Daizo Ishii

Carotid artery stenting for vulnerable plaques on MR angiography and ultrasonography: utility of dual protection and blood aspiration method

Background Carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis with vulnerable plaques is controversial. We analyzed the effect of a dual protection and blood aspiration method during CAS in patients with vulnerable plaques. Methods A total of 111 patients with ICA stenosis underwent CAS using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method. In 103 of 111 patients, preoperative carotid plaque was estimated by both 3u2005T MRI and ultrasonography (US). ICA plaques with a high intensity signal on time-of-flight-MR angiography (TOF-MRA) and/or mobile component on US were defined as vulnerable plaques. We assessed major adverse events (MAE) (ie, major stroke, myocardial infarction, and death) and hyperintense spots on diffusion-weighted images (DWI) after CAS. We then evaluated the visible debris captured by dual protection and blood aspiration during CAS. Results The preoperative ICA plaque on TOF-MRA and US was judged to be vulnerable in 48.5% (50/103 patients). The success rate of the CAS procedure was 100% with no MAE within 30u2005days. DWI showed small hyperintense spots in 18% (9/50 patients) and 18.9% (10/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively. Visible debris was captured in 68% (34/50 patients) and 45.3% (24/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively (p=0.0286). Conclusions The combination of dual protection and blood aspiration could provide effective distal embolic protection although vulnerable plaques on TOF-MRA and US had a high incidence of debris during CAS. Thus, CAS using dual protection and blood aspiration is safe in patients with vulnerable plaques.

Development of in vivo tissue-engineered microvascular grafts with an ultra small diameter of 0.6 mm (MicroBiotubes): acute phase evaluation by optical coherence tomography and magnetic resonance angiography.

Biotubes, i.e., in vivo tissue-engineered connective tubular tissues, are known to be effective as vascular replacement grafts with a diameter greater than several millimeters. However, the performance of biotubes with smaller diameters is less clear. In this study, MicroBiotubes with diametersxa0<1xa0mm were prepared, and their patency was evaluated noninvasively by optical coherence tomography (OCT) and magnetic resonance angiography (MRA). MicroBiotube molds, containing seven stainless wires (diameter 0.5xa0mm) covered with silicone tubes (outer diameter 0.6xa0mm) per mold, were embedded into the dorsal subcutaneous pouches of rats. After 2xa0months, the molds were harvested with the surrounding capsular tissues to obtain seven MicroBiotubes (internal diameter 0.59xa0±xa00.015xa0mm, burst pressure 4190xa0±xa01117xa0mmHg). Ten-mm-long MicroBiotubes were allogenically implanted into the femoral arteries of rats by end-to-end anastomosis. Cross-sectional OCT imaging demonstrated the patency of the MicroBiotubes immediately after implantation. In a 1-month follow-up MRA, high patency (83.3xa0%, nxa0=xa06) was observed without stenosis, aneurysmal dilation, or elongation. Native-like vascular structure was reconstructed with completely endothelialized luminal surfaces, mesh-like elastin fiber networks, regular circumferential orientation of collagen fibers, and α-SMA-positive cells. Although the long-term patency of MicroBiotubes still needs to be confirmed, they may be useful as an alternative ultra-small-caliber vascular substitute.

Efficacy of Cilostazol in Prevention of Bradycardia during Carotid Artery Stenting

BACKGROUNDnHypotension and bradycardia are known to occur frequently in carotid artery stenting (CAS), which may lead to postprocedural complications. The purpose of this retrospective study was to assess the efficacy of cilostazol, a phosphodiesterase 3 inhibitor, for preventing bradycardia and hypotension in the periprocedural period.nnnMETHODSnThe study population comprised 53 patients (54 lesions) with carotid artery stenosis who underwent CAS at our institution between 2004 and 2008. The patients were categorized by the use (group C, n = 26) or nonuse of cilostazol (group N, n = 28). The incidences of intraprocedural and postprocedural hypotension and bradycardia in each group were statistically assessed.nnnRESULTSnIntraprocedural hypotension and bradycardia occurred in 9 cases (34.6%) and 4 cases (15.3%) in group C and in 5 cases (17.9%) and 15 cases (53.6%) in group N, respectively. Postprocedural hypotension and bradycardia occurred in 4 cases (15.4%) and 0 cases in group C and in 1 case (3.6%) and 3 cases (10.7%) in group N, respectively. The incidence of intraprocedural bradycardia (IBc) was significantly lower in group C (P = .0035). Logistic regression analysis revealed that the use of cilostazol decreased the risk of IBc 99.5% (odds ratio [OR] = .01, 95% confidence interval [CI]: 5.46 × 10(-6) to .04, P = .001) and distance from carotid bifurcation to maximum stenotic lesion was independently associated with IBc (OR = .46, 95% CI: .29-.74, P = .001).nnnCONCLUSIONnUse of cilostazol was associated with a lower incidence of IBc. Cilostazol may be a useful drug for the prevention of this complication.

Analysis of outcome at discharge after aneurysmal subarachnoid hemorrhage in Japan according to the Japanese stroke databank

The outcomes at discharge for ruptured cerebral aneurysms after subarachnoid hemorrhage (SAH) were investigated using data from the Japanese stroke databank. Among 101,165 patients with acute stroke registered between 2000 and 2013, 4693 patients had SAH caused by ruptured saccular aneurysm. Of these, 3593 patients (1140 men and 2453 women; mean age 61.3xa0±xa013.7xa0years) were treated by surgical clipping (SC) and/or endovascular coiling (EC). The outcomes of modified Rankin scale (mRS) at discharge were compared between the SC and EC groups. There were 2666 cases in the SC group, 881 cases in the EC group, and 46 cases in the SC and EC group. The rates of poor outcome of mRS >xa02 were 33.0 and 45.5% in the SC and EC groups (pxa0<xa00.05), respectively. Cases were selected using two types of criteria compatible with both treatments. Under the first compatible criteria, the rates of poor outcome of mRS >xa02 were 18.9 and 24.8% in the SC and EC groups (pxa0<xa00.05), respectively. Under the second compatible criteria, the rates of poor outcome of mRS >xa02 were 16.0 and 14.8% in the SC and EC groups (pxa0=xa00.22), respectively. No significant differences were found in clinical characteristics or outcomes between the two groups. Multivariate analysis of aneurysmal SAH revealed no significant risk for poor outcome associated with the treatment method. The present study was not a randomized controlled study, but no significant differences in mRS at discharge were found between SC and EC in the Japanese stroke databank.

Postoperative Dilatation of Superficial Temporal Artery Associated with Transient Neurologic Symptoms After Direct Bypass Surgery for Moyamoya Angiopathy

OBJECTIVEnIn moyamoya angiopathy, transient neurologic symptoms (TNS) are occasionally observed after superficial temporal artery (STA)-middle cerebral artery direct bypass surgery. The purpose of this study was to investigate the correlation between TNS and postoperative magnetic resonance imaging as well as perform a perfusion study.nnnMETHODSnWe reviewed 52 hemispheres in 33 consecutive patients with moyamoya angiopathy. TNS were defined as reversible neurologic dysfunction without any apparent intracranial infarction or hemorrhage. All patients underwent magnetic resonance imaging and single-photon emission computed tomography before and within 5 days after surgery. Maximum diameter of STA on time-of-flight magnetic resonance angiography and the dilatation ratio of STA were calculated. The presence of signal changes on fluid-attenuated inversion recovery images and regional cerebral blood flow were also evaluated.nnnRESULTSnTNS were observed in 13 of 52 (25%) casesxa01-16 days after surgery. The mean preoperative STA dilatation, postoperative STA dilatation, and dilatation ratio of STA were 1.33 mm ± 0.27, 1.67 mm ± 0.30, and 29.31% ± 28.13%. Postoperative intraparenchymal cortical hyperintensity lesions and high-intensity signals in the cortex sulci (ivy sign) were detected in 24 (46.2%) cases and 29 (55.8%) cases, respectively. Univariate analyses demonstrated no association between TNS and postoperative signal change on fluid-attenuated inversion recovery images as well as cerebral blood flow. Onlyxa0>1.5-fold dilatation of STA was significantly correlated with TNS (P < 0.0001).nnnCONCLUSIONSnSTA dilatation was correlated with TNS after direct bypass surgery for moyamoya angiopathy.

Marked Changes in Blood-Brain Barrier Biomarkers After Direct Bypass Surgery for Moyamoya Angiopathy: Preliminary Study

OBJECTIVEnThe blood-brain barrier (BBB) of patients with moyamoya angiopathy (MMA) is unstable, which may contribute to transient neurologic symptoms (TNS) after direct bypass surgery. However, BBB-related proteins have never been investigated. The purpose of this study was to evaluate the perioperative serum levels of biomarkers representing BBB function in MMA patients based on the hypothesis that postoperative hemodynamic change may disrupt the BBB.nnnMETHODSnA total of 12 hemispheres in 11 patients with MMA were prospectively examined. Direct revascularization surgery was performed for all cases. The serum levels of tight junction (occludin and claudin 5), adherens junction (vascular endothelial-cadherin) proteins, and matrix metalloproteinase (MMP)-2 and MMP-9 were measured quantitatively 1 day before surgery and on postoperative days 1, 4, andxa07.nnnRESULTSnSuccessful patency of the direct bypass was achieved in all. The serum level of occludin was significantly increased on postoperative day 1, and the levels in 2 cases with TNS were markedly elevated over 10-fold higher than baseline. Furthermore, the postoperative MMP-9 levels were significantly elevated on each day. On the other hand, there was no significant fluctuation in claudin 5, vascular endothelial-cadherin, and MMP-2 level.nnnCONCLUSIONSnMarked changes in biomarkers representing the tight junction of the BBB were observed. These preliminary results suggest that marked hemodynamic change and TNS in some patients are associated with disruption of the BBB after direct bypass surgery for MMA.

Chronic Dilatation of Superficial Temporal Artery and Middle Meningeal Artery Associated with Development of Collateral Circulation After Bypass Surgery for Moyamoya Angiopathy

OBJECTIVESnDilatation of the superficial temporal artery (STA) and middle meningeal artery (MMA) were occasionally observed after bypass surgery for moyamoya angiopathy. The purpose of this study was to examine the correlation between angiographic outcomes and magnetic resonance imaging (MRI), specifically focusing on the postoperative dilatation ratio of the STA (rSTA) and MMA (rMMA).nnnMETHODSnFifty-six hemispheres in 36 consecutive patients who underwent revascularization for moyamoya angiopathy were evaluated. All patients underwent angiography and MRI before surgery and during the chronic phase. Angiographic outcomes were classified as good or poor according to the extent of the blood supply through direct or indirect bypass. The rSTA and rMMA was calculated in time-of-flight magnetic resonance angiography (MRA). The signal changes of ivy signs and flow voids in basal ganglia were also evaluated.nnnRESULTSnPostoperative collaterals through direct and indirect bypass was good in 30 (53.6%) and 33 (58.9%) patients, respectively. The mean rSTA and rMMA were 36.04 ± 28.79% and 29.15 ± 22.01%, respectively. Ivy signs and flow voids were decreased in 9 (16.1%) and 26 (46.4%) patients, respectively. Univariate analyses demonstrated no significant correlation between the angiographic outcomes and postoperative signal changes on MRI. However, rSTA was significantly correlated with good collaterals through direct bypass (Pxa0= 0.04), whereas rMMA was significantly correlated with good collaterals through indirect bypass (P < 0.001).nnnCONCLUSIONSnMRA may be an alternative to angiography. Both rSTA and rMMA estimated the development of collaterals after bypass surgery for moyamoya angiopathy.

Effect of actual age on outcome at discharge in patients by surgical clipping and endovascular coiling for ruptured cerebral aneurysm in Japan

The Japanese population features the highest rate of elderly individuals worldwide. However, the difference of actual age indication for surgical clipping (SC) and endovascular coiling (EC) has never reported. We clarified the effect of actual age on poor outcome at discharge in patients by each treatment for ruptured cerebral aneurysm according to the Japanese Stroke Data Bank. A total of 3593 patients with ruptured saccular cerebral aneurysm were treated by SC and/or EC between 2000 and 2013. The effect of actual age on poor outcome (modified Rankin scale [mRS] score >u20092) at discharge was evaluated by the cutoff age using receiver operating characteristic analysis for each treatment. There were 2666 cases in the SC group and 881 cases in the EC group. The cutoff age for poor outcome was 3 to 9xa0years older for EC than for SC. The gap of cutoff age between two treatments was 3xa0years shorter in mild subarachnoid hemorrhage than severe cases. The gap of cutoff age between two treatments was 7xa0years in elderly patients over 65xa0years old. The cutoff age was 78xa0years old for both SC and EC in elderly female patients. In conclusion, the cutoff age for poor mRS score >u20092 was 3 to 9xa0years older for EC than for SC. Actual age was one of the indications for elderly patients to achieve the optimum outcome; however, the treatment indication should be carefully considered based on the condition in each country.

Navigation of a 6-French guiding sheath into the common carotid artery using a tri-axial catheter system in transbrachial carotid artery stenting:

Background and purpose Placement of a large-bore guiding sheath or catheter into the common carotid artery (CCA) is crucial in transbrachial carotid artery stenting (CAS). Herein, we describe technical tips for the navigation of a 6-French guiding sheath into the CCA using a tri-axial catheter system in transbrachial CAS. Materials and methods A total of 27 patients underwent transbrachial CAS. For the right side, a 6-French straight guiding sheath was navigated directly into the CCA using a tri-axial catheter system, with a 4-French Simmons catheter placed through a 6-French straight guiding catheter. For the left side, a 6-French Simmons guiding sheath was navigated into the CCA using a tri-axial catheter system, with a 4-French Simmons catheter placed through a 6-French Simmons guiding catheter. After the placement of a 6-French guiding sheath into the CCA, CAS was performed under distal filter or balloon protection. Results Fifteen patients had a right carotid stenosis and 12 patients had a left carotid stenosis. The 6-French guiding sheath was safely placed with ease and provided adequate stabilization for CAS. All procedures were successfully performed without any complications. Conclusion The use of a tri-axial catheter system for the navigation of a 6-French guiding sheath into the CCA appears safe and efficient, allowing transbrachial CAS, with 6-French guiding sheath stabilization, to be performed without any complication.

Safety and efficacy of a new outreach distal access catheter, TACTICS, for coil embolization of unruptured intracranial aneurysms:

Background and purpose Current large-bore catheters can be easily and safely placed in the intracranial vessels for the stabilization of microcatheters in several neurointervention scenarios. We considered that a novel 3.4 French catheter (TACTICS, Technorat Corporation, Aichi, Japan) might be useful for intermediate/distal access in a triaxial system. Here, we present our initial experience using the TACTICS catheter for treatment of intracranial aneurysms. Materials and methods A total of 35 endovascular coils were placed to embolize unruptured intracranial aneurysms of the anterior circulation using the TACTICS catheter between December 2016 and November 2017. These procedures were retrospectively reviewed to assess aneurysmal obliteration (Raymond’s classification), the volume embolization ratio (VER) and procedural complications in comparison with 96 conventional coil treatments during the 3-year period up to 2016. Data were matched for aneurysmal morphology (location, maximum diameter and aspect ratio) by the propensity method. Results In all procedures, the TACTICS catheter was atraumatically landed beyond the carotid siphon. There were no hemorrhagic or symptomatic ischemic complications. After propensity matching, 68 procedures were assessed (34 in each group). Achievement of Raymond’s scale 1 (complete occlusion) showed the same frequency in both groups (50% vs. 50%, pu2009=u20090.23). The VER was significantly higher with the TACTICS catheter than with the conventional method (34.0% vs. 28.7%, pu2009=u20090.003). Conclusion We reviewed our initial experience of the TACTICS catheter. It can be used as an intermediate catheter for safe and effective endovascular coil embolization of anterior circulation aneurysms.