Recent advances in neuroendovascular therapy

Clinical Experience of Using an 8 French Newton Shaped Catheter (Neuro-EBU) During Endovascular Treatment: A Case Series of 21 Patients

The first step in endovascular treatment is the stable placement of a guide catheter (GC) into the target parent vessel. However, sufficient GC stabilization is sometimes difficult to obtain when the approach route has severe tortuosity. Here, we report our experience with and the usefulness of the 8 French (Fr) Newton-shaped Neuro-EBU vascular catheter (SILUX Co., Ltd., Kawaguchi City, Saitama Prefecture, Japan), which is rigid over its entire length except near the tip, in a case series of 21 patients. Of the 21 cases, 19 cases were successfully treated using the Neuro-EBU.

The 8 Fr Newton-shaped Neuro-EBU might be useful both as a special GC and as a wire exchange catheter when placement of the conventional GC is difficult due to severe tortuosity of the access route. Although rarely used, the Neuro-EBU catheter can serve as a practical alternative when the access route is challenging. To the best of our knowledge, there are no detailed reports on the technical use of the Newton-shaped vascular catheter in the field of neurointervention. We present the usefulness of the specially shaped 8 Fr guide catheter.

Coil embolization through the Marathon microcatheter: Advantages and pitfalls

Due to technical limitations, small, distal, and tortuous intracranial pathology is sometimes out of reach of the current armamentarium of microcatheters designed for intracranial coil embolization. The Marathon microcatheter (Medtronic, Minneapolis, Minnesota, USA), designed specifically for the delivery of Onyx, is longer and more flexible than most coil delivery catheters. We report on nine patients (three with arteriovenous fistula, three with arteriovenous malformation, two with intracranial aneurysm, and one with tumor) where Marathon was used to deliver commercially available platinum coils. We also conducted laboratory compatibility testing and conclude that the Marathon can be used as a coil delivery catheter for Barricade coils (Blockade Medical, Irvine, California, USA) with diameter less than 0.012 in.

Trends in mortality following mechanical thrombectomy for the treatment of acute ischemic stroke in the USA

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) for the treatment of acute ischemic stroke has been growing in popularity while the therapeutic benefit of MT has been increasingly debated. Our objective was to examine national trends in mortality following MT.

METHODS

We analyzed the National Inpatient Sample (2012) and the Nationwide Inpatient Sample (2008-2011) for patients with a primary diagnosis of acute ischemic stroke that received MT. Temporal trends in mortality were examined using Spearman's rank correlation. To account for confounding factors, mortality was further analyzed in binary logistic regression.

RESULTS

Hospitals performing MT comprised 8% of all hospitals treating ischemic stroke. The percentage of stroke cases treated with MT increased from 0.6% of cases in 2008 to 1.1% in 2012, totaling 16 307 MT cases in a 5 year period. Inhospital mortality decreased over the study period from 25.4% in 2008 to 16.1% in 2012 (r=-0.081, p<0.001). This finding was supported by regression analysis as each incremental year reduced the odds of mortality by 20% (OR=0.832, p<0.001). Administration of recombinant tissue plasminogen activator was associated with a decrease in the odds of mortality (OR=0.805, p<0.001).

CONCLUSIONS

Utilization of MT represents a small percentage of stroke cases, although the trend is increasing. Mortality following MT has been showing a steady decline over the past 5 years. This may be a result of a learning curve, improved patient selection, and/or device improvements. Randomized trials remain essential to evaluate the potential benefit of endovascular devices and identify the most appropriate patients.

Comparison of Solitaire thrombectomy and Penumbra suction thrombectomy in patients with acute ischemic stroke caused by basilar artery occlusion

Background and purpose

Acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) is a very severe neurological disease with a high mortality rate and poor clinical outcomes. In this study, we compared our experience of mechanical thrombectomy using the Solitaire stent (Solitaire thrombectomy) and manual aspiration thrombectomy using the Penumbra reperfusion catheter (Penumbra suction thrombectomy) in patients with AIS caused by BAO.

Materials and methods

Between March 2011 and December 2011, 13 patients received Solitaire thrombectomy. In January 2012, the Korean Food and Drug Administration banned the use of the Solitaire stent as a thrombectomy device, and a further 18 patients received Penumbra suction thrombectomy until December 2013. We compared parameters between patients treated with each device.

Results

Successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b: 84.6% vs 100%, p=0.168) and clinical outcomes (judged by the modified Rankin Scale scores recorded at 3 months: 3.6±2.6 vs 3.2±2.6, p=0.726) were not significantly different between the two groups. However, complete recanalization rates (TICI score of 3: 23.1% vs 72.2%, p=0.015) and total procedure times (101.9±41.4 vs 62.3±34.8 min, p=0.044) were significantly higher, and shorter, respectively, in patients treated by Penumbra suction thrombectomy.

Conclusions

The two thrombectomy devices were associated with similar recanalization rates and clinical outcomes in patients with AIS caused by BAO. However, Penumbra suction thrombectomy seemed to allow more rapid and complete recanalization than Solitaire thrombectomy.

Computational modeling of an endovascular approach to deep brain stimulation

OBJECTIVE

Deep brain stimulation (DBS) therapy currently relies on a transcranial neurosurgical technique to implant one or more electrode leads into the brain parenchyma. In this study, we used computational modeling to investigate the feasibility of using an endovascular approach to target DBS therapy.

APPROACH

Image-based anatomical reconstructions of the human brain and vasculature were used to identify 17 established and hypothesized anatomical targets of DBS, of which five were found adjacent to a vein or artery with intraluminal diameter ≥1 mm. Two of these targets, the fornix and subgenual cingulate white matter (SgCwm) tracts, were further investigated using a computational modeling framework that combined segmented volumes of the vascularized brain, finite element models of the tissue voltage during DBS, and multi-compartment axon models to predict the direct electrophysiological effects of endovascular DBS.

MAIN RESULTS

The models showed that: (1) a ring-electrode conforming to the vessel wall was more efficient at neural activation than a guidewire design, (2) increasing the length of a ring-electrode had minimal effect on neural activation thresholds, (3) large variability in neural activation occurred with suboptimal placement of a ring-electrode along the targeted vessel, and (4) activation thresholds for the fornix and SgCwm tracts were comparable for endovascular and stereotactic DBS, though endovascular DBS was able to produce significantly larger contralateral activation for a unilateral implantation.

SIGNIFICANCE

Together, these results suggest that endovascular DBS can serve as a complementary approach to stereotactic DBS in select cases.