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T J Balkany,
A V Hodges,
C A Buchman,
W M Luxford,
C H Pillsbury,
P S Roland,
J K Shallop,
D D Backous,
D Franz,
J M Graham,
B Hirsch,
M Luntz,
J K Niparko,
J Patrick,
S L Payne, F F Telischi,
E A Tobey,
E Truy,
S Staller
Ontology & Neurotology 08/2005; 26(4):815-8. · 1.90 Impact Factor
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ABSTRACT: Conventional follow-up of surgically and radiotherapy-treated paragangliomas is usually carried out with physical examinations and either magnetic resonance imaging and/or computed tomography. Up to now, octreotide has been reserved for primary diagnosis, for which it has been shown to be a reliable imaging modality. However, the postsurgical and postradiation changes seen on conventional imaging make the diagnosis of small recurrent lesions difficult. We sought to evaluate the role of octreotide scintigraphy in the detection of recurrent paragangliomas.
We based this case series on 3 patients who were found to have recurrent paragangliomas after primary surgical resection. All patients underwent octreotide scintigraphy during routine follow-up.
Three patients were found to have recurrent paragangliomas using octreotide scintigraphy. In one of the patients, conventional imaging (magnetic resonance imaging, computed tomography) failed to detect the recurrence.
The octreotide study was able to detect the small recurrences because octreotide binds directly to receptors on the tumor and is not affected by postsurgical or postradiotherapy changes. The intrinsic resolution of most commercially available gamma cameras is about 1 cm, making it quite sensitive to detect small tumors. Although this patient did not have synchronous lesions, octreotide scintigraphy can also aide in the detection of such lesions.
Otolaryngology Head and Neck Surgery 05/2004; 130(4):479-82. · 1.72 Impact Factor
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ABSTRACT: A neuromonitoring system using compound action potential (CAP) and cochlear blood flow (CBF) is developed to assess the functional status of the cochlea during hypoxia. The system uses a specially designed optic probe capable of acquiring CAP and CBF signals and modules to process and display these signals. The system is tested in rabbits by creating cochlear hypoxia by manual compression of the auditory nerve and acoustic artery. Results show that CAP and CBF measurements can provide almost real time information on the status of the cochlea under compromising situations.
Neural Engineering, 2003. Conference Proceedings. First International IEEE EMBS Conference on; 04/2003
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ABSTRACT: Cochlear ischemia is likely involved in sensorineural hearing loss after cerebellopontine angle (CPA) surgery.
To demonstrate the type of vascular damage to the cochlea, apart from arterial section, that can be induced by CPA surgery.
The effects on measures of both cochlear blood flow (CBF) and distortion-product otoacoustic emissions (DPOAEs) of partial or total mechanical compressions of the internal auditory artery (IAA) were compared in young adult rabbits.
When preocclusion baseline activity was compared with postocclusion CBF and DPOAEs, it was clear in the majority of cases that total compressions lasting < or =7 minutes produced the same full recoveries for both measures as did the shorter obstructions of only a few minutes. By contrast, both short and long partial occlusions in which ischemia was interrupted by periods of poor reperfusion (<50% of the initial CBF value) resulted in delayed and prolonged recoveries. In addition, at times, full recovery was not achieved, particularly for DPOAEs, because of vasospasm-like activity.
Vasospasm of the IAA was induced by a systematic series of IAA compressions and releases that did not provide for full reperfusion. These data support the concept that vasospasm should be prevented whenever hearing preservation is attempted in CPA surgery.
The American journal of otology 09/2000; 21(5):735-42.
