Objective: Embolic stroke is the most serious complication after carotid artery stenting (CAS). The incidence rate of embolic stroke is reduced by the use of embolic protection devices (EPDs); however, there is no consensus on which EPD is the most effective. The aspiration and re-transfusion technique (ART) with CAS under distal balloon protection was adopted at our center to reduce the incidence of embolic complications. This retrospective study investigated the effects of ART.

Methods: From November 2010, 243 consecutive patients treated by CAS under distal balloon protection were included. ART was performed on 202 patients (ART group) and the other 40 patients only received distal balloon protection (non-ART group). In ART, the blood from the aspiration catheter was continuously returned through a filter to the femoral vein. The amount of debris was assessed intermittently using a small blood sample and the rest was returned. We investigated the diffusion-weighted imaging (DWI)-positive rate and symptomatic ischemic stroke one day after CAS.

Results: Compared with the non-ART group, the incidence of DWI-positive lesions (22.7% vs 37.5%, P = 0.07) and frequency of symptomatic ischemic stroke (0.9% vs 5.0%, P = 0.12) were reduced in the ART group. The hemoglobin reduction rate was significantly reduced by ART (11.1% vs 14.9%, P <0.01). In the ART group, the frequency of multiple lesions (more than 5) and large lesions (more than 10 mm) was lower than that in the non-ART group (P <0.01, P = 0.14).

Conclusion: CAS under distal balloon protection with ART was effective at reducing the incidence of DWI-positive lesions and may be useful to reduce the incidence of symptomatic ischemic stroke.

Objective: The usage of oral anticoagulants (OACs) in the acute phase of cerebral infarction has increased, but the optimal timing for starting OACs after mechanical thrombectomy (MT) is unclear. We report the usage of OACs after MT at our hospital and evaluated the outcomes.

Methods: OACs were selected as secondary preventive drugs for 64 patients who underwent MT for anterior circulatory embolism between July 2016 and January 2019. Of the 64 patients, 28 and 36 received direct oral anticoagulants (DOACs) and warfarin (Wf), respectively. We compared the frequency of intracranial hemorrhage in the acute phase and that of recurrent cerebral infarction within 30 days.

Results: The median diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Scores + white matter (DWI-ASPECTS + W) score at admission was 7.5 (IQR 6–9)/8 (IQR, 6–9) in the DOACs group/Wf group. The rate of recanalization with modified thrombolysis in cerebral infarction (TICI) ≥2B by MT was 89.3/80.6%. In patients with subarachnoid hemorrhage (SAH) associated with MT and patients with hemorrhagic transformation (HT) on MRI the next day, administration was started after hemostasis. The median timing of the first anticoagulant administration was 3 (IQR, 2–4)/2 (IQR, 1–4) days. In the case of no HT the next day, the rate of new HT after 1 week was 7.1%/29.1%. In the case of HT the next day, the rate of HT deterioration the next day was 7.1%/16.6%. The percentage of symptomatic bleeding was 0%/2.8%. The percentage of recurrent cerebral infarction within 30 days was 0%/2.8%.

Conclusion: OACs in the acute phase after MT can be safely used and are expected to be effective at preventing recurrence.

Objective: Vascular injuries are severe complications associated with endovascular thrombectomy. In the present study, we evaluated the re-sheathing technique with the Solitaire stent retrieval system to overcome these complications.

Methods: We examined the diameter and resistance to retrieval of the Solitaire FR device (6 × 20 mm) during full and partial deployment in vitro model. We also examined a representative case in which the re-sheathing technique was used.

Results: We found that the Solitaire device spread elliptically during partial deployment. As the length of the partially deployed device decreased, the maximum diameter also decreased. The distal half of the stent retained 80% of the maximum diameter of the partially deployed Solitaire. The resistance to retrieval was significantly higher during full deployment (mean ± standard deviation; 0.32 ± 0.04 kg) than during half deployment (0.22 ± 0.04 kg) (Mann–Whitney U test; p = 0.006). The re-sheathing technique was used in the representative case due to the high resistance to retrieval, which enabled recanalization without extravasation.

Conclusion: In cases of high resistance to retrieval, minimal re-sheathing may be useful for capturing the thrombus without increasing the risk of vascular injury.

Objective: We report a case of carotid mobile plaques treated by carotid artery stenting (CAS) using a double-layer micromesh stent (CASPER stent).

Case Presentation: An 86-year-old male presented with lightheadedness. Carotid artery ultrasound revealed mobile plaques in the right internal carotid artery (ICA). Head and neck MRI demonstrated concomitant left ICA occlusion. We first started medical treatment, but it could not reduce the plaque size. Then, we performed CAS using a CASPER stent in addition to medical treatment. The procedure was finished without complications, and there was no plaque protrusion. The postoperative course was uneventful during 3 years of follow-up.

Conclusion: A mobile plaque of the carotid artery may be treated less-invasively with a micromesh stent.

Objective: We report a case of in-stent stenosis as a complication at 6 months after the deployment of Pipeline Flex. This case necessitated retreatment for parent artery occlusion.

Case Presentation: A 55-year-old woman with right-side visual disorder was referred to our hospital for the deployment of Pipeline Flex. Cerebral digital subtraction angiography (DSA) demonstrated a large right-side paraclinoid aneurysm in combination with severe internal carotid artery (ICA) stenosis just beyond the aneurysm. We deployed Pipeline Flex under general anesthesia. After deployment, we performed angioplasty through the Pipeline. Six months after deployment, this patient exhibited exacerbation of visual disorder. Follow-up DSA revealed in-stent stenosis at 6 months after the deployment of Pipeline Flex. Therefore, we performed parent artery occlusion. Right-side visual disorder was improved in this patient.

Conclusion: If Pipeline is deployed for patients with ICA stenosis just beyond an aneurysm, we need to be aware of in-stent stenosis after deployment.

Objective: A pipeline embolization device (PED; Medtronic, Minneapolis, MI, USA) is a new vascular reconstruction device used to treat large internal carotid artery (ICA) aneurysms in Japan. We herein present a PED-related complication and describe its rescue strategy. Rescue therapy using a snare via the posterior communicating artery from the contralateral side has already been reported. However, this is the first report of therapy via the anterior communicating artery (AcomA).

Case Presentation: A 49-year-old woman underwent vascular reconstruction with a PED for a large cavernous ICA aneurysm. During the placement of the PED, the proximal side of the PED slipped into the aneurysm. It was impossible to enter the true lumen of the PED from the proximal side because the orifice of the stent faced the aneurysmal wall. Contralateral trans-AcomA access to the PED was obtained through the distal ICA. The microwire from the distal ICA was connected with Goose Neck snares (Medtronic) from the proximal ICA. Pulling the snares to the proximal side, the PED was straightened and distal access was regained. Another PED was deployed such that it overlapped with the first PED to achieve vascular reconstruction. The patient finally recovered from aphasia, but paralysis of the right upper limb remained after rehabilitation.

Conclusion: If the stent slips into the aneurysm, distal access through the true stent lumen may be very difficult. We presented a rescue technique for this complication, through the AcomA from the contralateral side.

Objective: Direct traumatic carotid-cavernous fisulas (dtCCFs) exhibit a high blood flow velocity and are often difficult to be treated. We report three dtCCF cases in which disappearance of the dtCCF and preservation of the internal carotid artery (ICA) were achieved by stent-assisted coil embolization of the fistula. We report these cases and compare them with those previously reported using other treatments.

Case Presentations: In the first case, we performed coil embolization without stenting for the initial treatment. The cerebral venous reflux disappeared and the patient’s symptoms were temporarily ameliorated. However, 5 months after treatment, an aneurysm-like finding around the fistula was noted on MRA. Additional coils and insertion of a neck-bridging stent were required to obliterate the dtCCF and the symptoms disappeared. In the second and third cases, we intended to use stents initially to achieve tight embolization of the fistulas, and obliteration was achieved.

Conclusion: Use of neck-bridging stenting for dtCCFs may be a reliable method to preserve the parent artery while achieving tight packing around the fistula.

Objective: To report a patient who achieved complete recanalization using the parallel stent retriever (SR) technique for a refractory acute middle cerebral artery (MCA) embolism.

Case Presentation: An 86-year-old woman underwent an emergency thrombectomy for acute right MCA occlusion. Although thrombectomy has been attempted three times with the conventional technique using a single SR, no recanalization was achieved. Then, an innovative technique was used to deploy two SRs in parallel with the M1 segment of the MCA. Pulling them back simultaneously, the thrombus was retrieved, and complete recanalization was achieved.

Conclusion: The parallel SR technique is a feasible method and can be considered as one of the last treatment resorts for acute refractory embolisms at the major MCA trunk.

Objective: Several techniques have been reported for navigating devices to the basilar artery (BA). We report a case of acute BA reconstruction using the buddy wire technique to guide a coronary stent to the BA.

Case Presentation: The patient was a 74-year-old man without a history of stroke. He suddenly developed quadriplegia and coma due to basilar artery occlusion (BAO). Although mechanical thrombectomy with a stent retriever and subsequent balloon angioplasty were performed repeatedly for residual severe stenosis, recanalization was not maintained. Recanalization with a coronary stent was attempted, but guidance was difficult because of the tortuous vertebral artery (VA). The stent was successfully guided to the BA by navigating two microguidewires as far as possible to the contralateral VA across the union.

Conclusion: The cross-over buddy wire technique is a useful option for guiding a coronary stent to the BA.