摘要:

&NA;The first United States 201 cobalt‐60 source gamma knife for stereotactic radiosurgery of brain tumors and arteriovenous malformations became operational at the University of Pittsburgh on August 14, 1987. Four and one‐half years of intensive planning, regulatory agency review, and analysis of published results preceded the first radiosurgical procedure. Installation of this 18,000‐kg device and loading of the 201 cobalt‐60 sources posed major challenges in engineering, architecture, and radiophysics. In the first 4 months of operation, we treated 52 patients (29 with arteriovenous malformations, 19 with extra‐axial neoplasms of the skull base, and 4 with intra‐axial malignant tumors). Most patients either had lesions considered “inoperable” or had residual lesions after attempted surgical resection. Neither surgical mortality nor significant morbidity was associated with gamma knife radiosurgery. As compared with treatment by conventional intracranial surgery (craniotomy), the average length of stay for radiosurgery was reduced by 4 to 14 days, and hospital charges were reduced by as much as 65%. Based on both the previously published results of treatment of more than 2,000 patients worldwide and on our initial clinical experience, we believe that gamma knife stereotactic radiosurgery is a therapeutically effective and economically sound alternative to more conventional neurosurgical procedures, in selected cases. (Neurosurgery24:151‐159, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;We report the pathological accuracy of image‐directed stereotactic brain biopsy in 30 patients who had mass lesions of the brain and subsequently underwent resection of the mass. The histological diagnosis at stereotactic biopsy was appropriate for direction of clinical management in 28 of 30 patients. Correlation between the stereotactic and resection diagnoses was exact in 19 of 30 cases. These included 11 of 12 nonastrocytic neoplasms and 8 of 13 astrocytic neoplasms. Correlation was imperfect in 9 of 30 cases, but not to the extent of having significant clinical impact. These included 2 cases of anaplastic astrocytoma that were upgraded to glioblastoma multiforme, 2 cases of astrocytoma that had a significant oligodendroglial component, and 5 non‐neoplastic lesions that were reported on biopsy as showing nonspecific reactive changes. In 2 of 30 patients, the stereotactic biopsy was not accurate. This included one patient who had glioblastoma multiforme whose stereotactic biopsy showed only necrotic tissue. Serious diagnostic error that resulted in clinical mismanagement occurred in one patient who had a pineal germinoma that had large areas of granulomatous inflammation at which the stereotactic biopsy was directed. This study provides evidence that, with careful target placement, stereotactic biopsy can provide biopsy material that represents the entire lesion with an accuracy that is sufficient for clinical management. (Neurosurgery24:160‐165, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;A new technique, laser‐Doppler flowmetry, has been used intraoperatively to measure blood flow responses in normal brain tissue and brain tumor to blood pressure and arterial blood gas alterations. We have observed that blood flow is reduced in most cerebral tumors, and that most tumors retain the normal response to changes in arterial blood gas; however, these responses are varied. One group of tumors in our study demonstrated an autoregulatory capacity; a second behaved passively—that is, blood flow changes followed blood pressure—while a third showed no response. (Neurosurgery24:166‐170, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The natural history of postirradiation extracranial cerebrovascular disease is uncertain. Previous reported cases spanning 20 years of carotid surgery are difficult to evaluate, because patients may sometimes have unspecified symptoms, physical examinations, postoperative results, and follow‐up. Also, the evolution of carotid surgery over the past two decades makes it impossible to compare earlier operative technique with the state‐of‐the‐art technique of today. Our series of 7 patients underwent 9 carotid endarterectomies with an average follow‐up period of 46 months. The number of patients is small, and although technically this is a more difficult operation, we feel the results are favorable and may be comparable with endarterectomy procedures in nonirradiated patients. These patients should be approached as if radiation changes are not a major factor when they are considered for reconstructive arterial surgery. (Neurosurgery24:171‐178, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The efficacy of U74006F in the prophylaxis of chronic cerebral vasospasm (VSP) was evaluated in a randomized, double‐blind, placebo‐controlled trial. Forty cynomolgus monkeys were divided by restricted randomization into 2 treatment groups of 20. Five animals from each treatment group were randomized into subgroups 1 and 2. The animals of subgroup 1 were studied pathologically. Brain biopsies of the animals in subgroup 2 were performed and studied with high‐performance liquid chromatography (HPLC). The remaining 20 animals supplemented the number studied angiographically. Significant VSP (P< 0.05) was detected in the majority of vessels from the clot side (right) of both treatment groups. Electron microscopy results showed positive correlation with the angiographic data. When comparing the effects of U74006F to those of the placebo at day 7, there was a significant difference (P< 0.05) in the degree of VSP in the right extradural internal carotid and right middle cerebral arteries. This resulted from a greater degree of VSP in placebo animals. Two animals developed delayed ischemic deficits, one from each group. The infarct of the U74006F animal was smaller than the infarct in the placebo animal. Although overall changes in phosphagen levels did not reach statistical significance, HPLC analysis of the cortical biopsies did show a decrease in the ATP/ADP±AMP ratio of 54% in placebo animals and only 7% in animals receiving U74006F. The middle cerebral arteries of 2 animals were also studied with HPLC. The vessels from the clot side had moderate angiographic VSP and the ATP/ADP+AMP ratio was reduced by at least 50% compared with the middle cerebral arteries of the contralateral hemisphere. There may be a role for the use of U74006F in the prophylaxis of VSP following subarachnoid hemorrhage. (Neurosurgery24:179‐186, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;This study evaluated the changes in pathways of cerebrospinal fluid (CSF) outflow that accompanied acute and compensated hydrocephalus in the rabbit. Intraventricularly injected99mTc antimony sulfide was used as a tracer of outflow pathways, and specified structures were counted 12 to 24 hours after injection. Fifteen rabbits were divided into three groups: 1) an acutely hydrocephalic group in which 3 cisternal injections of blood were followed by a study of CSF pressure, ventricular size, and CSF outflow pathways 1 week after the last injection; 2) a control group treated according to the same protocol, except that sterile saline was injected instead of blood; and 3) a chronic group also treated according to the same protocol but in which the animals were maintained an average of 4 weeks after the last blood injection. Ventricular size was measured by computed digitation and expressed as an area ratio of ventricle to brain (VBR). In control animals, 11.8% of the injected colloid dosage was found in cranial perineural lymphatic channels, and 4.8% appeared in the spinal cord. The mean CSF pressure was 149 ± 20.2 mm H2O (mean ± SE) and the mean VBR was 0.040 ± 0.003. In animals evaluated 1 week after subarachnoid injection, accessory cranial perineural lymphatic outflow decreased significantly to 3.4%, and spinal cord activity increased to 9.8% (P< 0.05, two‐tailedt‐test). These animals were hydrocephalic and had CSF pressure of 247 ± 25.1 mm H2O (mean ± SE) and VBR of 0.083 ± 0.009. By 4 weeks, the percentage of activity in both the cranial perineural lymphatic channels (7.4%) and spinal cord (5.9%) had returned toward normal, as had the CSF pressure (154 ± 19.3 mm H2O) and VBR (0.045 ± 0.004). These data suggest that so‐called “accessory” spinal cord pathways are important in clearance of particulate matter and CSF after subarachnoid hemorrhage. In acute hydrocephalus, more CSF is shunted into the spinal cord and less escapes via the cranial lymphatic channels; with compensation of hydrocephalus, these both return toward control values. (Neurosurgery24:187‐192, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;In a retrospective study of 48 patients who underwent elective surgery for cerebral arteriovenous malformations, a statistical analysis of demographic, clinical, and neuroradiological data was undertaken in order to discover the best predictors of operative morbidity. In addition, the predictive value of different clinical grading systems as applied to this series was compared. All patients had a computed tomographic scan and a positive angiogram before surgery. Complete resection was proven angiographically. The univariate Mann‐Whitney‐Wilcoxon rank sum test, the Fisher exact test, Spearman's rank correlation coefficient analysis, and multivariate logistic regression were used as statistical methods. Duration of surgery, the development, of either new deficits or an increase in the preoperative neurological signs immediately after surgery, and rehabilitation (as measured by the Karnofsky index) were taken as target variables for the difficulty of operation and for postoperative morbidity, respectively. The largest diameter of the nidus of the arteriovenous malformation, eloquence of the adjacent brain, and deep venous drainage showed the most consistent correlation with these target variables. Intracerebral hematoma and other single factors, such as the age of the patient or localization of the arteriovenous malformation did not affect the outcome. The clinical grading scale of Spetzler and Martin provided better prediction of surgical risks than other proposed systems. (Neurosurgery24:193‐200, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;A new method of intraoperative measurement of adrenocorticotropic hormone for the localization of microadenomas in Cushing's disease is described and, in 21 cases, compared with preoperative bilateral sampling of the inferior petrosal sinus. By intraoperative measurement of adrenocorticotropic hormone in peripituitary venous blood, it was possible to determine a gradient for adrenocorticotropic hormone in 14 of 19 patients with surgically proven adenomas. In 4 of 6 patients in whom a false positive bilateral sample from the inferior petrosal sinus directed the surgeon to the wrong side of the pituitary, the localization could be correctly determined by intraoperative radioimmunoassay of adrenocorticotropic hormone. (Neurosurgery24:201‐205, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;In a consecutive series of 71 cases of extrinsic lesions involving the vertebral artery (VA), 51 patients presented with external compression of this vessel. The compressive agents included 34 tumors, 4 osteophytes, 5 fibrous bands, 4 traumatic lesions, 2 neural elements, and 2 infectious processes. The main site was the second portion of the VA (C2‐C6) (30 of 51 patients). Compression always induced at least significant stenosis, and in 8 patients caused complete occlusion. The compression was either permanent (44 patients) or intermittent (7 patients). Symptoms were observed in 11 patients, including 2 with permanent deficits. Surgical release of compression was performed each time symptoms could be explained by a reduction in VA flow and also when the compressing agent needed to be removed, as in the cases involving tumors. VA decompression was achieved by direct approach in 37 patients, by reduction and fixation of a traumatic dislocation in 2 patients, and by distal revascularization in 4 patients. Medical treatment or roentgenotherapy was used in the other patients. Results were excellent in all but 2 patients, who died from traumatic and ischemic lesions, respectively. Therefore, it seems important to identify external causes of compression of the VA for two reasons: 1) to suppress symptoms of vertebrobasilar insufficiency when their relation to VA compression is clearly established, and 2) to remove compressive agents like turnors safely while preserving the VA. (Neurosurgery24:206‐214, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;Conventional extensive laminectomy has been widely performed to reduce spinal cord compression, and is greatly facilitated by the use of an air drill. Laminectomy is recognized, however, as the occasional cause of problems after surgery, such as spinal instability or deformity, acceleration of spondylotic change, constriction of the dura mater caused by extradural scar formation, and lack of posterior bony protection for the spinal cord. In an effort to eliminate these negative aspects of conventional laminectomy, a surgical technique calledsuspension laminotomyhas been used. Fiftyfive patients treated with conventional extensive laminectomy and 55 others treated with suspension laminotomy were followed up clinically and compared. Flexibility and alignment of the cervical spine were assessed by plane radiographs, and dural configuration by computed tomographic scans. Neurologic improvement was also evaluated. Decrease of spinal movement after laminectomy was observed, notably during extension, probably as a result of functional insufficiency of paraspinal muscles. The incidence of postoperative spinal deformity was lower and the relief of dural constriction better in the patients treated with suspension laminotomy than in those treated with conventional laminectomy. Neurological recovery was significantly better in fully decompressed cases than in insufficiently decompressed cases. (Neurosurgery24:215‐222, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID