Haruka Miyata

Platelet reactivity and hemorrhage risk in neurointerventional procedures under dual antiplatelet therapy

Background and purpose Hemorrhagic complications during neurointerventional procedures have various etiologies and can result in severe morbidity and mortality. This study investigated the possible association between low platelet reactivity measured by the VerifyNow assay and increased hemorrhagic complications during elective neurointervention under dual antiplatelet therapy. Methods From May 2010 to April 2013 we recorded baseline characteristics, P2Y12 reaction units (PRU), and aspirin reaction units using VerifyNow. The primary endpoint was post-procedural hemorrhagic complications. Results A total of 279 patients were enrolled and 31 major hemorrhagic complications (11.1%) were identified. From receiver-operating characteristic curve analysis, PRU values could discriminate between patients with and without major hemorrhagic complications (area under the curve 0.63). Aspirin reaction unit values had no association with the primary outcome. The optimal cut-off for the primary outcome (PRU ≤175) was used to identify the low platelet reactivity group. The incidence of hemorrhagic complications was 20.0% in this group and 8.9% in the non-low platelet reactivity group. Multivariate analysis identified low platelet reactivity as an independent predictor for hemorrhagic complications. Conclusions The risk of hemorrhagic complications during elective neurointervention including cerebral aneurysm coil embolization and carotid artery stenting under dual antiplatelet therapy is associated with the response to clopidogrel but not to aspirin. A PRU value of ≤175 discriminates between patients with and without hemorrhagic complications. Future prospective studies are required to validate whether a specific PRU value around 170–180 is predictive of hemorrhagic complications.

Prediction of Cerebral Hyperperfusion After Carotid Artery Stenting by Cerebral Angiography and Single-Photon Emission Computed Tomography Without Acetazolamide Challenge

BACKGROUND: Definitive preoperative predictors of cerebral hyperperfusion following carotid artery stenting are yet to be established. OBJECTIVE: To determine the preprocedural risk factors for cerebral hyperperfusion phenomenon (CHP) following carotid artery stenting. METHODS: Patients undergoing preprocedural single‐photon emission computed tomography (SPECT) and cerebral angiography prior to their first carotid artery stenting were monitored for occurrence of CHP. In addition to patient characteristics, we investigated imaging parameters, such as cerebral blood flow, cerebral vasoreactivity, and asymmetry index on SPECT, and presence of near occlusion and leptomeningeal anastomosis on cerebral angiography. RESULTS: Out of 100 patients (mean age: 73.0 ± 7.6 years; 85 men), 9 developed CHP. On multivariate logistic regression analysis, asymmetry index (%) on SPECT (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.70–0.93, P = .003) and presence of leptomeningeal anastomosis on cerebral angiography (OR 72.1, 95% CI 3.52–1480, P = .006) were independent predictors of CHP. CONCLUSION: Combined use of cerebral angiography and SPECT may obviate the need for acetazolamide challenge to predict the risk of CHP following carotid artery stenting.

Rare complication characterized by late-onset transient neurological symptoms without hyperperfusion after carotid artery stenting: A report of three cases:

We experienced a rare complication after carotid artery stenting (CAS) characterized by transient neurological symptoms with no evidence of distal emboli or hyperperfusion. Using neuroimaging, we investigated the pathogenesis of the complication that occurred after CAS in three patients who developed neurological symptoms over a period of ten hours after CAS and improved within two days. None of the three patients showed signs of fresh infarctions on diffusion-weighted imaging or hyperperfusion on single-photon emission computed tomography. However, high signal intensity was observed in the leptomeningeal zone of the cerebral hemisphere on the stent side in all three patients and in the leptomeningeal zone of the contralateral anterior cerebral artery territory in one patient. These areas were assessed using fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging without gadolinium administration. The high signal intensity in the leptomeningeal zone disappeared as the symptoms improved. Based on the transient nature of the neurological disorders and the normalization of FLAIR imaging findings in these patients, the pathogenesis of this complication might have been vasogenic edema due to vasoparalysis of the local vessels caused by the hemodynamic changes occurring after CAS.

The Maze-Making and Solving Technique for Coil Embolization of Large and Giant Aneurysms

These authors describe the use of 2 intra-aneurysmal catheters to deploy first large coils and then smaller, more traditional coils that ultimately fill the interstices left by the larger coils until aneurysms are tightly packed. When this technique was used to occlude large/giant aneurysms, follow-up angiography revealed no recurrences compared with nearly 40% in a group of similar lesions treated in conventional fashion. BACKGROUND AND PURPOSE: Despite major progress in treating aneurysms by coil embolization, the complete occlusion of aneurysms of >10 mm in diameter (large/giant aneurysms) remains challenging. We present a novel endovascular treatment method for large and giant cerebral aneurysms called the “maze-making and solving” technique and compare the short-term follow-up results of this technique with those of conventional coil embolization. MATERIALS AND METHODS: Eight patients (65 ± 11.5 years of age, 7 women) with large/giant unruptured nonthrombosed cerebral aneurysm (mean largest aneurysm dimension, 19 ± 4.4 mm) were treated by the maze-making and solving technique, a combination of the double-catheter technique and various assisted techniques. The coil-packing attenuation, postoperative courses, and recurrence rate of this maze group were compared with 30 previous cases (conventional group, 65.4 ± 13.0 years of age; 22 women; mean largest aneurysm dimension, 13.4 ± 3.8 mm). RESULTS: Four maze group cases were Raymond class 1; and 4 were class 2 as indicated by immediate postsurgical angiography. No perioperative deaths or major strokes occurred. Mean packing attenuation of the maze group was significantly higher than that of the conventional group (37.4 ± 5.9% versus 26.2 ± 5.6%). Follow-up angiography performed at 11.3 ± 5.4 months revealed no recurrence in the maze group compared with 39.2% in the conventional group. CONCLUSIONS: The maze-making and solving technique achieves high coil-packing attenuation for efficient embolization of large and giant cerebral aneurysms with a low risk of recurrence.