Faculty Bibliography

Objective: Facial nerve paralysis or compromise can be caused by lesions of the temporal bone and cerebellopontine angle and their treatment. When the facial nerve is transected or severely compromised and primary end-to-end repair is not possible, hypoglossal-facial nerve anastomosis remains the most popular method for accomplishing three main goals: restoring facial tone, restoring facial symmetry, and facilitating return of voluntary facial movement. Our objectives are to evaluate the surgical feasibility and long-term outcomes of our technique of direct facial-to-hypoglossal neurorrhaphy with a parotid-release maneuver. Design: Prospective cohort. Setting: Academic tertiary care referral center. Patients: Ten patients with facial paralysis from proximal nerve injury underwent the facial-hypoglossal neurorrhaphy with a parotid-release maneuver. Main outcome measures: The Repaired Facial Nerve Recovery Scale, questionnaires, and photographs. Results: Facial-hypoglossal neurorrhaphy with parotid release was technically feasible in all cases, and anastomosis was performed distal to the origin of the ansa hypoglossi. All patients had good return of facial nerve function. Nine patients had scores of C or better, indicating strong eyelid and oral sphincter closure and mass motion. There was no hemilingual atrophy and no subjective tongue dysfunction. Conclusions: The parotid-release maneuver mobilizes additional length to the facial nerve, facilitating a tensionless communication distal to the ansa hypoglossi. The technique is a viable option for facial reanimation, and our patients achieved good clinical outcomes with continual improvement

Reoperation on a patient with an indwelling cochlear implant is uncommon. When necessary, surgery is performed for explantation of an existing device with immediate or delayed reimplantation, or for scalp flap revision and receiver-stimulator repositioning in the case of infection or device migration. Rarely, revision surgery is performed to reintroduce intracochlear electrodes that may have partly or entirely extruded from the cochlea or were placed inappropriately. Successful revision cochlear implant surgery requires attention to certain surgical principles. Good outcomes, asa measured by speech perception tests, are common, but are not guaranteed. This article outlines the indications for revision cochlear implant surgery, the recommended surgical principles, and published outcomes from reimplantation

OBJECTIVES AND HYPOTHESIS: This study has the specific aim of evaluating the insertion characteristics of a new cochlear implant electrode. Techniques for evaluation of fluoroscopic real time mechanical insertion dynamics, histologic electrode position and trauma results, hydraulic force, and mechanical insertion forces are presented. In addition, this study should serve to present a novel model for cochlear implant electrode insertion evaluations. STUDY DESIGN: Prospective analysis using a series of analytical techniques. METHODS: All studies are conducted in fixed cadaveric temporal bones. Real time fluoroscopic insertion evaluations, histologic evaluations for trauma and electrode position in embedded bones, hydraulic measures, and mechanical intracochlear force measurements are conducted with a current and new electrode. RESULTS: The Contour Advance electrode provides a more reliable and less traumatic insertion when deployed with the Advance Off Stylet technique. This is largely because of a reduction in intracochlear outer wall force generation. Fluoroscopic and histologic analysis reveal a smooth insertion without reliance on cochlear outer wall contact. No hydraulic forces were detected when measured from the superior semicircular canal ampulla. CONCLUSION: The model used for this study provides valuable information to cochlear implant surgeons and design engineers. The Contour Advance electrode, inserted with the Advance Off Stylet technique, represents an improvement over the Contour electrode inserted with the standard insertion technique

Cochlear implant electrode insertion is the most important step in cochlear implant surgery. Optimal placement facilitates optimal results. This article describes cochlear implant electrode insertion techniques in normal and abnormal cochleae and the currently available electrodes

OBJECTIVES: As a result of universal newborn hearing screening and improved evaluation tools, many children with severe to profound hearing loss are being diagnosed as infants. This affords the opportunity to provide these children access to cochlear implantation, although medical and audiologic challenges must be addressed. The purpose of this study was to investigate the safety and efficacy of cochlear implantation in children who are younger than 1 year. METHODS: A prospective study was conducted of 18 children who had confirmed severe to profound sensorineural hearing loss and received cochlear implants at our medical center before 12 months of age. The length of device usage ranged from 6 months to 4 years, 5 months. The main outcomes measured were perioperative and postoperative surgical/medical aspects, the Infant-Toddler Meaningful Auditory Integration Scale and age-appropriate phoneme, and word and sentence recognition tests, when appropriate. RESULTS: All children had full insertions of the electrode array without surgical complications and are developing age-appropriate auditory perception and oral language skills. CONCLUSIONS: Early implantation is feasible and beneficial in some children who are younger than 12 months and should be considered with attention to variables involved in the decision-making process, including possible increased surgical risk, skull size and scalp thickness, and mastoid development

In recent years, new designs of cochlear implant electrodes have been introduced in an attempt to improve efficiency and performance by locating stimulation sites closer to spiral ganglion neurons and deeper into the scala tympani. The goal of this study was to document insertion depth, intracochlear position and insertion trauma with the Nucleus Contour electrode and to compare results to those observed with the earlier generation Nucleus banded electrode. For this comparison eight Nuclears banded electrodes and 18 Contour electrodes were implanted in cadaver temporal bones using a realistic surgical exposure. Two experienced cochlear implant surgeons and two otology fellows with specialized training in cochlear implant surgery were selected for the study to represent a range of surgical experience similar to that of surgeons currently performing the procedure throughout the world. Following insertion of the electrodes, specimens were imaged using plain film X-ray, embedded in acrylic resin, cut in radial sections with the electrodes in place, and each cut surface was polished. Insertion depth was measured in digitized X-ray images, and trauma was assessed in each cross-section. The Contour electrode inserted more deeply (mean depth=17.9 mm or 417 degrees ) than the banded electrode (mean depth=15.3 mm or 285 degrees ). The incidence and severity of trauma varied substantially among the temporal bones studied. However, the nature and frequency of injuries observed with the two devices were very similar. The Contour electrode was clearly positioned closer to the modiolus than the banded model, and also appeared easier to use. Based on this difference in position and data from previous studies we conclude that the Contour electrode may provide lower thresholds and improved channel selectivity, but the incidence of trauma remains a problem with the newer design. The relative influences of electrode positioning and neural degeneration that may result from trauma are as yet unclear

OBJECTIVES/HYPOTHESIS: Postoperative cerebrospinal fluid (CSF) leak is reported in 2% to 30% of cases following vestibular schwannoma surgery. The authors' current surgical techniques for translabyrinthine, retrosigmoid transmeatal, and middle cranial fossa approaches have evolved from analysis of their prior experience in an effort to minimize their complication rate. The authors evaluated the efficacy of their current surgical technique in decreasing the postoperative CSF leak rate. STUDY DESIGN: Retrospective review. METHODS: The vestibular schwannoma database from the New York University Medical Center (New York, NY) neurotological service was reviewed. Data were extracted for type of approach, tumor size, and CSF leak rate. Liberal leak criteria were used. Surgical techniques and management of CSF leak were reviewed. RESULTS: Data from 215 patients who had surgery from 1995 to 2000 manifested a 6.6% CSF leak rate for primary surgeries. This compared favorably with the authors' 17% overall CSF leak rate in 555 total primary surgeries performed between 1979 and 1995. Translabyrinthine closure was performed with dural sutures used as a sling across the posterior fossa dura and abdominal fat placed as a series of corks through the sutures. Abdominal fat was used to obliterate the mastoid cavity in conjunction with aditus and mastoid obliteration. Attention must be paid to soft tissue obliteration of potentially open air cell tracts. Retrosigmoid transmeatal closure was performed with a soft tissue graft in the internal auditory canal drill-out held in position by a 'saloon-door' dural flap. Bone wax was used to block perimeatal cells in all cases. Watertight dural closure was achieved with a sutured temporalis fascia graft. Abdominal fat obliteration of the mastoidectomy cavity was performed with an additional firm pressure from the 'Palva' periosteal flap. Middle cranial fossa closure was performed with attention to potential air cell tracts of the internal auditory canal drill-out, as well as abdominal fat graft, tissue glue, and bone wax. Fibrin glue was used in all approaches to temporarily secure fat in situ. Management of CSF leaks starts with nonoperative measures including bed rest, oversewing of incisional wounds, and placement of a lumbar subarachnoid spinal fluid diversion drain. If these conservative measures fail, repeat exploration is necessary and is directed at identifying and corking the cell or cells (usually perimeatal or perilabyrinthine) opening directly into the posterior fossa. CONCLUSION: Evolution in surgical techniques, with particular attention to exposed air cell tracts, abdominal fat graft, and Palva periosteal flap for closure, has had a significant effect in decreasing the author's CSF leak rate after vestibular schwannoma surgery. Conservative management was successful in approximately 50% of cases. Repeat exploration, when needed, was directed at blocking the air cell tract (usually perimeatal or perilabyrinthine) responsible for the CSF leak

