Fibrin Glue-Coated Collagen Complex Patch: A Novel Material for Surgical Repair of Spontaneous Temporal Bone Cerebrospinal Fluid Leak and Encephalocele.

OBJECTIVE: To compare outcomes of surgical repair of temporal bone encephalocele and cerebrospinal fluid (CSF) leak using fibrin glue-coated collagen (FGCC) complex patch versus other materials for repair of dura. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care hospital. PATIENTS: Fifty-two adult patients undergoing transmastoid (TM), middle fossa (MF) or combined approach repair of spontaneous MF CSF leak between 2016 and 2020. INTERVENTIONS: Exposure of bony defect via TM approach, MF craniotomy, or combined TM/MF, and repair of the associated dura defect with FGCC complex patch, or other materials (acellular collagen matrix, bovine collagen, autologous fascia, fibrin tissue sealant). MAIN OUTCOME MEASURES: Successful repair without recurrent CSF leak or encephalocele throughout follow-up. Cost of materials used in duraplasty. RESULTS: Sixty-four percent of patients were female. Mean (standard deviation) age at repair was 61.4 (12.1) years. Mean (standard deviation) body mass index was 35.0 (8.3) kg/m 2 . Forty-nine (94%) patients had successful repair without known recurrence of CSF leak or encephalocele over a median follow-up interval of 11.7 months. Average duraplasty material cost was significantly lower with FGCC in comparison with other nonautologous materials (FGCC+: $1259.94, FGCC-: $1652.58; p = 0.004). No significant differences in recurrence risk (FGCC+: 6.9%, FGCC-: 6.9%; p > 0.999) or operative time (FGCC+: 153.7 min, FGCC-: 155.4 min; p = 0.88) were detected based on material used for duraplasty. CONCLUSIONS: All materials studied demonstrate effective and sustained means of repair for MF CSF leak and encephalocele, including in the presence of multiple defects. Use of FGCC for duraplasty produces noninferior surgical results to other nonautologous materials in repair of spontaneous CSF leaks of the temporal bone and may be more cost-effective.

Outcomes of Mastoidectomy With Antibiotic Catheter Irrigation for Patients With Draining Ventilation Tubes.

OBJECTIVES: To evaluate the effectiveness of mastoidectomy with antibiotic catheter irrigation in patients with chronic tympanostomy tube otorrhea. METHODS: A chart review of adult and pediatric patients with persistent tympanostomy tube otorrhea who had failed outpatient medical management and underwent mastoidectomy with placement of a temporary indwelling catheter for antibiotic instillation was performed. Patients were retrospectively followed for recurrent drainage after 2 months and outcomes were categorized as resolution (0-1 episodes of otorrhea or otitis media with effusion during follow-up), improvement (2-3 episodes), or continued episodic (>3 episodes). RESULTS: There were 22 patients and 23 operated ears. Median age was 46 years (interquartile range, IQR = 29-65). The median duration of otorrhea from referral was 5.5 months (IQR = 2.8-12). Following surgery, 14 ears had resolution of drainage, 6 had improvement, and 3 had episodic. The observed percentage of resolved/improved ears (87%) was significant (P = .0005, 95% CI = 67.9%-95.5%). Median follow-up time was 25 months (IQR = 12-59). Pre and postoperative pure tone averages improved (difference of medians = -3.3 dB, P = .02) with no significant difference in word recognition scores (P = .68). Methicillin-resistant Staphylococcus aureus was the most common isolated microbe while no growth was most frequently noted on intraoperative cultures. CONCLUSIONS: Mastoidectomy with antibiotic catheter irrigation may be an effective surgical strategy, and single stage alternative to intravenous antibiotics, for select patients with persistent tube otorrhea who have failed topical and oral antibiotics.

A Deep Learning Model for Automated Classification of Intraoperative Continuous EMG.

