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Object Superficial temporal artery (STA)–middle cerebral artery (MCA) bypasses have continually evolved, and new strategies have been advocated for reducing anesthetic or surgical morbidity and mortality. Further simplifying, and decreasing the invasiveness of, STA-MCA bypass by performing this operation without endotracheal general anesthesia was believed to be feasible in certain subsets of patients. Methods The authors performed STA-MCA bypass using local anesthesia with a sedative in 10 patients with hemodynamically compromised occlusive cerebrovascular disease, as well as multiple comorbidities, between February 2010 and September 2011. The technique is based on the preoperative identification of the point at which the donor and recipient vessels are in closest proximity. Preoperative use of CT angiography allowed the authors to identify the target point precisely and use a minimally invasive procedure. All patients received dexmedetomidine as the sole sedative agent, together with scalp-blocking local anesthesia, with an unsecured airway. Results Successful STA-MCA bypass surgeries were achieved via a preselected minimally invasive approach in all cases. There was good hemodynamic stability throughout surgery. No airway or ventilation complications occurred, and no patients were converted to general anesthesia. Subjectively, patients tolerated the technique well with a high rate of satisfaction. There were no perioperative morbidities or deaths. Postoperative MR angiography confirmed a patent bypass in all patients. All patients remained symptom free and returned to normal daily life following the operation. Conclusions This initial experience confirms the feasibility of performing STA-MCA bypass without endotracheal general anesthesia. This novel technique produced a high degree of patient satisfaction.

✓ The authors have recently performed a fluorescence-guided tumor resection procedure by using high-dose fluorescein sodium without any special surgical microscopes for the intraoperative visualization of glioblastoma multiforme (GBM), and they report on the actual procedure and clinicopathological findings. Thirty-two patients with GBMs underwent tumor resection during which this fluorescence-guided procedure was used. Fluorescein sodium (20 mg/kg) was intravenously injected after dural opening at the craniotomy site. The tumor was stained almost homogeneously yellow and the color was intense enough to be readily perceived for resection. The center of the solid lesion was stained a deep yellow and surrounded by a transition zone that was faintly stained. The colored lesion was clearly distinguishable from the unstained zone outside the GBM, particularly in the white matter. Both the deeply and faintly stained regions included endothelial proliferation and dense tumor cells. In the unstained region, less dense tumor cells were consistently revealed; however, no endothelial proliferation could be seen. Grosstotal resection (GTR) was successful in 84.4% of the patients who received an injection of fluorescein sodium, which accounted for 100% of those in whom all the visible yellow color (both the deeply and faintly stained regions) was judged to have been resected during operation. Gross-total resection was performed in 100% of the patients who underwent the fluorescence-guided procedure and assigned to Stage I, a GBM stage in which, as a therapeutic policy, the tumor should be resected as radically as possible. The GTR rates in patients who received fluorescein sodium were significantly higher than those in patients who did not (73 patients with GBMs who underwent tumor resection without the fluorescence-guided procedure). Although the extent of surgery was revealed to be one of the significant and independent prognostic factors for GBM, the fluorescein sodium—guided resection procedure was not a significant or independent prognostic factor in this series. This surgical procedure does not require any special surgical microscopic equipment and is simple, safe, useful, readily accomplished, and universally available for resection of GBMs. Its efficacy simplifies the surgical procedure of navigating the stained lesion from the unstained area to achieve GTR of GBMs, which can be demonstrated on magnetic resonance images.

Object. It is well known that the central nervous system (CNS) is an immunologically privileged site. To characterize CD8+ tumor-infiltrating lymphocytes (TILs) recovered from the CNS, the authors compared these cells with TILs recovered from subcutaneous tissue by using a B7.1 gene—modified tumor implantation model. Methods. The authors established a B7.1 gene—modified EL4 murine lymphoma cell line (EL4-B7.1) and implanted the cells into the CNS to observe the duration of tumor-free survival. Although EL4-B7.1 cells were completely rejected in a subcutaneous implantation model, 40% of animals died after the CNS implantation (all animals in which the parent tumor was implanted died within 16 days). Therefore, the authors isolated TILs from each implantation site and analyzed the expressions of activation antigens CD25 and CD69 by performing the anti-CD8 magnetic beads separation method and flow cytometric analysis. After implantation of the parent tumor, there was no difference in the number of TILs from each site (CD25 1.7–3.2%, CD69 21.9–34.3%). After implantation of the B7.1-modified tumor, the CD25-expressing TIL population from the subcutaneous site was 4.68 times higher than that from the CNS site (17.8% compared with 3.8%). Based on these findings, the authors used a mitomycin C—treated EL4-B7.1 subcutaneous vaccination with various protocols. Vaccination before tumor challenge was sufficient to prevent the development of the tumor. For animals with established tumor, the vaccination protocol was able to prolong host survival (p = 0.0053). Conclusions. The data clearly demonstrate that the CNS environment fails to activate CD8+ TILs fully. These are the first data indicating in detail a difference between CD8+ TILs from the CNS and those from other sites based on a B7.1-modified tumor model.

✓ The supracerebellar transtentorial (SCTT) approach, a modification of the infratentorial supracerebellar approach, facilitates simple and minimally invasive access to posterior temporomedial structures without requiring retraction of the temporal or occipital lobe. The SCTT approach was used in 16 patients over a 3-year period. Eleven patients harbored tumors confined to, or located mainly within, the posterior hippocampal formation, three patients harbored aneurysms (one ruptured posterior cerebral artery [PCA] aneurysm at the P2-P3 junction, one ruptured giant PCA [P2] aneurysm, and one giant basilar artery—superior cerebellar artery aneurysm), one patient had juvenile-type moyamoya disease, and one patient suffered from medically intractable epilepsy. In these patients, the SCTT approach enabled tumor removal, aneurysm clipping, and vascular bypass procedures. The authors' experience suggests that this approach can be used routinely in treating lesions in the posterior temporomedial region.

Object. The purpose of the present study was to assess cerebral oxygenation patterns and brain lactate concentration changes before, during, and after intraarterial infusion of papaverine with or without balloon angioplasty in patients with symptomatic vasospasm. Methods. A total of 23 vascular territories were successfully treated in 10 patients. In three patients balloon angioplasty was performed before the papaverine infusion. Continuous monitoring of jugular bulb vein oxygen saturation with a fiberoptic catheter and blood sampling allowed the assessment of the cerebral arteriovenous oxygen and lactate differences. A significant and rapid improvement in jugular bulb oxygen saturation was observed in all cases, with critical values reflecting an improvement in cerebral oxygenation after endovascular treatment of vasospasm (p = 0.005). Lactate concentration in the jugular bulb normalized within 4 hours in all patients who had evidence of brain lactic acidosis before superselective intraarterial infusion of papaverine. Recurrence of abnormal metabolic and oxygenation patterns were observed in one case in which an optimal hypertension and hypervolemic therapy could not be achieved after the procedure. Conclusions. Improvement in cerebral oxygenation as well as prevention of cerebral lactic acidosis can be successfully achieved after intraarterial infusion of papaverine. Normalization of the oxygen supply after endovascular treatment has to be supported by optimal and well-monitored hypertension and hypervolemic hemodilution.

✓ This report describes the successful treatment of cerebral vasospasm after subarachnoid hemorrhage with superselective intra-arterial infusion of papaverine hydrochloride. Thirty-seven vascular territories in 10 patients with symptomatic vasospasm were treated according to the following protocol. Percutaneous transluminal angioplasty was performed in two steps. First, a silicone balloon was used for dilation of the internal carotid artery and the proximal portions of the middle cerebral artery. A silicone leak balloon or Tracker-18 catheter was then introduced into or just proximal to the site of vasospasm not accessible to the angioplasty balloon catheter for superselective infusion of 0.2% papaverine. Thirty-four of 37 vascular territories were successfully dilated, and eight of 10 patients showed improvement in neurological function after the procedure. There were no serious side effects due to infusion of papaverine. It is essential to infuse the papaverine just proximal to the spastic vessels in order to deliver sufficient concentration of drug, and infusion should be carried out as early as possible before the artery loses its ability to return to a normal luminal size. Superselective intra-arterial infusion of papaverine is an alternative method of treatment for symptomatic vasospasm.