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Biomedical subjects

J N Fayad

Publications and source records attributed to J N Fayad.

14 recordsLinked to original sources
PubMed2003

The expanding domain of implantable hearing devices: an update on current status in the United States.

Several implantable devices are now approved in the United States for rehabilitation of conductive, mixed, and sensorineural hearing loss. This paper will review current rehabilitative options including middle ear implants, used for mild to severe sloping sensorineural loss, and bone-anchored hearing aids, for conductive or mixed hearing loss. The indications for these devices differ, as do the bases for exclusion. Audiologic evaluation parameters will be reviewed as a guideline to selection, and as a baseline to determine potential rehabilitative impact. We will also describe emerging applications, based on our ongoing research projects, for these devices that are anticipated to broaden the indications.

Cochlear Implants↗
PubMed2001

Early proactive management of vestibular schwannomas in neurofibromatosis type 2.

OBJECTIVE: The treatment of patients with neurofibromatosis Type 2 has always been challenging for neurosurgeons and neurotologists. Guidelines for appropriate management of this devastating disease are controversial. METHODS: A retrospective study of 28 patients with neurofibromatosis Type 2 who underwent 40 middle fossa craniotomies for excision of their acoustic tumors is reported. Eleven patients underwent bilateral procedures. The study focused on hearing preservation and facial nerve results for this group of patients. The 16 male patients and 12 female patients ranged in age (at the time of surgery) from 10 to 70 years, with a mean age of 22.6 years. The mean tumor size was 1.1 cm (range, 0.5-3.2 cm), and the majority of tumors were less than 1.5 cm. RESULTS: Measurable hearing was preserved in 28 ears (70%), with 42.5% being within 15 dB pure-tone average and 15% speech discrimination score of preoperative levels. In 55% of cases there was no change in the hearing class, as defined by the American Academy of Otolaryngology-Head and Neck Surgery. Of the 11 patients who underwent bilateral operations, 9 (82%) retained some hearing bilaterally. After 1-year follow-up periods (mean, 12.8 mo), 87.5% of patients exhibited normal facial nerve function (House-Brackmann Grade I). CONCLUSION: Early surgical intervention to treat acoustic tumors among patients with neurofibromatosis Type 2 is a feasible treatment strategy, with high rates of hearing and facial nerve function preservation.

Adolescent↗
PubMed2000

The Clarion electrode positioner: temporal bone studies.

OBJECTIVE: To study the relationship of the Clarion electrode to the modiolus when using an intracochlear positioner. BACKGROUND: There are theoretical advantages to positioning a cochlear implant electrode in close proximity to the modiolus. This may allow more focused, discrete fields of electrical current, reducing both requirements to achieve threshold and the channel interactions associated with the simultaneous and nonsimultaneous stimulation of closely spaced electrodes. METHODS: Ten fresh temporal bones were used to assess the position of the electrode in the scala tympani with the positioner in place. The bones were X-rayed after implantation. The relationship of the electrode to the modiolus was studied by calculating a ratio between the curve assumed by the electrode in relationship to the outer wall of the cochlea. The depth of insertion was evaluated in degrees or number of turns around the modiolus. RESULTS: The electrode was brought closer to the modiolus and a greater depth of insertion was achieved in all cases with the positioner. CONCLUSION: The intracochlear positioner is capable of bringing the electrode consistently closer to the neural elements within the modiolus.

Cochlear Implantation↗
PubMed2000

Conservative facial nerve management in jugular foramen schwannomas.

OBJECTIVE: Although transposition of the facial nerve is crucial in infiltrative vascular lesions involving the jugular foramen, the objective was to show that a conservative approach to management of the facial nerve is sufficient with jugular foramen neuromas because of their noninfiltrative, less vascular nature and medial location in the jugular foramen. STUDY DESIGN: Retrospective case review. SETTING: Tertiary, private, multiphysician, otologic practice. PATIENTS: Sixteen patients with jugular foramen schwannoma (18 procedures) treated between January 1975 and October 1995. The 8 male and 8 female patients ranged in age from 13 to 66 years (mean age 47.7 years). INTERVENTION: One-stage, total jugular foramen neuroma removal without transposition of the facial nerve, using a variety of surgical approaches. MAIN OUTCOME MEASURES: Facial nerve transposition (yes or no), House-Brackmann facial nerve grade, lower cranial nerve status, complications. RESULTS: One-stage total tumor removal was accomplished in all the cases. In 13 (72%) of the neuromas, removal was accomplished without facial nerve transposition. Transposition was performed in 2 revision cases in which scar tissue from a previous operation prevented complete control of the carotid artery and safe removal, 2 cases with large tumor extension anteriorly to the petrous apex, and 1 case with extensive involvement of the middle ear. A House-Brackmann facial nerve Grade I or II was obtained in 16 of the 18 procedures, with 1 Grade III and 1 case that remained Grade V, as it was preoperatively. CONCLUSIONS: One-stage, total tumor removal can be achieved with excellent control of the important vascular structures and without transposition of the facial nerve in a majority of jugular foramen schwannomas.

Adolescent↗
PubMed2000

Prognostic factors for hearing preservation in vestibular schwannoma surgery.

OBJECTIVE: To determine whether prognostic indicators for hearing preservation could be identified in patients with vestibular schwannoma undergoing middle fossa craniotomy resection. STUDY DESIGN: Prospective case review. SETTING: Private practice tertiary referral center. PATIENTS: 333 patients with serviceable hearing and vestibular schwannoma resected by middle fossa craniotomy from 1992 to 1998. MAIN OUTCOME MEASURES: Potential prognostic indicators, including tumor size and nerve of origin, preoperative pure-tone average, speech discrimination, distortion product otoacoustic emission testing, age, auditory brainstem response (ABR), and electronystagmography. RESULTS: Postoperative hearing near preoperative levels was attained in 167 patients (50%), with an American Academy of Otolaryngology-Head and Neck Surgery Class A hearing result in 33% and a Class B result in 26%. Comparison of potential prognostic indicators between groups with hearing preserved and the group with no measurable hearing revealed significant differences in preoperative hearing, ABR, and tumor origin data. Better preoperative hearing, shorter intraaural wave V latency, shorter absolute wave V latency, and superior vestibular nerve origin were associated with higher rates of hearing preservation. CONCLUSIONS: Preoperative hearing status, ABR, and intraoperative tumor origin data were shown to be of value as prognostic indicators.

Adolescent↗
PubMed2000

Revision stapedectomy.

OBJECTIVE: To evaluate results of revision stapedectomy with and without use of the laser and determine factors predictive of hearing outcome. STUDY DESIGN AND SETTING: Retrospective review of 356 revision stapedectomy operations performed at the House Ear Clinic, a tertiary neurotologic private practice, between 1983 and 1995. RESULTS: A postoperative gap of < or =10 dB was obtained in 60% of cases. Results were similar with and without the use of a laser. Sensorineural hearing loss of >10 dB occurred in 7.7%, with 3 (1.4%) ears with profound hearing loss. A poorer outcome was related to incus necrosis, multiple revisions, and indications for surgery other than conductive hearing loss. CONCLUSION: Revision stapedectomy can provide good gap closure in 60% of cases, with small risk of sensorineural hearing loss. SIGNIFICANCE: Although not as satisfactory as primary stapedectomy, revision stapedectomy can be offered to patients with reasonable expectations for good gap closure.

Adolescent↗
PubMed2000

Complications of venous insufficiency after neurotologic-skull base surgery.

OBJECTIVE: To characterize the incidence and complications resulting from venous insufficiency after neurotologic-skull base surgery. STUDY DESIGN: Retrospective case review of >3,500 cases. SETTING: Tertiary referral center, inpatient surgery. PATIENTS: Six patients: four with complications related to chronic venous insufficiency and two with complications related to acute venous insufficiency. INTERVENTION(S): Medical (steroids, acetazolamide, hyperventilation, mannitol) and surgical (lumboperitoneal shunt, optic nerve decompression, embolectomy) interventions were undertaken. MAIN OUTCOME MEASURE(S): Chronic venous insufficiency: nonobstructive hydrocephalus manifested by headache, disequilibrium, and papilledema with resultant visual loss. Acute venous insufficiency: acute nonobstructive hydrocephalus resulting in mental status abnormalities in the postoperative period. CONCLUSIONS: (1) Incidence of 1.5 per 1,000 cases. (2) Acute and chronic forms with different pathogenesis. (3) Acute form presents postoperatively with change in consciousness and herniation, and may proceed to death. (4) Chronic form presents months or years postoperatively with headache, disequilibrium, and visual changes from papilledema. (5) Occurs almost solely in patients with preoperative abnormalities of the venous collecting system. (6) Causes mental status changes postoperatively.

Acute Disease↗
PubMed1999

Detection and management of childhood cholesteatoma.

