Marc L. Bennett

Contemporary management of intracranial complications of otitis media.

Objectives: Intracranial complications as a result of otogenic infections occur even in the antibiotic era. Meningitis is the most common reported intracranial complication, followed by brain abscess and lateral sinus thrombosis. The purpose of this study is to review our experience and management of these serious complications. Materials and Methods: A retrospective chart review was performed at a tertiary referral medical center for the period from 1998 to 2007. Charts with acute or chronic otitis media as primary diagnosis were reviewed, and intracranial complications secondary to either were included in the study. Age, sex, clinical presentation, radiographic findings, management, and outcome were studied. Patients with meningitis or petrous apicitis were not included in the study. Results: Ten cases reviewed had intracranial complications. Five patients had brain abscesses, 1 patient had a subdural empyema, and 4 patients had lateral sinus thrombosis. All patients received broad-spectrum intravenous antibiotics for 6 weeks. Mastoidectomy was performed in all patients, but not all patients were treated with direct drainage of the intracranial abscess, especially if clinical and serial radiographic response was favorable. Conclusion: Otogenic intracranial complications can be fatal if not managed appropriately. Broad-spectrum intravenous antibiotics for 6 weeks is usually sufficient treatment. Management of the intracranial disease takes precedence, but direct drainage of the abscess may not be necessary if a patients symptoms, neurologic status, and radiographic findings progress favorably. A high index of suspicion should be maintained on all patients presenting with symptoms not typically seen with routine otitis media.

Postnatal development of a large auditory nerve terminal: The endbulb of Held in cats

The endbulbs of Held are formed by the ascending branches of myelinated auditory nerve fibers and represent one of the largest synaptic endings in the brain. Most of the developmental changes in structure occur during the first 30 postnatal days of age. The neonatal endbulb begins as a flattened expansion with many filopodia, resembling a growth cone and characterized by numerous puncta adherentia and synapses associated with small postsynaptic densities; the most impressive feature of the ending at this age is its highly irregular plasma membrane that interdigitates with that of the postsynaptic spherical bushy cell. During these first 30 days, the number of puncta adherentia diminishes, postsynaptic densities nearly double in size, intermembraneous cisternae emerge, and plasma membranes flatten. These features endow the endbulb with an adult-like appearance. On the other hand, synaptic vesicle density increases progressively from approximately 50/microm2 at birth to 100/microm2 at adulthood. Mitochondria size remains constant over this developmental period but mitochondrial volume fraction increases until 60 days postnatal. Although many features of endbulb morphology stabilize by 30 days, other features suggest that endbulb development continues into the third month of age. Many of these observations correlate with the maturation of physiological response properties and suggest issues for further study.

Predictive Properties of the Video Head Impulse Test: Measures of Caloric Symmetry and Self-report Dizziness Handicap

Objectives: The purpose of this investigation was to determine whether a predictable relationship existed between self-reported dizziness handicap and video Head Impulse Test (vHIT) results in a large sample of patients reporting to a dizziness clinic. Secondary objectives included describing the characteristics of the vHIT ipsilesional and contralesional vestibulo-ocular reflex slow-phase velocity in patients with varying levels of canal paresis. Finally, the authors calculated the sensitivity and specificity of the vHIT for detecting horizontal semicircular canal impairment using the caloric test as the “gold standard.” Design: Participants were 115 adults presenting to a tertiary medical care center with symptoms of dizziness. Participants were administered a measure of self-report dizziness handicap (i.e., Dizziness Handicap Inventory) and underwent caloric testing and vHIT at the same appointment. Results: Results showed that (1) there were no significant group differences (i.e., vHIT normal versus vHIT abnormal) in the Dizziness Handicap Inventory total score, (2) both ipsilesional and contralateral velocity gain decreased with increases in caloric paresis, and (3) a caloric asymmetry of 39.5% was determined to be the cutoff that maximized discrimination of vHIT outcome. Conclusions: The level of self-reported dizziness handicap is not predicted by the outcome of the vHIT, which is consistent with the majority of published reports describing the poor relationship between quantitative tests of vestibular function and dizziness handicap. Further, the study findings have demonstrated that vHIT and caloric data are not redundant, and each test provides unique information regarding the functional integrity of the horizontal semicircular canal at different points on the frequency spectrum. The vHIT does offer some advantages over caloric testing, but at the expense of sensitivity. The vHIT can be completed in less time, is not noxious to the patient, and requires very little laboratory space. However, the study data show that a caloric asymmetry of 39.5% is required to optimize discrimination between an abnormal and normal vHIT. It is the authors’ contention that the vHIT is a complementary test to the balance function examination and should viewed as such rather than as a replacement for caloric testing.