OBJECTIVE: Intraoperative neurophysiological monitoring (IONM) is the use of electrophysiological methods during certain high-risk surgeries to assess the functional integrity of nerves in real time and alert the surgeon to prevent damage. However, the efficiency of IONM in current practice is limited by latency of verbal communications, inter-rater variability, and the subjective manner in which electrophysiological signals are described. METHODS: In an attempt to address these shortcomings, we investigate automated classification of free-running electromyogram (EMG) waveforms during IONM. We propose a hybrid model with a convolutional neural network (CNN) component and a long short-term memory (LSTM) component to better capture complicated EMG patterns under conditions of both electrical noise and movement artifacts. Moreover, a preprocessing pipeline based on data normalization is used to handle classification of data from multiple subjects. To investigate model robustness, we also analyze models under different methods for processing of artifacts. RESULTS: Compared with several benchmark modeling methods, CNN-LSTM performs best in classification, achieving accuracy of 89.54% and sensitivity of 94.23% in cross-patient evaluation. CONCLUSION: The CNN-LSTM model shows promise for automated classification of continuous EMG in IONM. SIGNIFICANCE: This technique has potential to improve surgical safety by reducing cognitive load and inter-rater variability.

The Role of Mastoidectomy in Draining Ventilation Tubes.

OBJECTIVES: To discuss the indication for performing a mastoidectomy with catheter placement in patients with chronic tympanostomy tube otorrhea. METHODS: The Medical Literature Analysis and Retrieval System Online was searched via PubMed for relevant articles using serous mastoiditis, mastoidectomy, chronic otorrhea, tube otorrhea, tympanostomy tubes, and biofilm as keywords. RESULTS: Further understanding of the pathophysiology of otorrhea and the development of ototopical fluoroquinolones have made a draining tympanostomy tube more manageable. Nevertheless, chronic otorrhea refractory to an otolaryngologist's traditional treatment algorithm still occurs and may benefit from a mastoidectomy with antibiotic irrigation using a catheter in certain cases. We theorize that resolution of otorrhea results from this technique by decreasing the burden of diseased mucosa and providing a larger concentration or dose of antibiotic to the middle ear cleft through the antrum. High-resolution images of the technique and catheter placement are included in this review. CONCLUSIONS: Despite being an uncommon management strategy, the literature suggests an indication for performing a mastoidectomy in a small percentage of patients with a chronically draining tympanostomy tube.

Deletion of genes involved in the ketogluconate metabolism, Entner-Doudoroff pathway, and glucose dehydrogenase increase local and invasive virulence phenotypes in Streptococcus pneumoniae.

Streptococcus pneumoniae displays increased resistance to antibiotic therapy following biofilm formation. A genome-wide search revealed that SP 0320 and SP 0675 (respectively annotated as 5-keto-D-gluconate-5-reductase and glucose dehydrogenase) contain the highest degree of homology to CsgA of Myxococcus xanthus, a signaling factor that promotes cell aggregation and biofilm formation. Single and double SP 0320 and SP 0675 knockout mutants were created in strain BS72; however, no differences were observed in the biofilm-forming phenotypes of mutants compared to the wild type strain. Using the chinchilla model of otitis media and invasive disease, all three mutants exhibited greatly increased virulence compared to the wild type strain (increased pus formation, tympanic membrane rupture, mortality rates). The SP 0320 gene is located in an operon with SP 0317, SP 0318 and SP 0319, which we bioinformatically annotated as being part of the Entner-Doudoroff pathway. Deletion of SP 0317 also resulted in increased mortality in chinchillas; however, mutations in SP 0318 and SP 0319 did not alter the virulence of bacteria compared to the wild type strain. Complementing the SP 0317, SP 0320 and SP 0675 mutant strains reversed the virulence phenotype. We prepared recombinant SP 0317, SP 0318, SP 0320 and SP 0675 proteins and confirmed their functions. These data reveal that disruption of genes involved in the degradation of ketogluconate, the Entner-Doudoroff pathway, and glucose dehydrogenase significantly increase the virulence of bacteria in vivo; two hypothetical models involving virulence triggered by reduced in carbon-flux through the glycolytic pathways are presented.

Long-term outcomes of cartilage-buttressed T-tube tympanoplasty for prolonged middle ear ventilation.