OBJECTIVE: Perimodiolar electrode arrays were developed to improve stimulation of specific neural populations and to decrease power consumption. Postoperative radiographs suggest that some arrays are more tightly coiled than others. The purpose of this study was to evaluate whether the degree of modiolar coil correlates with electrical threshold and/or performance measures postimplantation with the Nucleus CI24RCS (Contour) device. STUDY DESIGN: Retrospective review. SETTING: Cochlear implant center and a tertiary care hospital. PATIENTS: Twenty-eight adult cochlear implant recipients with normal cochlear anatomy who underwent implantation with the Nucleus C124RCS perimodiolar electrode and are at least 1 year postimplantation. INTERVENTIONS: Therapeutic. MAIN OUTCOME MEASURES: Radiologic degree of perimodiolar electrode placement (determined by a computer algorithmic analysis) compared with electrical thresholds and standard speech perception outcome measures at 1 year postcochlear implantation. RESULTS: No significant correlations were found between the degree of modiolar coiling of the electrode array and electrical thresholds and speech perception outcome measures at 1 year postcochlear implantation. CONCLUSIONS: The degree of coiling of a modiolar hugging electrode array was not directly correlated with the level of electrical thresholds or postoperative speech perception outcome measures. Appearance of coil tightness on postoperative radiographs could reflect either differences in array placement or intrinsic variations in cochlear anatomy, and variations in speech perception performance can be influenced by other factors, including length of deafness

INTRODUCTION: Until recently, postimplant meningitis was infrequently reported and felt to be uncommon. However, in the spring of 2002, there was a sudden increase in the number of reported cases of postimplantation meningitis in both Europe and North America. OBJECTIVE: Because complications of surgery often tend to be underreported, we decided to survey all cochlear implant centers in North America to determine the true incidence of postimplant meningitis and to learn more about the demographics and risk factors. STUDY DESIGN: We conducted a prospective study. A survey instrument was designed asking surgeons the number of implants performed and whether they had seen any cases of meningitis after implantation. If the answer was affirmative, they were asked to respond to a 20-point questionnaire. This instrument was sent to all 401 cochlear implant centers in North America. SETTING: Tertiary care referral centers. PATIENTS: We studied all patients having received cochlear implants in North America. MAIN OUTCOME MEASURES: Number of cases of postimplant meningitis, age of patients, device used, cochlear and temporal bone abnormalities, treatment, and outcomes. RESULTS: Meningitis is more common than previously thought. Risk factors included young age, cochlear dysplasia, temporal bone abnormalities, and the use of a two-part electrode system. This survey led to the involvement by the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention in a much more intensive analysis of a subset of the cases. CONCLUSIONS: Postimplant meningitis is related to patient, surgical, and device factors. By being aware of the risk factors involved, adhering to sound surgical principles such as packing of the cochleostomy with soft tissue, appropriately vaccinating patients, and eliminating any potentially traumatic electrode arrays, the incidence of meningitis should be significantly diminished