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ABSTRACT: Paragangliomas are neuroendocrine tumors located primarily in the head and neck region, but they can also occur at other sites. Confirming the preoperative diagnosis and detecting synchronous tumors may be difficult in some patients. Octreotide is a somatostatin analog that, when coupled to a radioisotope, produces a scintigraphic image of tumors expressing somatostatin type 2 receptors. Paragangliomas, like many neuroendocrine tumors, have been found to have a high density of somatostatin type 2 receptors on the cell surface. This study compared the results of preoperative octreotide scintigraphy with the histopathology in 21 patients who underwent surgery for presumed head and neck paragangliomas. Octreotide scan findings were positive in 16 patients with paragangliomas and negative in 3 patients with other pathology. One false-positive and 1 false-negative result were obtained. Thus, this test had an accuracy of 90%, a sensitivity of 94%, and a specificity of 75%. Previously unidentified synchronous tumors were identified in 5 patients. On the basis of this series of patients, octreotide scintigraphy appears to be a reliable test to detect paragangliomas and may be quite helpful in preoperative planning.
Otolaryngology Head and Neck Surgery 04/2000; 122(3):358-62. · 1.72 Impact Factor
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ABSTRACT: The case of an 11-month old infant with petrous apex abscess drained through the supracochlear air cells prompted an anatomic study of the dimensions of this approach. Of the various approaches to the petrous apex, the supracochlear dissection has been the least described.
Twenty temporal bones were dissected to completely expose the epitympanum. This required mastoidectomy, exenteration of zygomatic root and epitympanic air cells, and removal of the incus. Measurements were taken from three sides of a triangle described by the tegmen tympani (TT), tympanic facial nerve (TFN), and superior semicircular canal (SSCC). Similar measurements were obtained from standard coronal computerized tomographic (CT) scans from a random series of 20 patients.
Mean lengths of the sides of the triangle were 7.0 mm (TT), 5.3 mm (TFN), and 4.8 mm (SSCC). The superior petrous apex air cells or marrow space was accessible through the supracochlear exposure in all specimens. Mean lengths from the coronal CT images were 4.2 mm (TT), 3.2 mm (TFN), and 8.45 mm (SSCC).
The authors conclude that the supracochlear approach may provide adequate access to the superior petrous apex for drainage and biopsy in selected cases.
The American journal of otology 08/1999; 20(4):500-4.
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ABSTRACT: A small number of multichannel cochlear implant (CI) recipients require reimplantation. This study describes the causes of failure, surgical technique, and hearing outcomes in a consecutive series of 16 patients undergoing reimplantation of multichannel devices. We hypothesize that reimplantation is safe and that hearing results are at least as good as those measured following primary implantation.
Retrospective analysis of consecutive clinical series.
Chart analysis of 191 consecutive CI operations performed at the University of Miami Ear Institute between 1990 and 1997 revealed 16 patients who received a second multichannel device. All but one had a minimum follow-up of 1 year after reimplantation. Ten of these patients had initial implantation performed by us, and six were initially operated on elsewhere. Main outcomes of the initial procedure were compared with those of the reimplantation, including electrode insertion length, number of channels programmed, and audiometric results. In addition, cause of failure and relevant surgical findings at the second procedure are described.
There were no surgical complications after reimplantation surgery. Device failure was the most frequent cause for reimplantation. Time between initial implantation and failure ranged from 0 to 46 months (mean, 22.4 mo; median, 23 mo). Common intraoperative findings include mastoid fibrosis, bone growth at the cochleostomy, and skin flap breakdown. Following reimplantation, mean length of insertion, number of channels actively programmed, and speech recognition scores were at least as good as findings before initial implant failure.
CI reimplantation is safe and effective.
The Laryngoscope 04/1999; 109(3):351-5. · 1.75 Impact Factor
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ABSTRACT: Examine and compare in detail the time courses of the auditory brainstem response (ABR) wave I amplitude and latency to the distortion-product otoacoustic emission (DPOAE) amplitude and phase measured in the rabbit model following deliberate obstruction of cochlear blood flow (CBF).
Using a posterior fossa craniotomy in five rabbits, the internal auditory artery (IAA) was compressed with a probe. ABR and otoacoustic emission were continuously monitored before, during, and after the compressions.
ABR wave I amplitudes demonstrated measurable decreases at a mean of 28.3 s after IAA compression, whereas DPOAE amplitudes decreased after a mean of 14.8 s. Wave I latencies began to increase at a mean of 18.3 s after occlusion, while DPOAE phase measures changed after a mean of only 4.8 s following IAA compression. The time-course patterns were similar for the amplitudes of both ABR wave I and DPOAE.
ABR wave I amplitude follows a similar, though delayed (by approximately 10 s) time-course pattern to that of the DPOAE following IAA compression. The implication of these findings for intraoperative auditory monitoring is that changes in many currently employed measures will lag actual surgically induced alterations in CBF by at least 20 to 30 s.
The Laryngoscope 03/1999; 109(2 Pt 1):186-91. · 1.75 Impact Factor
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ABSTRACT: Among the technical challenges of cochlear implant surgery is electrode insertion into the fully ossified cochlea. Earlier drill-out techniques have two significant drawbacks: 1. up to one half fail when the electrode pulls away from the cochlea; and 2. extended radical mastoidectomy, abdominal fat graft for obliteration, and closure of the external auditory meatus are required. A simplified technique is described that allows positive fixation of the cochlear implant electrode and in selected cases avoids a radical cavity with obliteration.
Technical description with case reports and hearing outcomes.
Ten cadaver temporal bones were dissected to determine middle ear landmarks that overlie the basal turn of the cochlea from the transcanal approach and to establish the feasibility of the intact canal wall procedure. Surgery was performed on four patients who had preoperative imaging evidence of full ossification, two with the canal wall down, and two with canal wall up. Standard measures of speech recognition were used to evaluate hearing.
Critical surgical landmarks are the round window, carotid artery, cochleariform process, and oval window. The procedure was successfully performed on four patients and open-set speech recognition is present in each.
This canal wall up procedure allows long electrode insertion without radical cavity/obliteration in patients with fully ossified cochleas and prevents distraction of the electrode from the cochlea. While open-set word recognition was achieved by all subjects, results are poorer than expected for patients with limited or no ossification.
The Laryngoscope 08/1998; 108(7):988-92. · 1.75 Impact Factor
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ABSTRACT: Distortion-product otoacoustic emissions (DPOAEs) have been shown to be ideally sensitive to interruptions of the cochlear blood flow. However, a 15- to 30-second latency typically occurs between cessation of circulation and measurable DPOAE level changes. DPOAEs can also be characterized by phase measures. The aim of the present study was to determine in 10 rabbits the effects on DPOAE phase of repetitively compressing the internal auditory artery. In contrast to the delays measured by DPOAE level, phase changes were detected 1 to 5 seconds after internal auditory artery compression. These data suggest that the essentially "real time" monitoring of cochlear function with DPOAE phase can be used to ensure hearing preservation during surgery involving the porus acousticus and skull base.
The Laryngoscope 07/1998; 108(6):837-42. · 1.75 Impact Factor
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ABSTRACT: The objective was to describe surgical techniques helpful in implanting children with inner ear malformations.
This was a retrospective chart review and description of surgical techniques in the setting of a tertiary referral center.
The study population was composed of 10 children with inner ear deformities who received 22-channel implants.
The primary surgical challenges encountered in these procedures include complete electrode insertion, cerebrospinal fluid gusher, identification of cochleostomy site in the absence of the round window and aberrant facial nerve, and fixation and stabilization of the electrode.
The techniques described allow safe and effective insertion of multichannel electrodes in patients with inner ear malformations.
The American journal of otology 12/1997; 18(6 Suppl):S66.
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ABSTRACT: To describe a simplified drill-out technique for insertion of a multichannel electrode in the completely ossified cochlea without radical mastoidectomy and obliteration.
Description of a new surgical technique and case report.
Temporal bone dissection laboratory and tertiary referral center.
Adult and pediatric cochlear implant (CI) recipients.
Access for circum-modular drill-out and electrode insertion without radical mastoidectomy and adequate function of multichannel CI.
Dissection of 10 cadaver temporal bones demonstrated feasibility of this technique. Highlights include facial recess cochleostomy and 8 mm tunnel; elevation of superiorly based tympanomeatal flap; removal of incus, cochleariform process, and tensor tympani; and identification of carotid canal and use of facial nerve monitor. A case report of an 11-year-year old child with total cochlear ossification and previous failure of a short (8 electrode) CI electrode insertion is presented. Complete insertion of a 22-channel electrode was successful and open-set word recognition is commencing.
The canal wall-up drill-out procedure allows complete electrode insertion without mastoid obliteration in patients with obliterated cochleas. Appropriate attention to the carotid artery and facial nerve is essential.
The American journal of otology 12/1997; 18(6 Suppl):S58-9.
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ABSTRACT: To describe clinical experiences with multichannel cochlear implantation in children with inner ear malformations, including surgical indications and techniques, imaging findings, and outcomes.
A retrospective review of a series of 10 consecutive cases with a mean follow-up of 29 months, as well as a review of the literature.
Academic referral center.
Ten children who underwent multichannel cochlear implantation for inner ear malformations. High-resolution computed tomographic scans demonstrated a common cavity deformity in 3, an incomplete cochlear partition in 4, and an enlarged vestibule in 1. Two had membranous anomalies as indicated by cerebrospinal fluid gushers at surgery, but the results of imaging were normal.
All subjects received multichannel cochlear implants. Two subjects underwent mastoid obliteration at the time of implantation owing to preoperative recurrent meningitis or chronic otitis media with episodes of clinical mastoiditis.
The 10 subjects were evaluated for electrode insertion and stability and auditory function for up to 7 years.
All 22 electrodes are functional in each child with an incomplete partition, an enlarged vestibule, or a membranous anomaly. Of 3 subjects with common cavities, 2 had full insertion of electrodes and 1 had 16 electrodes inserted. All subjects had speech awareness thresholds detected at 25 dB or better. Three (75%) of the 4 subjects with at least 30 months of experience, including 1 subject with a common cavity, have developed open-set word recognition.
Electrode insertion and hearing results in children with an incomplete partition, an enlarged vestibule, or a membranous anomaly are similar to those in children with normal cochleas. Specific surgical techniques are effective for children with a common cavity, and the results are less certain. Cerebrospinal fluid gushers were encountered frequently but were not difficult to control.
Archives of Otolaryngology - Head and Neck Surgery 10/1997; 123(9):974-7. · 1.63 Impact Factor
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ABSTRACT: In a retrospective review of seven patients with AIDS who were diagnosed with necrotizing external otitis between 1990 and 1995, it was found that the presentation of necrotizing external otitis in patients with AIDS differed from the classic description of malignant external otitis in several respects. The patient population was significantly younger and nondiabetic. Granulation tissue was usually absent from the external auditory canal and Pseudomonas aeruginosa was not the predominant pathologic organism. Also, outcome was found to be significantly worse. Thus a high index of suspicion must be entertained and vigorous local and systemic treatment initiated early in the course of disease to achieve a satisfactory outcome.
The Laryngoscope 05/1997; 107(4):456-60. · 1.75 Impact Factor
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Otolaryngology Head and Neck Surgery 10/1995; 113(3):319-22. · 1.72 Impact Factor
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ABSTRACT: Distortion product otoacoustic emissions (DPOAEs) elicited by a bitonal stimulus complex are low-level sounds that are generated within the cochlea, and are easily measured by a miniature microphone system placed in the external auditory canal. Under conditions of rapid measurement, DPOAEs have been shown in an animal model to be exquisitely sensitive to interruption of the blood supply to the inner ear. Currently, there is no real-time procedure available for monitoring hearing function intraoperatively during neurotologic surgery. The goal of the present study was to determine the utility of DPOAEs in monitoring cochlear status intraoperatively, particularly during procedures commonly used to remove acoustic neuromas. Distortion product otoacoustic emissions were measured pre- and intraoperatively in 11 patients, who were under general anesthesia for a variety of otolaryngologic procedures, including acoustic neuroma resection. High frequency emissions (i.e., > or = 4 kHz) were less affected by the elevated levels of acoustic noise present in the operating-room environment, thus permitting emitted responses to be updated as quickly as every 2 seconds. However, a number of technical problems were encountered and addressed during development of the emission monitoring technique. Despite these difficulties, overall, DPOAEs appear to be a promising adjunct to the intraoperative monitoring of auditory function.
