摘要:

OBJECTIVEAlthough direct clipping remains the treatment of choice for intracranial aneurysms, not all aneurysms can be clipped. This report reviews the results of bipolar coagulation followed by parent vessel reinforcement for the treatment of intracranial microaneurysms (maximal diameter of ≤3 mm), with immediate and delayed postoperative angiographic evaluation in all cases.METHODSDuring a 1-year period, 20 intracranial microaneurysms in 12 patients were treated with bipolar electrocoagulation followed by reinforcement of the parent artery with muslin gauze. All patients underwent intraoperative or immediate postoperative angiographic evaluation, and all underwent follow-up angiographic evaluation approximately 1 year later. No patient was lost to follow-up monitoring.RESULTSMicroaneurysms involved the middle cerebral artery (eight cases), internal carotid artery (six cases), anterior cerebral/anterior communicating artery (five cases), and superior cerebellar artery (one case). In all cases, the patient was undergoing a craniotomy for clipping of a larger aneurysm, and the microaneurysms were treated concurrently. At the time of the immediate angiographic examinations, 19 of 20 (95%) microaneurysms were no longer visible and 1 was substantially smaller (<1-mm irregularity on the parent vessel). No patient experienced an adverse event related to microaneurysm treatment. In the 1-year follow-up examinations, there was no angiographic evidence of recurrence in the 19 cases with complete obliteration; the one residual aneurysm remained stable.CONCLUSIONAt 1 year, direct coagulation followed by parent vessel reinforcement seems to provide a satisfactory treatment option for intracranial microaneurysms.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVEIntracerebral microdialysis has been demonstrated to be a useful method for detection of brain ischemia in experimental models and in patients. We have applied new mobile microdialysate analysis equipment that allows a bedside comparison of changes in neurochemistry with the neurological status of the patient. Ten patients with severe aneurysmal subarachnoid hemorrhage (that is, with a high risk of vasospasm and a high risk of subsequent ischemic deficits) were selected.METHODSMicrodialysis catheters were inserted into the temporal and subfrontal cortex at the end of aneurysm surgery. Samples, collected hourly for 4 to 11 days, were analyzed immediately at the bedside for glucose, lactate, and glycerol and later for pyruvate and glutamate. The patients’ neurological status was monitored constantly, and daily recordings of blood flow velocities were performed using transcranial Doppler sonography.RESULTSConcentrations of the measured substances varied widely. Individual analyses revealed that patients with uneventful clinical courses generally demonstrated low and stable levels of the different metabolites, and those with signs of cerebral ischemia demonstrated various patterns of neurochemical changes. Lactate and glutamate seemed to be sensitive markers of impending ischemia, and increased glycerol levels were associated with severe ischemic deficits. Obtaining the microdialysis data directly at the bedside seemed to be of great advantage when relating the values to other clinical findings.CONCLUSIONBedside intracerebral microdialysis monitoring of patients with subarachnoid hemorrhage and signs of delayed ischemia revealed dramatic changes in extracellular concentrations of glucose, lactate, and glycerol that could be directly correlated to the clinical status of the patients. These findings emphasize the potential of microdialysis in neurosurgical intensive care patients.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVEThis study was undertaken to assess the utility of digital camera-derived intraoperative images in the planning of neurosurgery for children with epilepsy.METHODSA hand-held digital camera was used to capture the exposed surgical field at the time of craniotomy for 11 children with medically intractable seizure disorders. Intraoperative somatosensory evoked potential recordings of phase reversals and direct cortical stimulation were used to map areas of eloquent brain tissue. Digital camera images were obtained to mark regions of functional brain tissue with respect to cortical surface landmarks and subdural grid placement. The digital camera images were then immediately downloaded, in the operating room, to a laptop computer, which was placed next to the electroencephalographic recording device. Using computer software, the epileptologist highlighted the primary and secondary zones of epileptogenesis, as well as the functional brain areas identified during the monitoring period, on the digital camera images on the computer screen. A neurosurgical map was thus created to aid the neurosurgeon and the epileptologist with the proposed cortical resections and multiple subpial transections.RESULTSWith the images obtained using the digital camera, the epilepsy team was able to observe the contacts of the grid electrodes with the brain during the procedure. Color printouts of the images served as references during the period of invasive monitoring. Zones of primary and secondary epileptogenesis, as well as areas of functional brain tissue, were identified and plotted on the digital camera images. Other benefits of the digital camera-derived images included the ability to accurately reposition the grids or letters marking eloquent brain tissue if they were inadvertently shifted during the procedure, the ease with which the images could be obtained and manipulated, the ability to assess postresection epileptiform activity of the surrounding brain tissue with images obtained while an electrocorticographic array was in place, the ability to provide the entire epilepsy team with updated information on the neurosurgical field while minimizing movement in the operating room, and facilitation, with neurosurgical maps, of discussions with the patients and their families concerning proposed cortical resections.CONCLUSIONDigital camera images have become essential components for the planning of cortical resections for children with intractable epilepsy at our institution. We envision widespread application of this technology to other neurosurgical fields.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVETo address the several disadvantages of currently available ultrasonic aspirators used in microsurgery, new instruments were designed for neurosurgical use under a microscope.DESCRIPTION OF INSTRUMENTATIONThe weight of the handpiece was reduced to 90 g. Two types of angled probes were constructed. Keyhole-type probes have 93- and 112-mm lengths, a 2.2-mm tip diameter, and 9.5- and 11.2-mm sheath diameters at the most proximal site and produce a tip amplitude of 300 &mgr;m (supplied by 23.5-kHz ultrasonic power). Needle-type probes have 89- and 171-mm lengths, a 1.9-mm tip diameter, and 3.5- and 3.3-mm sheath diameters at the proximal site and produce a tip amplitude of 70 &mgr;m. All of these instruments are compatible with magnetic resonance imaging.METHODSThe newly developed handpiece and probes were used in an experimental model. The 119 mass lesions treated included giant thrombosed aneurysms, various gliomas, vestibular schwannomas, deep-seated meningiomas, clival tumors, and suprasellar tumors.EXPERIENCE AND RESULTSThe handpiece and probes were safely used in regions that are difficult to access, such as the third ventricle and the cerebellopontine angle. It was possible to manipulate the needle-type probe in the suprasellar region through the transsphenoidal route, and the probe was very efficient for thrombectomy in giant aneurysms. The ultrasonic power of keyhole-type probes was sufficient to remove meningiomas.CONCLUSIONThis newly developed neurosurgical handpiece with angled probes has great utility for microscopic dissections, because of its small size and light weight.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVEImage-guided neurosurgery incorporating preoperatively obtained imaging information is subject to spatial error resulting from intraoperative brain displacement and deformation. A strategy to update preoperative imaging using readily available intraoperative information has been developed and implemented.METHODSPreoperative magnetic resonance imaging is used to generate a patient-specific three-dimensional finite element model of the brain by which deformation resulting from multiple surgical processes may be simulated. Sparse imaging data obtained subsequently, such as from digital cameras or ultrasound, are then used to prescribe the displacement of selected points within the model. Based on the model, interpolation to the resolution of preoperative imaging may then be performed.RESULTSThe algorithms for generation of the finite element model and for its subsequent deformation were successfully validated using a pig brain model. In these experiments, the method recovered 84% of the intraoperative shift resulting from surgically induced tissue motion. Preliminary clinical application in the operating room has demonstrated feasibility.CONCLUSIONA strategy by which intraoperative brain deformation may be accounted for has been developed, validated in an animal model, and demonstrated clinically.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVEPreliminary studies have demonstrated that the Ras family and related guanosine triphosphate-dependent proteins are overactivated in malignant gliomas and that inhibition of the activation of such proteins, by blockade of their post-translational processing, reduces tumor cell growth in vitro. The current study evaluates the utility of this therapeutic strategy in vivo, using preclinical glioma model systems.METHODSWe examined the efficacy against U-87 human malignant glioma cells, in both subcutaneous and intracranial nude mouse models, of selective peptidomimetic inhibitors of farnesyltransferase (FTI-276) and geranylgeranyltransferase (GGTI-297), which are involved in critical steps in the post-translational processing of Ras and related guanosine triphosphate-dependent proteins. For the subcutaneous model, 2 × 105U-87 cells were implanted; after measurable tumors were detected on Day 7, animals were treated with either FTI-276, GGTI-297, or vehicle, administered by continuous infusion for 7 days. Differences in tumor volumes among the treatment groups were examined for significance using a Student’sttest. For the intracranial model, 2 × 105U-87 cells were implanted in the right frontal lobe and treatment was initiated on Day 7. In initial studies, animals received a 7-day course of either FTI-276, GGTI-297, or vehicle. In subsequent studies, a 28-day treatment period was used. Comparisons of survival times among treatment groups were performed using a rank-sum test.RESULTSAlthough the two agents exhibited comparable antiproliferative activities in previous in vitro studies, an obvious difference in efficacy was apparent in this study. Whereas the geranylgeranyltransferase inhibitor failed to improve survival rates, compared with those observed for control animals, in either the subcutaneous or intracranial model, the farnesyltransferase inhibitor produced objective regression of tumor growth in the subcutaneous model and significant prolongation of survival times in the intracranial model, without apparent toxicity. In the subcutaneous model, tumor volumes for the control, GGTI-297-treated, and FTI-276-treated animals on Day 28 after implantation were 621 ± 420, 107 ± 104, and 18.5 ± 12.7 mm3, respectively (P< 0.05). In the 7-day-treated intracranial model, survival times for the control, GGTI-297-treated, and FTI-276-treated groups were 27.7 ± 2.9, 29.8 ± 2.1, and 43.6 ± 2.7 days, respectively (P< 0.001). In the 28-day-treated intracranial model, survival times for the control, GGTI-297-treated, and FTI-276-treated groups were 29.2 ± 3.7, 28.3 ± 3.9, and 58.7 ± 6.2 days, respectively, with five of six animals in the latter group surviving more than 55 days after tumor implantation (P< 0.001).CONCLUSIONThese studies demonstrate that farnesyltransferase inhibition is effective in diminishing the growth of human glioma cells in vivo. Evaluation of this treatment approach in clinical trials is warranted.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID