses. Physiological studies are necessary to further elucidate the roles of the identified genes and novel sequences in vestibular function.

Afferent Pathways↗
PubMed2005

Molecular characterization of two novel splice variants of G alphai2 in the rat vestibular periphery.

GTP binding proteins play an important role in mediating signals transduced across the cell membrane by membrane-bound receptors. We previously described a partial sequence, termed Galphai2vest, obtained from rat vestibular tissue that was nearly identical to rat Galphai2. Using an experimental strategy to further characterize Galphai2vest (GenBank accession number AF189020) and identify other possible Galphai2-related transcripts expressed in the rat vestibular periphery, we employed a RecA-based gene enrichment protocol in place of conventional library screening techniques. We identified two novel Galphai2 splice variants, Galphai2(a) (GenBank accession number AY899210) and Galphai2(b) (GenBank accession number AY899211), that have most of exons 8 and 9 deleted, and exons 5 through 9 deleted, respectively. In situ hybridization studies were completed to determine the differential expression of Galphai2 between the vestibular primary afferent neurons and the vestibular end organs. Computer modeling and predicted 3D conformation of the wild type Galphai2 and the two splice variants were completed to evaluate the changes associated with the Gbetagamma and GTP binding sites. These two novel alternatively spliced isoforms of Galphai2 putatively encode truncated proteins that could serve unique roles in the physiology of the vestibular neuroepithelium. Galphai2vest was found to be a processed pseudogene.

Alternative Splicing↗
PubMed2005

Assessment of differential gene expression in vestibular epithelial cell types using microarray analysis.

Current global gene expression techniques allow the evaluation and comparison of the expression of thousands of genes in a single experiment, providing a tremendous amount of information. However, the data generated by these techniques are context-dependent, and minor differences in the individual biological samples, methodologies for RNA acquisition, amplification, hybridization protocol and gene chip preparation, as well as hardware and analysis software, lead to poor correlation between the results. One of the significant difficulties presently faced is the standardization of the protocols for the meaningful comparison of results. In the inner ear, the acquisition of RNA from individual cell populations remains a challenge due to the high density of the different cell types and the paucity of tissue. Consequently, laser capture microdissection was used to selectively collect individual cells and regions of cells from cristae ampullares followed by extraction of total RNA and amplification to amounts sufficient for high throughput analysis. To demonstrate hair cell-specific gene expression, myosin VIIA, calmodulin and alpha9 nicotinic acetylcholine receptor subunit mRNAs were amplified using reverse transcription-polymerase chain reaction (RT-PCR). To demonstrate supporting cell-specific gene expression, cyclin-dependent kinase inhibitor p27kip1 mRNA was amplified using RT-PCR. Subsequent experiments with alpha9 RT-PCR demonstrated phenotypic differences between type I and type II hair cells, with expression only in type II hair cells. Using the laser capture microdissection technique, microarray expression profiling demonstrated 408 genes with more than a five-fold difference in expression between the hair cells and supporting cells, of these 175 were well annotated. There were 97 annotated genes with greater than a five-fold expression difference in the hair cells relative to the supporting cells, and 78 annotated genes with greater than a five-fold expression difference in the supporting cells relative to the hair cells.

Acoustic Maculae↗
PubMed2005

Stereotactic radiosurgery, microsurgery, and expectant management of acoustic neuroma: basis for informed consent.

There is diversity in the techniques and instrumentation used to perform stereotactic radiosurgery. The field continues to evolve rapidly, and improvements are being made in accuracy, effective radiation dose, and parameters necessary to maximize patient outcome. Stereotactic radio-surgery, like any other treatment modality, has advantages and disadvantages that must be discussed with a patient who has an acoustic neuroma or other skull base tumor. An informed decision to pursue observation,microsurgery, stereotactic radiosurgery, or a combination of these methods must be made, and it remains the responsibility of the surgeon to provide a balanced view of the relative advantages and disadvantages of each method.

Dose Fractionation, Radiation↗
PubMed2005

Distortion of magnetic resonance images used in gamma knife radiosurgery treatment planning: implications for acoustic neuroma outcomes.

