Clinical results of 30 consecutive patients of carotid artery stenosis treated with CASPER stent placement: 1-year follow-up and in-stent findings on intravascular ultrasound examination immediately and 6 months after treatment.

BACKGROUND: The CASPER stent is expected to reduce periprocedural ischemic complications, but there is concern about restenosis in the early period. One-year follow-up results of CASPER stenting and findings on intravascular ultrasound (IVUS) immediately and 6 months after treatment are evaluated. METHODS: Thirty consecutive patients were treated with CASPER stents for carotid artery stenosis. IVUS was performed immediately after stenting, and MRI and carotid ultrasonography were performed the next day, at 1 week, at 2 weeks, and then every 3 months. One-year follow-up results were evaluated. Twenty-five patients underwent follow-up angiography and IVUS after 6 months and their findings were investigated. RESULTS: All patients were treated without complications during the intraoperative and periprocedural periods. After 6 months, all 25 patients with follow-up angiography and IVUS showed various degrees of intimal formation on IVUS and 8 of them had ≥50% stenosis on angiography. Three of the 30 patients required retreatment within 6 months because of severe restenosis. In these patients, the inner layer of the stent was deformed toward the inside due to intimal hyperplasia on follow-up IVUS, and there was dissociation between the inner and outer layers. All but the 3 of 30 patients with 1-year follow-up did not lead to symptomatic cerebrovascular events or retreatment. CONCLUSIONS: The CASPER stent appears to be effective for preventing periprocedural ischemic complications. IVUS showed various degrees of intimal formation within 6 months after treatment, and it is possible that the CASPER stent is structurally prone to intimal formation or hyperplasia.

Factors related to insufficient hemostasis using the EXOSEAL vascular closure device with five-minutes compression for femoral artery punctures after neuro-endovascular therapy: A retrospective, single-center experience.

OBJECTIVES: The aim was to identify the factors related to inadequate hemostasis with five minutes of manual compression using the EXOSEAL vascular closure device (VCD), and to evaluate the optimal time to hemostasis (TTH). METHODS: A total of 119 consecutive patients who underwent neuro-endovascular therapy via common femoral arterial puncture between February 2019 and August 2021 were included. These patients underwent hemostasis using an EXOSEAL with manual compression for five minutes. In this retrospective study, the 119 patients were divided into two groups: (1) achieved hemostasis with five minutes (n = 76); and (2) required more than five minutes to achieve hemostasis (n = 43, Add group). In both groups, patient's characteristics, endovascular procedures, and closure procedures were assessed. RESULTS: On univariable analysis, activated clotting time (ACT), multiple antiplatelets, closure with an under-sized EXOSEAL VCD (U-VCD), endovascular procedure, and use of a 7Fr. VCD were significantly associated with additional compression (p < 0.05). On multivariate logistic regression analysis, the following three factors were found to be associated with additional compression: pre-closure ACT (adjusted OR, 0.136; 95% CI, 1.017-1.056; p < 0.001); multiple antithrombotics (adjusted OR, 12.843; 95% CI, 3.458-47.693; p < 0.001); and closure with a U-VCD (adjusted OR, 5.653; 95% CI, 1.751-18.151; p = 0.004). On the receiver-operating characteristic curve analysis for prediction of the need for additional compression, the cutoff point for pre-closure ACT was calculated to be 268 s. In the Add group, mean TTH was 9.8 ± 1.5 min. CONCLUSION: Multiple antiplatelets and closure with a U-VCD may increase the risk of insufficient hemostasis with five-minutes compression using an EXOSEAL VCD for femoral puncture sites if the pre-closure ACT is greater than 268 s. In these patients, mean TTH was 9.8 ± 1.5 min.

Cerebral Aneurysm Coil Embolization with a Coil-Assisted Technique Using a Small-Diameter Helical Coil.

Objective: We introduce a coil-assisted technique using a small diameter helical coil to preserve a branch artery in the aneurysm neck or dome during coil embolization of a cerebral aneurysm. Case Presentations: We report three cases that were treated with the coil-assisted technique. Using this method, the branch artery was preserved with a small diameter helical coil that was placed to support another frame coil. The first case was a ruptured internal carotid artery-posterior communicating artery (IC-Pcom) aneurysm, the second case was a ruptured anterior communicating artery aneurysm, and the third case was an unruptured IC-Pcom aneurysm, with branching of the Pcom, A2, and Pcom, respectively, from the neck or dome of the aneurysm. We were able to preserve the branch artery in all cases. Conclusion: This technique is feasible and safe for coil embolization of intracranial branch-incorporated aneurysms. The technique is especially useful for preserving branch arteries that are difficult to preserve by conventional techniques.

Renal Artery Injury Caused by a 0.035-Inch Guidewire in Navigating a Guiding Sheath during Coil Embolization: A Case Report of Rescue Embolization with n-Butyl-2-Cianoacrylate.

Objective: We report renal artery injury by a guidewire during coil embolization of a cerebral artery aneurysm, which was successfully treated by transarterial embolization using n-butyl-2-cianoacrylate (NBCA). Case Presentation: A 65-year-old woman underwent coil embolization for an unruptured cerebral aneurysm, resulting in its complete occlusion. However, her blood pressure decreased during embolization and postoperative abdominal computed tomography (CT) revealed a retroperitoneal hematoma. Intraoperative video revealed that the 0.035-inch guidewire had passed deeply into the right renal artery when the guiding sheath was navigated into the abdominal aorta, suggesting renal artery perforation. Transarterial embolization using NBCA was performed immediately, which resulted in hemostasis. Conclusion: Although renal artery perforation with a guidewire is a rare complication, it can have severe consequences. Early diagnosis with prompt and definitive hemostasis is important.

Clinical Evaluations of the Ischemic Core in Acute Ischemic Stroke Using Modified Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores by Ischemic Reversibility Using the Signal Intensity.

Objective: Early recanalization of acute stroke caused by large vessel occlusion (LVO) may improve high signal intensity (HSI) on diffusion-weighted imaging (DWI). In this study, we investigated whether subtraction of reversible ischemic lesions (RIL) from the HSI lesions on DWI improves the diagnostic accuracy for the ischemic core. Methods: A total of 35 patients from April 2013 and December 2019 were included in this study. These patients presented acute ischemic stroke due to anterior circulation LVO and underwent thrombectomy. All patients underwent DWI within 48 hours after thrombectomy. HSI ratios were calculated, and compared between ischemic lesions and contralateral normal tissue. Ischemic lesions with improvement in the HSI ratio from initial to postoperative DWI were defined as RIL. Based on a receiver operating characteristic (ROC) curve analysis that compared the HSI ratio of all ischemic lesions, the cutoff value of HSI ratio of RILs was calculated. Results: In all, 127 ischemic lesions were identified in 35 patients. HSI ratios of RILs were significantly lower than those of irreversible ischemic lesions (IILs) (p <0.0001). Based on a ROC curve analysis that compared the HSI ratio of all 127 lesions, the cutoff value of the HSI ratio of RILs was 1.4. After applying this cutoff value to the 127 ischemic lesions of the 35 patients, 20 patients (57%) were identified as having RILs with a HSI ratio of <1.4. In this 20 patients, the postoperative National Institutes of Health Stroke Scale (NIHSS) score at 24 hours was significantly lower (p = 0.007) and improvement in the NIHSS score was significantly higher (p = 0.018) than in the other patients. Conclusion: A HSI ratio of <1.4 on preoperative DWI may reflect ischemic reversibility. In this study, the HSI ratio correlated with clinical findings associated with cerebral ischemia, and our method may be useful in assessing ischemic cores.

Simple and Reproducible Microcatheter Shaping Method for Coil Embolization of Medially-directed Paraclinoid Internal Carotid Artery Aneurysms.

Objective: It is important to guarantee intra-aneurysmal stability of microcatheters during coil embolization. We developed a simple and reproducible microcatheter shaping method for medially-directed paraclinoid internal carotid artery aneurysms. Methods: An injection needle cap was used to make a smooth curve on the mandrel, which was first wound around the back end of the cap to create a primary curve. Next, a secondary curve was created using near the tip of the cap. Thus, a two-dimensional (2D), pigtail-shaped mandrel with a two-stage curve was created. The pigtail-shaped mandrel was inserted from the tip of a straight microcatheter and heat-shaped using a heat gun. Lastly, a microcatheter having a curve whose tip was approximately 6 mm longer than that of the preshaped J was created. We evaluated the ease of navigating the microcatheter into the aneurysm and its stability during coil embolization. Results: In all, 34 consecutive medially-directed paraclinoid internal carotid artery aneurysms were treated using the shaped catheters. It took 50-300 seconds (intermediate value: 90 seconds) from inserting the microcatheter with a microguide wire to navigate and place it into an aneurysm. There were no cases that required reshaping of the microcatheters during navigation into the aneurysm. There were no cases that resulted in kickback of the microcatheters from the aneurysm during coil placement, and microcatheter stability was good until the end of the procedure. In all, 12 cases required the balloon-assisted technique and three cases required stent-assisted coiling. The angiographic outcomes immediately after embolization were as follows: 25 cases (73.5%) with complete occlusion; 3 cases (8.8%) with dome filling; and 6 cases (17.6%) with a neck remnant. There were no perioperative complications. Conclusion: The shaping method with a pigtail-shaped mandrel using an injection needle cap is simple and reproducible, and is useful for medially-directed paraclinoid internal carotid artery aneurysms.