OBJECTIVES/HYPOTHESIS: To report on the safety and efficacy of cartilage-buttressed T-tube tympanoplasty for long-term middle ear ventilation, specifically by examining duration of tube survival, as well as adverse events associated with prolonged middle ear intubation, including persistent tympanic membrane perforation. STUDY DESIGN: Retrospective case series of patients undergoing cartilage-buttressed T-tube tympanoplasty between January 2005 and December 2016 in a tertiary-care neurotology private practice. METHODS: Patients who underwent cartilage T-tube tympanoplasty with complete pre- and postoperative audiometric data and a minimum follow-up duration of 12 months were analyzed. T-tube survival and adverse events including persistent tympanic membrane perforation were recorded and compared to published data for other long-term middle ear ventilation techniques. RESULTS: The study cohort included 72 cartilage-buttressed T-tube tympanoplasties in 68 patients. Median tube survival was 34 months (range, 2-131 months). Incidence of persistent tympanic membrane perforation (n = 1) was 1.4% CONCLUSIONS: Cartilage-buttressed T-tube tympanoplasty is a safe and effective means of accomplishing long-term middle ear ventilation with a considerably lower rate of persistent tympanic membrane perforation as compared to alternative methods of prolonged middle ear ventilation. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:203-208, 2019.

Promiscuous signaling by a regulatory system unique to the pandemic PMEN1 pneumococcal lineage.

Streptococcus pneumoniae (pneumococcus) is a leading cause of death and disease in children and elderly. Genetic variability among isolates from this species is high. These differences, often the product of gene loss or gene acquisition via horizontal gene transfer, can endow strains with new molecular pathways, diverse phenotypes, and ecological advantages. PMEN1 is a widespread and multidrug-resistant pneumococcal lineage. Using comparative genomics we have determined that a regulator-peptide signal transduction system, TprA2/PhrA2, was acquired by a PMEN1 ancestor and is encoded by the vast majority of strains in this lineage. We show that TprA2 is a negative regulator of a PMEN1-specific gene encoding a lanthionine-containing peptide (lcpA). The activity of TprA2 is modulated by its cognate peptide, PhrA2. Expression of phrA2 is density-dependent and its C-terminus relieves TprA2-mediated inhibition leading to expression of lcpA. In the pneumococcal mouse model with intranasal inoculation, TprA2 had no effect on nasopharyngeal colonization but was associated with decreased lung disease via its control of lcpA levels. Furthermore, the TprA2/PhrA2 system has integrated into the pneumococcal regulatory circuitry, as PhrA2 activates TprA/PhrA, a second regulator-peptide signal transduction system widespread among pneumococci. Extracellular PhrA2 can release TprA-mediated inhibition, activating expression of TprA-repressed genes in both PMEN1 cells as well as another pneumococcal lineage. Acquisition of TprA2/PhrA2 has provided PMEN1 isolates with a mechanism to promote commensalism over dissemination and control inter-strain gene regulation.

Hydroxyapatite cement cranioplasty following translabyrinthine approach: Long-term study of 369 cases.

OBJECTIVE: To report the authors' experience with hydroxyapatite cement (HAC) cranioplasty and analyze the material's long-term safety and efficacy in repairing translabyrinthine skull-base defects by examining adverse events, specifically cerebrospinal fluid (CSF) leaks and surgical site infections. STUDY DESIGN: Retrospective case-control study (primary study arm); prospective cross-sectional study of patients not examined within the last 5 years (secondary arm). SETTING: tertiary-care neurotology private practice and academic practice (two centers). METHODS: Hydroxyapatite cement implanted following translabyrinthine approach, with or without fat graft, was included. Combined approaches were excluded. Implant-associated adverse events were defined as 1) CSF leaks requiring reoperation or spinal drainage, and (2) infections requiring reoperation. Patients not examined within 5 years were interviewed by telephone to update their condition. Incidence of adverse events was compared to published data for translabyrinthine cranioplasty using fat graft alone. Implant survival analysis was performed. RESULTS: The study cohort included 369 HAC implants in the same number of patients. There were seven CSF leaks and seven infections. Combined (n = 14) incidence of adverse events was 3.8% (2.09%, 6.28%). Compared to fat graft alone, the adverse events associated with HAC were fewer (P < 0.001). Up to 15 years (5,475 days), HAC cement maintained 95% adverse event-free survival. There were no cases of meningitis. CONCLUSION: Cranioplasty using HAC with autologous fat following translabyrinthine skull-base surgery is safer and more effective than fat graft alone, up to 15 years after surgery. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2120-2125, 2017.

