Takafumi Mitsutake

Treatment outcomes of carotid artery stenting with two types of distal protection filter device

PurposePreventing cerebral embolism from debris produced during carotid artery stenting (CAS) is important. This study compared the treatment outcomes of CAS using two types of filter-based embolic protection devices currently in use in Japan.Materials and methodsWe assessed 121 consecutive cases of CAS performed with FilterWire EZ™ between July 2010 and November 2012 and 37 consecutive cases of CAS performed with the Spider FX™ between November 2012 and June 2013. A Carotid Wallstent™ was used in all cases. The incidence of positive lesions on diffusion-weighted magnetic resonance imaging (DWI) and stroke were compared between the groups.ResultsPostoperative DWI-positive lesions were observed in 38 (31.4%) and 14 (37.8%) patients in the FilterWire and Spider groups, respectively. In the FilterWire group, complications were transient ischemic attacks in 3 (2.5%) patients, cerebral infarction in 2 (1.7%) patients (1 patient each with minor and major stroke), and cerebral hemorrhage due to hyperperfusion syndrome in 1 (0.8%) patient. In the Spider group, except for cerebral infarction (minor stroke) in 1 (2.7%) patient, no complications were observed. No significant differences were observed in the incidence of complications between the groups.ConclusionFilterWire EZ and Spider FX are comparable in terms of treatment outcome.

Comparison of Flow Impairment during Carotid Artery Stenting Using Two Types of Eccentric Filter Embolic Protection Devices

We investigated the angiographic findings and the clinical outcomes after carotid artery stenting (CAS) using two different, eccentric filter embolic protection devices (EPDs). Between July 2010 and August 2015, 175 CAS procedures were performed using a self-expandable closed-cell stent and a simple eccentric filter EPD (FilterWire EZ in 86 and Spider FX in 89 procedures). The angiographic findings (i.e., flow impairment and vasospasm) at the level of EPDs, neurologic events, and post-operative imaging results were compared between the FilterWire EZ and the Spider FX groups. The CAS was angiographically successful in all 175 procedures. However, the angiographs were obtained immediately after CAS-detected flow impairment in the distal internal carotid artery (ICA) in 11 (6.3%) and ICA spasms at the level of the EPD in 40 cases (22.9%). The incidence of these complications was higher with FilterWire EZ than Spider FX (ICA flow impairment of 10.5% vs. 2.2%, P = 0.03; vasospasm 30.2% vs. 15.7%, P = 0.03). There were nine neurologic events (5.1%); five patients were presented with transient ischemic attacks, three had minor strokes, and one had a major stroke. New MRI lesions were seen in 25 (29.1%) FilterWire-group and in 36 (40.4%) Spider-group patients. The neurologic events and new MRI lesions were not associated with the type of EPD used. Although the ICA flow impairment may result in neurologic events, there was no significant association between the FilterWire EZ and the Spider FX CAS with respect to the incidence of neurologic events by the prompt treatment such as catheter aspiration.

Evaluation of Acute In-stent Thrombosis during Stent-assisted Coil Embolization of Unruptured Intracranial Aneurysms

Stent-assisted coil embolization (SACE) is used to address wide-necked or complex aneurysms. However, periprocedural and/or late in-stent thrombosis (IST) elicit neurological events. We investigated the incidence and timed the development of acute IST during SACE with braided- or laser-cut stents in a retrospective study. Between May 2013 and April 2018, we evaluated 11 ISTs that occurred in the course of 185 SACE procedures (self-expandable laser-cut stent, n = 128; braided stent, n = 57). The onset of IST was measured from the time of stent placement. All 11 patients with IST were treated with anticoagulants and underwent hypertension induction. Post-procedural neurological events due to IST were also recorded. The implantation of a laser-cut stent elicited IST in 5 of 128 patients (3.9%); braided stent placements resulted in IST in 6 of 57 patients (10.5%) (P = 0.1). The mean stent diameter was significantly smaller in patients with-IST than without IST (3.0 ± 0.9 mm vs. 4.5 ± 0.7 mm, P = 0.007). The mean interval between stent placement and IST onset was 19 ± 7.7 min; it was significantly earlier for braided- than laser-cut stents (17.5 ± 4.1 min vs. 29.0 ± 4.8 min, P = 0.006). All ISTs were resolved during the procedure. Three patients experienced postoperative neurologic events. We recommend the meticulous and prolonged monitoring of images after stent placement because delayed intraoperative IST can occur especially when laser-cut stents are used.

Cerebellopontine angle meningioma diagnosed based on symptoms of trigeminal neuralgia in late pregnancy and showing spontaneous reduction in the early postpartum period: A case report

We describe a case of cerebellopontine angle meningioma, diagnosed by the initial symptoms of trigeminal neuralgia in late pregnancy, that showed spontaneous tumor volume reduction in the puerperal period. A 28‐year‐old woman developed left facial pain at 30 weeks of pregnancy. Magnetic resonance imaging showed a left cerebellopontine angle tumor. She decided to undergo gamma knife treatment at her local hospital. Fifty‐five days postpartum, magnetic resonance imaging was repeated to plan for this treatment. Gadolinium‐enhanced T1‐weighted imaging showed that the tumor had decreased, with no mass effect. The tumor was considered a low‐grade meningioma present before pregnancy, which grew as a result of hypervascular changes or hormone‐induced cellular proliferation in late pregnancy, and subsequently decreased in volume because of blood flow normalization or hormone normalization. The differential diagnosis and treatment of cerebellopontine meningioma during puerperium require careful observation, as the tumor can spontaneously decrease in size despite being symptomatic.

Usefulness of Consciousness Sedation with Dexmedetomidine and Pentazocine during Endovascular Treatment for Acute Stroke

We investigated the safety and efficacy of consciousness sedation with dexmedetomidine (DEX) during the endovascular treatment of patients with acute cerebral infarction. Between April 2014 and November 2016, 38 stroke patients underwent endovascular thrombectomy (EVT) under local anesthesia and DEX consciousness sedation. The continuous intravenous administration of low-dose DEX (0.3–0.4 μg/kg/h) was started before entering the operating room. Patients not completely immobilized received an iv bolus of pentazocine (PTZ) and/or DEX (0.5–0.6 μg/kg/h). EVT was performed using a stent retriever and/or direct thrombo-aspiration. DEX sedation was stopped as soon as the operation was finished. A stent retriever was used in 8 (21.1%), direct thrombo-aspiration in 10 (26.3%), a stent retriever plus thrombo-aspiration in 14 (36.8%), and other devices in 6 patients (15.8%). Reperfusion exceeding 50% (thrombolysis in cerebral infarction >2b) was obtained in 30 patients (78.9%). DEX sedation alone immobilized 24 patients (63.2%), 14 (36.8%) required the additional injection of DEX or PTZ when EVT devices were navigated to the lesion. The administration of DEX and PTZ elicited no significant respiratory depression or cardiac dysfunction interfering with the procedures. Consciousness sedation by DEX was effective during the endovascular treatment of acute stroke patients. Under DEX sedation and the injection of PTZ, EVT was possible without significantly changing the patients’ vital signs.

A Manual Carotid Compression Technique to Overcome Difficult Filter Protection Device Retrieval during Carotid Artery Stenting

BACKGROUND We investigated the incidence of embolic protection device retrieval difficulties at carotid artery stenting (CAS) with a closed-cell stent and demonstrated the usefulness of a manual carotid compression assist technique. METHODS Between July 2010 and October 2013, we performed 156 CAS procedures using self-expandable closed-cell stents. All procedures were performed with the aid of a filter design embolic protection device. We used FilterWire EZ in 118 procedures and SpiderFX in 38 procedures. The embolic protection device was usually retrieved by the accessory retrieval sheath after CAS. We applied a manual carotid compression technique when it was difficult to navigate the retrieval sheath through the deployed stent. We compared clinical outcomes in patients where simple retrieval was possible with patients where the manual carotid compression assisted technique was used for retrieval. RESULTS Among the 156 CAS procedures, we encountered 12 (7.7%) where embolic protection device retrieval was hampered at the proximal stent terminus. Our manual carotid compression technique overcame this difficulty without eliciting neurologic events, artery dissection, or stent deformity. CONCLUSIONS In patients undergoing closed-cell stent placement, embolic protection device retrieval difficulties may be encountered at the proximal stent terminus. Manual carotid compression assisted retrieval is an easy, readily available solution to overcome these difficulties.

Stent Coning Induces Distal Stent Edge Stenosis

Purpose: Stent coning is conular morphological changes at the distal end of wire-braided closed-cell stents. We discuss its incidence, predictors, and outcomes. Materials and Methods: We reviewed data on 178 carotid arteries (172 patients) that were treated by carotid artery stenting (CAS) with wire-braided stents. All patients were followed-up by carotid duplex ultrasound (DUS) studies to detect in-stent restenosis (ISR) and stent-edge stenosis. In patients manifesting stent coning, we also obtained neck radiographs. Results: Stent coning was detected in 11 arteries (6.2%). Internal carotid artery/common carotid artery ratio and use of a post dilation balloon were associated with coning (p<0.05). On radiographs obtained at 3-months follow-up, all instances of coning had disappeared spontaneously. Follow-up DUS detected 5 instance of stent-edge stenosis at 3- or 6 months. Stent-edge stenosis occurred only in arteries with coning. At 6 months post-CAS, Kaplan-Meier analysis revealed a cumulative freedom from stent-edge stenosis of 54.5% in vessels with coning; stent-edge stenosis was not observed in arteries without coning (p<0.05). At DUS follow-up performed a mean of 32.8 months post-CAS, 2 arteries without coning manifested ISR >50% (p=0.72). At clinical follow-up carried out a mean of 38.4 months after the procedure, none of our patients had developed new neurologic ischemic symptoms. Conclusions: While stent coning is self-curing, it may be associated with the late development of stent-edge stenosis.