Postoperative imaging of vestibular schwannomas

Objectives Assess the need for serial magnetic resonance imaging after vestibular schwannoma surgery. Study Design Retrospective case review. Subjects and Methods Study included all patients who underwent vestibular neuromas surgery over a five-year period from 1996 to 2000 at a single tertiary referral center. Analysis of tumor recurrence and correlation with enhancement types on postoperative imaging was performed. Results During the five-year period, 359 cerebellopontine angle tumors were removed. The 299 patients had MRI imaging at one and five years for analysis and a five-year follow-up examination. Of these patients, 284 were found to have no enhancement at both one and five years. Linear enhancement was seen in ten patients but did not enlarge in any patient. Nodular enhancement of the internal auditory canal was observed in three patients. Two patients with nodular enhancement had tumor recurrence. Conclusions Complete vestibular schwannoma resection has a low recurrence rate. Initial imaging should be performed at one year. Only patients with enhancement, subtotal resections, or neurofibromatosis type II need serial imaging.

Novel use of electronic whiteboard in the operating room increases surgical team compliance with pre-incision safety practices

BACKGROUND Despite evidence that use of a checklist during the pre-incision time out improves patient morbidity and mortality, compliance with performing the required elements of the checklist has been low. In an effort to improve compliance, a standardized time out interactive Electronic Checklist System [iECS] was implemented in all hospital operating room (OR) suites at 1 institution. The purpose of this 12-month prospective observational study was to assess whether an iECS in the OR improves and sustains improved surgical team compliance with the pre-incision time out. METHODS Direct observational analyses of preprocedural time outs were performed on 80 cases 1 month before, and 1 and 9 months after implementation of the iECS, for a total of 240 observed cases. Three observers, who achieved high interrater reliability (kappa = 0.83), recorded a compliance score (yes, 1; no, 0) on each element of the time out. An element was scored as compliant if it was clearly verbalized by the surgical team. RESULTS Pre-intervention observations indicated that surgical staff verbally communicated the core elements of the time out procedure 49.7 ± 12.9% of the time. After implementation of the iECS, direct observation of 80 surgical cases at 1 and 9 months indicated that surgical staff verbally communicated the core elements of the time out procedure 81.6 ± 11.4% and 85.8 ± 6.8% of the time, respectively, resulting in a statistically significant (P < .0001) increase in time out procedural compliance. CONCLUSION Implementation of a standardized, iECS can dramatically increase compliance with preprocedural time outs in the OR, an important and necessary step in improving patient outcomes and reducing preventable complications and deaths.

Facial nerve outcomes in facial nerve schwannomas.

Objective To better understand the characteristics and outcomes of facial nerve schwannomas (FNSs) over a 30-year period. Study Design Retrospective study. Setting Subspecialty practice at a tertiary hospital. Patients Fifty-six patients diagnosed with FNS over a 30-year period. Methods Preoperative data (audiologic data, facial nerve [FN] function, and patient symptoms), intraoperative data (tumor location, total versus subtotal resection, and FN status), and postoperative data (audiologic data, FN function, and recurrence) were collected. Mann-Whitney and &khgr;2 analyses were done to determine which factors correlated with poor FN outcomes (defined as House-Brackmann ≥4). Results Of the 56 patients in this study, 53 (94.6%) underwent surgical resection of their FNS. Of those patients, 45 (84.9%) underwent total resection, and 8 (15.1%) underwent subtotal resection. Subtotal resection was associated with a statistically significant decreased risk of having postoperative HB grade ≥4 (odds ratio, 0.09; 95% confidence interval, 0.01–0.77; p = 0.028). Of those undergoing a subtotal resection, no patient had further tumor growth seen on postoperative magnetic resonance imaging (average time of last magnetic resonance imaging since operation, 44.9 mo). Tumor location was not statistically associated with poor FN outcome (all p > 0.05). Preoperative FN paralysis was the only preoperative clinical finding statistically associated with poor FN outcomes (p = 0.004). Conclusion We have identified multiple characteristics of FNS as well as multiple factors associated with increased statistical risk of poor FN outcomes.

Management of cerebrospinal fluid leaks after vestibular schwannoma surgery.