The American journal of otology 09/1995; 16(5):597-608.
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ABSTRACT: Evoked otoacoustic emissions (OAEs) are assumed to reflect healthy outer hair cell function. Over the past few years, evoked OAEs have been shown to be useful as indicators of cochlear hearing loss. Because basic studies have shown that OAEs are extremely sensitive to cochlear anoxia and hypoxia, as well as to the adverse effects of many inner ear diseases, it is possible that these objective tests can provide some insight into the fundamental basis of the hearing loss exhibited by patients with acoustic neuromas. The primary aim of the present study was to examine the effects of acoustic neuromas on the amplitudes of evoked OAEs and to compare these findings with tumor-induced hearing levels. To this end, tests of behavioral audiometry, distortion-product otoacoustic emissions and transiently evoked otoacoustic emissions were performed on 44 patients with verified acoustic neuromas. The results demonstrated that the majority of ears with acoustic neuromas displayed one of two distinct patterns of evoked OAEs: a cochlear pattern or a noncochlear pattern. Although behavioral hearing thresholds were higher with larger tumors, OAE levels exhibited no clear relationship to tumor size. The present findings support the notion that acoustic neuromas may cause hearing impairment according to two types of influence that act at different levels of the peripheral auditory system. The tumor's cochlear effect on evoked OAE activity is most likely caused by an indirectly mediated compromise of the organ of Corti's vascular supply. It is probable that the direct pressure of the tumor on the eighth cranial nerve is responsible for the observed noncochlear effects.
The Laryngoscope 08/1995; 105(7 Pt 1):675-82. · 1.75 Impact Factor
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ABSTRACT: To determine the long-term effectiveness of various approaches to surgical drainage of petrous apex cholesterol granulomas.
A retrospective cohort study in which patients treated by surgical drainage for petrous apex cholesterol granulomas were followed up for a minimum of 1 year (mean, 4.6 years).
House Ear Clinic, an otologic tertiary care center in Los Angeles, Calif.
A total of 25 patients who underwent either transcanal infracochlear, infralabyrinthine, middle fossa, or translabyrinthine drainage and who had at least 1 year of clinical and, in some cases, radiologic postoperative follow-up.
Relief or recurrence of symptoms, need for revision surgery, postoperative hearing, appearance on postoperative imaging studies.
Twenty-three patients had improvement or complete resolution of preoperative noncranial nerve VIII nerve dysfunction. Hearing was preserved in cases of middle fossa, infralabyrinthine, and infracochlear approaches with serviceable preoperative hearing. Hearing did not improve in cases of total preoperative hearing loss. Of the patients who underwent postoperative imaging, over three fourths had reduction in lesion size and one third developed aeration of the petrous apex. Revision surgery was required in three patients. Recently developed, the infracochlear approach has shown excellent early results. Lesion size was reduced in five of five patients, and the petrous apex contained air in three of five patients who underwent the infracochlear approach.
Drainage via the infracochlear and infralabyrinthine approaches offers effective long-term decompression of petrous apex cholesterol granulomas, while preserving hearing.
Archives of Otolaryngology - Head and Neck Surgery 05/1995; 121(4):426-30. · 1.63 Impact Factor
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The Laryngoscope 03/1995; 105(2):217-8. · 1.75 Impact Factor
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The Laryngoscope 03/1995; 105(2):219-20. · 1.75 Impact Factor
