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Biomedical subjects

M A Arriaga

Publications and source records attributed to M A Arriaga.

At least 19 recordsLinked to original sources
PubMed1998

Stapedectomy in military aircrew.

Stapedectomy in military aircrew is generally considered to be the end of an aviation career. Perilymphatic fistulae, prosthesis dislodgement, and perforation of the vestibule are recognized complications of stapedectomy. Consequently, barotrauma, G forces, and otherwise hostile conditions and their effects on the poststapedectomy ear are usually cited as reasons for grounding. Data supporting such a restrictive policy, however, are limited. This study examined the aeromedical outcome of 16 U.S. Air Force aircrew members who returned to flight duty after stapedectomy between 1965 and 1992. Selected patients were subjected to centrifuge and altitude chamber testing before they returned to flight duty. No episodes of sudden hearing loss or vestibulopathic conditions have occurred in the entire study group. Guidelines for surgical technique, reconstruction materials, and postoperative aeromedical testing are proposed for evaluating selected stapedectomy patients before their return to flight status.

Aerospace Medicine↗
PubMed1998

Educational outcomes of an otitis media workshop for primary care providers in Latin America.

Otitis media is a prevalent condition that can be diagnosed and treated by primary care providers skilled in otoscopy. Previous analysis demonstrated that brief, intensive instruction at one site in rural Mexico improved the test scores of health care providers and changed long-term practices (Eavey R, et al. Otolaryngol Head Neck Surg 1993; 109:895-8). We wanted to confirm these test score findings at other sites. A didactic course on otitis media with a practical otoscopy workshop was conducted at six Mexican locations and in one Venezuelan city by an interdisciplinary group of physicians. The same coded test was given immediately before and after the course. The Wilcoxon test for significance of intrasubject performance before and after intervention was used as a nonparametric assessment. At all seven sites (n = 190 subjects), test scores demonstrated statistically significant improvement (range = p < 0.001 to p < 0.0001). We conclude that this educational method consistently improved short-term knowledge of otitis media and that further teaching efforts and a longer term practice-impact study are warranted.

Child↗
PubMed1998

Hearing results of intratympanic steroid treatment of endolymphatic hydrops.

OBJECTIVES/HYPOTHESIS: This study evaluated the effectiveness of a single application of steroids to the open middle ear in improving short-term hearing in patients with Meniere's disease and cochlear hydrops. STUDY DESIGN: Retrospective study in which each patient's pretreatment hearing served as the control compared with posttreatment hearing. METHODS: Patients were treated with a single application of dexamethasone, 8 mg, in hyaluronan. Following tympanotomy and lysis of round window adhesions, steroids were placed in the round window niche with absorbable gelatin sponge and the remainder of the middle ear was then filled with the steroid solution. Systemic steroids were not administered. Audiograms were performed within 1 month before surgery and at least 1 month after surgery. RESULTS: Between September 1996 and July 1997, 21 ears in 19 patients underwent intratympanic steroid treatment. The criterion for hearing change was a 10-dB or greater change in pure-tone average (PTA), or a 15% change in speech discrimination score (SDS). Of the 15 ears meeting inclusion criteria for this study, five (33%) demonstrated hearing improvement and three (20%) demonstrated hearing deterioration. Maximum improvement was a 38-dB improvement in PTA and a 32% improvement in SDS. CONCLUSION: A single application of intratympanic dexamethasone/hyaluronan solution directly to the round window did not produce dramatic short-term hearing improvement in patients with endolymphatic hydrops. Although the theoretical basis for intratympanic steroid treatment of endolymphatic hydrops is appealing, we urge close evaluation of the results of specific protocols of intratympanic steroid administration before widespread utilization of this treatment. The choice of steroid, route of administration, frequency of application, and need for simultaneous systemic administration require standardization to adequately assess the efficacy of this treatment.

Adjuvants, Immunologic↗
PubMed1998

Cytotoxicity of cytokeratin monoclonal antibody against keratinocytes: a possible therapeutic adjunct for cholesteatoma?

HYPOTHESIS: Monoclonal antibodies directed against cytokeratin subtypes in cholesteatoma produce growth inhibition of keratinocytes. BACKGROUND: Despite elegant surgical procedures for cholesteatoma, residual disease is an important clinical problem. Although gross cholesteatoma removal usually is feasible, microscopic foci of residual keratinocytes may develop into clinically significant disease. This study was designed to evaluate the keratinocyte cytotoxicity of monoclonal antibodies directed against a cytokeratin subtype relatively unique to cholesteatoma. METHODS: Keratinocytes and skin fibroblasts were trypsinized, counted, and seeded in multiwell plates. The cells were exposed to mouse monoclonal antibody to cytokeratin 10 at dilutions of 1:10, 1:25, 1:50, 1:100, and 1:200 with six replicates. After 24-, 48-, and 96-hour incubations, cells that had been pulsed with 3H-thymidine were harvested. Cellular DNA was processed for quantification of 3H-thymidine incorporation with a beta scintillation counter. Cells exposed to antibody are reported as percent inhibition relative to controls. RESULTS: Inhibition ranged from 88.9% for the 1:10 concentration to 26.9% for the 1:200 concentration after 24 hours of incubation. Similar effects were noted at the 48- and 96-hour intervals. Overall, the effect was significantly more pronounced on the keratinocytes than inhibition on skin fibroblasts. CONCLUSIONS: These results suggest that monoclonal antibodies have in vitro activity against keratinocytes. Additional investigation of a possible role for cytokeratin monoclonal antibodies should be pursued with a goal of developing a clinically useful biologic adjunct for cholesteatoma management.

Animals↗
PubMed1998

Technical refinements in retraction for middle fossa surgery.

OBJECTIVE: This report describes an alternative technique for exposure of the floor of the middle fossa. STUDY DESIGN: Descriptive review of alternative middle fossa retraction techniques on a retrospective case series. SETTING: Tertiary referral center. PATIENTS: Patients undergoing middle fossa or combined petrosal craniotomy were studied. INTERVENTIONS: Dural elevation was carried anteriorly past the middle meningeal artery to permit separation of the dura from connective tissue over the Gasserian ganglion. With the dural release, flexible spatula retractors (Fukushima) can be used. RESULTS: The advantages of this technique are 1) this system is "low profile," with the back of the retractor posing no obstruction to vision or angle of instrument manipulation; 2) the anterior dural release permits extensive exposure with less force than is necessary when dural attachments to the trigeminal nerve remain intact; and 3) anterior exposure of the clivus and petrous apex is achieved without the need for transection of V3 (3rd division fifth cranial nerve). CONCLUSIONS: The authors find these refinements of practical benefit for breadth of exposure, visibility, and room for instrumentation during middle fossa surgery.

Brain↗
PubMed1997

Cost-effective evaluation of asymmetric sensorineural hearing loss with focused magnetic resonance imaging.

The poor sensitivity of audiometric brain stem response for small vestibular schwannomas (acoustic neuromas) creates a dilemma for the physician evaluating a patient with signs and symptoms of retrocochlear disease. Magnetic resonance imaging is recognized as the gold standard for the evaluation of these problems, but if a complete examination of the internal auditory canals and head is done on every patient, the cost is high. Although less expensive, screening with audiometric brain stem response risks missing up to 33% of small tumors. Therefore we developed a focused magnetic resonance imaging sequence for evaluation of patients with asymmetric sensorineural hearing loss and/or nonpulsatile tinnitus. The protocol includes a T1-weighted sagittal localizer, pregadolinium and postgadolinium T1-weighted 3-mm contiguous axial slices through the internal auditory canal and the region of the cerebellopontine angle, and T2-weighted axial images through the entire brain. Total scanning time is about 12 minutes, and the estimated cost is $300 to $500. We retrospectively reviewed the imaging records of 485 screening examinations done during an 18-month period. Twenty-four patients had diagnoses definitely or probably producing the hearing loss for an overall positive rate of 5%. By eliminating the need for follow-up audiometric or electrophysiologic studies, we believe a focused magnetic resonance imaging-based diagnostic scheme is actually more cost-effective on a cost-perpatient basis.

Cost-Benefit Analysis↗
PubMed1997

Clinical pathways in acoustic tumor management.

Clinical pathways are tools for cost containment and quality improvement in the managed care environment. This report describes our experience with developing and implementing a clinical pathway for acoustic neuroma surgery. Intensive care unit bed days and inpatient hospitalization days for cerebellopontine angle surgery significantly decreased during the months that the pathway was developed, and the incidence of complications was unchanged after adoption of the algorithm. We conclude that with joint neurootology and neurosurgery leadership clinical pathways can be a safe, cost-effective, and clinically useful technique in acoustic neuroma surgery in a managed care setting. As this management scheme evolves, surgeons must take the leadership to ensure that decisions are based on clinically relevant parameters.

Algorithms↗
PubMed1997

Individualizing hearing preservation in acoustic neuroma surgery.

Surgical series of hearing preservation in acoustic neuroma usually emphasize a team's results with one particular technique. This report reviews acoustic neuroma outcomes of individualizing the surgical approach to patient and tumor characteristics. This study reviews 60 consecutive hearing preservation acoustic neuroma surgeries in a total series of 330 acoustic neuromas. Tumor sizes ranged from 0.3 to 4 cm in patients ranging from 23 to 74 years of age. Middle fossa surgery was performed in 57%, retrosigmoid in 43%. Overall, measurable hearing was preserved in 77%, and useful hearing in 67%. Among middle fossa cases, 85% had measurable and 74% had useful hearing. Among retrosigmoid surgeries, 65% had measurable hearing and 58% had useful hearing. Overall, long-term facial nerve function was excellent (grade I or II) in 90% and poor (grade V or VI) in 2%. There was one case of bacterial meningitis (2%), and cerebrospinal fluid leaks requiring surgery occurred in four patients (7%). The hearing preservation and other outcome parameters in this series compare favorably with other reports. We believe that individualizing the surgical approach to the patient's tumor characteristics and clinical features contributed to the high rate of hearing preservation.

Hearing Disorders↗
PubMed1997

Cerebellopontine angle tumor outcomes in patients with hazardous occupations.

Cerebellopontine angle (CPA) tumor surgery can produce a spectrum of sensory and motor deficits that can alter a patient's lifestyle and occupation. An important consideration is whether patients can return to full occupational status especially when hazardous duties are involved. Outcome data in CPA tumor surgery usually report that most patients are able to return to preoperative function; however, whether these patients can return to hazardous duties is not specified. A retrospective study of 380 consecutive, operated CPA tumor patients was performed and 37 were identified who engaged in hazardous occupations including active military service, working at dangerous heights, piloting jet aircraft, aircraft navigating, and factory work with high-impact machinery. Overall, patients were able to resume full-time work in their previous occupations and 86% of patients reported that they were able to resume hazardous duties. CPA tumor surgery is compatible with continued full occupational duties after surgery, even for patients employed in hazardous situations.

Adult↗
PubMed1997

Preoperative embolization of anastomoses of the jugular bulb: an adjuvant in jugular foramen surgery.

We describe the technique of preoperative embolization of the inferior petrosal sinus/anterior condylar vein complex and the posterior condylar vein in three patients undergoing skull base surgery that required opening of the jugular bulb. Contrary to the usual situation, essentially no blood was lost during the operation, resulting in decreased surgical time and reduced risk to the lower cranial nerves.

Adult↗
PubMed1997

Surgical treatment of uncompensated vestibular disease.

Uncompensated vestibular disease is a serious, disabling disorder that substantially alters quality of life. Fortunately, most dizziness and vestibular disorders are managed conservatively or with medications and are self-limited. When medical management is unsuccessful, however, there is a wide array of surgical interventions that can significantly improve the symptoms. This article reviews the broad array of surgical techniques available for managing dizziness.

Cerebellopontine Angle↗
PubMed1997

Post-traumatic hydrops.

Post-traumatic Meniere's disease is a true clinical entity based on clinical observations and histopathologic study. The traumatic insult may be a blow to the head, a temporal bone fracture, infectious sequelae of measles, mumps, syphilis, or even acoustic trauma. Although there are many cases of Meniere's disease for which no definite etiologic agent can be identified, a detailed clinical history is the only way to identify possible etiologic causes for Meniere's disease. In all forms of post-traumatic Meniere's disease, the symptoms manifest in a delayed fashion following the insult, usually years.

Adult↗
PubMed1996

Indications and variations of transcochlear exposure of the ventral brainstem.

The transcochlear exposures represent a spectrum of three approaches (transotic to transcochlear to transpetrous) that provide progressively wider lateral skull base exposure. The approaches all combine the translabyrinthine approach with removal of the cochlea. The facial nerve remains in situ in the transotic approach. The facial nerve is mobilized posteriorly in the transcochlear approach, and the transpetrous exposure adds resection of the petrous apex with carotid artery mobilization. This report focuses on the indications for each of the variations of transcochlear exposure. These lateral skull base exposures can be individualized to the needs of each patient.

Adult↗
PubMed1996

MRI and clinical decisions in cochlear implantation.

High-resolution computed tomography (HRCT) is the standard imaging technique used in cochlear implantation. However, cochlear and retrocochlear soft-tissue abnormalities may not be detected with HRCT alone. To determine whether magnetic resonance imaging (MRI) provides clinically significant information in addition to HRCT in the evaluation of candidates for cochlear implants, we performed a prospective study of 13 consecutive patients with cochlear implant patients receiving preoperative, high-resolution fast spin-echo T2-weighted MRI scans of the temporal bone. MRI identified unanticipated cochlear fibrosis in one patient, vestibular schwannoma in one patient, patency in the second turn of the cochlea in a patient with labyrinthitis ossificans, and disproved cochlear fibrosis suspected on HRCT imaging in one patient. These findings were significant for clinical decisions regarding candidacy for surgery, side selection for surgery, and surgical technique in cochlear implantation. Our experience suggests a high-resolution T2-weighted MRI of the temporal bone should be used preoperatively in addition to HRCT before cochlear implantation.

Adolescent↗
PubMed1995

Metastatic melanoma to the cerebellopontine angle. Clinical and imaging characteristics.

OBJECTIVE: To describe the clinical and imaging features of metastatic melanoma to the cerebellopontine angle (CPA). DESIGN: A case series study with world literature review. SETTING: House Ear Clinic and St Vincent's Hospital, Los Angeles, Calif. PATIENTS: Three cases of metastatic CPA tumors operated on at the House Ear Clinic. INTERVENTIONS: All patients underwent surgical removal of CPA metastatic melanoma. MAIN OUTCOME MEASURE: Survival and duration of disease-free interval are reported. RESULTS: Two patients died of melanoma within 5 months of diagnosis and resection of CPA melanoma metastases. One patient survived for 5 years after undergoing total resection of an isolated CPA melanoma metastasis. Magnetic resonance imaging features were not uniform. CONCLUSIONS: Metastatic melanoma to the CPA should be suspected in patients with a history of melanoma and a rapid progression of audiovestibular or facial nerve symptoms. Surgical removal of solitary metastases to the CPA may be valuable in patients without other melanoma focus; however, the long-term prognosis for patients with CPA melanoma is grim.

Adult↗