OBJECTIVE: To quantify the image distortion of our series of acoustic neuromas treated with gamma knife radiosurgery. STUDY DESIGN: Retrospective chart and digital radiographic file review with quantitative assessment of gamma knife treatment plans. SETTING: Tertiary referral center. PATIENTS: Patients undergoing gamma knife radiosurgery for the treatment of acoustic neuromas. INTERVENTION: Gamma knife radiosurgery. MAIN OUTCOME MEASURES: Gamma knife treatment plans containing magnetic resonance images were reviewed at each axial, sagittal, and coronal slice. The length of the greatest displacement of the treatment plan was measured and the volume of the treatment plan that fell outside of the internal auditory canal calculated. Known clinical measurements of audiometric, vestibular, facial, and trigeminal nerve functions were then compared with current measurements of tumor size. RESULTS: Twenty-two of the 23 patients had measurable image shifts on the axial images. The range of the image shift was 0 to 5.8 mm, with a mean shift of 1.92 +/- 1.29 mm (+/- standard deviation). Tumor volumes of the treatment plan that fell outside of the internal auditory canal ranged from 0 to 414 mm, with a mean of 90.5 mm. The mean percentage that fell outside of the internal auditory canal was 16.7% of total tumor volume (range, 2.4-77.6%). We could not draw any consistent correlations between degree of image shift and continued tumor growth or objective examination values. CONCLUSION: We have demonstrated a small but potentially significant shift in the treatment plan of gamma knife radiosurgery when based on magnetic resonance images. Although the image shift does not seem to affect the growth of the acoustic neuromas or auditory or facial nerve function, longer term follow-up is required to fully appreciate the true impact of this image shift.

Artifacts↗
PubMed2005

G-protein Golfalpha (GNAL) is expressed in the vestibular end organs and primary afferent neurons of Rattus norvegicus.

Guanine nucleotide binding proteins (G-proteins) play an important role in mediating signals transduced across the cell membrane by membrane-bound receptors. The precise role of these proteins and their coupled receptors in the physiology of the vestibular neuroepithelium is poorly understood. Although Golfalpha was originally discovered in the olfactory neuroepithelium and striatum, we recently identified this G-protein alpha subunit in a normalized cDNA library constructed from rat vestibular end organs and vestibular nerves including Scarpa's ganglia. In order to further characterize Golfalpha in the rat vestibular periphery, we used in situ hybridization and reverse transcription polymerase chain reaction to determine the anatomic context of this gene expression. Golfalpha was found in both the end organs and the ganglia and could serve unique roles in the physiology of the vestibular neuroepithelium.

Animals↗
PubMed2004

Auditory sensitivity in children using the auditory steady-state response.

OBJECTIVE: To determine the effectiveness of auditory steady-state response (ASSR) as a measure of hearing sensitivity in young children suspect for significant hearing loss. DESIGN: Within-subject comparisons of click auditory brainstem response (ABR) thresholds and ASSR thresholds. SUBJECTS: The study population comprised 42 children suspect for hearing loss and subsequently referred for hearing assessment using electrophysiologic techniques. MAIN OUTCOME MEASURES: Electrophysiologic threshold responses for click ABR and ASSR stimuli (0.5, 1, 2, and 4 kHz) for right and left ears. RESULTS: Based on ABR and ASSR thresholds, 50% of the subjects demonstrated significant hearing loss in the severe to profound range. In some subjects, ASSRs were present at higher stimulus levels when click ABRs were absent. Significant correlations (P<.05) were found between high-frequency ASSR and click ABR thresholds for this study sample. For some subjects, ASSR findings suggested differences between ears that were not observable from the no-response click ABR results. CONCLUSIONS: Auditory steady-state response testing may provide additional information for children who demonstrate hearing levels in the severe to profound range. This information may be helpful when selecting the ear for cochlear implantation for a young hearing-impaired child. Multiple objective methods, such as ABR and ASSR testing, may be needed to determine accurate hearing sensitivity for young children being considered for sensory devices, and in particular, cochlear implants.

Audiometry, Pure-Tone↗
PubMed2004

Selective acquisition of individual cell types in the vestibular periphery for molecular biology studies.

