摘要:

FUELED BY A buoyant economy, popular attitudes and demands, and parallel progress in transferable technical and biological areas, neurosurgery has enjoyed a remarkable quarter of a century of progress. Developmental trends in the discipline have included the following: 1) a refinement of preoperative definition of the structural substrate, 2) miniaturization of operative corridors, 3) reduction of operative trauma, 4) increased effectiveness at the target site, and 5) incorporation of improved technical adjuvants and physical operative tools into treatment protocols. In particular, the computer has become a formidable ally in diagnostic and surgical events. Trends in technical development indicate that we are entering an exciting era of advanced surgery of the human cerebrum, which is heralded by the following: 1) current developments in areas of imaging, sensors, and visualization; 2) new devices for localization and navigation; 3) new capabilities for action at the target point; and 4) innovative concepts related to advanced operative venues. Imaging has provided structurally based surgical maps, which now are being given the new dimension of function in complex and integrated formats for preoperative planning and intraoperative tactical direction. Cerebral localization and navigation based on these advances promise to provide further refinement to the field of stereotactic neurosurgery, as linked systems are superseded by more flexible nonlinked methodologies in functionally defined volume-oriented navigational databases. Target point action now includes not only ablative capabilities through micro-operative methods and the use of stereotactically directed high-energy forms but also the emergence of restorative capabilities through applications of principles of genetic engineering in the areas of molecular and cellular neurosurgery. Complex, dedicated, and self-contained operative venues will be required to optimize the emergence and development of these computer-oriented micro/stereotactic capabilities, which appear to be unavoidably required as locales for the practice and development of virtual reality-based stations for operative rehearsal, simulation, training, and, ultimately, enhancement of operative events through robotic interfaces. Primary impetus for progress has relied upon new combinations of technologies, disciplines, and industries. Philosophical and practical problems include the spectrum of availability of these methods to the population at large, the training of individuals to properly administer these methods, defining the acceptable envelope of expertise, and maintaining suitable delivery and progress while containing spiraling costs. Advanced neurological surgery and the use and development of high-technology adjuvants require a robust economy that has a populace willing to invest in the luxury of such developments. The current socioeconomic situation is fragile from the standpoint of both economics and attitudes of the patients and health care providers, with diversion of economic resources, redistribution of funding bases, modification of patient referrals, practice styles, and service attitudes undermining progress. Economic pressures have brought high-technology methods under great scrutiny regarding their effectiveness and cost-effectiveness. Reform proposals have specifically targeted technology-oriented services, and the Office of Technology Assessment has recommended increasing the use of managed care providers who look to information on cost-effectiveness and clinical practice guidelines to establish efficient management strategies and issue “report cards.” Although the premise is laudable and “gimmickry” needs to be identified, it might be argued that such scrutiny and control might be overbearing and overused, impeding appropriate delivery and progress. Diverting funds from the patient, delivery, and research corridors by management organizations is deleterious to the quality of care and progress. Such practice is clearly operational in a number of influential health care maintenance organizations, as reported by theWall Street Journal(December 21, 1994). Such reordering is clearly harmful to the progress and delivery of high technology-related practices and tends to support simplistic and frequently regressive approaches, diverting patients as well as funds from progressive methods. High technology has brought with its application a myriad of “middle men” between the product and the provider. Some indication of this is evidenced by the increase, during the past decade, of the number of company exhibits of high-technology products at the American Association of Neurological Surgeons Annual Meeting. The number of exhibits has increased ≈150%, whereas the number of company representatives has increased 600%. Regularly, more representatives than doctors attend the Annual Meeting. Some scrutiny of the role, need, and expense related to this aspect of free enterprise seems appropriate, because it impacts upon the costs of high-technology medicine. Academic health centers, the “ground breakers” for progress in technology-oriented neurological surgery, are economically fragile, research fund-dependent bearers of large educational cost burdens. They, by their very nature, compete poorly in a managed care environment. The economic and organizational burden of reordering will no doubt have a seriously detrimental effect on proper training, advanced care delivery, and progress in the area of high-technology neurosurgery. It seems that major economic and reorganizational trends are underway that will specifically undermine and reduce the pace of progress in areas of high-technology neurosurgery. Creative action and a hardy temperament are needed to sustain the momentum and promise for the extraordinary.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

WE HAVE USED three-dimensional reconstruction magnetic resonance imaging techniques to understand the anatomic complexity of operative brain lesions and to improve preoperative surgical planning. We report our experience with 14 cases, including intra- and extra-axial tumors and a vascular malformation. In each case, preoperative planning was performed using magnetic resonance imaging-based three-dimensional renderings of surgically critical structures, such as eloquent cortices, gray matter nuclei, white matter tracts, and blood vessels. Simulations, using the interactive manipulation of three-dimensional data, provided an efficient and comprehensive way to appreciate the anatomic relationships. Interactive three-dimensional computer-assisted preoperative simulations provided otherwise inaccessible information that was useful for the surgical removal of brain lesions.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

TO ANALYZE THE effect of stereotactic radiosurgery on the hemorrhage rate of arteriovenous malformations (AVMs), we reviewed the clinical and angiographic characteristics of 315 patients with AVMs before and after radiosurgery. One hundred ninety-six patients sustained 263 bleeds in 10,939 patient-years before radiosurgery, for an annual nonfatal hemorrhage rate of 2.4%. Clinical follow-up after radiosurgery was available in 312 patients(mean, 47 ± 20 mo); follow-up ≥24 months was obtained in 295 patients (94%). Twenty-one patients had AVM bleeds at a median of 8 months(range, 1-60 mo) after radiosurgery. Two additional patients had three aneurysmal bleeds (at 5, 27, and 32 mo, respectively) for a 7.4% total risk of hemorrhage per patient. The actuarial hemorrhage rate until AVM obliteration was 4.8% per year (95% confidence interval, 2.4-7.0%) during the first 2 years after radiosurgery and 5.0% per year (95% confidence interval, 2.3-7.3%) for the third to fifth years after radiosurgery. Multivariate analysis of clinical and angiographic factors demonstrated that the presence of an unsecured proximal aneurysm was associated with an increased risk of postradiosurgical hemorrhage (relative risk, 4.56; 95% confidence interval, 1.77-11.70%;P< 0.001). No AVM hemorrhages were observed after radiosurgery in seven patients with intranidal aneurysms. No protective effect against hemorrhage was observed in patients who received an “optimal” radiation dose (≥25 Gy to the AVM margin) compared with patients who received <25 Gy to the AVM margin (P= 0.36). No patient suffered a hemorrhage after angiography had confirmed complete obliteration (n = 140) or suffered from an early draining vein without residual nidus (n = 19). Stereotactic radiosurgery was not associated with a significant change in the hemorrhage rate of AVMs during the latency interval before obliteration. No protective benefit was conferred on patients who had incomplete nidus obliteration in early (<60 mo) follow-up after radiosurgery. AVM patients with unsecured proximal aneurysms should have aneurysms obliterated either before radiosurgery or at the time of surgical resection of their AVMs.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

IN A SERIES of 145 patients with brain cavernous angiomas treated at our hospital in the last 16 years, the angiomas of 18 patients exhibited aggressive biological behavior characterized by recurrent overt bleeding, growth, or de novo appearance. The cavernomas were in the cerebellum in three patients, in the brain stem in one, in the thalamus in four, in the caudate nucleus in two, in the diencephalon in one, and in the white matter of the cerebral hemispheres in seven. Three of these patients suffered from the familial or multiple form of the disease, two were pregnant, three had previously been irradiated for other tumors, and one had been treated by radiosurgery in the past. Overall, new cavernous malformations not previously shown were discovered in six patients. In 10 patients (3 male and 7 female) presenting with recurrent hemorrhages, the mean period of time between bleedings was 11 months (range, 1 wk-3 yr). Eleven patients were treated by definitive surgery, and seven were conservatively treated. One patient with a diencephalic cavernoma died from progressive hypothalamic dysfunction; three patients in the nonsurgical group had repeated symptoms and were left with additional neurological deficits. The outcome of the surgical group was the same (seven patients) or improved (four patients). Risk factors favoring an aggressive behavior included pregnancy, familial or multiple form of the disease, previous whole brain or stereotactic radiotherapy, incomplete removal, brain location, and associated venous malformation. The female preponderance (female to male ratio, 13:5) may also suggest some role of hormonal factors in influencing the biological behavior of cavernous malformations.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

