Objective: Thin-walled regions of cerebral aneurysms are areas of risk for rupture, particularly during surgical procedures. Prediction of thin-walled regions before surgery can lead to safer treatment, avoiding interactions with thin-walled regions. It is considered that blood flow influences aneurysm wall thickness reduction. The objective of this study was to establish a parameter to accurately identify thin-walled regions using computational fluid dynamics (CFD) analysis.
Methods: The surgical field was photographed during craniotomy in 50 patients with unruptured middle cerebral artery aneurysms and red regions of the aneurysm wall were compared with the color of the parent vessel and defined as a thin-walled region. CFD analysis was performed and the distribution map of wall shear stress divergence (WSSD*) was compared to the surgical image of the cerebral aneurysms.
Results: The WSSDmax region and thin-walled region were coinciding in 41 (82.0%) of the 50 patients. There was a significant difference (P = 0.00022) between the patients with and without coincidence between the WSSDmax and thin-walled regions, and the threshold, sensitivity, specificity, and area under the curve (AUC) on receiver operating characteristic (ROC) analysis of WSSDmax were 0.230, 0.900, 0.875, and 0.883, respectively.
Conclusion: High-WSSD regions tended to be coinciding with thin-walled regions, suggesting that WSSDmax is useful to identify thin-walled regions of cerebral aneurysms.
Objective: For patients with tandem occlusion (TO), it is controversial whether an antegrade approach or retrograde approach should be undertaken. Here, we report our strategy for treating patients with TO by simultaneous approach. First, a microcatheter was advanced to the distal occlusion site along with a microwire. Second, a stent retriever (SR) was deployed as an anchor at the distal lesion, and percutaneous transluminal angioplasty (PTA) was performed at the proximal lesion using push wire of SR. After that, the microwire was removed and PTA balloon as well as the guiding catheter (GC) was advanced along the wire of SR. Finally, the SR was withdrawn with clot.
Case Presentations: Cases 1 and 2, who were confirmed as TO, were treated by the method described above. We could re-perfuse successfully. These two cases had favorable outcomes, indicating a modified Rankin scale 2 at the time of discharge.
Conclusion: Our therapeutic strategy for TO might be useful for early reperfusion of a distal occlusion site and associated with favorable outcome.
Objective: We report a first case of stent-assisted coiling for the left vertebral artery aneurysm via the left distal radial approach.
Case Presentation: The patient was a 47-year-old male with unruptured left vertebral artery aneurysm. Transfemoral approach was infeasible because of the history of thoracoabdominal aortic dissection, the left distal radial approach was selected. Distal radial artery in the left anatomical snuffbox was punctured and a 4 Fr guiding sheath was introduced to the left vertebral artery, followed by successful coil embolization with stent.
Conclusion: The left distal radial approach via the anatomical snuffbox is a feasible method for left vertebral artery lesions.
Objective: In transarterial embolization (TAE) of spinal epidural arteriovenous fistula (SEDAVF), it is essential to control the blood flow at the shunt point. We report a case of SEDAVF treated with TAE with occluding one of several segmental arteries (SAs) involved in the shunt using a balloon.
Case Presentation: A 68-year-old male presented with gait disturbance and bladder bowel dysfunction. Lumbar spinal MRI showed a dilated and tortuous vein around the spinal conus. Spinal angiography revealed a SEDAVF with intradural venous reflux through the epidural venous plexus fed by the branches of the right 2nd and 3rd lumbar arteries (L2 and L3). We infused 14% n-buthyl-2-cyanoacrylate (NBCA) from the feeder of the L2 under the flow control by occluding L3 using a balloon and achieved complete obliteration of the arteriovenous shunt.
Conclusion: In treatment of SEDAVF with feeders from several SAs, TAE with occluding one of the SAs using a balloon is a useful method.
Objective: We report a case of cavernous sinus dural arteriovenous fistula (CSdAVF) presenting with medulla oblongata dysfunction in parallel to thrombosis of a varix on a drainage route after transvenous embolization (TVE).
Case Presentation: A 76-year-old male presented with deep sensory disturbance. Cerebral angiogram revealed a right CSdAVF with retrograde venous drainage refluxing to the anterior medullary vein. A varix arising from the vein was buried in the medulla oblongata, and an edematous change was shown in the nerve tissue around the varix. TVE was successfully performed and the shunt flow completely disappeared. The neurological symptoms improved immediately after TVE. The following day after TVE, medulla oblongata dysfunction appeared again, which was more severe than that before TVE. MRI showed thrombosis and a volume increase of the varix, and an enlargement of edematous change in the nerve tissue around the varix. Administration of corticosteroids gradually improved neurological and imaging findings.
Conclusion: A varix on a drainage route can cause brainstem dysfunction in CSdAVF. Thrombosis of the varix may exacerbate neurological symptoms.
Objective: To introduce our experience of endovascular treatment for craniofacial arteriovenous fistula/malformation (AVF/M).
Methods: We retrospectively analyzed the medical records of 13 patients (7 females and 6 males) with craniofacial AVF/M who were treated between 2001 and 2017 in our institution. We classified into three categories including single AVF (sAVF), multiple AVF (mAVF), and arteriovenous malformation (AVM). Treatment plans included 1) curative embolization, 2) preoperative embolization, and 3) palliative embolization. These strategies were decided by the discussion with plastic surgeons in every individual case.
Results: Complete cure by embolization alone was obtained in all six patients with sAVF, in two among three patients with mAVF, and in none among four patients with AVM. Curative embolization was aimed at in eight patients, and complete cure obtained in all eight patients. Preoperative embolization was aimed at in three patients, and three patients resulted in total resection by surgery after successful partial embolization. Palliative embolization was aimed at in two patients, and these patients were kept in a stable condition after partial embolization. No permanent complications related to embolization were counted.
Conclusion: Endovascular treatment for craniofacial AVF/M is safe and effective treatment, especially in the case with sAVF.
Objective: We report a patient in whom direct puncture of the superior ophthalmic vein for a cavernous sinus dural arteriovenous fistula led to rapidly progressing thrombosis and postoperative non-arteritic ischemic optic neuropathy (NA-ION), and review the pathogenesis.
Case Presentation: A 74-year-old female. Detailed examination of diplopia and visual disorder suggested a cavernous sinus dural arteriovenous fistula. As approaching via a posterior route was difficult, transvenous embolization by direct puncture of the superior ophthalmic vein was performed. As drainage routes were aggregated around this vein, thrombosis of this vein occurred, inducing postoperative NA-ION through a rapid change in hemodynamics.
Conclusion: When performing direct puncture of the superior ophthalmic vein, puncture methods and heparinization should be considered after sufficiently investigating drainage routes.
Objective: We report a patient in whom encephalopathy developed after coil embolization of an unruptured basilar artery aneurysm and stent placement for vertebral artery stenosis.
Case Presentation: A 69-year-old female. When the unruptured basilar artery aneurysm was treated with coil embolization, a balloon-expandable stent was placed for left vertebral artery stenosis, and treatment was completed without complication. Loss of appetite and lightheadedness developed from 2 weeks after discharge, and multiple FLAIR high-intensity areas, and nodular contrast enhancement in the left vertebral artery territory were observed on MRI. Steroid pulse therapy was performed suspecting metal allergy and foreign body granuloma, and symptoms improved.
Conclusion: Encephalopathy associated with foreign body granuloma and metal allergy may be caused by coil and stent placement. Patients should be sufficiently interviewed, and when allergies are suspected, reconsideration of the treatment method may be necessary in advance.
Objective: Patients who undergo stent-assisted cerebral aneurysm coiling require long-term antiplatelet therapy (AT). Recently, the low-profile visualized intraluminal support (LVIS) stent (LS) has been available for cerebral aneurysm treatment in Japan as a new design braided stent with excellent wall apposition due to manipulation even if the parent artery is tortuous, like the carotid siphon. The aim of this study was to evaluate whether AT could be terminated without increasing the risk of ischemic events among patients who have undergone LS-assisted cerebral aneurysm coiling.
Methods: In all, 15 consecutive patients with 15 unruptured aneurysms who underwent LS-assisted cerebral aneurysm coiling and were confirmed to have neointimal formation by follow-up angiography at 3 months were evaluated in this study. All aneurysms were located in the internal carotid artery (ICA). Dual AT was given for 1 month, and then a single antiplatelet agent was given for 2 months until confirmation of neointimal formation. After confirmation of neointimal formation, AT was terminated. The incidences of ipsilateral ischemic events and stent occlusion, as evaluated by angiography or contrast-enhanced MRA, after termination of AT were prospectively assessed.
Results: During follow-up, no ipsilateral ischemic events (mean, 10.3 months; range, 3.1–19.8 months) occurred, and no stent occlusion (mean, 8.0 months; range, 1–17.5 months) was observed in any cases.
Conclusion: Termination of the antiplatelet drugs 3 months after the procedure may be safe who underwent LS-assisted coil embolization.
Objective: Reperfusion by endovascular mechanical thrombectomy has been proven effective for patients with acute ischemic stroke. Although most embolization sources are thrombi, other types of clots could also be embolic sources. We report a sporadic case of acute ischemic stroke caused by mobilization of cardiac papillary fibroelastoma (CPF).
Case Presentation: A 79-year-old man presented was hospitalized with chronic heart failure due to disdialysis syndrome. He developed sudden consciousness disturbance and was diagnosed with basilar artery occlusion. Mechanical thrombectomy with only one pass of the Penumbra 5MAX ACE (Penumbra Inc., Alameda, CA, USA) was successful with a direct aspiration first-pass technique. Histopathological examination of the papilla-shaped fragile clot with white granular surface, revealed papillary fibroelastoma. Slight improvement in his clinical symptoms was seen after thrombectomy, but the patient died of deterioration of the disdialysis syndrome. CPF diagnosis was based on the pathological findings of the embolus, not on transesophageal echocardiography (TEE) or open heart surgery due to disdialysis syndrome in our patient. In addition, the presence of cardiac tumor could not be confirmed in the autopsy.
Conclusion: CPF is a rare benign cardiac tumor, which might cause cerebral infarction either directly or through thrombus formed by platelets and fibrin. While mechanical thrombectomy is safe and effective, but histopathological diagnosis of the aspirated clot can be recommended, especially if the appearance of the embolic material is unusual.
Objective: In this study, we report a patient in whom a dural arteriovenous fistula (dAVF) developed after mechanical thrombectomy for acute ischemic stroke, and embolization was performed.
Case Presentation: The patient was a 44-year-old male. He was brought to the emergency room of our hospital by ambulance with cervical pain. Head MRI revealed ischemic stroke related to right internal carotid artery occlusion. Mechanical thrombectomy was performed and thrombolysis in cerebral infarction (TICI) 2b recanalization was achieved. Middle cerebral artery (M2) occlusion and internal carotid artery dissection were observed. Follow-up was conducted. The postoperative course was favorable, and he was referred to another hospital for rehabilitation. However, cerebral angiography 4 months after surgery showed a dAVF. Transarterial embolization was performed. The postoperative course was uneventful and she was discharged.
Conclusion: In the present case, dissection-related dilation/elevation of the internal carotid artery may have resulted in venous compression, leading to the development of a dAVF. We could confirm these serial changes in images before and after its development.
Objective: A newly developed application for cerebral C-arm computed tomography perfusion imaging (C-arm CTP) using an angiography system was investigated.
Case Presentation: C-arm CTP protocol continuously collects X-ray projection images during 10 back and forth C-arm rotations. From the collected data, cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) images and multiphase vascular images are reconstructed. C-arm CTP images acquired in patients with acute and chronic major artery occlusion are presented.
Conclusion: C-arm CTP using an angiography system is capable of evaluating perfusion parameters in real time, similar to conventional evaluation using multi-detector row CT perfusion (MD-CTP), suggesting its usefulness for examination of ischemic stroke in the angiographic suite.
Objective: After internal trapping for ruptured vertebral artery dissection (VAD), serious complications related to medullary infarction influence the prognosis.
Methods: The subjects were 15 patients with ruptured VAD who had undergone internal trapping between 2004 and 2017. Targeted embolization of dilated segment was performed while neither adjacent stenotic sites nor normal segments were embolized. We retrospectively analyzed the incidence and extent of medullary infarctions, neurologic sequelae, and outcome.
Results: In all patients, endovascular procedures were successful. There were no intraoperative complications. In two patients, embolization with the double-catheter method through bilateral approaches was performed. Postoperative medullary infarction was noted in two patients, but they had dorsolateral-type minor infracted foci. There were no serious sequelae in any patient, and there were no rebleedings during the follow-up period.
Conclusion: The results suggest that internal trapping in which the extent of embolization is limited to the site of morbid dilation prevents rebleeding, reducing the risk of postoperative medullary infarctions. Tight packing of a dilated segment with the preservation of perforators from vertebral arteries (VAs) is extremely important. The double-catheter method through bilateral approaches may be useful for tight packing of the dilated segment of ruptured VAD.
Objective: We herein report a new technique using double microcatheters to treat a wide-necked aneurysm in which the neck is incorporated with the parent artery.
Case Presentations: Case 1: The patient was a 71-year-old woman with a large, wide-necked unruptured aneurysm of the basilar bifurcation area with the right posterior cerebral artery (PCA) incorporated in the aneurysm sac. We previously placed a scaffolding coil around the right PCA orifice via a microcatheter placed near the right PCA to avoid a framing coil via another microcatheter involving the right PCA orifice. After confirming that the framing coil did not obstruct the right PCA flow, the “scaffolding” coil was repositioned in the framing coil. Complete occlusion of the aneurysm was achieved with the stable frame of these two coils. Case 2: The patient was a 68-year-old woman who presented with subarachnoid hemorrhaging due to a ruptured aneurysm with a wide neck of the basilar bifurcation. Coiling with a conventional double-catheter technique failed to form suitable framing because the tips of both microcatheters faced the same direction (posterior) even after changing the shapes of the tips. After leading the tip of one microcatheter to face the anterior direction by inserting part of the first coil via the microcatheter, we placed the second coil via another microcatheter with its tip facing posteriorly. The second coil then came to functions as the scaffolding, holding the tip of the first catheter anteriorly. A stable frame was made when the remaining part of the first coil was deployed.
Conclusion: We termed this method the “scaffolding technique.” This technique is an effective and safe option for treating wide-necked aneurysms.
Objective: To evaluate cerebral blood flow immediately after reperfusion following thrombectomy for acute large vessel occlusion, and to examine whether cerebral blood flow after reperfusion is related to hemorrhagic transformation.
Methods: The patients with acute large vessel occlusion in the anterior circulation who obtained reperfusion by thrombectomy were included. Cerebral blood flow was evaluated using single photon emission computed tomography (SPECT) within 6 hours after reperfusion. The patients were divided into two groups with or without hemorrhagic transformation, and basic characteristics, the ratio of cerebral blood flow (affected-side to unaffected-side ratio) in the perfusion area of the middle cerebral artery (MCA asymmetry index), and functional prognosis were compared among two groups.
Results: In all, 23 patients were included; 11 presented hemorrhagic transformation, and 12 did not. The hemorrhagic group exhibited significantly higher MCA asymmetry index than the non-hemorrhagic group (median: 1.54 [1.30–1.83] vs. 1.12 [1.07–1.24], respectively, P = 0.02), and a lower rate tendency of modified Rankin Scale (mRS): 0-2 after 3 months (1 patient [9%] vs. 6 patients [50%], respectively, P = 0.06).
Conclusion: In patients with successful reperfusion by thrombectomy, hemorrhagic transformation is predisposed to occur when high MCA asymmetry index is presented. Care should be taken in periprocedural management of blood pressure and sedation for those with high MCA asymmetry index.
Objective: In this report, we discuss the cases of two patients with a ruptured blood blister-like aneurysm (BBA) of the basilar trunk, who we treated with overlapping stent-assisted coil embolization (SACE).
Case Presentation: Case 1: The first patient was a 52-year-old male with a World Federation of Neurosurgical Societies (WFNS) Grade IV subarachnoid hemorrhage (SAH). A 2 mm anterior wall BBA of the basilar artery (BA) was detected on cerebral angiography on day 10 and treated with overlapping SACE. No recanalization was observed at 12 months after surgery. Case 2: The second patient was a 62-year-old female with WFNS Grade I SAH. A 1.7 mm posterior wall BBA of the BA was detected on cerebral angiography on day 5, which was treated with overlapping stents alone, but a residual aneurysm was noted on day 14, and SACE was additionally performed. Infarction of the perforating branch was noted after surgery, but the aneurysm was completely occluded on follow-up after 1 week. No recanalization was observed at 10 months after surgery.
Conclusion: Although overlapping SACE may be effective for ruptured BBAs of the basilar trunk, attention should be paid to the damage of the perforating branch after surgery in cases of aneurysm of the posterior wall of the BA. For appropriate multiple overlapping stents, accumulation of cases and further investigations are necessary.