OBJECTIVES: To develop a method for characterizing the transcriptome of individual cell types in the inner ear sensory epithelia. STUDY DESIGN: We employed the technique of laser capture microdissection to obtain enriched populations of hair cells and supporting cells. The respective mRNAs were extracted, reverse transcribed, and amplified using PCR. RESULTS: We were able to isolate RNAs with good integrity from enriched cell populations obtained with laser capture microscopy and amplify specific mRNA targets. CONCLUSIONS: We can now investigate the molecular differences between the different cell types in the inner ear sensory epithelia as identified by morphological criteria. SIGNIFICANCE: Analysis of gene expression profiles in the inner ear cell types has been hampered by the small size of this tissue and by the compact histoarchitecture of the sensory epithelia; however, the present technique offers new possibilities for the analysis of transcriptomes in the vestibular periphery using available high-throughput gene expression analysis methods.

Animals↗
PubMed2004

Effect of magnetic resonance imaging on internal magnet strength in Med-El Combi 40+ cochlear implants.

OBJECTIVE: Magnetic resonance imaging (MRI) has been contraindicated when cochlear implants containing an internal magnet are in place because of concerns regarding torque, force, demagnetization, artifacts, induced voltages, and heating. The objective was to determine the magnetic field strength of Med-El Combi 40+ cochlear implant internal magnets after MRI studies. STUDY DESIGN/METHODS: Two fresh cadavers were used to study demagnetization using a repeated measures design and a magnetometer. Pre- and postMRI measurement of magnetic field strength was completed. Five sets of sagittal T1-weighted, axial T1-weighted, and axial T2-weighted sequences were performed on a cadaver at 0.2 Tesla in the device-up and device-down positions. In the other cadaver, 15 sets of sagittal T1-weighted, axial T1-weighted, and axial T2-weighted sequences were performed on a cadaver at 1.5 Tesla were conducted, 5 each with the head oriented at 80, 90, and 100 degrees rotated around the yaw plane (rotated around the z-axis). Subsequently, three cochlear implant patients completed 0.2 Tesla MRIs. For these patients, subjective and objective assessment of cochlear implant performance was performed. SETTING: Academic medical center. RESULTS: In the cadaver studies, analysis of variance showed no significant difference in the magnetic field strength after the 0.2 or 1.5 Tesla scans. There was no significant difference in the magnetic field strength for the three patients undergoing 0.2 Tesla MRIs and no adverse consequences, including no changes in telemetry, auditory sensations, nonauditory sensations, and sound quality. CONCLUSIONS: No significant demagnetization of the internal magnet occurred during repeated 1.5 Tesla MRI scans with the head orientations used in this study. In the cochlear implant patients, no significant demagnetization of the internal magnet occurred after a 0.2 Tesla MRI.

Artifacts↗
PubMed2004

Serial analysis of gene expression in neurofibromatosis type 2-associated vestibular schwannoma.

HYPOTHESIS: The genesis, morphology, and growth characteristics of vestibular schwannomas are determined by genetic alterations which vary gene transcript expression and this transcript expression can be qualitatively and quantitatively evaluated using the SAGE technique. By use of such technique, gene products with tumorigenic potential may be identified, providing insight and targets for future study. BACKGROUND: Serial analysis of gene expression (SAGE) is a powerful new technique that allows detailed qualitative and quantitative evaluation of cellular gene transcript expression. Tissue in limited quantity (5 x 10 to 2 x 10 cells) may be analyzed by a modified version of SAGE called microSAGE. Application of SAGE or microSAGE to study vestibular schwannoma gene expression has not been previously reported. METHODS: Fresh, vestibular schwannoma specimen from an individual with the diagnosis of neurofibromatosis type 2 was attained intraoperatively and maintained in a sealed container at -80degreesC until the time of analysis. The tissue was processed according to the microSAGE protocol, using 180 mg of vestibular schwannoma as starting material. RESULTS: The protocol resulted in the generation and sequencing of a tag library involving 458 tags representing 277 different gene products, including many transcripts known to be expressed in vestibular schwannomas. Several gene products with tumorigenic potential were identified. CONCLUSIONS: These data demonstrate that microSAGE is a useful technique to study vestibular schwannoma gene expression. Future studies will include building more comprehensive libraries and comparing libraries from various vestibular schwannoma phenotypes to identify useful diagnostic or prognostic markers, and targets for therapeutic intervention.

