摘要:

OBJECTIVE:The benefits of intraoperative magnetic resonance (MR) imaging for diagnostic and therapeutic measures are as follows: 1) intraoperative update of data sets for navigational systems, 2) intraoperative resection control of brain tumors, and 3) frameless and frame-based on-line MR-guided interventions. The concept of an intraoperative MR scanner in the sterile environment of the operating theater is presented, and its advantages, disadvantages, and limitations are discussed.METHODS:A 0.2-tesla magnet (Magnetom Open; Siemens AG, Erlangen, Germany) inside a radiofrequency cabin with a radiofrequency-shielded sliding door was installed adjacent to one of the operating theaters. A specially designed patient transport system carried the patient in a fixed position on an air cushion to the scanner and back to the surgeon.RESULTS:In a series of 27 patients, intraoperative resection control was performed in 13 cases, with intraoperative reregistration in 4 cases. Biopsies, cyst aspirations, and catheter placements (mainly frameless) were performed under direct MR visualization with fast image sequences. The MR-compatible equipment and the patient transport system are safe and reliable.CONCLUSION:Intraoperative MR imaging is a safe and successful tool for surgical resection control and is clearly superior to computed tomography. Intraoperative acquisition of data sets eliminates the problem of brain shift in conventional navigational systems. Finally, on-line MR-guided interventional procedures can be performed easily with this setting. As with all MR systems, individual testing with phantoms, application of correction programs, and determination of the optimal amount of contrast media are absolute prerequisites to guarantee patient safety and surgical success.

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

OBJECTIVE:α1-Antitrypsin (AAT) and α2-macroglobulin(AMG) are elastase inhibitors that bind the enzyme and reduce measured levels of free elastase. It was recently demonstrated that some patients with intracranial aneurysms have significantly elevated plasma elastase (PE) levels. Although this elevation is unrelated to plasma AAT, it is unknown whether abnormal AAT phenotypes or reduced AMG levels play a role. Moreover, the pathological significance of this elevation is not understood.METHODS:Plasma from 24 patients with aneurysms (ruptured, n = 15; unruptured, n = 9) and 10 age-matched patients who comprised a control group was analyzed for PE and AMG levels by enzyme-linked immunosorbent assay and for AAT phenotype by isoelectric focusing. Sections of superficial temporal artery obtained from these patients at the time of surgery were examined for evidence of elastin degradation by using a van Gieson stain, with scoring on a nine-point quantitative scale.RESULTS:Patients with aneurysms showed significantly elevated PE levels (119± 28 versus 17 ± 7 µg/ml,P< 0.05), but AMG levels were not decreased. AAT phenotypic abnormalities were observed in 10% (2 of 20) of the patients with aneurysms, but this was not different from the expected population incidence (7%). Elastin degradation scores were significantly higher in patients with aneurysms than in patients in the control group (4.26 ± 0.54 versus 1.21 ± 0.43,P< 0.05). In addition, patients with higher elastase levels (>80µg/ml) demonstrated 55% higher degradation scores than did those with lower elastase levels (<80 µg/ml).CONCLUSION:These data suggest that high PE levels may play a role in the systemic arterial elastin degradation seen in patients with intracranial aneurysms. These data also support the contention that elevated elastase levels are not the result of decreased protease inhibitor levels. Although PE levels were significantly higher for the entire group of patients with aneurysms, this assay has relatively low sensitivity for predicting the presence of unruptured aneurysms. Additional study is necessary to determine whether serum elastase levels greater than 80 µg/ml, in the setting of other risk factors, are useful in identifying asymptomatic patients for additional screening.

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

OBJECTIVE:To determine the effect of initial therapy (surgery and external beam radiation) on the proliferative capacity of glioblastoma and whether adjunctive high focused doses of radiation therapy can further reduce the proliferative capacity of the tumor. This would provide a rationale for attempting to further control local tumor growth with the different forms of high-dose focused radiation available.METHODS:Patients with glioblastoma were initially treated within a randomized, controlled study with or without iodine-125 (125I) brachytherapy after initial surgical resection and external beam radiation (50 Gy in 25 fractions). Specimens from 24 consecutive patients later reoperated for"recurrence" were used to determine the effects of125I brachytherapy on the histological features and proliferating cell nuclear antigen index of the tumor tissue.RESULTS:125I brachytherapy reduced histological features prognostic for tumor progression, i.e., cellularity, pleomorphism, vessel hyperplasia, and degree of mitosis (P< 0.05). The degree of mitosis (marker for the mitotic or "M" phase) and proliferating cell nuclear antigen index(marker for the late G1 and S phase) provide complementary data on the cell kinetics of the tumor. Proliferating cell nuclear antigen immunostaining was lower in the125I brachytherapy group (34.6 ± 8.2%, mean± standard error) compared with the control nonimplant group (68.2± 3.5%).125I brachytherapy produced a dramatic reduction in mitotic figures (mean histological score = 0.0 ± 0.0).CONCLUSION:Adjunctive treatment of glioblastoma with discrete high doses of radiation therapy delivered by125I brachytherapy allows further control of the proliferative capacity of the tumor.

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

OBJECTIVE:From 1978 to 1993, 1000 vestibular schwannomas were operated on at the Department of Neurosurgery at Nordstadt Hospital. The goal was to improve the chances of hearing preservation by recording auditory brain stem responses(ABRs). ABRs can be used for preoperative classification of cochlear nerve impairment and for prediction of the changes of hearing preservation.PATIENTS AND METHODS:In addition to the previously described audiometric testing, the patients underwent perioperative and intraoperative bilateral ABR recording at 100-dB condensation and rarefaction click stimulation. The classification system of five types of ABRs, as presented before, is based on the presence and on the latencies of Waves I, III, and V, with a special emphasis on Wave III's representing the activity of the first brain stem nuclei within the auditory pathway. According to an analysis of 420 preoperative ABRs, in case of a preoperative Type 1 or 2, the rate of hearing preservation is 80%.DISCUSSION:In the case of good clinical and audiometric hearing, a severely deteriorated ABR is mostly an indicator of severe nerve compression and adhesion by the tumor. In view of subsequently reported experiences with intraoperative ABR monitoring, the value of the presented system emphasizing the importance of Wave III is stressed and discussed with other views in the literature. The criteria presented here are not designed for recognition of retrocochlear disease but aim for evaluation of the state of the auditory nerve and its perspective.CONCLUSION:By the presented classification of ABR Types B1 through B5, preoperative prediction of the likelihood of hearing preservation is improved.

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

OBJECTIVE:We have developed a telemetric intracranial pressure sensor (OSAKA telesensor; Nagano Keiki Seisakusyo Co. Ltd., Tokyo, Japan) and investigated the clinical usefulness of new ventriculoperitoneal shunting with an OSAKA telesensor, an on-off valve, and a programmable valve.METHODS:The OSAKA telesensor was applied in 94 patients at Osaka Medical College between March 1986 and December 1995. Postoperative management, postoperative course, postural change of intracranial pressure (ICP), and zero drift of the OSAKA telesensor were investigated.RESULTS:ICP was measured easily in all patients with no inconvenience. The setting of the programmable valve was adjusted postoperatively 38 times in 25 patients. Postoperative ICP in the upright position was -14.9 ± 4.5 mm Hg, and the difference in ICP between the supine and the upright position was about 20 mm Hg. The slope of the decrease in ICP with continuous postural changes from the supine to the upright position was steep until about 30 to 45 degrees but became incrementally less or even rose slightly above this angle. The initial slope was steeper when the shunt was open than when the shunt was closed; it was also steeper postoperatively than preoperatively. This initial slope, therefore, may indicate the intracranial compliance. Seven cases of shunt malfunction were diagnosed correctly by ICP measurements. Zero drift of the OSAKA telesensor was easily corrected by comparing the ICP reading from the telesensor with the puncture pressure in the on-off valve.CONCLUSION:The OSAKA telesensor is very useful in the postoperative care and pathophysiological evaluation of patients with hydrocephalus.

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1997

数据来源: OVID