摘要:

ObjectiveTo review complications that occur during the course of acoustic neuroma surgery.Study DesignDatabase and retrospective case review.SettingTertiary referral center, private neurotologic practice.PatientsA series of 1,687 patients undergoing acoustic neuroma surgery between 1987 and 1997. The 822 male and 865 female patients ranged in age from 10 to 87 years (mean age at time of surgery, 50 yr; standard deviation, 14 yr). The most common surgical approach was translabyrinthine (72.5%), followed by middle fossa (25.7%). The tumors ranged in size from 3 to 7 cm in diameter (mean, 2.0 cm; SD, 1.1 cm).Main Outcome MeasureFrequency of occurrence of all surgical and medical complications.ResultsThe most common complications were cerebrospinal fluid leaks (9.4%; 2.1% requiring reoperation) and meningitis (1.5%). Other surgical complications included cerebral edema, hydrocephalus, pneumocephalus, lower cranial nerve dysfunction, and wound infection. Medical complications in order of frequency included cystitis, sacral root syndrome, anemia, and pneumonia/bronchitis. Complications were related to tumor size and diagnosis of neurofibromatosis type 2.ConclusionsPerioperative complications will occur with acoustic neuroma surgery, but the overall rate in this large series was low. The authors believe that this supports an aggressive treatment approach for management of acoustic tumors. The findings of this study provide a basis for comparison with other treatment approaches and also are useful for preoperative patient counseling.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThis article highlights the clinical presentation and management issues of unilateral vestibular schwannomas in children. We demonstrate how the presentation differs from neurofibromatosis type 2 (NF2) and from adult unilateral vestibular schwannomas.Study DesignThis article is composed of a series of three cases and a literature review.SettingThe study was performed at a university hospital (tertiary referral center).PatientsThree children, aged 9, 11, and 13 years, with histologically confirmed vestibular schwannomas were studied. All children under 16 years of age in the world literature with unilateral vestibular schwannomas were reviewed.InterventionAnalysis of presentation and surgical management of these three children and those children reported in the literature.Main Outcome MeasurePattern of presentation relative to children with NF2 and people with adult unilateral vestibular schwannomas.ResultsTwo patients had multiple cranial nerve weakness and recurrence, and one patient had successful removal of the tumor with preservation of all functions of the cranial nerves, including the facial nerve.ConclusionVestibular schwannomas in children are very uncommon. It is likely that it is the first manifestation of NF2, but it may also be a variant of sporadic vestibular schwannomas. A presentation of three cases and a review of 36 other cases in the literature demonstrates how the presentation is different from adult sporadic vestibular schwannomas and NF2 because it lacks primary audiological symptoms. The study also provides evidence of non-NF2 vestibular schwannomas presenting in children and suggests that it is likely that these are a variant of unilateral sporadic vestibular schwannomas. The search for the features of NF2 in these cases remains mandatory.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveIn an effort to improve patient confidentiality as well as cosmesis, the authors have stopped shaving for all intracranial procedures. The objective was to determine whether this lack of shaving increased the postoperative infection rate.DesignA retrospective study was performed comparing all intracranial surgical procedures performed in the last 2½ years, when hair was not shaved, with the infection rate in patients who did have their hair shaved in the preceding 3½ years.SettingAn academic tertiary care referral center.PatientsEvery patient (children and adults) who underwent an intracranial procedure by the skull base surgery team was included. Similar patient demographics were used for the hair-shaved group.Intervention(s)Intracranial procedures consisted of acoustic tumor removal, vestibular nerve sections, skull base surgery procedures, vascular decompressions, and craniotomies for benign and malignant tumors.Main Outcome MeasuresThe most essential criterion was to determine whether postoperative wound infection developed in a patient. This was documented as either minor (stitch abscess or wound dehiscence), moderate (wound breakdown requiring inpatient or outpatient therapy, such as oral or intravenous antibiotics), or severe (significant wound breakdown that required hospitalization, with surgical debridement and antibiotics).ResultsIn all, 150 patients were not shaved for their intracranial procedures; postoperative wound infections developed in 11 (7%). The infections were minor(6), moderate(5), and severe (0). By comparison, 100 patients undergoing intracranial procedures had their hair shaved. In this group, the number of infections noted was 6 (6%). Their categorization into mild, moderate, and severe was 4, 2, and 0, respectively. Statistical analysis did not reveal any significant difference between the two infection rates.ConclusionsThe rate of postoperative wound infection was statistically no greater when the hair was shaved than when it was not. Thus, for patient confidentiality as well as patient esteem, we recommend not shaving hair for intracranial procedures.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveFactors that play a role in the selection of surgical approach for acoustic neuromas include patient health and age, size of tumor, hearing status, and location of tumor in the internal auditory canal (IAC) and the cerebellopontine angle. Deep extension into the IAC makes hearing preservation extremely difficult when a retrosigmoid craniotomy is used, and the best approach is a middle fossa subtemporal route. Modern gadolinium-enhanced magnetic resonance imaging (MRI) can be inaccurate in identifying the presence of tumor laterally in the IAC. This may affect the selection of a surgical approach.Study DesignThis study was a retrospective case review.SettingPatients were accrued from a tertiary referral otologic practice.PatientsFrom 1997 through 2000, the authors identified six patients who had undergone acoustic neuroma surgery, had adequate imaging and intraoperative data, and demonstrated a lack of correlation between MRI and intraoperative findings of the lateral IAC.InterventionThe interventions were preoperative MRI of the IAC and surgical resection of an acoustic neuroma.Main Outcome MeasureComparison of MRI and intraoperative findings of the lateral IAC were the main outcome measures.ResultsSix patients demonstrated a lack of correlation between MRI and intraoperative findings of the lateral IAC.ConclusionsGadolinium-enhanced T1-weighted MRI findings of the depth of penetration into the lateral aspect of the IAC do not always correlate with intraoperative findings and thus may have implications in the selection of surgical approaches to acoustic neuromas.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThe preoperative, intraoperative, and postoperative variables of patients experiencing hearing improvement after middle fossa resection of vestibular schwannomas were evaluated as potential prognostic indicators.Study DesignRetrospective case review with new objective postoperative data collected on patients with documented hearing improvement.SettingCalifornia Ear Institute at Stanford and Stanford University Hospital, a tertiary referral center.PatientsThe patient group consisted of 30 consecutive patients undergoing middle fossa approach to vestibular schwannoma between October 24, 1994, and November 11, 1998.InterventionHearing preservation surgery via the middle cranial fossa approach was performed on all patients.Main Outcome MeasuresPure-tone averages (PTAs) and speech discrimination scores (SDS) were used to document hearing preoperatively and postoperatively. Preoperative electrophysiologic studies of auditory brainstem response, electronystagmography, electrical neuronography, transient evoked otoacoustic emissions, and distortion product otoacoustic emissions were evaluated. Intraoperative continuous nerve action potential and auditory brainstem response tracings were reviewed. Postoperative auditory brainstem response and transient evoked otoacoustic emissions were obtained when possible on patients whose hearing improved. Statistical analysis was completed using Student'sttest and chi-square test.ResultsSeventeen (57%) of 30 patients with tumors ranging from 2 to 31 mm maintained hearing postoperatively. Among patients with hearing preservation, 7 (41% or 23% of the overall group) exhibited hearing improvement (PTA2improved by ≥5 dB and/or SDS improved by ≥12%). Three of these 7 patients moved from nonfunctional (AAOHNS class C/D) to functional (AAOHNS class A/B) categories. All patients who enjoyed postoperative hearing improvement had preoperative absence or abnormality of ABRs. No patient with normal preoperative ABR experienced hearing improvement. Hearing improvement patients also had lower preoperative caloric function on electronystagmography compared with the entire group (p < 0.02) and were more likely to have superior vestibular nerve tumors. No differences were noted for electrical neurography and otoacoustic emissions.ConclusionsMiddle fossa resection of vestibular schwannoma offers patients the possibility of hearing improvement after treatment. The chance of hearing improvement is significantly higher than with other forms of treatment such as radiation therapy or translabyrinthine surgery. Although preoperative ABR abnormality may be an indicator of poor prognosis for hearing preservation, those patients who enjoy hearing improvement come from the group of patients with abnormal preoperative ABRs. Other factors identified as associated with hearing improvement include poor SDS with more normal PTA2, and significantly decreased electronystagmographic caloric function (as an indicator of superior vestibular nerve tumors). Hearing improvement to the functional range after surgical resection is possible in some patients previously thought to be poor candidates for hearing preservation attempts. Hearing improvement may continue for many months after surgery.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo examine the relationship between histopathology, immunohistochemistry, and clinical behavior in atypical and low-grade malignant vestibular schwannomas.Study DesignThe study design was a retrospective case review in conjunction with a histopathologic and immunohistochemical proliferation marker study of archival specimens.Data SourcesA tertiary referral center's anatomic pathology and vestibular schwannoma computerized databases.MethodsThe diagnosis of atypical or low-grade malignant vestibular schwannoma was based on the number of mitotic figures present per tumor slide. MIB1 labeling indices were used to compare the proliferative activity of the atypical and low-grade malignant groups with that in an age-matched and size-matched control group.ResultsEight cases of atypical and six cases of low-grade malignant vestibular schwannoma were diagnosed from 1990 to 1998. In the atypical and low-grade malignant groups, respectively, the average patient age was 54.3 years (range, 38–74 yr) and 50 years (range, 38–72 yr), and the average total tumor size was 1.53 cm (range, 0.7–3.5 cm) and 1.55 cm (range, 1.5–2 cm). Two recurrences were identified from the low-grade malignant group, and there was one postoperative House-Brackmann Grade III facial weakness. There were no recurrences or facial palsies in the atypical group. No distant metastasis or aggressive local invasion was observed in either group. MIB1 labeling indices were significantly (p ≤ 0.001) higher in the atypical (4.69%) and low-grade malignant (5.23%) groups than in the control group (1.99%).ConclusionsThese findings suggest a tendency for recurrence in proliferative tumors; however, the designation of malignancy should be reconsidered.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo describe the use of a digital camera to document facial nerve function after skull base surgery.SettingPatients undergoing skull base surgery at a tertiary care otologic and neurotologic clinic were used in the study.InterventionsNone.ResultsA digital camera system provided still images and a video strip lasting less than a minute to document facial nerve motion.ConclusionsAn inexpensive digital camera system can be used to capture still and moving images of facial nerve function on a floppy disk. The images can then be transferred to compact disks for storage of many patient files. Such a system allows documentation for research, exchange of data between offices, and patient education, and it can be used for medical-legal purposes among other uses.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