Fungal skull base osteomyelitis: Emerging microbial identification techniques.

Culture-based pathogen identification in skull base osteomyelitis, particularly for fungi, is often inaccurate. We report the case of patient with fungal skull base osteomyelitis cured by sustained antifungal therapy after 16 months of debilitating illness. Due to medical complications, a strong clinical rationale was needed to justify long-term antifungal therapy. The offending fungus was identified by experimental molecular technology (Ibis T5000 universal biosensor); invasive fungal disease was corroborated by biochemical assays. Our discussion will help familiarize the otolaryngologist with existing biochemical and molecular diagnostics for invasive fungal disease. We encourage future investigators to study their application in cases of skull base osteomyelitis. Laryngoscope, 127:E5-E7, 2017.

Identification and Characterization of msf, a Novel Virulence Factor in Haemophilus influenzae.

Haemophilus influenzae is an opportunistic pathogen. The emergence of virulent, non-typeable strains (NTHi) emphasizes the importance of developing new interventional targets. We screened the NTHi supragenome for genes encoding surface-exposed proteins suggestive of immune evasion, identifying a large family containing Sel1-like repeats (SLRs). Clustering identified ten SLR-containing gene subfamilies, each with various numbers of SLRs per gene. Individual strains also had varying numbers of SLR-containing genes from one or more of the subfamilies. Statistical genetic analyses of gene possession among 210 NTHi strains typed as either disease or carriage found a significant association between possession of the SlrVA subfamily (which we have termed, macrophage survival factor, msf) and the disease isolates. The PittII strain contains four chromosomally contiguous msf genes. Deleting all four of these genes (msfA1-4) (KO) resulted in a highly significant decrease in phagocytosis and survival in macrophages; which was fully complemented by a single copy of the msfA1 gene. Using the chinchilla model of otitis media and invasive disease, the KO strain displayed a significant decrease in fitness compared to the WT in co-infections; and in single infections, the KO lost its ability to invade the brain. The singly complemented strain showed only a partial ability to compete with the WT suggesting gene dosage is important in vivo. The transcriptional profiles of the KO and WT in planktonic growth were compared using the NTHi supragenome array, which revealed highly significant changes in the expression of operons involved in virulence and anaerobiosis. These findings demonstrate that the msfA1-4 genes are virulence factors for phagocytosis, persistence, and trafficking to non-mucosal sites.

Vibrant Soundbridge rehabilitation of sensorineural hearing loss.

The Vibrant Soundbridge is a means to rehabilitate patients with sensorineural hearing loss. It differs from hearing aids in that it uses mechanical energy rather than acoustic sound to deliver better sound quality to the inner ear. The implant's crucial component is a floating mass transducer that is directly fixed to the incus to drive it, which is introduced into the middle ear through a facial recess approach. Although this is a newer technology, studies thus far have demonstrated better hearing results compared with hearing aids in terms of functional gain and speech intelligibility, and better outcomes on subjective assessments.

Round window stimulation for conductive and mixed hearing loss.

OBJECTIVE: Assess surgical complications, postoperative residual hearing, and speech perception outcomes of placement of a middle ear implant on the round window in conductive and mixed hearing loss cases. STUDY DESIGN: Single-subject, repeated-measures design where each subject served as his or her own control. SETTING: Tertiary referral medical systems. SUBJECTS: Eighteen subjects with either conductive or mixed hearing loss who could not benefit from conventional amplification were enrolled in a clinical trial investigating vibratory stimulation of the round window. INTERVENTION: The floating mass transducer (FMT) was positioned in the round window niche. MAIN OUTCOME MEASURES: Unaided residual hearing, and aided sound field thresholds and speech perception abilities were evaluated preoperatively, and at 1, 3, 6, and 10 months post-activation of the external speech processor. RESULTS: Six subjects experienced complications that either required further medical management or resolved on their own. There was no difference in residual bone conduction thresholds or unaided word discrimination over time. All subjects experienced a significant improvement in aided speech perception abilities as compared to preoperative performance. CONCLUSION: Subjects with conductive and mixed hearing loss with placement of the FMT in the round window niche experienced improved sound field thresholds and speech perception, without compromising residual hearing thresholds. Vibratory stimulation of the round window via a middle ear implant may be an appropriate treatment option for patients with conductive and mixed hearing loss. Additional research is needed on the preferred placement of the FMT, improvement of functional gain, and methods to limit postoperative complications and need for revision surgery.

