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Biomedical subjects

Michael P Colreavy

Publications and source records attributed to Michael P Colreavy.

7 recordsLinked to original sources

Surface microstructure of the perilymphatic space: implications for cochlear implants and cell- or drug-based therapies.

OBJECTIVE: To study the surface microstructure of the scala tympani and scala vestibuli in humans and cats using scanning electron microscopy. DESIGN: Cochleas from 8 humans and 4 cats were harvested and the otic capsule and soft tissue removed before the cochleas were prepared for scanning electron microscopy. Micrographs were taken of the bony surface of both the scala tympani and scala vestibuli in each cochlear turn. The diameter and density of the micropores (canaliculi perforantes) and the thickness of the osseous spiral lamina (OSL) adjacent to Rosenthal's canal was measured. RESULTS: The human cochlea exhibits numerous canaliculi on the surface of the scala tympani, particularly associated with the OSL. There was a large range of diameters in the modiolar region of the OSL (0.2-23.0 micro m). The OSL was also very thin, with a mean thickness of 26.8 micro m in the base, tapering to 8.4 micro m in the apical turn. Far fewer canaliculi were evident in the scala vestibuli. Examination of the cat cochleas showed a similar distribution of canaliculi to that seen in the human; however, they were smaller in diameter and the OSL was thicker than in the human cochleas. CONCLUSIONS: The OSL is a thin and highly porous bony lamina that would appear to provide an open and extensive fluid communication channel between the scala tympani and Rosenthal's canal. These findings have important implications for the design and application of perimodiolar cochlear implant electrode arrays and may provide a potential route for drug- and cell-based cochlear therapies delivered via the scala tympani.

Animals↗

Tracheal juvenile xanthogranuloma in a child.

Juvenile xanthogranuloma is the most common form of non-Langerhans cell histiocytosis in children. It usually presents in the form of cutaneous lesions. Occasionally, the disease may affect other organs. Visceral forms are usually associated with cutaneous lesions, and are easily diagnosed. In isolated visceral occurrence, however diagnosis may prove difficult. Having the same spontaneous remission as cutaneous lesions, visceral lesions require treatment only in the case of serious dysfunction. We describe a case of isolated juvenile xanthogranuloma of the trachea, which has not previously been reported in children. The patient presented with serious respiratory symptoms that required immediate intervention.

Airway Obstruction↗

Argon plasma coagulation in the treatment of tonsil remnants.

Tonsil remnants are a problematic outcome in a subset of patients undergoing tonsillectomy. Treatment options are rarely discussed in the literature. This is the first description of the use of argon plasma coagulation (APC) in this setting. APC is based on the principle of ionised argon gas creating a conductive plasma between an activating electrode and a tissue surface. We describe the usability and clinical efficacy of this modality in a group of six patients.

Adolescent↗

Randomized controlled trial comparing argon plasma coagulation tonsillectomy with conventional techniques.

Argon plasma coagulation (APC) is based on the principle of ionized argon creating a conductive plasma between an activating electrode and a tissue surface. To date, its use in tonsillectomy has not been extensively examined. The purpose of this randomized controlled trial was to assess the clinical efficacy of APC as a tool for this common surgical procedure. Forty patients were randomized into two groups--treatment A (conventional tonsillectomy, n = 20) and treatment B (APC tonsillectomy, n = 20). Trial end-points included a) operative time, b) intra-operative blood loss, and c) objective assessment of post-operative pain, by completion of a visual analogue pain score chart, over a two-week period. Thirty-one patients were available for analysis. There was a statistically significant reduction in the intra-operative blood loss with treatment B (p = 0.02). There was no statistical difference between both groups for the other outcome measures. First clinical experience with this treatment modality shows that it is an attractive alternative to conventional tonsillectomy and may offer possible benefits.

Adolescent↗

A post-traumatic nasal epidermoid: an endoscopic approach.

BACKGROUND: Epidermoid cysts are thought to arise as a result of implantation of epidermal cells into the deeper dermal elements. These cysts have previously been described postsurgery but not after accidental nasal trauma. METHODS: We outline a case of a nasal epidermoid occurring post-blunt nasal trauma and its subsequent excision. RESULTS: The lesion was excised successfully endoscopically without recourse to an open technique. CONCLUSION: We describe, for the first time, the successful intranasal removal of a post-traumatic epidermoid cyst via an endoscopic approach.

Adolescent↗