Adult↗
PubMed2004

Complication rate of transtemporal hydroxyapatite cement cranioplasties: a case series review of 76 cranioplasties.

OBJECTIVE: The objective of this study was to evaluate the complication rate of transtemporal cranioplasties using hydroxyapatite cement (HAC) for repair. STUDY DESIGN: We conducted a retrospective case review of patients receiving HAC cranioplasties in the Acoustic Neuroma and Skull Base Surgery Program between July 1998 and December 2002. SETTING: This study was conducted at a tertiary referral center. PATIENTS: A total of 76 HAC cranioplasties were performed in 72 patients undergoing lateral skull base surgery. Patients undergoing anterior skull base surgery or those in which HAC was used for other reconstructive purposes were excluded from the study. INTERVENTIONS: We studied transtemporal approaches for otologic procedures requiring cranioplasty. MAIN OUTCOME MEASURES: Main outcomes measures consisted of complications requiring medical or surgical intervention. RESULTS: Of the 76 HAC cranioplasties, two cranioplasty grafts became infected, requiring explantation. The first case involved a wound infection that extended into and involved the HAC graft; the second involved seeding of the HAC graft after meningitis after a percutaneous, endoscopic gastrostomy tube placement performed several days after the primary skull base surgery. This gives our series a wound infection incidence rate of 1.3% and an overall complication incidence rate of 2.63%. CONCLUSIONS: This retrospective review provides the largest series to date evaluating the incidence of infection in HAC cranioplasties. Despite having a much larger series, our complication rate is the lowest published rate of HAC cranioplasty explantation, and the incidence of superficial wound infections reported here is consistent with the published data for neurosurgical and neurotologic procedures.

Adolescent↗
PubMed2004

Gamma knife radiosurgery for acoustic neuromas performed by a neurotologist: early experiences and outcomes.

OBJECTIVE: To assess early outcomes after Gamma knife radiosurgery of acoustic neuromas and other skull base tumors. BACKGROUND: Gamma knife radiosurgery is one of the available methods to treat acoustic neuromas, in addition to micro-surgical resection. Neuro-otologists have long been associated with microsurgical resection of these tumors; however, the application of Gamma knife radiosurgery to the treatment of these tumors by neuro-otologists has not been previously described. SETTING: Acoustic Neuroma and Skull Base Surgery Program / Tertiary Referral Center. STUDY DESIGN/PATIENTS/INTERVENTION: Prospective clinical study of all patients treated by the senior author and our gamma knife team beginning in June 2000. MAIN OUTCOME MEASURES: Preoperative MRI, audiometry, vestibular testing and facial nerve electromyography were completed. At six-month intervals postoperatively, audiometry, caloric testing and MRI were performed to determine thresholds and speech discrimination ability, vestibular function, and the size of the tumor. RESULTS: From June 2000 until March 2004, 38 patients were treated, and these included 33 acoustic neuromas, two meningiomas, one glomus jugulare tumor, and two facial neuromas. Greater than 36 month follow-up was available in 7 patients, > 24 months in 24, > 12 months in 31, and > 6 months in 34 patients. Statistically significant reduction in tumor size was seen over time, and tumor control was achieved in all but two patients. Various patterns of changes in auditory function, both in threshold and speech discrimination were observed in either positive or negative directions. CONCLUSIONS: Preliminary experience with Gamma knife radiosurgery indicates that this treatment method represents another option for neuro-otologists to use in managing patients with skull base tumors.

Follow-Up Studies↗
PubMed2004

Recognition of speech presented at soft to loud levels by adult cochlear implant recipients of three cochlear implant systems.