Association of benign intracranial hypertension and spontaneous encephalocele with cerebrospinal fluid leak.

OBJECTIVE: To determine the incidence of intracranial hypertension in patients with spontaneous encephalocele with cerebrospinal fluid (CSF) leak. STUDY DESIGN: Retrospective case review. SETTING: Tertiary care neurotology practice. PATIENTS: Patients presenting between 2008 and 2011 with spontaneous encephalocele and CSF leak in the temporal bone. INTERVENTION(S): Lumbar puncture with opening pressure measurement after encephalocele repair. MAIN OUTCOME MEASURES: Patient age, sex, postoperative course, body mass index, and postoperative intracranial pressure. RESULTS: Of the 26 patients identified with spontaneous encephalocele with CSF leak, 9 patients had postoperative lumbar puncture data. Of those 9, 89% were female subjects, and 11% were male, with a mean age of 57 and a mean BMI of 41 kg/m (morbidly obese). The mean opening pressure was 24.5 cm H(2)O. Approximately 33% had normal intracranial pressure (mean, 15 cm H(2)O; range, 10-17 cm H(2)O); 67% had elevated intracranial pressure (mean, 29 cm H(2)O; range, 23.5-40 cm H(2)O). The incidence of BIH in the general population is 0.001%. Of the 6 with intracranial hypertension, 3 (50%) were placed on acetazolamide for fundoscopic findings, postoperative headache, and/or visual changes. Mean time to LP after repair of encephalocele was 13 months (range, 4 days to 75 months). CONCLUSION: This study shows that benign intracranial hypertension is prevalent in a significant number of patients presenting with spontaneous encephalocele with CSF otorrhea at a rate much higher than is found in the general population. This finding has direct clinical implications and suggests that all patients with spontaneous encephalocele/CSF leak warrant evaluation for benign intracranial hypertension.

In vivo capsular switch in Streptococcus pneumoniae--analysis by whole genome sequencing.

Two multidrug resistant strains of Streptococcus pneumoniae - SV35-T23 (capsular type 23F) and SV36-T3 (capsular type 3) were recovered from the nasopharynx of two adult patients during an outbreak of pneumococcal disease in a New York hospital in 1996. Both strains belonged to the pandemic lineage PMEN1 but they differed strikingly in virulence when tested in the mouse model of IP infection: as few as 1000 CFU of SV36 killed all mice within 24 hours after inoculation while SV35-T23 was avirulent.Whole genome sequencing (WGS) of the two isolates was performed (i) to test if these two isolates belonging to the same clonal type and recovered from an identical epidemiological scenario only differed in their capsular genes? and (ii) to test if the vast difference in virulence between the strains was mostly - or exclusively - due to the type III capsule. WGS demonstrated extensive differences between the two isolates including over 2500 single nucleotide polymorphisms in core genes and also differences in 36 genetic determinants: 25 of which were unique to SV35-T23 and 11 unique to strain SV36-T3. Nineteen of these differences were capsular genes and 9 bacteriocin genes.Using genetic transformation in the laboratory, the capsular region of SV35-T23 was replaced by the type 3 capsular genes from SV36-T3 to generate the recombinant SV35-T3* which was as virulent as the parental strain SV36-T3* in the murine model and the type 3 capsule was the major virulence factor in the chinchilla model as well. On the other hand, a careful comparison of strains SV36-T3 and the laboratory constructed SV35-T3* in the chinchilla model suggested that some additional determinants present in SV36 but not in the laboratory recombinant may also contribute to the progression of middle ear disease. The nature of this determinants remains to be identified.

