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Biomedical subjects

R F Canalis

Publications and source records attributed to R F Canalis.

At least 19 recordsLinked to original sources

Nonneoplastic enhancing lesions mimicking intracanalicular acoustic neuroma on gadolinium-enhanced MR images.

The authors describe five patients with nonneoplastic lesions of the facial and/or vestibulocochlear nerves that demonstrated focal enhancement within the internal auditory canal on magnetic resonance (MR) images. MR and surgical findings for four patients with unilateral sensorineural hearing loss and one with Ramsay Hunt syndrome were reviewed. Three patients with hearing loss underwent surgical exploration and decompression of the internal auditory canal. The MR findings in all four patients with hearing loss were similar: Focal enhancement of the internal auditory canal was depicted on postcontrast T1-weighted images. Nonneoplastic lesions of the seventh and eighth cranial nerves may show focal enhancement on MR images, which mimics the appearance of a small intracanalicular neuroma. This potential for misdiagnosis may have important therapeutic implications.

Cranial Nerve Diseases

Extended retrolabyrinthine transtentorial approach to petroclival lesions.

In this communication, an extension of the retrolabyrinthine approach that has permitted safe, effective access to the petrous tip and clivus is presented. The basic technique involved complete mastoidectomy, preservation of the middle and inner ear structures, removal of the sigmoid and middle fossa plates, middle and posterior fossa craniotomies, ligation of the superior petrosal sinus, and division of the tentorium. Nine cases that exemplified the versatility of this approach constituted the basis of this paper: 2 cholesteatomas, 2 basilar artery aneurysms, 2 chordomas, and 3 meningiomas. The indications for, and complications of, this method have been discussed.

Adult

Auditory screening of infants.

Within the last 20 years, infant hearing screening has progressed from a laudable goal to a state-mandated reality in many areas of the United States. The high risk register provides a means by which history and neonatal physical examination can be used to identify the infant at risk for hearing loss. Two procedures (crib-O-gram and auditory brainstem-evoked response) have been the most common methods of screening for hearing loss in the newborn or in intensive care nurseries. Evoked cochlear emissions reportedly are identifiable in 90 to 100% of normal-hearing infants. This observation has lead to the use of evoked otoacoustic emissions as a hearing screening procedure with infants.

Acoustics

Subdural empyema of otorhinological origin.

The UCLA experience with subdural empyema (SDE) of otorhinological origin was reviewed. All cases of SDE with additional intracranial complications were excluded. Thirteen cases of SDE were identified with the predisposing factors being sinusitis (ten), mastoiditis (two), and otitis media (one). Based on data obtained from this review and from studies previously published in the literature, the keys to optimal outcome are rapid diagnosis, craniotomy with complete evacuation of the purulent collection followed by immediate surgical management of the otorhinological source of the SDE, and appropriate antibiotic therapy. Computed tomography is nearly always diagnostic but can be equivocal and magnetic resonance imaging may become the diagnostic study of choice. Of the five patients initially treated with burr holes. None of the patients initially managed with craniotomy were worse or died, whereas of the four patients initially managed with burr holes, two were worse (25 per cent) and two died (25 per cent). Antibiotic therapy is guided by the organisms found in the empyema and the site of origin of the infection. The otolaryngologist must remain aware of the clinical features and management of SDE and work closely with his neurosurgical colleagues to provide early, decisive surgical treatment.

Adolescent

Neurogenic sarcoma of the head and neck.

We discuss our experience in the diagnosis and management of seven cases of neurogenic sarcomas of the head and neck. These uncommon tumors, which affect all ages, arise most frequently from the brachial plexus, sympathetic chain, and the cranial nerves or their branches. An enlarging mass is the most common initially appearing symptom. Diagnosis may be difficult and rests heavily on gross evidence of a relationship between the tumor and its nerve of origin. Histologically, the lesions are composed of spindle cells with varying degrees of pleomorphism in a pattern that is frequently undistinguishable from fibrosarcomas. Ultrastructural studies may be helpful in establishing the neurogenic origin of these tumors. Neurogenic sarcoma of the head and neck has an extremely poor prognosis. Surgery remains the cornerstone of treatment, although radiotherapy is important for palliation.

Accessory Nerve

A technique for pharyngeal reconstruction in heavily irradiated patients.

A technique for esophageal reconstruction using a staged deltopectoral tubed, pedicled flap has been highly successful in irradiated patients. The basic principle involves use of the neck skin as the posterior wall and the dorsal and lateral aspects of the tubed flap to form the anterior and lateral walls of the newly constructed pharynx. The ventral surface forms the cutaneous covering. The submental area and base of tongue are used for implantation of the distal end of the flap, taking advantage of the abundant blood supply of this area. It is a fail-safe method of reconstruction, particularly applicable in cases in which the local skin is of poor quality.

Female

Nasopharyngeal rhabdomyosarcoma. A clinical perspective.

Embryonal rhabdomyosarcoma of the nasopharynx is an uncommon tumor occurring almost exclusively in children. The clinical characteristics of 56 previously reported cases are analyzed and four patients recently treated at the UCLA Center for the Health Sciences are described. Special attention has been given to the prognosis of these tumors as it relates to current methods of treatment.

Adolescent

Epidermoid carcinoma of the palate.

A retrospective study was made of 80 cases of epidermoid carcinoma of the palate that were treated at the UCLA Center for the Health Sciences between 1955 and 1977. Tumor size larger than 3 cm, extension to neighboring structures, and contralateral, bilateral, and "fixed" lymph node metastases substantially decreased survival. The presence of ipsilateral nodes and the modality of treatment used (surgery or irradiation) did not appear to affect the outcome. Three-year cure rates for all cases was 40%. Ninety percent of recurrences took place during the first two years after treatment, and additional cancers developed in the upper aerodigestive tract of 20% of the patients.

Adult

Ethmoidal mucoceles.

Twenty ethmoidal mucoceles were treated and observed for a minimum of two years after surgery. Unilateral exophthalmos was the initial complaint in all cases and nasal polyposis was a noteworthy finding in more than half of the patients. The lesions always extended into the orbit and usually eroded the floor of the frontal sinus. Exenteration through an ethmoidectomy approach was successful in 16 cases. Failure was due to recurrence of the mucocele in one case and in three cases to uncontrolled polypoid disease that produced recurrence of the exophthalmos. Long-term follow-up is mandatory since recurrences may take several years to occur.

Adolescent

Lethal thyroid carcinoma.

Forty-three patients who died of thyroid carcinoma (29 well-differentiated and 14 poorly differentiated tumors) were evaluated to define the parameters that affect the lethal nature of this tumor. Differentiated, limited extent of tumor and a young age at diagnosis correlated favorably with length of survival. Sex showed a trend in favor of female patients, while specific histologic characteristics and extent of resection showed no positive correlation. Based on these findings and a review of the literature, we recommend a radical approach in the management of localized, poorly differentiated tumors. For well-differentiated cancer, resection of the thyroid gland and the paratracheal, jugular, and upper mediastinal lymph nodes is advised.

Adenocarcinoma

Experimental repair of orbital floor fractures.

Eight rhesus monkeys (16 orbits) were used to evaluate the treatment of experimentally created orbital floor fractures. The fractures were repaired with antral bone, Silastic, and gelatin film implants and studied clinically and histologically. Four orbits were used as controls. All implants appeared to favorably influence healing by preventing entrapment of the orbital contents within the reparative tissue. Autogenous bone appeared to be the best implant. Silastic and gelatin film were also effective and well tolerated.

Animals

Management of brachial plexus tumors.

Brachial plexus neoplasms are uncommon. When this diagnosis is suspected, the functional and anatomical integrity of the brachial plexus and cervical spinal cord must be carefully assessed. A thorough search for other signs of neurofibromatosis (von Recklinghausen's disease) must also be completed. The distinction between neurilemoma and neurofibroma is an important and useful one to know. Evaluation by a pathologist who is well versed in neural tumors is mandatory for appropriate treatment of these usually benign lesions. Surgical intervention, adequately prepared on the basis of the patient's age, the amount of neural impairment, and the extent and histology of the tumor requires a surgeon who is experienced in peripheral nerve surgery and in microdissection techniques. Long-term follow-up is necessary to monitor the growth of known tumors, the detection of malignant change, and the appearance of other stigmata of von Recklinghausen's disease.

Adolescent

Transpalatal approach to deeper cranial structures.

The approach to deep midline cranial structures is technically difficult. The transpalatal approach has a relatively wide exposure as compared to the transnasal, transantral and transethmoidal approches. The added advantage of a medial approach which follows medial landmarks and the flexibility of being able to extend exposure to the maxillary sinuses and pterygomaxillary space makes this an attractive approach for large lesions in the nasal passages, nasopharynx and sphenoid sinuses. Large mucoperiosteal flaps, care to avoid the palatine vessels, and application of palatal splint postoperatively, minimize complications and patient discomfort. The authors have used this approach to repair nasopharyngeal atresia, remove nasopharyngeal angiofibromas, approach the pituitary, craniopharyngioma and isolated sphenoid sinus opacification as well as sphenoid sinusitis with cavernous sinus thrombosis.

Biopsy

The fate of pedicle osteocutaneous grafts in mandibulo-facial restoration.

To overcome some of the problems encountered in the repair of extensive composite defects of the head and neck, several means of transfering bone and soft tissue--while preserving the blood supply by means of a pedicle--have been clinically attempted. The superiority of pedicle osteocutaneous grafts compared to free grafts is demonstrated in a series of experiments in monkeys and dogs. Conventional and tetracycline labelled histological specimens, from animals sacrificed at intervals from two weeks to six months after grafting, illustrate the dynamic changes in the grafts. Pedicle supported grafts appeared superior to free grafts and partivipated actively in bone reconstruction.

Animals