OBJECTIVE: The purpose of this study was to conduct a large-scale investigation with adult recipients of the Clarion, Med-El, and Nucleus cochlear implant systems to (1) determine average scores and ranges of performance for word and sentence stimuli presented at three intensity levels (70, 60, and 50 dB SPL); (2) provide information on the variability of scores for each subject by obtaining test-retest measures for all test conditions; and (3) further evaluate the potential use of lower speech presentation levels (i.e., 60 and/or 50 dB SPL) in cochlear implant candidacy assessment. DESIGN: Seventy-eight adult cochlear implant recipients, 26 with each of the three cochlear implant systems, participated in the study. To ensure that the data collected reflect the range of performance of adult recipients using recent technology for the three implant systems (Clarion HiFocus I or II, Med-El Combi 40+, Nucleus 24M or 24R), a composite range and distribution of consonant-nucleus-consonant (CNC) monosyllabic word scores was determined. Subjects using each device were selected to closely represent this range and distribution of CNC performance. During test sessions, subjects were administered the Hearing in Noise Test (HINT) sentence test and the CNC word test at three presentation levels (70, 60, and 50 dB SPL). HINT sentences also were administered at 60 dB SPL with a signal-to-noise ratio (SNR) of +8 dB. Warble tones were used to determine sound-field threshold levels from 250 to 4000 Hz. Test-retest measures were obtained for each of the speech recognition tests as well as for warble-tone sound-field thresholds. RESULTS: Cochlear implant recipients using the Clarion, Med-El, or Nucleus devices performed on average equally as well at 60 compared with 70 dB SPL when listening for words and sentences. Additionally, subjects had substantial open-set speech perception performance at the softer level of 50 dB SPL for the same stimuli; however, subjects' ability to understand speech was poorer when listening in noise to signals of greater intensity (60 dB SPL + 8 SNR) than when listening to signals presented at a soft presentation level (50 dB SPL) in quiet. A significant correlation was found between sound-field thresholds and speech recognition scores for presentation levels below 70 dB SPL. The results demonstrated a high test-retest reliability with cochlear implant users for these presentation levels and stimuli. Average sound-field thresholds were between 24 and 29 dB HL for frequencies of 250 to 4000 Hz, and results across sessions were essentially the same. CONCLUSIONS: Speech perception measures used with cochlear implant candidates and recipients should reflect the listening challenges that individuals encounter in natural communication situations. These data provide the basis for recommending new candidacy criteria based on speech recognition tests presented at 60 and/or 50 dB SPL, intensity levels that reflect real-life listening, rather than 70 dB SPL.

Adult↗
PubMed2004

Fungal biofilm formation on cochlear implant hardware after antibiotic-induced fungal overgrowth within the middle ear.

Cochlear implantation in patients with chronic suppurative otitis media is managed with perioperative antibiotics; however, fungal overgrowth can occur. We present a child who received oral cefdinir and topical ofloxacin (Floxin). After 6 weeks, a fungal (Candida) biofilm was demonstrated on the implant surface. In this clinical setting, an antimicrobial strategy using an oral antifungal to prevent fungal overgrowth is a possibility.

Anti-Infective Agents↗
PubMed2004

Electrosurgery after cochlear implantation: eighth nerve electrophysiology.

HYPOTHESIS: Monopolar electrosurgery below the neck in cochlear implant recipients can be performed without damage to the internal cochlear stimulator, electrode array, and the cochlear nerve. STUDY DESIGN: Prospective pre- and postintervention electrically evoked compound action potential (ECAP) study of cochlear nerve function and behavioral sound perception assessment. METHODS: Neural response telemetry (NRT) was used to measure ECAPs before and after the use of monopolar electrosurgery during coronary artery bypass surgery to assess prosthetic device function and electrophysiologic function of the cochlear nerve. In addition, electrode voltage impedances and behavioral sound perception was measured at the same time intervals. RESULTS: ECAPs, behavioral sound perception, and electrode voltage impedances were within the normal range, within compliance, and similar preoperatively and on postoperative day 6. CONCLUSION: The studies reported herein were a series of measurements designed to test neural integrity and prosthetic device function before and after the use of monopolar electrosurgery. With appropriate precautions, use of monopolar electrosurgery below the neck in cochlear implant recipients can be performed safely.

Blood Loss, Surgical↗