Prevention of Stroke with Closed-Cell Stent-in-Stent for Carotid Artery Stenosis Due to Stent Fracture.

Objective: Stent fracture is a risk factor for stroke. It has not been fully elucidated whether stent-in-stent procedures can effectively treat stent fractures. Case Presentation: An 80-year-old man underwent carotid artery stenting (CAS) with an open-cell stent to treat asymptomatic right internal carotid artery (ICA) stenosis. Type III stent fracture occurred during CAS. Six months later, in-stent stenosis progressed on DSA. Repeat CAS with a closed-cell stent was performed. CT showed expansion of the narrowed lumen. The patient remained stroke-free and carotid artery restenosis did not occur for 3 years postoperatively. Conclusion: Repeat CAS with a closed-cell stent is a viable treatment option for stent fracture.

A Case of Mechanical Thrombectomy for Acute Occlusion of the Left Internal Carotid Artery Later than 24 Hours after Onset.

Objective: Mechanical thrombectomy is performed on ischemic stroke patients with acute major cerebral artery occlusion within 24 hours of symptom onset. We report a case of delayed mechanical thrombectomy for acute left internal carotid artery occlusion. Case Presentation: A 76-year-old woman suddenly presented with dysarthria and right hemiparesis was admitted to her previous hospital. She was treated by conservative therapy. The next day, she was transferred to our hospital 26 hours after onset with a diagnosis of ischemic stroke due to left carotid artery acute occlusion. Contrast CT revealed left carotid artery occlusion. Arterial fibrillation was detected. Mechanical thrombectomy through the right brachial artery was immediately performed. Complete recanalization was achieved without hemorrhagic complication. Her postoperative course was uneventful. Conclusion: In this case, delayed mechanical thrombectomy for acute major cerebral artery occlusion was safely performed 24 hours after symptom onset.

Unified Total Synthesis of Pentacyclic Stemoamide-type Alkaloids.

The collective synthesis of pentacyclic stemoamide-type alkaloids is recognized as a daunting task despite high demand for a comprehensive biological profiling of these natural products. In this Letter, we report a unified synthesis of seven pentacyclic alkaloids and two unnatural derivatives. The keys to success are (1) the chemoselective assembly of four five-membered building blocks, (2) the direct oxidation of pyrrolidine natural products to pyrrole derivatives, and (3) the stereodivergent construction of totally E- or Z-substituted butenolides.

Association between CYP2C19 genotype and the additional effect of cilostazol to clopidogrel resistance in neuroendovascular therapy.

We investigated the association between CYP2C19 genotype and additional effect of cilostazol on clopidogrel resistance (CR) in neuroendovascular therapy. Between January 2012 and January 2016, 447 consecutive patients were administered with 75-mg cilostazol/day. The VerifyNow System was used for evaluating P2Y12 reaction units (PRU) > 230 and/or percentage inhibition of platelet function (% Inhibition) ≤ 20 as CR. Among 158 patients with CR, 31 were administered with additional 100- or 200-mg cilostazol/day and their platelet function was evaluated. According to CYP2C19 genotypes revealed using the Spartan RX and DNeasy Blood & Tissue Kit, patients were classified into three phenotypic groups: extensive metabolizer (EM, three patients), intermediate metabolizer (IM, 12 patients), and poor metabolizer (PM, 16 patients). Administration of additional cilostazol decreased PRU (EM group: 160.7 ± 85.2 after vs 278.3 ± 40.1 before, P = 0.15; IM group: 205.6 ± 74.0 vs 254.3 ± 35.0, P = 0.02; and PM group: 227.8 ± 52.2 vs 282.1 ± 30.4, P = 0.003), and increased % Inhibition (EM group: 40.0 ± 27.9 vs 9.3 ± 3.8, P = 0.25; IM group: 31.4 ± 18.0 vs 11.8 ± 8.2, P = 0.001; and PM group: 24.6 ± 15.0 vs 10.4 ± 9.3, P = 0.001). However, the rate of normalized-clopidogrel response, thromboembolic lesions, and bleeding complications were not significantly different among the three groups. Thus, the addition of cilostazol was effective on CR in terms of PRU, % Inhibition, rate of change of normalized-clopidogrel response, thromboembolic events, and bleeding complications irrespective of phenotype.

Total synthesis of complex alkaloids by nucleophilic addition to amides.

Nucleophilic addition to amides has been recognized as a promising transformation for total synthesis of complex alkaloids. Amides can accept two different organometallic reagents through the nucleophilic addition, which enables it to serve as a stable surrogate of multi-substituted amines. However, the nucleophilic addition has been overlooked for a long time due to three main reasons: low electrophilicity of amide carbonyls, potential hydrolysis of the reaction intermediate and excess addition of an organometallic reagent. This mini review focuses on the recent progress of total synthesis of complex alkaloids based on the nucleophilic additions to N-alkoxyamides, tertiary amides and secondary amides.

Unified Total Synthesis of Stemoamide-Type Alkaloids by Chemoselective Assembly of Five-Membered Building Blocks.

A unified total synthesis of stemoamide-type alkaloids is reported. Our synthetic approach features the chemoselective convergent assembly of five-membered building blocks via stemoamide as the common precursor to tetracyclic natural products. The synthesis consists of two successive coupling reactions of the three five-membered building blocks. The first coupling reaction is the vinylogous Michael addition/reduction sequence, which enables the gram-scale synthesis of stemoamide. The second coupling reaction is a chemoselective nucleophilic addition to stemoamide. While the lactone-selective nucleophilic addition to stemoamide affords saxorumamide and isosaxorumamide, the lactam-selective reductive nucleophilic addition leads to the formation of stemonine. Both chemoselective nucleophilic additions enable direct modification of stemoamide, resulting in highly concise and efficient total syntheses of the stemoamide-type alkaloids.

Clinical Application of Insertion Force Sensor System for Coil Embolization of Intracranial Aneurysms.

INTRODUCTION: In endovascular embolization for intracranial aneurysms, it is important to properly control the coil insertion force. However, the force can only be subjectively detected by the subtle feedback experienced by neurointerventionists at their fingertips. The authors envisioned a system that would objectively sense and quantify that force. In this article, coil insertion force was measured in cases of intracranial aneurysm using this sensor, and its actual clinical application was investigated. METHODS: The sensor consists of a hemostatic valve (Y-connector). A little flexure was intentionally added in the device, and it creates a bend in the delivery wire. The sensor measures the change in the position of the bent wire depending on the insertion force and translates it into a force value. Using this, embolization was performed for 10 unruptured intracranial aneurysms. RESULTS: The sensor adequately recorded the force, and it reflected the operators' usual clinical experience. The presence of the sensor did not affect the procedures. The sensor enabled the operators to objectively note and evaluate the insertion force and better cooperative handling was possible. Additionally, other members of the intervention team shared the information. Force records demonstrated the characteristic patterns according to every stage of coiling (framing, filling, and finishing). CONCLUSIONS: The force sensor system adequately measured coil insertion force in intracranial aneurysm coil embolization procedures. The safety of this sensor was demonstrated in clinical application for the limited number of patients. This system is useful adjunct for assisting during coil embolization for an intracranial aneurysm.

Coiling of a Ruptured Large Internal Carotid Artery Aneurysm via Extracranial-Intracranial Saphenous Vein Bypass Graft Just After Proximal Ligation of the Internal Carotid Artery.

BACKGROUND: Combined direct and endovascular surgery has been performed to treat large to giant internal carotid artery (ICA) aneurysms. This report describes successful treatment of a large ICA aneurysm by coiling of the aneurysm via an extracranial-intracranial saphenous vein (SV) graft just after bypass and ICA proximal ligation. CASE DESCRIPTION: A 66-year-old woman presented with a left ICA supraclinoid aneurysm with progressive visual field defect and impaired visual acuity in the left eye. While waiting for scheduled surgery, she experienced a subarachnoid hemorrhage. An extracranial-intracranial high-flow bypass using an SV graft and proximal ligation of the ICA were performed. Coiling of the aneurysm was immediately performed successfully via the SV bypass graft. The patient experienced no new neurologic deficit after this treatment. Follow-up radiologic evaluations using magnetic resonance imaging and magnetic resonance angiography revealed complete aneurysm occlusion. CONCLUSIONS: Aneurysm coiling via an extracranial-intracranial SV bypass graft could offer an alternative when an antegrade access route to the ICA is not used because of prior parent artery ligation.

Relationship between low response to clopidogrel and periprocedural ischemic events with coil embolization for intracranial aneurysms.

OBJECTIVES: Low response to antiplatelet drugs is one of the risk factors for ischemic events. We examined the influence of low response to clopidogrel on symptomatic ischemic events and new ischemic MRI lesions with endovascular intracranial aneurysmal coil embolization. MATERIALS AND METHODS: Between August 2010 and July 2013, 189 procedures in 181 consecutive patients who underwent endovascular coiling and received clopidogrel before treatment were investigated retrospectively. Platelet aggregation activity was examined by VerifyNow analysis. Low response to clopidogrel was defined as P2Y12 reaction units ≥230 in this study. Symptomatic ischemic complications within 30 days and postoperative new ischemic lesions on MRI-diffusion weighted imaging were evaluated. RESULTS: 66 of 189 (34.9%) cases were low responders to clopidogrel. Ischemic complications occurred in 2 of 66 (3.0%) low responders compared with 6 of 123 (4.9%) responders (p=0.72). A new high intensity spot larger than 5 mm was significantly more frequent in low responders (26 of 66; 39.4%) than in responders (26 of 121; 21.2%; p=0.01). On multivariate analysis, independent risk factors for larger new ischemic lesions were low response to clopidogrel, smokers, posterior location, and aneurysms with a larger neck. CONCLUSIONS: Low response to clopidogrel had little effect on clinical outcome although it increased asymptomatic large ischemic lesions in this cohort.

[Case of an anterior communicating artery aneurysm with acute in-stent occlusion during coil embolization].

PURPOSE: We report a case of acute in-stent occlusion during a stent-assisted coil embolization of a communicating artery aneurysm. CASE PRESENTATION: A 58-year-old man presented with a regrowth of an anterior communicating artery aneurysm one year after the initial coil embolization. An acute in-stent occlusion occurred during coil filling through the stent strut. We performed a successful recanalization of the stent using antithrombotic agents. CONCLUSIONS: Acute in-stent occlusion is a possible complication of stent-assisted coil embolization of aneurysms, particularly in narrow parent arteries. Our patient was recovered using antithrombotic drugs and did not present any major ischemic symptoms.

Combined endovascular and endoscopic surgery for acute epidural hematoma in a patient with poor health.

A 74-year-old woman presented with right acute epidural hematoma (AEDH) associated with a skull fracture after a fall. Emergency craniotomy under general anesthesia could not be performed because of her poor medical condition. Therefore, transfemoral endovascular embolization and hematoma evacuation via a burr hole were performed using endoscopy under local anesthesia. The patient recovered and was discharged without neurological deficits. AEDH is a common traumatic disease often requiring emergency craniotomy to prevent death and restore neurological function. The present combined surgical approach was effective in treating AEDH that could not be treated under general anesthesia in a patient with poor medical condition.