Childhood cholesteatoma is an aggressive disease that demonstrates higher rates of recidivism than its adult counterpart. The priorities in ideal management include total removal, followed by hearing restoration, followed by preserving the ear anatomy. Especially in children, one must endeavor to preserve ear anatomy if it does not jeopardize total removal of cholesteatoma. Absolute indications for CWD surgery include an only-hearing ear, a severely destroyed posterior canal wall, an extremely contracted mastoid, and matrix overlying a semicircular canal fistula. Reasons for staging childhood cholesteatoma include suspected residual disease, uncertainty about total removal of cholesteatoma, severe mucosal disease, and CWU procedures in which the cholesteatoma has diffusely invaded the bone. Adequate long-term follow-up is imperative. Patients and their families should be reminded frequently of the importance of close follow-up because recidivism is frequent. Successful management of cholesteatoma in children does not involve a rigid, "one-way" approach. The surgeon must be flexible and capable of employing the most appropriate procedure for the patient.

Age of Onset↗
PubMed1997

Venous channels of the petrous apex: their presence and clinical importance.

A methyl methacrylate casting technique was used to make detailed casts of the intracerebral venous system of four human cadaver specimens. Seven of the eight petrous apices studied were diploeic (n = 5), or pneumatic (n = 2) and had venules coursing in the anterior petrous apex. These venules form conduits connecting the cavernous to the inferior petrosal sinus or the jugular bulb and have not been previously described. In addition to the air cell system of the petrous apex, these venules may represent pathways for the spread of infection and the development of petrous apicitis, Gradenigo's syndrome, and the rare otogenic cavernous sinus thrombophlebitis. Their presence also may help explain the location of cholesterol granulomas, which afflict this area of the skull base.

Humans↗
PubMed1997

Medical treatment of Meniere's disease.

The aim of this article is to review the pharmacologic therapy used in the treatment of Meniere's disease. The first portion of the article discusses the treatment of acute labyrinthine crisis, which includes medication for patients that provides relief of the nausea, vomiting, and vertigo that accompanies acute attack. The second half of the article discusses medication used to help prevent attacks of Meniere's disease.

Aminoglycosides↗
PubMed1996

Tracheal autograft prefabrication using microfibrillar collagen and bone morphogenetic protein.

OBJECTIVE: To investigate the feasibility of prefabricating a tracheal autograft capable of microvascular free tissue transfer using microfibrillar collagen (Avitene) as a carrier for bone morphogenetic protein (BMP). METHODS AND DESIGN: Using heterotopic bone induction and soft tissue molding, an attempt was made to prefabricate a homologous tracheal autograft in a rodent free flap model. In 12 male Sprague-Dawley rats, linear troughs were dissected along the length of the gracillis muscle, filled with BMP-saturated microfibrillar collagen, molded around a silicone tracheal stent, and left pedicled on the femoral vessels. Untreated microfibrillar collagen was buried in muscle at a distant control site in 3 animals. Autografts were susequently evaluated for lumen integrity, vascular patency, and bone induction at 3 weeks. RESULTS: With the exception of 2 nonviable grafts, rings of heterotopic bone were created in all 10 animals. Rings spanning at least one third of the tracheal circumference maintained a noncollapsible lumen. Microfibrillar collagen was replaced by cancellous bone that reproduced the exact shape and volume of the collagen carrier. The lumen was lined by smooth fibroplasia, and there was no significant inflammatory response, bone exposure, or overgrowth. Soft tissue between rings allowed longitudinal flexibility, homologous to the native trachea. Bone induction did not occur in any of the control sites. CONCLUSIONS: Microfibrillar collagen is an effective carrier for BMP and may serve as the ideal substrate for tracheal reconstruction without the need for stenting. The potential use of BMP to bioengineer microvascular free flaps with intrinsic skeletal support has an unlimited potential and will add a new dimension to head and neck reconstruction.

Animals↗
PubMed1993

Arterial supply of the human endolymphatic duct and sac.

The arterial anatomy of the endolymphatic duct and sac was studied in vascular casts of methyl methacrylate of six human heads. The chief source of arterial blood supply to the endolymphatic duct and sac appeared to be the occipital artery. Arterioles entered the bone of the mastoid process. Arterioles in bone, the walls of the sigmoid sinus, and the posterior fossa dura coursed medially to supply the endolymphatic sac. The orientation of arterioles tended to be along the long axis of the endolymphatic duct and sac, whereas venules were more likely to be circumferentially oriented. Arterioles arising from dural vessels divided into deeper branches, which supplied periductal connective tissue, and superficial branches, which entered canaliculi of the vestibular aqueduct. Gross anatomic findings were confirmed by histologic examination of temporal bones.

Arteries↗