Biomedical subjects

Nikolas H Blevins

Publications and source records attributed to Nikolas H Blevins.

11 recordsLinked to original sources

PubMed2006

Otologic manifestations of relapsing polychondritis. Review of literature and report of nine cases.

OBJECTIVE: Relapsing polychondritis (RP) is an episodic disease most likely of autoimmune etiology, characterized by recurrent inflammation of cartilaginous structures. METHODS: Retrospective case study at two tertiary referral centers with presentation of nine patients with otologic involvement of RP, review of the spectrum of otologic disorders seen, and treatment. RESULTS: The clinical course of otologic manifestations of RP was highly variable and ranged from mild to moderate. In 6/9 patients there was an association with other autoimmune disorders. In addition to recurrent auricular chondritis, which was present in 8/9 patients, our patients had otitis externa, chronic myringitis, Eustachian tube dysfunction, conductive hearing loss, sensorineural hearing loss, and tinnitus. All patients had their diagnosis of RP made on the basis of their otologic involvement and the response to systemic corticosteroids. CONCLUSION: The diagnosis of RP is primarily clinical, but laboratory studies and biopsy may contribute as well. Once the diagnosis is suspected, the otolaryngologist should consider consultation with a rheumatologist to assist in the management of additional systemic manifestations.

Adult↗

PubMed2006

The challenges of revision skull base surgery.

Because the skull base is an anatomically complex structure, skull base tumors can hide easily in the crevices that interconnect the intra- and extracranial spaces and intermingle with important neurovascular structures. Often, total surgical resection of these tumors is not possible, and even with postoperative adjuvant radiotherapy, some recurrences after treatment are inevitable. Early detection of recurrent skull base tumors requires clinical vigilance and periodic imaging studies. The management of recurrent skull base tumors presents many challenges beyond those associated with primary procedures. A multidisciplinary setting that includes modern microsurgery and stereotactic radiation therapy provides patients with optimal care.

Chondrosarcoma↗

PubMed2006

Virtuosity with the Mallet and Gouge: the brilliant triumph of the "modern" mastoid operation.

The development of mastoid surgery can be traced through the past 4 centuries. Once used as a means of evacuating a postauricular abscess, it has evolved to become a method for gaining entry into the middle ear for diagnostic purposes, to control chronic ear disease, or for otologic and neuro-otologic procedures. Earlier works led the way to the Wilde postauricular incision, which gave rise to Schwartze mastoidectomy. Stacke's technique of mastoidectomy was practiced for some time before Bondy, Heath, and Bryant introduced the modified radical mastoidectomy. By the 1930s, the mastoidectomy had evolved into a generally accepted otologic procedure. Endowed with a rich history, the future of mastoid surgery promises to be equally momentous.

History, 15th Century↗

PubMed2006

In vivo imaging of mammalian cochlear blood flow using fluorescence microendoscopy.

AIMS: We sought to develop techniques for visualizing cochlear blood flow in live mammalian subjects using fluorescence microendoscopy. BACKGROUND: Inner ear microcirculation appears to be intimately involved in cochlear function. Blood velocity measurements suggest that intense sounds can alter cochlear blood flow. Disruption of cochlear blood flow may be a significant cause of hearing impairment, including sudden sensorineural hearing loss. However, inability to image cochlear blood flow in a nondestructive manner has limited investigation of the role of inner ear microcirculation in hearing function. Present techniques for imaging cochlear microcirculation using intravital light microscopy involve extensive perturbations to cochlear structure, precluding application in human patients. The few previous endoscopy studies of the cochlea have suffered from optical resolution insufficient for visualizing cochlear microvasculature. Fluorescence microendoscopy is an emerging minimally invasive imaging modality that provides micron-scale resolution in tissues inaccessible to light microscopy. In this article, we describe the use of fluorescence microendoscopy in live guinea pigs to image capillary blood flow and movements of individual red blood cells within the basal turn of the cochlea. METHODS: We anesthetized eight adult guinea pigs and accessed the inner ear through the mastoid bulla. After intravenous injection of fluorescein dye, we made a limited cochleostomy and introduced a compound doublet gradient refractive index endoscope probe 1 mm in diameter into the inner ear. We then imaged cochlear blood flow within individual vessels in an epifluorescence configuration using one-photon fluorescence microendoscopy. RESULTS: We observed single red blood cells passing through individual capillaries in several cochlear structures, including the round window membrane, spiral ligament, osseous spiral lamina, and basilar membrane. Blood flow velocities within inner ear capillaries varied widely, with observed speeds reaching up to approximately 500 microm/s. CONCLUSION: Fluorescence microendoscopy permits visualization of cochlear microcirculation with micron-scale optical resolution and determination of blood flow velocities through analysis of video sequences.

Animals↗

PubMed2005

Sensorineural hearing loss, early greying, and essential tremor: a new hereditary syndrome?

OBJECTIVE: To present a syndrome composed of sensorineural hearing loss, early greying of scalp hair, and adult-onset essential tremor. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care academic hospital. RESULTS: Three individuals were seen with this triad, each with family members with similar features. Our patients are a 65-year-old man and two women in their 40s. Two noted hearing loss in adulthood, one as a child. All had complete greying in their 20s. The women developed essential tremor in their 20s, and the man in his 50s. All individuals have blue eyes without heterochromia. Additional evaluation failed to further categorize these patients. Each has two or more immediate family members with a combination of these findings. Molecular genetic testing suggests this is not a variant of Waardenburg syndrome. CONCLUSION: We believe this represents a previously unreported hereditary syndrome. SIGNIFICANCE: This new syndrome should be considered in the context of other syndromes involving audition, pigmentation, and movement.

Adult↗

PubMed2004

Transfacial recess ossicular reconstruction: technique and early results.

OBJECTIVES: The objective of this study was to present the technique of transfacial recess ossicular chain reconstruction (TFROCR) for potential use in selected patients with cholesteatoma. STUDY DESIGN: The author conducted a retrospective case review of all candidates for TFROCR between August 1998 and March 2003. SETTING: A tertiary referral center. PATIENTS: At first-stage tympanomastoidectomy, 22 ears (21 patients; 8 children and 13 adults) with cholesteatoma and ossicular discontinuity were identified as candidates for TFROCR. Seven patients had undergone previous tympanomastoid surgery. INTERVENTION: The first stage included canal wall up mastoidectomy with resection of disease, wide opening of the facial recess, cartilage graft tympanoplasty, and placement of silicone elastomer in the middle ear. Approximately 6 months later, patients underwent a second-stage postauricular procedure. Endoscopes were used to inspect the middle ear through the facial recess. When possible, TFROCR was then performed without elevating a tympanomeatal flap. MAIN OUTCOME MEASURES: Variations in anatomy, disease control, and hearing results were studied. RESULTS: Of the 22 candidate ears, 17 successfully underwent TFROCR, whereas 5 required traditional second-stage procedures with canal incisions. There were no surgical complications. Early hearing results are promising with an average air-bone gap of less than 20 dB. There have been no early failures from recurrent disease or prosthesis displacement. CONCLUSIONS: In carefully selected patients, TFROCR could be safe and effective for disease control and hearing restoration. It could provide for optimal prosthesis placement and almost immediate hearing improvement, avoiding the need for canal incisions, middle ear packing, and dry ear precautions. One must consider the potential risk of missing residual disease secondary to limited exposure.

Adolescent↗

PubMed2003

Otalgia.

The patient presenting with otalgia poses a diagnostic challenge for which orderly and diligent evaluation and management is needed. The etiology of otalgia can be either primary or referred, and a detailed history and physical examination with directed studies as indicated can elucidate the cause of the pain.

Diagnosis, Differential↗

PubMed2003

Current digital imaging for the otolaryngologist.

Digital imaging has arrived as a standard tool for the otolaryngologist. There is no better evidence of this than the American Academy of Otolaryngology-Head and Neck Surgery moving to an all-digital format for its 2003 national meeting. No longer will 35-mm slide projectors be available for any presentations in the country's largest otolaryngology program. Also, all of the major journals in the field now accept or require digital files of illustrations and photographs. With this change in standard, the question is no longer if, or even when to incorporate digital imaging techniques, but how to do so most efficiently. This can be quite a challenge, given the ever-changing field of computer technology. This article is intended to introduce the fundamentals of digital imaging, and how this technology can best be integrated into an otolaryngology practice.

Computers↗

PubMed2003

External auditory canal duplication anomalies associated with congenital aural atresia.

Maldevelopment of the first branchial cleft can produce a broad spectrum of anomalies in its derivative structure, the external auditory canal (EAC). Failure of the cleft to develop normally can result in either the absence of a normally patent EAC (atresia, or stenosis) or a duplication anomaly (cyst, sinus, or fistula). Despite their common origins, the coexistence of these anatomical abnormalities is quite unusual. We present four patients with both aural atresia and duplication anomalies of the EAC. Three patients had non-syndromic unilateral aural atresia and presented with periauricular lesions originating from the first branchial cleft. The other patient had a variant of Treacher Collins syndrome and presented with draining infra-auricular fistulae. The classification and management of first branchial cleft anomalies is reviewed in light of these cases. An understanding of the embryogenesis of the external ear is necessary to successfully recognize and treat this spectrum of deformities. A classification system is presented that encompasses the full spectrum of first cleft anomalies.

Adult↗

PubMed2002

Potential use of diode laser soldering in middle ear reconstruction.

BACKGROUND AND OBJECTIVES: To assess the potential use of diode laser soldering to improve mechanical stability of middle ear reconstruction. The diode laser with a biological solder may offer benefits over traditional methods. We evaluated the strength of soldered bonds and a means to apply such a technique in the human middle ear. STUDY DESIGN/MATERIALS AND METHODS: The strength of soldered junctions using fascia, cartilage, bone, and hydroxyappatite was evaluated in vitro. A diode laser (810-nm wavelength) and 50% albumin with 0.1% indocyanine green dye was used. Soldered bonds were compared to those obtained with adhesive alone. A fiberoptic delivery system was evaluated. Ten hydroxyappatite prostheses were soldered to the stapes in human cadaver temporal bones, and the force required to disrupt the bonds were measured. RESULTS: Statistically significant greater strength was obtained with soldering. Ossicular prostheses can be effectively secured to the stapes in a cadaver model. CONCLUSIONS: Soldering techniques show promise in middle ear reconstruction.

Albumins↗

PubMedDate not supplied

Visuohaptic simulation of bone surgery for training and evaluation.

Visual and haptic simulation of bone surgery can support and extend current surgical training techniques. The authors present a system for simulating surgeries involving bone manipulation, such as temporal bone surgery and mandibular surgery, and discuss the automatic computation of surgical performance metrics. Experimental results confirm the system's construct validity.

Bone and Bones↗