Differences in genotype and virulence among four multidrug-resistant Streptococcus pneumoniae isolates belonging to the PMEN1 clone.

We report on the comparative genomics and characterization of the virulence phenotypes of four S. pneumoniae strains that belong to the multidrug resistant clone PMEN1 (Spain(23F) ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinants.

Resorbable plate cranioplasty after the translabyrinthine approach.

OBJECTIVE: To determine the safety of resorbable plate cranioplasty after translabyrinthine cerebellopontine angle tumor excision and to determine efficacy of this technique in the reduction of cerebrospinal fluid (CSF) leaks compared with fat grafting alone. STUDY DESIGN: Prospective clinical trial with matched, historic case controls. SETTING: University tertiary referral center. PATIENTS: Seventy-one patients with tumors of the cerebellopontine angle undergoing a translabyrinthine approach had the temporal bone defect repaired by a fat graft secured with a resorbable fixation plate. This cranioplasty technique was designed to improve pressure on the fat graft to block the egress of CSF. Historic controls included 149 consecutive patients undergoing a translabyrinthine approach who were closed with fat cranioplasty only. INTERVENTION: Resorbable plate cranioplasty versus fat graft cranioplasty. MAIN OUTCOME MEASURES: Wound complication rate, incidence of postoperative CSF leak, treatment required, and length of hospitalization. RESULTS: There were no surgical site infections in either group. The incidence of postoperative CSF leak was 12.7% (9/71) in the study group and 13.4% (20/149) in the controls (p = 0.88). There was no significant difference in the rate of lumbar drain placement or surgical revision requirement between the groups. There were no short- or long-term complications attributable to the placement of the plate, and additional operative time for the procedure averaged 7 minutes. CONCLUSION: Cranioplasty with a resorbable plate after translabyrinthine craniotomy is safe. This technique results in a CSF leak rate equivalent to fat grafting alone.

Patterns of failure in heat-activated crimping prosthesis in stapedotomy.

OBJECTIVE: To understand potential causes of failure in heat-activated crimping prosthesis in stapedotomy. STUDY DESIGN: Retrospective chart review of all primary and subsequent revision stapedotomy operations performed by the senior authors with heat-activated-crimping prosthesis between June 2003 and September 2009. Patients who had history of previous stapedotomy performed elsewhere were excluded. SETTING: Private neurotologic tertiary referral center. PATIENTS: The 335 primary stapedotomies reviewed included 190 with a SMart prosthesis and 145 with a manual-crimp De La Cruz prothesis. Twenty-one patients in the SMart prosthesis group underwent revision stapedotomy. Six patients in the De La Cruz prosthesis group underwent revision stapedotomy. Average length of time between initial and revision surgery for each prosthetic group was 16.5 months and 11 months, respectively. INTERVENTION: Primary and revision stapedotomy using heat-activated nitinol (SMart) or manual crimp-on platinum (De La Cruz) prosthesis. RESULTS: A total of 190 primary stapedotomies using heat-activated crimping prosthesis were performed between this period. There were 21 patients who had initial good hearing results that required revision or replacement with a different type of prosthesis. A common finding was lateral displacement of the prosthesis from the stapedotomy with detachment of the nitinol hook from the incus. This group of patients was compared with a control group that used manual-crimp prosthesis. CONCLUSION: Heat-activated crimping prosthesis has been reported to enhance stapedotomy hearing outcomes on short- and long-term follow-up studies. Longitudinal analysis on its complications has not been reported. This case series demonstrated 11% rate of possible lateral displacement of the prosthesis out of the vestibule and/or incus. Reopening of the nitinol hook off the incus also was a common associated finding. Failure rates are classified. The advantages and disadvantages of this popular prosthesis are reviewed.

Audiometric outcomes for acoustic neuroma patients after single versus multiple fraction stereotactic irradiation.

