Biomedical subjects

M O Kelleher

Publications and source records attributed to M O Kelleher.

5 recordsLinked to original sources

PubMed2006

The use of ciliary neurotrophic factor to promote recovery after peripheral nerve injury by delivering it at the site of the cell body.

Despite a body of evidence showing that various neurotrophic factors support the survival of nerve cells and stimulate axonal outgrowth, doubt remains about their optimal site of application as well as the more compelling question of what clinical benefit, if any, they would confer. Ciliary neurotrophic factor (CNTF) supports the survival of motorneurons in vitro and in vivo. Direct delivery of CNTF to the cell bodies may help reduce the side effects and overcome the problem of rapid systemic clearance. The aim of this study was to establish whether nerve regeneration may be improved upon by the controlled addition of a specific humoral neurotrophic substance (CNTF) at the level of the cell body. Three groups of five adult sheep were used. The first group acted as normal controls. In the second and third groups, the median nerve was divided and repaired using an epineurial suture technique. In the second group, CNTF was supplied into the CSF at the level of C6 by an implanted osmotic pump. In the third group physiological saline was placed in the osmotic pump. The animals underwent comprehensive electrophysiological and isometric tension experiments at six months. All of the animals had reduced electrophysiological, morphometric and isometric tension indices after surgery compared to normal. The CNTF group had better results than the saline group in the following; (1) area and amplitude of the muscle action potential (2) the percentage of tetanus and muscle mass preserved after repair. These differences were only statistically significant for amplitude of the muscle action potential. No statistical difference was found in the morphological indices (fibre diameter, axon diameter, myelin thickness and internodal length) between the CNTF and saline groups. CNTF does not confer a functional benefit when applied at the level of the cell body.

Animals↗

PubMed2005

Cranio-orbital approach for complex aneurysmal surgery.

Certain aneurysms of the anterior circulation continue to offer a technical challenge for safe exposure and clipping. The purpose of this paper was to describe the cranio-orbital approach for surgical clipping of complex aneurysms and to evaluate prospectively the associated complications of this approach. Prospective audit of all patients undergoing cranio-orbital approach for aneurysm surgery from 1997 to 2004 by the senior author. Twenty-five patients, eight male and 17 female, median age of 52 years, range 28-73. All patients had a standard pterional approach supplemented by an orbital osteotomy. In the 7-year period 367 patients underwent treatment for their aneurysms (169 clipped and 198 coiled). Of the 169 patients who were operated on, 29 had a skull base approach, of which 25 were cranio-orbital. The aneurysm location was as follows: 16 middle cerebral artery (MCA), three carotid bifurcation, four anterior communicating artery (ACOMM), one ophthalmic and one basilar. There were no approach-related complications. The cranio-orbital craniotomy can be a useful adjunct in the surgical treatment of giant or complex aneurysms. It offers the following advantages over a standard pterional approach: reduces operative distance; allows easy splitting of the sylvian fissure; and provides a wide arc of exposure with multiple working corridors.

Adult↗

PubMed2003

The pretzel sign: angiographic pattern of tortuous intra-aneurysmal blood flow in a giant serpentine aneurysm.

Giant serpentine aneurysms (GSAs) form a specific subgroup of giant cerebral aneurysms that have pathognomonic angiographic features. We report the angiographic findings of a GSA demonstrating a striking convoluted dynamic flow pattern, which we have called the 'pretzel sign'. The aneurysm was successfully treated by permanent occlusion of the parent vessel using a detachable balloon. GSAs should be identified prior to treatment in view of their particular management requirements.

Adult↗

PubMed2002

Health-related quality of life in patients with skull base tumours.

The objective of the investigation was to report on the health-related quality of life (HRQoL) of patients diagnosed with skull base tumours using the Short Form Health Survey questionnaire (SF-36). Those patients suffering with vestibular schwannoma were examined to determine the effect facial nerve function had on their quality of life. It took place at the tertiary referral centre at the Department of Clinical Neurosciences, Western General Hospital, Edinburgh. A prospective study of 70 consecutive patients was taken, who harboured the following tumours: 54 vestibular schwannomas, 13 meningiomas, two haemangioblastomas and one hypoglossal schwannoma. Patients were interviewed using the short form 36 (SF-36) questionnaire. Facial nerve function was assessed in those patients who had vestibular schwannomas. The entire cohort of live skull base patients were assessed after a median follow-up time of 38.4 months. Patients with vestibular schwannoma treated conservatively with interval MRI had a quality of life similar to t he normal population. Those who underwent surgery had a significant difference in two of the SF-36 domains. No statistically significant correlation was found at final assessment between the degree of facial nerve functioning and any of the domains of SF-36. Patients with non-vestibular tumours had an impaired HRQoL in seven of the eight domains. Patients with skull base tumours have a significant impairment of their HRQoL. A conservative policy of follow up with interval MRI for patients with small vestibular schwannomas may therefore be more appropriate to preserve their HRQoL. Facial nerve outcome has little influence on quality of life in vestibular schwannoma patients.

Adult↗

PubMed2001

The use of conventional and invaginated autologous vein grafts for nerve repair by means of entubulation.

Nerve repair by entubulation has re-emerged recently as a possible means of enhancing the microenvironment at the site of repair by inclusion within the tube of various trophic factors. To this end, a modification of the vein-graft technique has been used by turning it inside out before repair, to expose the adventitial surface to the regenerating axons. A comparative study of standard vein grafting versus the inside-out technique was carried out in two equal-sized groups of inbred Lewis rats. Jugular vein isografts were derived from litter mates. The sciatic nerve was transected and repaired by entubulation using the standard vein graft in one group and the inside-out graft in the other group. Morpho-metric and electrophysiological assessment were carried out 3 months after repair. When the animals were assessed it was found that both the standard-vein-graft group and the inside-out group exhibited a reduction in all of the morphometric and electrophysiological variables when compared to normal nerves. The mean axon diameter, fibre diameter and myelin sheath thickness were, however, found to be greater in the group that underwent the inside-out repair. The superior morphometric results seen in the inside-out group were not matched by improved electrophysiological performance. It is concluded that the use of the inside-out technique confers no functional benefit over standard vein grafting.

Animals↗