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Biomedical subjects

J E Dervin

Publications and source records attributed to J E Dervin.

5 recordsLinked to original sources

The impact of interventional neuroradiology on service in a neurosurgical unit.

Endovascular treatment of cerebral aneurysms has rapidly evolved and has transformed neurosurgical practice. We evaluated the influence of an interventional neuroradiology service on cerebral aneurysm management. We performed a retrospective analysis of all aneurysms treated in our unit before and after the establishment of endovascular treatment. All patients (n = 248: 78M: 170F aged 10-78 years) who underwent aneurysm treatment between 1996 and 1999 were included in the analysis. Length of in-patient stay on neurosurgical ward, GOS at 6-month follow-up and complications of treatment were the factors chosen for the analysis. Definitive treatment was attempted in 306 of 374 aneurysms detected (203 surgical and 103 endovascular). During the last 2 years of the study period, 46% of all aneurysms were coiled. Endovascular treatment of ruptured aneurysms tended to be sooner than surgery, but in-patient stay following treatment was the same. No significant difference in GOS at 6-month follow-up was found (chi2 = 0.18). Coiling of unruptured aneurysms reduced in-patient stay when compared with surgery (t-test, p < 0.001), fewer complications occurred, but no difference in outcome was seen at follow up (chi2 = 1.09). Our data suggest that the long-term morbidity following subarachnoid haemorrhage is not related to treatment modality. Coiling is the preferred treatment for unruptured aneurysms. The GOS is insensitive to the detection of the perceived benefits of coiling. The increasing role of interventional neuroradiology has direct effects on many aspects of neurosurgical practice.

Adolescent↗

The impact of interventional neuroradiology on neurosurgical training.

Aneurysmal subarachnoid haemorrhage carries a high mortality and morbidity. Surgical treatment (craniotomy and clipping of the aneurysm) has been, until recently, the gold standard treatment. Endovascular embolisation treatment has rapidly evolved and the evidence available suggests that the results are as good as surgery. Endovascular treatment successfully occludes the aneurysm to prevent re-haemorrhage, whilst reducing the procedural morbidity when compared to craniotomy and clipping. It is perceived to be of particular benefit for aneurysms in the posterior cerebral circulation where operative morbidity and mortality are significantly higher than for aneurysms on the anterior circle of Willis. The establishment of endovascular treatment has reduced the number of cases being treated surgically, and this has had a significant effect on surgical training. We analysed the management of all ruptured aneurysms treated in our unit over a 4-year period. During the same period, an endovascular service was established in the unit. We devised a novel system for the angiographic grading of aneurysms in order to evaluate the impact that coiling has had on surgical training. The results show that as few as four aneurysms per year would be appropriate for specialist registrars to operate upon. We propose some mechanisms for maintaining high quality surgical training.

Adolescent↗

CT findings in orbital tumours of nerve sheath origin.

The clinical and CT features of orbital nerve sheath tumours (13 neurofibromas and 17 neurilemmomas, including one malignant neurilemmoma) have been reviewed. The commonest clinical findings were proptosis, mild impairment of visual acuity and disorders of eye movements. No significant correlation with intra- or extraconal location and these symptoms was found. The two types of tumour were morphologically similar, most being smooth retrobulbar masses, elongated in the long axis of the orbit; lobulation was slightly more common with neurofibromas. The neurilemmomas were generally larger than the neurofibromas. The distribution of neurilemmomas in the retrobulbar space, and in its intra- and extraconal compartments appeared random, but most neurofibromas occurred in the upper orbit and three quarters lay extraconally. The apex of the orbit was seen to be clear of tumour in all intraconal neoplasms (except the one case of malignant neurilemmoma); this observation may be useful in differentiation from intrinsic optic nerve tumours and pseudotumour. Focal or generalised enlargement of the bony orbit was common, being seen in four-fifths of neurilemmomas and three-quarters of neurofibromas. Tumour density was homogeneous for all the neurilemmomas and in the majority of neurofibromas: attenuation coefficients were slightly higher for the neurofibromas. Subcutaneous extension was more common in neurofibromas, occurring in approximately one third of cases but was observed in about a tenth of the neurilemmomas. Enhancement with intravenous contrast medium was variable; contrast medium was helpful in showing intracranial extension. Although the CT findings did not allow unequivocal presurgical diagnosis, they were suggestive in many cases and facilitated biopsy.

Humans↗

A simple system for image directed stereotaxis.

A simple system for CT directed stereotaxis has been developed. This technique represents a true three-dimensional solution to the problems of CT stereotaxis and is therefore free of positional constraints relating to the orientation of the patient/stereotactic instrument/CT scan plane, but is not dependent on the relatively complicated mathematical methods required by existing techniques. The preliminary series of 17 procedures are presented, 13 of these were designed to obtain tissue diagnosis. One patient had effective stereotactic aspiration of a colloid cyst of the third ventricle. The stereotactic instrument itself is lightweight and easy to use, a wide range of target trajectories including low sites are possible. The design of this instrument would be particularly well suited for MR directed stereotaxis.

Biopsy↗

Development of an analogue method to link stereotactic surgery to computed tomography.

The mathematical problems involved in linking computed tomography with stereotactic surgery are complicated. The use of an analogue has provided a simple, precise solution to the problems and gives the neurosurgeon a clearer understanding of the complexities of stereotactic target location. The feasibility and accuracy of this technique has been demonstrated in preclinical trials. A prototype stereotactic instrument compatible with any CT scanner has been suggested and used in the preclinical trials. The analogue method of linking computed tomography and stereotactic surgery requires no modification of the CT scanner.

Brain Diseases↗