OBJECTIVE: To compare tumor control and changes in audiometric parameters of acoustic neuroma patients treated with either linac-based stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) at Allegheny General Hospital. STUDY DESIGN: Twenty-three patients with acoustic neuroma were treated between February 2003 and April 2009 with either SRS (n = 13) or SRT (n = 10). The median age for all patients was 69 years and the median size of lesions was 1.2 cm (range 0.5-2.2 cm). The prescribed dose was a single dose of 1250 cGy for all SRS patients compared to 2500 cGy in 5 daily fractions for SRT patients. All patients had pre- and post-procedure audiometry including hearing acuity assessed using pure tone average (PTA), speech discrimination score (SDS), and speech reception threshold (SR). The results of treatment type and tumor variables resulting in hearing degradation were evaluated and compared. RESULTS: At a median follow-up of 13 months (range 3-36 months), only 1 of 13 patients treated with SRS and 2 of 10 patients treated with SRT develped progression of disease. However; all patients developed deterioration in PTA, SDS, or SR on the treated side. There were no statistically significant audiometric differences between patients treated with SRT or SRS and tumor response was similar regardless of irradiation technique. CONCLUSION: Both SRS and SRT provide excellent local control rates for the treatment of acoustic neuroma. While SRS demonstrated a trend toward worsening of SDS and the treatment of lesions >1.2 cm demonstrated a trend toward worsening of PTA, neither reached statistical significance. Our data suggest that single dose irradiation using the SRS technique should be considered primarily for patient convenience. All patients treated with radiotherapy for acoustic neuromas should undergo formal hearing testing before and after treatment.

Acoustic tumor observation and failure to follow-up.

OBJECTIVE: To review the clinical course of patients undergoing observation for their acoustic tumor with evaluation of the incidence and contributing variables to failure to follow-up. STUDY DESIGN: Case series with chart review and telephone interview. SETTING: Single subspecialty practice. SUBJECTS AND METHODS: One hundred twenty-two patients underwent an observation period after their unilateral acoustic tumor was diagnosed. Follow-up patterns were noted and multiple patient variables were analyzed to determine risk factors that contributed to risk of failing to keep prescribed follow-up. Telephone interviews and/or public record reviews were conducted to determine the reasons for failing to follow-up. RESULTS: Fifty-two (42.6%) patients failed to keep prescribed follow-up. No preoperative patient or tumor variables were correlated with the risk of failure to follow-up. The investigators were able to contact and interview 20 patients to determine reasons for not keeping follow-up. Of these patients, nine (45%) electively chose not to follow-up, six (30%) did not appear to have a clear understanding of their diagnosis or treatment options despite adequate counseling, and five (25%) had medical problems that took precedence over the acoustic tumor. Very few patients elected to reschedule follow-up even after contact was made. CONCLUSION: Failure to follow-up is a serious problem with acoustic tumor observation protocols. It is difficult to detect which patients are at risk for noncompliance. Patient noncompliance with observation protocols should be considered when determining the most appropriate treatment for each acoustic tumor patient.

Facial nerve function and hearing preservation acoustic tumor surgery: does the approach matter?

OBJECTIVE: The retrosigmoid and middle fossa approaches to acoustic tumor excision allow for hearing preservation but differ in the angle of approach to the facial nerve. The authors comparatively examined facial nerve results of each approach. STUDY DESIGN: Case series with chart review. SETTING: Multiple physician subspecialty practice. SUBJECTS AND METHODS: The authors reviewed facial nerve outcomes of patients undergoing acoustic tumor excision at a single subspecialty practice that had used a hearing preservation approach for the past 15 years. The retrosigmoid and middle fossa approaches were compared. Hearing results and recurrence rates were also examined. RESULTS: One hundred thirty-eight patients had adequate data for inclusion in this study. Of the patients undergoing a middle fossa approach, 80 percent had a House-Brackmann (HB) grade I-II outcome, whereas 90 percent of patients undergoing the retrosigmoid approach had an HB grade I-II. When classifying HB I and II outcomes together, we did not find a statistically different result between the surgical groups. Upon more critical analysis, however, facial function recovered faster and there were more long-term HB grade I function results in the retrosigmoid group. There were more recurrent/residual tumors in the retrosigmoid group and better hearing preservation in the middle fossa group. CONCLUSION: There are small but important functional outcome differences between the retrosigmoid and middle fossa approach for acoustic tumors. The clinician needs a working understanding of these differences so that the correct approach can be used to produce the best results for each patient.