AimsThis study investigated the development of the fallopian canal with particular reference to the mode of ossification and dehiscences, sites of incomplete closure around the facial nerve.BackgroundThe precise sequence of events surrounding ossification of the tissues around the facial nerve is uncertain. Incomplete ossification results in dehiscence of the adult structure, which places the nerve at increased risk of damage from disease processes in the middle ear and iatrogenic trauma during otologic surgery.MethodsTwenty-four temporal bones from 12-to 36-week human fetuses were resected. Eight temporal bones from 22-to 36-week fetuses were microsliced to produce 1.5-mm horizontal sections and radiographed. Sixteen temporal bones from 12-to 35-week fetuses were serially microtomed to produce 7-&mgr;m slices, which were stained with hematoxylin and eosin. Quantitative and qualitative analyses of these sections were performed to document patterns of closure of the primitive canal and dehiscence formation.ResultsThe tympanic part of the primitive fallopian canal, the facial sulcus, developed anteroposteriorly from the geniculate fossa to enclose the facial nerve. The mesenchyme that formed the facial sulcus underwent endochondral ossification, while the bone which capped or closed the sulcus developed in membrane. In the tympanic segment, permanent congenital dehiscences were elliptical and about 1 mm in length.ConclusionsThis study clarifies the mode of development of the fallopian canal, with particular reference to dehiscences, and provides a scientific basis for otologic practice.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

HypothesisHuman endolymphatic sac cells have been notoriously difficult to maintain in culture. It was hypothesized that an in vitro environment intended for growth of keratinocytes would also be suitable for human endolymph sac cells.BackgroundStudies on cell physiology of human endolymphatic sac cells have been hampered by difficulties in maintaining them in culture.MethodsHuman endolymphatic sac cells were taken from 10 patients during translabyrinthine skull base surgery for vestibular schwannoma, one of whom also had Ménière's disease. Cell lines of proliferating epithelial cells were obtained after trypsinization and growth in a 3:1 mixture of Dulbecco's modified Eagle medium and Ham's F12 medium supplemented with 10% fetal calf serum. Fibroblast overgrowth was counteracted by the use of so-called cloning rings. During various stages, cells were investigated with transmission electron microscopy and/or immunohistochemistry.ResultsProliferation took place after 2 to 3 days of primary cell culture. The cells were cytokeratin-positive and pleomorphic, and they had abundant polarized microvillus-like projections, numerous coated cytoplasmic pits and vesicles, and a well-developed rough endoplasmic reticulum.ConclusionCell lines of proliferating human endolymphatic sac cells can be produced with the technique described here and may be a valid tool in studies of human endolymph sac physiology.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

HypothesisThe goal of this study was to map the VIIIth cranial nerve by electrical stimulation. Specifically, the authors sought to 1) characterize auditory and vestibular evoked responses elicited by electrical stimuli delivered directly to the exposed surface of the VIIIth cranial nerve and 2) compare electrically evoked responses elicited in brainstem nuclei with extracranially recorded far-field potentials.BackgroundIntraoperative monitoring of auditory brainstem responses is useful during cerebellopontine angle surgery. Identification of the vestibular portion of the VIIIth cranial nerve, which traditionally has been performed by physical characteristics and some electrophysiologic properties, is important because the vestibular subdivision in humans is indistinct in approximately 25% of cases. Positive identification of evoked responses emanating from the vestibular nerve would constitute a marked improvement over existing intraoperative techniques that use acoustic stimuli only.MethodsExperiments were performed on 12 anesthetized cats. Electrical pulse stimuli were delivered using a bipolar electrode placed directly on the surface of the exposed VIIIth cranial nerve at several sites. Computer-averaged evoked responses were recorded from far-field electrodes placed on the scalp and from near-field electrodes stereotaxically positioned in or near the inferior colliculus and abducens nucleus.ResultsLatencies and morphologies of waves recorded in brainstem nuclei were compared with those of waves recorded extracranially. Direct electrical stimulation of the cochlear nerve elicited a four-wave, auditory brainstem response–like extracranial response, strong activity in the inferior colliculus, and weak activity in the abducens nucleus. Direct stimulation of the vestibular nerve produced a two-wave extracranial response, weak inferior colliculus activity, and strong abducens activation. Stimulation at the border of the cochlear and vestibular nerves produced intermediate responses that possessed both cochlear and vestibular characteristics.ConclusionDirect electrical stimulation of the cochlear and vestibular subdivisions elicits evoked responses with distinctly different wave morphologies. Obtaining electrically evoked responses intraoperatively is feasible and may be of substantial value in the unambiguous identification of VIIIth cranial nerve subdivisions.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID