Flow alteration therapy for impending rupture of intracranial giant aneurysm after flow diverter placement

Background:

Flow diverter (FD) placement is generally effective for intractable internal carotid artery (ICA) aneurysms. However, salvage treatment for the aneurysm enlarging even after FD placement remains to be elucidated. Additional overlapping FD placement is considered the first-line treatment for residual or recurrent aneurysms. However, it is unclear whether overlapping FD is also effective for enlarging giant aneurysms that are considered impending rupture status. Although parent artery occlusion is a promising option, treatment strategy must be optimized, especially when a critical perforating artery is involved.

Case Description:

A 74-year-old woman experienced rapid symptomatic growth of her giant supraclinoid ICA aneurysm 10 months after FD placement. We assumed that reinforcement of flow diverting effect alone would be less effective for this extremely intractable aneurysm with more aggressive clinical feature so that surgical bailout by parent artery occlusion was planned. Complete ICA obliteration underneath the aneurysm was unavailable due to the presence of anterior choroidal artery. Thus, we took a flow alteration strategy, where we created minimal retrograde flow through the parent artery by a combination of an extracranial-intracranial bypass and targeted endovascular proximal parent artery obliteration, resulting in prevention of aneurysmal rupture and further growth.

Conclusion:

Impending rupture of the intracranial giant aneurysm after FD placement may be controllable with a tailor-made parent artery occlusion strategy even when a critical perforating artery is involved.

Association of 5-aminolevulinic acid with intraoperative hypotension in malignant glioma surgery

BACKGROUND

Use of 5-aminolevulinic acid for photodynamic malignant tumor diagnosis reportedly causes intraoperative hypotension (systolic blood pressure < 70 mmHg) during urologic surgery. However, its association with intraoperative hypotension in malignant glioma surgery and underlying mechanisms has not yet been elucidated.. This study aimed to investigate whether 5-aminolevulinic acid administration is associated with intraoperative hypotension in malignant glioma surgery and explore the mechanisms of 5-aminolevulinic acid-induced hypotension in vitro.

METHODS

In this retrospective multicenter cohort study, we investigated intracellular nitric oxide as a candidate mediator of hypotension in response to 5-aminolevulinic acid in vitro in human umbilical vein endothelial cell cultures.

RESULTS

Of 142 patients, 94 underwent 5-aminolevulinic acid-guided surgery. Systolic blood pressure was significantly lower throughout surgery with 5-aminolevulinic acid administration. 5-Aminolevulinic acid administration was an independent risk factor for intraoperative hypotension according to multivariable logistic regression analysis (89% vs. 56%; odds ratio = 6.72, 95% confidence interval [2.05-22.1], P = 002). In subgroup analysis of the 5-aminolevulinic acid group, increasing age and use of renin-angiotensin system inhibitors had a synergistic effect with 5-aminolevulinic acid on decreased blood pressure. In the vascular endothelial cell culture study, 5-aminolevulinic acid induced a significant increase in intracellular nitric oxide generation.

CONCLUSIONS

5-Aminolevulinic acid administration was associated with intraoperative hypotension in malignant glioma surgery, with increasing age and use of renin-angiotensin system inhibitors boosting the blood pressure-lowering effect of 5-aminolevulinic acid. According to in vitro results, the low blood pressure induced by 5-aminolevulinic acid may be mediated by a nitric oxide increase in vascular endothelial cells.

Acute Proximal Anterior Circulation Occlusion after Pulmonary Lobectomy Treated by Endovascular Therapy: Two Case Reports

Objective

We report two cases of acute proximal anterior circulation occlusion after pulmonary lobectomy.

Case Presentation

Case 1 was a 64-year-old male who presented with occlusion of the right middle cerebral artery (MCA) one day after left lower lobectomy. Case 2 was a 68-year-old male who presented with occlusion of the right internal carotid artery (ICA). In both cases, mechanical thrombectomy was performed for complete recanalization and symptoms were improved.

Conclusion

Prompt mechanical thrombectomy in the acute phase after pulmonary lobectomy improved the prognosis of patients with acute proximal anterior circulation occlusion. It is important to share information about ischemic complications with medical staff engaged in thoracic surgery.

Optimizing in-hospital triage for large vessel occlusion using a novel clinical scale (GAI2AA)

Objective

To identify a proximal anterior circulation occlusion for effectively administering immediate mechanical thrombectomy by developing a novel, simple diagnostic scale to predict the occlusion, to compare its validity with available scales, and to assess its utility.

Methods

To develop a novel clinical scale, we retrospectively analyzed a cohort of 429 patients with acute ischemic stroke from a single center. The novel scale GAI₂AA was applied to a prospective cohort of 259 patients from 3 stroke centers for external validation. The utility of the scale as an in-hospital triage was compared for the temporal factors of 158 patients with the occlusion.

Results

In a scale-developmental phase, those with a proximal anterior circulation occlusion had significantly more frequent signs of hemispheric symptoms, including gaze palsy, aphasia, inattention, arm paresis, and atrial fibrillation. The GAI₂AA scale was developed using consolidated hemispheric symptoms and was scored as follows: score = 2, arm paresis score = 1, and atrial fibrillation score = 1. A cutoff value ≥3 was optimal for the correlation between sensitivity (88%) and specificity (81%), with a C statistic of 0.90 (95% confidence interval 0.87–0.93). External validation indicated that discrimination was significantly better than or not different from that of available complex scales. Door-to-puncture time was significantly reduced (91 [82–111] vs 52 [32–75] minutes, p < 0.001).

Conclusion

The GAI₂AA scale showed high sensitivity and specificity when an optimal cutoff score was used and was useful as an in-hospital triage tool.

Mechanical Thrombectomy in Anterior Circulation Occlusion Could Be More Effective than Medical Management Even in Low DWI-ASPECTS Patients

The purpose of this study was to investigate whether patients with low preoperative Diffusion-weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) could benefit from mechanical thrombectomy for acute anterior circulation occlusion. This was a retrospective, non-blinded, cohort study. From September 2012 to August 2016, 83 consecutive patients of acute anterior circulation occlusion were treated with thrombectomy using second-generation devices or medical management. The DWI-ASPECTS was scored after the first MRI. Patient characteristics and clinical outcomes were compared between the treatment groups. Significant dependence was defined as a modified Rankin scale score ≥3 at 90 days. As a result, 33 patients underwent mechanical thrombectomy and 50 received medical management. In the mechanical thrombectomy group, the variable of lower DWI-ASPECTS (5, 4–6 vs. 8, 7–8, P < 0.001), especially ≤6, was significantly associated with poor prognosis. However, compared with patients of DWI-ASPECTS ≤ 6 who received medical management, there were significantly fewer patients with poor outcomes in thrombectomy (dependent in 11 of 15 vs. 23 of 23, respectively; P = 0.019). Although patients with lower pretreatment DWI-ASPECTS could benefit less from thrombectomy, their outcomes were still better than medical management. Therefore, mechanical thrombectomy could be considered in some patients with low pretreatment DWI-ASPECTS.

A direct aspiration first pass technique for retrieval of a detached coil

A 64-year-old man was referred to our hospital for treatment of a cerebral aneurysm that was incidentally found. The aneurysm was 7 mm in size and located on the left anterior communicating artery. Using a balloon assisted technique, we performed coil embolization. During the second coil insertion, the first coil was dislodged into the anterior communicating artery. We attempted coil retrieval using a snare, which was unsuccessful. We applied a direct aspiration first pass technique (ADAPT) and advanced a Penumbra 4MAX immediately proximal to the dislodged coil; the dislodged coil was then successfully retrieved. ADAPT is a simple procedure for retrieval of a detached coil, and it can be used as an alternative to the snare technique.

A direct aspiration first pass technique for retrieval of a detached coil

A 64-year-old man was referred to our hospital for treatment of a cerebral aneurysm that was incidentally found. The aneurysm was 7 mm in size and located on the left anterior communicating artery. Using a balloon assisted technique, we performed coil embolization. During the second coil insertion, the first coil was dislodged into the anterior communicating artery. We attempted coil retrieval using a snare, which was unsuccessful. We applied a direct aspiration first pass technique (ADAPT) and advanced a Penumbra 4MAX immediately proximal to the dislodged coil; the dislodged coil was then successfully retrieved. ADAPT is a simple procedure for retrieval of a detached coil, and it can be used as an alternative to the snare technique.

Use of fat-suppressed T2 -weighted sagittal images after infusion of excess saline into the subarachnoid space as a new diagnostic modality for cerebrospinal fluid hypovolemia: technical note

The diagnosis of CSF hypovolemia remains controversial. The primary diagnostic factor relies on confirmation of leakage of the CSF based on reduced spinal fluid pressure. Determining the specific leakage site is the most important issue for effective treatment but remains a difficult task. Although CT myelography, radioisotope cisternography, and MRI are commonly performed in the diagnosis of CSF hypovolemia, these techniques can rarely identify the precise leakage site. Therefore, an epidural blood patch is performed in the lumbar spine in many cases. This study reports a new diagnostic modality that can help to confirm the leakage site. Fat-suppressed T2-weighted sagittal images were compared before and after the infusion of 20 ml of saline into the subarachnoid space of the lumbar region to detect the specific leakage site with high probability. Three patients were successfully treated by the epidural blood patch based on data obtained with the new diagnostic modality. Two patients were treated in the cervical region and 1 in the lumbar region. The use of fat-suppressed T2-weighted sagittal images after saline infusion could be a relevant diagnostic modality compared with images obtained by CT myelography, radioisotope cisternography, and ordinary MRI to achieve accurate diagnosis and effective treatment of patients with CSF hypovolemia.

Evaluation of two- and three-dimensional visualization for endoscopic endonasal surgery using a novel stereoendoscopic system in a novice: a comparison on a dry laboratory model

BACKGROUND

Three-dimensional (3-D) stereoscopic vision is theoretically superior to two-dimensional (2-D) vision in endoscopic endonasal surgery. However, only few reports have quantitatively compared endoscopic performance under the two visual conditions. We introduced a newly designed stereoendoscopic system with a "dual-lens and single camera" for endoscopic endonasal surgery and objectively compared the performances under 3-D and high-definition 2-D visualizations on a dry laboratory model.

METHODS

Thirty subjects without experience performing endoscopic surgery, computer-simulated training or any 3-D video system were recruited and divided into two groups (Group A and Group B) for performing two different tasks. The novel 4.7-mm-diameter stereoendoscope provided high-definition (HD) images. In Task 1, Group A started the task under the 3-D condition followed by the 2-D condition, and Group B vice versa. In Task 2, Group A started the task under the 2-D condition followed by the 3-D condition, and Group B vice versa. The performance accuracy and speed under the two visual conditions were analyzed.

RESULTS

Significant improvement in performance accuracy and speed was seen under 3-D conditions in the both "3-D first" and "2-D first" subgroups during both tasks (P < .001). Regardless of order, the inaccuracy rate and performance time under 3-D conditions was significantly lower than that under 2-D conditions in each subject.

CONCLUSIONS

We demonstrated the advantage of 3-D visualization over 2-D visualization for inexperienced subjects. Further quantitative clinical studies are required to confirm whether stereoendoscopy actually provides benefits in clinical settings.

Remora technique to approach the affected, difficult to approach sinus at transvenous embolization for dural arteriovenous fistulae: case report

BACKGROUND AND IMPORTANCE

We describe a novel technique that uses a goose neck snare for microcatheterization at transvenous embolization (TVE) for dural arteriovenous fistulae (dAVF). We have named our method the "remora technique."

CLINICAL PRESENTATION

A 48-year-old man reported with dizziness. Angiography disclosed a transverse-sigmoid sinus (T-SS) dAVF with proximal sigmoid sinus occlusion, an open distal transverse sinus, narrow multiple divided confluence sinus, and multiple retrograde leptomeningeal venous drainage. We attempted TVE via the confluence sinus from the contralateral open side; it was narrow, steep, and divided into cavities, rendering the procedure very difficult. Although we were able to pass a 0.035-inch guidewire to the affected transverse sinus, we could not advance via the same route with the microguidewire. One month later we attempted transfemoral TVE again using the remora technique. We caught the 0.035-inch guidewire in the left internal jugular vein with a goose neck micro snare bearing a microcatheter. By advancing the 0.035-inch wire across the confluence sinus to the affected sinus, we were able to pass the microcatheter through the lesion using the snare like a remora. We then performed transvenous coil packing.

CONCLUSION

In TVE for dAVF, passage of the microguidewire is often difficult. Even if the affected sinus can be reached with the stiff 0.035-inch guidewire, it may not be possible to follow with the microguidewire. We report on a patient with T-SS dAVF who underwent successful microcatheterization in which we used our remora technique with a goose neck snare.

A Migraine-Like Headache Induced by Carotid-Cavernous Fistula

Carotid-cavernous fistula (CCF) generally causes periorbital aching with ocular symptoms due to high venous pressure in the cavernous sinus, while migraine is caused by arterial dilatation-stimulating trigeminal nerves around the vessels. The authors present a case of 47-year-old woman with a 4-month history of a temporal throbbing headache. As her symptoms were well controlled by triptans, her headache was considered to be migraine in type. However, a Barrow's type-D CCF was revealed by radiological examinations. Self-compression of common carotid artery method was initially tried for therapy of the CCF, but endovascular embolization was finally necessary due to intractable headache. Although the headache was considered arterial in origin, transvenous embolization of the left cavernous sinus successfully ameliorated the patient's symptoms. CCF should be considered as an unusual etiology of headaches that appear arterial in origin.

Olig2-positive progenitors in the embryonic spinal cord give rise not only to motoneurons and oligodendrocytes, but also to a subset of astrocytes and ependymal cells

Motoneurons and oligodendrocytes in the embryonic spinal cord are produced from a restricted domain of the ventral ventricular zone, termed the pMN domain. The pMN domain is the site of expression of two basic helix-loop-helix transcription factors, Olig1 and Olig2, which are essential for motoneuron and oligodendrocyte development. Previous lineage-tracing experiments using Olig1-Cre and Olig2-GFP mice suggested that motoneurons and oligodendrocytes, but not astrocytes, are produced from the pMN domain. However, important questions remain, including the fate of neuroepithelial cells in the pMN domain, and specifically whether motoneurons and oligodendrocytes are the only types of cells produced in the pMN domain. We performed lineage-tracing experiments using a tamoxifen-inducible Cre-recombinase inserted into the Olig2 locus. We demonstrated that motoneurons and oligodendrocyte progenitors are derived from the Olig2+ progenitors in the pMN domain, and also found that a subset of astrocytes at the ventral surface of the spinal cord and ependymal cells at the ventricular surface are also produced from the pMN domain. These findings demonstrate that motoneurons and oligodendrocytes are not the only cell types originating from this domain.

Involvement of the Olig2 transcription factor in cholinergic neuron development of the basal forebrain

Cholinergic neurons, which express choline acetyltransferase (ChAT), are a major neuron subset generated in the basal forebrain. Areas presumed to be sites of origin of cholinergic neurons are roughly demarcated by expression of Olig2, a basic helix-loop-helix transcription factor, which includes the medial ganglionic eminence, septal area, and anterior entopeduncular/preoptic area. In the present study, we examined the involvement of Olig2 in cholinergic differentiation. When the Olig2-expressing cells at E12.5 were permanently modified to express the lacZ or EGFP gene by tamoxifen-induced Cre-mediated recombination, the cells marked by reporter gene expression were widely distributed in the basal forebrain by E18.5, some of which expressed neuronal markers. We showed that a small number of cells were double-positive for ChAT and X-gal or EGFP in almost all cases. In addition, the number of ChAT+ cells was reduced to 60% in the Olig2 knockout mouse basal forebrain. No evidence of elevated apoptosis or reduced proliferation was observed in the knockout mouse forebrain. The present study provides the first direct evidence for involvement of the Olig2 gene in cholinergic differentiation in the basal forebrain.

Improved preservation of X-gal reaction product for electron microscopy using hydroxypropyl methacrylate

In lineage tracing analysis, the beta-galactosidase (beta-gal) gene is a commonly used as a reporter gene because it is relatively stable and highly sensitive in histochemical detection using 5-bromo-4-chloro-3-indolyl-beta-d-galactoside (X-gal). Clear determination of the types and characteristics of labeled cells requires transmission electron microscopic (TEM) examination of their morphology. X-gal staining, which involves the precipitate formed by the reaction between beta-gal and X-gal, is usually recognized as a light blue or green reaction product on light microscopic (LM) examination. However, the standard protocol for TEM preparation weakens the intensity of or results in the loss of X-gal reaction product at the step of substitution of ethanol with Epon using propylene oxide. To solve this problem, we show that hydroxypropyl methacrylate achieves good preservation of X-gal reaction products. The protocol presented here appears to be useful for lineage determination by TEM of all types of X-gal-stained tissues.