WE REPORT SEVEN patients with scalp arteriovenous malformations, including two patients with lesions >10 cm in diameter, who were successfully treated. The principal complaint of each patient was a deforming mass. Each of four patients had a history of blunt traumatic injury. The lesions, each consisting of the nidus, feeders, and draining veins, evolved in all patients. The nidus consisted of fistulae, which exhibited various angioarchitectures as revealed by angiography. A hemangiomatous component was histologically recognized in one patient. In five patients, in whom the lesions were relatively small and whose nidi included only large fistulae, the malformations were remedied by surgical intervention alone or were cured with embolization alone using liquid adhesives. In the two patients with lesions<10 cm, the nidi consisted of numerous large fistulae and plexiform fistulae in one patient and plexiform fistulae and a hemangiomatous component in the other patient. These patients were treated with a combination of transarterial embolization and surgical intervention. Preoperative embolization greatly reduced blood loss during resection. Total excision and scalp reconstruction using a soft tissue expander were performed in both patients. The cosmetic results were excellent in all of the patients, and no recurrence has been recognized during the follow-up period, which ranges from 31 to 99 months. The treatment of scalp arteriovenous malformations should strive to improve deforming features and to attain a permanent cure. Because each nidus includes a variety of anomalous angioarchitectural features, there should be different means and a combination of treatments for each patient. Embolization alone could be adequate treatment in relatively small lesions, the nidi of which consist only of several large fistulae. For malformations with more extensive, large fistulae or with anomalous components other than large fistulae, a combined endovascular and surgical approach and scalp reconstruction seems to be the best treatment.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

SOME NEUROSURGEONS STATE that intra-axial tumors may be resected with a low risk of neurological deficit if the tumor removal stays within the confines of the grossly abnormal tissue. This is thought to be so even when the lesion is presumably located in a functional area, providing that the adjacent normal-appearing cortex and subcortical white matter are not disturbed. This retrospective analysis presents evidence that this view is not always correct, because functioning motor, sensory, or language tissue can be located within a grossly obvious tumor or the surrounding infiltrated brain. Intraoperative stimulation mapping techniques identified 28 patients, ranging in age between 22 and 73 years, who showed evidence of functional tissue within the boundaries of infiltrative gliomas, as identified by correlation with computed tomography and magnetic resonance imaging scans, intraoperative ultrasound, gross visualization, and histological confirmation. Direct stimulation mapping of cortical and subcortical portions of the tumor during resections identified motor, sensory, naming, reading, or speech arrest function. Nineteen patients had new or worsened neurological deficits immediately after the operation, but after 3 months, only 6 continued to show new deficits whereas 18 showed no deficits and 2 improved. These results demonstrate that regardless of the degree of tumor infiltration, swelling, apparent necrosis, and gross distortion by the mass, functional cortex and subcortical white matter may be located within the tumor or the adjacent infiltrated brain. Therefore, to safely maximize glioma resection in these functional areas, intraoperative stimulation mapping may be used to identify functional cortical or subcortical tissue within, as well as adjacent to, the tumor, thus avoiding permanent injury.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

THE SUCCESS OF medical and surgical treatment for hemifacial spasm, an involuntary paroxysmal unilateral contraction of the facial muscles, has been mixed. Although microvascular decompression has the greatest reported success, symptom recurrence affects many patients in whom treatment was initially successful. In this study, we report the results of 34 patients who underwent microvascular decompression of the facial nerve from 1976 to 1989 as well as review the literature concerning the incidence and timing of recurrence in more than 600 patients who underwent microvascular decompression. In this series, 94% of 34 patients had continuous relief of spasm after surgical treatment (mean duration, >6 yr). Of those patients whose spasms were completely initially relieved, 10.3% developed some degree of recurrent spasm; however, no patient developed a recurrence after 24 months without spasm. Our review of the literature discloses that 86% of all recurrences occurred within 2 years of surgery. Patients who have no recurrence of symptoms 2 years after surgical treatment have only a 1% chance of developing recurrent hemifacial spasm. We also comment on possible causes of treatment failure and recurrence of hemifacial spasm after surgical treatment.

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1996

数据来源: OVID