Objective To evaluate the incidence and treatment of cerebrospinal fluid (CSF) leaks after resection of vestibular schwannomas and to propose a treatment algorithm for their management. Study Design Retrospective chart review. Setting Tertiary referral center. Patients Review of 1,922 subjects who underwent resection of vestibular schwannomas from 1970 to 2010. Intervention Surgical resection of vestibular schwannoma. Main Outcome Measures Patient demographics, surgical approach used, CSF leak incidence, meningitis, treatment, and success in the management of CSF leaks. Results Postoperative CSF leaks were observed in 12.9% of our patients. There was no significant difference between the type of approach and the presence of CSF leak with translabyrinthine, suboccipital and middle fossa CSF leak rates of 12%, 12%, and 13%, respectively (p = 0.07). Patients presented with a wound leak or rhinorrhea almost equally. Ultimately, 92% of patients with rhinorrhea underwent surgical intervention. The probability of a patient with rhinorrhea requiring a second intervention was higher when the initial intervention was conservative rather than surgical. However, the probability of a patient with a wound leak requiring a second intervention was essentially the same when initially treated conservatively or surgically. Conclusion Our data suggests that there is no difference in CSF leak rates between the different surgical approaches. The appropriate treatment strategy is dependent on the presentation of the CSF. Although conservative treatment is effective for managing wound leaks, it is less effective in managing patients with rhinorrhea. Therefore, surgical treatments should play an early role in the treatment algorithm of patients with CSF rhinorrhea.

Congenital cholesteatoma of the mastoid temporal bone.

Objective: Congenital mastoid cholesteatomas are rare lesions of the temporal bone. The clinical presentation of these lesions is variable, making them difficult to identify preoperatively. We evaluated our series of mastoid congenital cholesteatomas (CCs) in an effort to better define the clinical presentation, imaging characteristics, and surgical challenges specific to this lesion.

Comparison of Middle Ear Visualization With Endoscopy and Microscopy.

Introduction: The primary goal of chronic ear surgery is the creation of a safe, clean dry ear. For cholesteatomas, complete removal of disease is dependent on visualization. Conventional microscopy is adequate for most dissection, but various subregions of the middle ear are better visualized with endoscopy. Objective: The purpose of the present study was to quantitatively assess the improved visualization that endoscopes afford as compared with operating microscopes. Methods: Microscopic and endoscopic views were simulated using a three-dimensional model developed from temporal bone scans. Surface renderings of the ear canal and middle ear subsegments were defined and the percentage of visualization of each middle ear subsegment, both with and without ossicles, was then determined for the microscope as well as for 0-, 30-, and 45-degree endoscopes. Using this information, we analyzed which mode of visualization is best suited for dissection within a particular anatomical region. Results: Using a 0-degree scope provides significantly more visualization of every subregion, except the antrum, compared with a microscope. In addition, angled scopes permit visualizing significantly more surface area of every subregion of the middle ear than straight scopes or microscopes. Conclusions: Endoscopes offer advantages for cholesteatoma dissection in difficult-to-visualize areas including the sinus tympani and epitympanum.

Subtotal Resection for Management of Large Jugular Paragangliomas with Functional Lower Cranial Nerves

Objectives To evaluate tumor control following subtotal resection of advanced jugular paragangliomas in patients with functional lower cranial nerves and to investigate the utility of salvage radiotherapy for residual progressive disease. Study Design Case series with planned chart review. Setting Tertiary academic referral center. Subjects and Methods Patients who presented with advanced jugular paragangliomas and functional lower cranial nerves were analyzed. Primary outcome measures included extent of resection, long-term tumor control, need for additional treatment, and postoperative lower cranial nerve function. Results Twelve patients (mean age, 46.2 years; 7 women, 58.3%) who met inclusion criteria were evaluated between 1999 and 2013. The mean postoperative residual tumor volume was 27.7% (range, 3.5%-75.0%) of the preoperative volume. When the residual tumor volume was less than 20% of the preoperative volume, no tumor growth occurred over an average of 44.6 months of follow-up (P < .01). Four tumors (33.3%) demonstrated serial growth at a mean of 23.5 months following resection, 2 of which were treated with salvage stereotactic radiotherapy providing control through the last recorded follow-up. No patient experienced permanent postoperative lower cranial neuropathy as a result of surgery. Conclusion Subtotal resection of jugular paragangliomas with preservation of the lower cranial nerves is a viable management strategy. If more than 80% of the preoperative tumor volume is resected, the residual tumor seems less likely to grow.