Continuous selective intraarterial infusion of nimodipine for therapy of refractory cerebral vasospasm.

BACKGROUND: For endovascular treatment of vasospasm after aneurysmal subarachnoid hemorrhage (aSAH), an intraarterial treatment course with the calcium channel antagonist nimodipine infused for 30 min is proposed. As some patients still show ongoing vasospasm thereafter, we report on our experience with an extended time period of selective intraarterial nimodipine administration. METHODS: In nine patients with aSAH and refractory cerebral vasospasm, we left the catheter in place within the internal carotid artery after angiography. On the neurosurgical ICU, a continuous infusion of intraarterial nimodipine was commenced, combined with intraarterial heparin anticoagulation. Therapy was controlled with extended neuromonitoring techniques. RESULTS: Three patients died from refractory vasospasm and a fourth suffered lethal sepsis. Three patients survived in a good clinical condition, two of them without apparent neurologic deficit. The efficacy of intraarterial nimodipine was best verified with regional CBF monitoring. TCD failed to detect vasospasm in two patients and missed improvement in four. Brain tissue oxygenation increased in all patients, but was not indicative of vasospasm in one. CT perfusion reflected the treatment course adequately in the qualitative scans. CONCLUSION: Selective continuous intraarterial nimodipine treatment for refractory cerebral vasospasm after aSAH seems feasible and may add to the endovascular therapeutic options. Appropriate monitoring technology is essential for further investigation of this novel technique.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) in gliomas with intraoperative morphologic monitoring in an open MR: clinical expierence.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) is a minimal invasive method to produce thermonecrosis in cerebral tumour tissue. Clinical data are sparse due to its limited application until now and the value of this approach for tumour control and survival time remain to be defined. Twenty-four patients (7 low-grade gliomas, 11 anaplastic gliomas, 6 glioblastomas) with brain tumours, most recurrences, were treated with SLITT, in total 30 laser procedures were performed. Under local anaesthesia a 600 micro m laser-fiber was inserted by the stereotactic-guided technique. In open low-field MR the denaturation of the tumour by a Nd-YAG-laser (1064 nm) was monitored using T 1 -weighted 3-D turbo FLASH sequences. The ablation procedure had to be stopped twice because of neurological deficit, one major infection occurred. In two cases neurological improvement was observed. Mean survival times for low grade astrocytomas, anaplastic gliomas and glioblastomas were 144 months, 39 months, 17 months, respectively. Mean survival times after SLITT were 34 months, 30 months and 9 months, respectively. Mean times to progression after SLITT for the 3 histological subgroups were 16 months, 10 months and 4 months, respectively. Five patients with low grade astrocytoma and a KI greater or equal 70 maintained a high quality functional status for 11, 20, 21, 33 and 43 months. In anaplastic tumours patients maintained a KI of 70 for a median time of 15 months and for those with glioblastoma the respective high quality duration was 7.5 months after SLITT. SLITT for selected patients with glioma could have a clinical value in a multimodality treatment schedule maintaining quality of live. Due to the minimal invasive technique, the method is a therapy of choice and may be favoured to reoperation. Major indications of this treatment are small tumours, in eloquent regions and deep seated, as well as in older patients or patients in poor functional status.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) in gliomas with intraoperative morphologic monitoring in an open MR-unit.

Stereotactic guided laser-induced interstitial thermotherapy (SLITT) represents a minimal invasive method to produce necrosis in cerebral tumor tissue by local heating. The dose/response relationship relies on experimental studies and few clinical data performed in high field MR systems. A better understanding of the energy-dose/tissue response in human brain tumors is important to optimize this treatment modality. Twenty-four patients with gliomas were treated with SLITT, with a total of 30 laser procedures performed. Under local anesthesia 600 microns laser-fibers were inserted by stereotactic-guided technique into the center of the tumor. In a low field open MR system (0.2 T) the denaturation of the tumor using a neodymium YAG laser (1064 nm) was monitored by 3D-turbo FLASH T1-weighted sequences. Laser energy was applied in steps of 400 to 1200 Joules. Development of necrosis at a mean total energy dose of 2979 Joules could be monitored in all procedures. Two different thermal lesion architectures were observed. First signal changes were monitored after a mean of 1108 Joules and 1393 Joules, respectively. Mean max. total lesion size was 21.2 mm. The higher the total energy the larger was the thermolesion, but no linear relationship could be seen. Tumor tissue response showed no dependency on tumor grading. Monitoring of stereotactic guided laser-induced thermolesions in the low-power MR OPEN is feasible and safe. Although lesion size basically is energy dependent, it should be applied individually, since the thermal response in brain tumors varies due to different optical properties, even in the same tumor gradings.

Three-dimensional computer-assisted stereotactic-guided microneurosurgery combined with cortical mapping of the motor area by direct electrostimulation.

TIM (Zeppelin Chirurgische Instrumente GmbH, 82 049 Pullach, Germany) is a tomographic imaging system which enables surgeons to visualize the pathologic lesions three dimensionally in relationship to the surrounding structures. The distance and the angle between the pathologic lesion and the anatomical and/or bony landmarks as well as the volume of the mass lesion can be measured. Therefore an accurate localization of the lesion is possible with this technique. It is very applicable for planning of surgery on skull base tumors. The surgical procedure for small and well-defined, intrinsic pathologic deep-seated brain lesions, however, becomes much easier by using the stereotactic techniques of this system. The target point and the direction brain-surface-to-lesion can be determined within seconds. Before the aiming probe is inserted to the target, the cortical motor area is mapped by direct electrical stimulation. The approach can be varied depending on the results of these neurophysiologic investigations of the brain surface. The dissection is made along the aiming probe up to the target point. Because of the fixation of the brain with the needle, a brain shifting due to the dissection as well as to CSF release is diminished. Forty patients with deep-seated intracerebral lesions were operated on during a 13 months period by these combined techniques in our service. Using this technique, we never made a negative exploration. In all but three patients, total removal of the mass lesion was achieved. Permanent neurological deficits were observed in two patients only. In our opinion, this combined imaging and neurophysiological technique is easy to perform, and of major benefit for the patients due to its accuracy and is preferable in comparison with other single computer localizer techniques without neurophysiological monitoring.

Protein and amino acid metabolism after severe cerebral trauma.

Fourteen patients (20-48 years) suffering from severe head injury were followed for changes in amino acid and protein metabolism during the first 8 days after trauma. All patients received a standardized intravenous nutrition containing 15.7 g of nitrogen per day and additional carbohydrates. Electrolytes, free water, and blood constituents were given as needed. Additional treatment included surgical decompression of space-occupying hematomas, high dose dexamethasone therapy, and controlled hyperventilation for at least 5 days. Gross changes of protein metabolism were observed particularly on the days 5 and 6. The duration and chronological sequence of these changes are different from those usually found in patients with multiple injuries.