[Percutaneous Transluminal Sinus Stenting for Sigmoid Sinus Stenosis Associated with Transverse-Sigmoid Sinus Dural Arteriovenous Fistula:A Case Report].

We report a case of transverse sinus-sigmoid sinus dural arteriovenous fistula(T-S dAVF)with venous flow congestion, which was accompanied by sigmoid sinus stenosis and treated with percutaneous transluminal sinus stenting. A 76-year-old woman presented with dementia and disturbance of consciousness. Magnetic resonance imaging(MRI)on admission revealed subcortical edema in the left occipital lobe and angiography demonstrated a left T-S dAVF with right transverse sinus occlusion and sigmoid sinus stenosis. Hemodynamics of the shunt flow from several feeders demonstrated retrograde flow to the straight sinus and superior sagittal sinus, and antegrade flow into the left internal jugular vein. These hemodynamics caused cortical venous congestion and intracranial venous hypertension. We performed percutaneous transluminal sinus stenting for left sigmoid sinus stenosis. Immediately after stent placement, retrograde shunt flow to the straight sinus and superior straight sinus dramatically disappeared and cortical venous congestion improved. Follow-up angiography 1 year after treatment showed neither new development of T-S dAVF nor re-stenosis of the stent in the left sigmoid sinus, although some shunt flow remained. Percutaneous transluminal sinus stenting for sinus stenosis associated with dAVF appears effective to improve venous congestion and intracranial venous hypertension.

[A Case of Tentorial Dural Arteriovenous Fistula Treated with Transvenous Embolization Using NBCA].

We report a case of tentorial dural arteriovenous fistula(dAVF)treated with transarterial and transvenous embolization using n-butyl-2-cyanoacrylate(NBCA). A 70-year-old man presented with dysarthria and trunk ataxia. Computed tomography(CT)on admission revealed right cerebellar hemorrhage. Right external carotid angiography demonstrated a tentorial dAVF fed by the marginal tentorial artery, petrosquamous branch of the middle meningeal artery, ascending pharyngeal artery, and artery of foramen rotundum. Right internal carotid angiography demonstrated a shunt fed by the meningohypophyseal trunk. The draining vein was the right basal vein with a varix, which drained into the straight sinus. Thin-slice axial images on magnetic resonance angiography demonstrated a shunt point located on the right tentorial incisura. The lesion was diagnosed as Cognard type IV tentorial dAVF. It was initially treated with transarterial embolization using 25% NBCA, which was injected into the marginal tentorial artery and the petrosquamous branch of the middle meningeal artery. However, owing to partial persistence of the shunt after the procedure, transvenous embolization using NBCA was performed. A microcatheter was navigated through the straight sinus into the basal vein, and a balloon catheter was also navigated to the confluence of the straight sinus and the basal vein to interrupt blood flow and prevent the NBCA from flowing back to the sinus. 80% NBCA was injected into the draining vein near the shunt point. Angiography performed immediately after the procedure revealed complete occlusion of the shunt, and postoperative CT showed no evidence of hemorrhage. Transvenous embolization of tentorial dAVF can be an effective method if a microcatheter can be safely advanced close to the shunt point.

Initial clinical experience using the two-stage aspiration technique (TSAT) with proximal flow arrest by a balloon guiding catheter for acute ischemic stroke of the anterior circulation.

BACKGROUND: Our initial experience using the two-stage aspiration technique (TSAT) with proximal flow arrest by a balloon guiding catheter is presented. In TSAT, aspiration is applied with the 5MAX ACE and also with the 3MAX catheter with a Penumbra aspiration pump, while arresting proximal flow by balloon inflation. METHODS: In patients treated with TSAT, clinical data including National Institutes of Health Stroke Scale (NIHSS) score at admission and the modified Rankin Scale (mRS) score at discharge, as well as procedural data including the Thrombolysis in Cerebral Infarction (TICI) score, procedural time, and complications were analyzed. RESULTS: Thirty-four consecutive patients (19 men (56%); mean age 73 years) were treated with TSAT using a balloon guiding catheter. The patients presented with a mean NIHSS score of 17.4 and 23 (68%) patients received IV tissue plasminogen activator. Median time from groin puncture to successful recanalization was 41 min (range 15-160 min). All patients were successfully revascularized; TICI 2b or better recanalization was achieved in 30 (88%) patients. No patient required an additional procedure such as use of a stent retriever. Procedure-related complications occurred in two (5.9%) patients (vessel injury and guidewire perforation). Symptomatic intracranial hemorrhage occurred in one patient and asymptomatic hemorrhagic infarction occurred in two patients. There were no cases of embolization to new territory (ENT). The mean NIHSS score at discharge improved to 6.1. Sixteen patients (47%) achieved a good outcome with an mRS score of 0-2 at discharge (mean hospitalization period 20 days). CONCLUSIONS: TSAT with proximal flow arrest by a balloon guiding catheter is an effective and safe method to achieve good clinical and angiographic outcomes. This method may reduce ENT in the direct aspiration first-pass thrombectomy (ADAPT) technique.

[A Case of Percutaneous Transluminal Angioplasty and Stenting for Dacron Bypass Graft Stenosis with Cerebral Infarction].

A 62-year-old man presented to the emergency room with mild dysarthria and right motor weakness. The patient was diagnosed with aortic dissection (DeBakey type III) in the cardiovascular department of our institution two years ago and was then treated with left carotid-bilateral subclavian bypass with collagen-seated Dacron graft followed by thoracic endovascular aortic repair (TEVER) with stent-graft placement. Magnetic resonance imaging on admission showed cerebral infarction with left proximal middle cerebral artery occlusion in the left cerebral hemisphere. Three-dimensional computed tomography angiography (3D-CTA) demonstrated a stenotic lesion at the anastomosis of the right subclavian artery and the bypass graft. It also showed the partial left common carotid artery, suggestive of an endoleak in the thoracic stent graft. The patient was diagnosed with artery-to-artery embolism due to bypass graft stenosis or endoleak in the thoracic stent graft and was treated with conservative therapy. He gradually recovered from the neurological deficit and underwent endovascular angioplasty with a balloon-expandable stent for bypass graft stenosis by using the distal balloon protection method and the left proximal common carotid artery occlusion with coils 1 month later. One-year follow-up 3D-CTA showed good patency of the stent in the bypass graft. No recurrence of cerebral infarction was observed during the postoperative course.

[Cis-diamminedichloroplatinum penetration into the cerebrospinal fluid of the lateral ventricle, postoperative cavity, and lumbar subarachnoid space with or without pre-intravenous mannitol administration in patients with brain metastasis from lung cancer].

We have previously reported that repeated intravenous administration of cis-diamminedichloroplatinum(CDDP)prevented local recurrence of metastatic brain tumors after surgical total excision; however, data on CDDP distribution in the postoperative cavity after intravenous CDDP administration are not available. In the present study, we evaluated the penetration of total platinum(Pt)into the cerebrospinal fluid(CSF)and the effect of intravenous administration of 20%mannitolon total Pt distribution in the plasma and CSF. Total Pt levels in the plasma and CSF were determined immediately after intravenous infusion of CDDP(80mg/m2)for 1 hour, with or without pre-intravenous infusion of 20% mannitol(200mL), in 11 patients with brain metastasis from lung cancer. CSF samples were obtained via Ommaya reservoirs placed in the anterior horn of the lateral ventricle(CSF-V)and the postoperative cavity(CSF-C). Spinal CSF (CSF-L)was also obtained in the last 4 patients of the series via spinal drainage. CDDP was administered intravenously without mannitol 10 days after brain tumor excision, and 1 week after the initial administration of CDDP, CDDP was intravenously administered again after intravenous mannitol administration. CDDP was always administered intravenously at 1:00 PM to rule out the influence of circadian variation. Plasma and CSF were sequentially sampled after intravenous CDDP administration, and their Pt levels were analyzed for Pt content by using atomic absorption spectroscopy. The area under the concentration time curve(AUC)was calculated for plasma and CSF using the moment method. The AUC for total Pt in plasma showed a significantly higher level with the administration of mannitol than without the administration of mannitol(p<0.01, paired t-test). Total Pt levels(AUCs and peak concentrations)in CSF-C were much higher than were those in CSF-V and CSF-L both with and without the administration of mannitol. The ratio(%)of CDDP penetration into CSF(CSF AUC/plasma AUC)was much higher for CSF-C than for CSF-V(p<0.0001)both with and without mannitol administration. However, the CSF penetration ratio with mannitol administration did not differ significantly from that without mannitol administration. Thus, the administration of mannitol did not significantly increase the penetration ratio of total Pt. Creatinine clearance was moderately reduced in all patients during the first administration of CDDP. However, 7 of the 11 patients showed an increase in creatinine clearance after the second administration of CDDP with mannitol.