Clinical Efficiency of an Artificial Intelligence-Based 3D-Angiography for Visualization of Cerebral Aneurysm: Comparison with the Conventional Method.

PURPOSE: Artificial intelligence (AI)-based three-dimensional angiography (3D-A) was reported to demonstrate visualization of cerebral vasculature equivalent to that of three-dimensional digital subtraction angiography (3D-DSA). However, the applicability and efficacy of the AI-based 3D­A algorithm have not yet been investigated for 3D-DSA micro imaging. In this study, we evaluated the usefulness of the AI-based 3D­A in 3D-DSA micro imaging. MATERIALS AND METHODS: The 3D-DSA micro datasets of 20 consecutive patients with cerebral aneurysm (CA) were reconstructed with 3D-DSA and 3D­A. Three reviewers compared 3D-DSA and 3D­A in terms of qualitative parameters (degrees of visualization of CA and the anterior choroidal artery [AChA]) and quantitative parameters (aneurysm diameter, neck diameter, parent vessel diameter, and visible length of AChA). RESULTS: Qualitative evaluation of diagnostic potential revealed that visualization of CA and the proximal to middle parts of the AChA with 3D­A was equal to that with conventional 3D-DSA; in contrast, visualization of the distal part of the AChA was lower with 3D­A than with 3D-DSA. Further, regarding quantitative evaluation, the aneurysm diameter, neck diameter, and parent vessel diameter were comparable between 3D­A and 3D-DSA; in contrast, the visible length of the AChA was lower with 3D­A than with 3D-DSA. CONCLUSIONS: The AI-based 3D­A technique is feasible and evaluable visualization of cerebral vasculature with respect to quantitative and qualitative parameters in 3D-DSA micro imaging. However, the 3D­A technique offers lower visualization of such as the distal portion of the AChA than 3D-DSA.

Four-dimensional digital subtraction angiography for the vascular anatomical diagnosis of dural arteriovenous malformation: Comparison with the conventional method.

BACKGROUND: Two-dimensional digital subtraction angiography (2D-DSA) and conventional three-dimensional digital subtraction angiography (3D-DSA) are used for the detailed analysis of dural arteriovenous fistula (DAVF). Recently, four-dimensional digital subtraction angiography (4D-DSA), a novel technology, has been attracting attention. The current study aimed to evaluate the capability of 4D-DSA in assessing anatomical angioarchitecture in DAVF. METHODS: In total, 10 consecutive patients with DAVF who underwent 3D-DSA and 4D-DSA at a single institution were included in the analysis. Initially, one-slice multiplanar reconstruction (MPR) images obtained via 4D-DSA and 3D-DSA were compared to investigate the visibility of the feeding artery, fistulous point, and draining vein. Next, 4D-DSA images alone were compared and evaluated with and the MPR images of conventional 3D-DSA in terms of diagnosis of the angioarchitecture. RESULTS: In total, six men and four women (with a mean age of 65.6 ± 10.0 years) were included in the study. The MPR image obtained via 3D-DSA had a significantly better visibility of the feeding artery and fistulous point than that acquired via 4D-DSA (p < 0.05). As for the draining vein, the score was equivalent and not significant. The diagnosis of the vascular architecture of only 4D-DSA images was nearly equivalent to that of MPR images of 3D-DSA. There were no inter-rater differences. CONCLUSION: The MPR images obtained via 4D-DSA may be slightly inferior to those acquired via 3D-DSA in identifying fine angioarchitecture in DAVF. However, they were comparable in terms of diagnostic accuracy.

Bilateral Distal Transradial Approach for Coiling of Basilar Artery Aneurysm: A Technical Note.

Distal transradial approach (dTRA) for neuroendovascular procedures has received much attention in recent years as a newer and less invasive alternative to the conventional transfemoral or transradial approaches. We present the case of an 89-year-old woman with a basilar artery aneurysm requiring simultaneous catheterization of the bilateral vertebral arteries who was successfully embolized using bilateral dTRA. The aneurysm was accessed from the right vertebral artery using the right dTRA. Control angiograms during the procedure were performed from the left vertebral artery via the left dTRA. The operator's posture was ergonomically comfortable, and the catheters were easy to handle during the procedure. To the best of our knowledge, this is the first case of a bilateral dTRA used for neuroendovascular procedures. Bilateral dTRA is a safe and minimally invasive method for patients and ergonomically comfortable for operators.

An Institutional Retrospective Study of Coil Loop Herniation and its Management.

INTRODUCTION: Endovascular coiling is a method of aneurysm embolization. Sometimes coil loops herniate in the lumen after deployment of the coil. It is usually seen in wide-necked aneurysms. It can cause migration of the coil and thromboembolic complications. There are different methods such as the use of a balloon, stent, and coil retriever to treat coil loop herniation. There are very few case series on coil loop herniation management. Most series are about the use of a stent/balloon for reposition. We are going to describe simple, novel techniques to treat coil loop herniation. MATERIALS AND METHODS: In the last five years, 13 aneurysms out of 325 coiled aneurysms had coil loop herniation. We used three different techniques in these patients according to our selection criteria. The first technique was loop trap with another coil, the second was balloon and coil-plasty to trap, and the third was rescue stent and flow control. RESULTS: The first, second, and third techniques were successfully used in five, five and three patients, respectively. There was a complete reposition of herniated coil and thus embolization of aneurysm in all cases. All patients recovered completely without any thromboembolic complications. CONCLUSIONS: We recommend the use of these techniques according to the proper selection criteria.

Double-balloon Trapping for Coil Embolization of Ruptured Internal Carotid Artery Aneurysm: A Novel Technique.

INTRODUCTION: Endovascular treatment of complex ruptured aneurysms in the internal carotid (IC) artery is extremely challenging. Navigation of double-balloon catheters becomes all the more difficult in tortuous vessels. PATIENTS AND METHODS: A 57-year-old female with more than three times previously ruptured left IC artery aneurysm with subarachnoid hemorrhage had a left IC small aneurysm with a neck of 3.2 mm. Proximal and distal balloons were inflated in left IC artery in respect to the aneurysm, to prevent further rupture during navigation of the microcatheter and first coil. DISCUSSION: The technique uses two balloons placed proximal and distal to the ruptured aneurysm, to reduce further bleeding, just as the application of temporary clips, followed by inertion of coils rapidly to obliterate the aneurysm. CONCLUSION: It is a novel technique of double-balloon trapping of proximal and distal segment of IC artery with aneurysm coiling technique as an alternative to balloon-assisted coiling and stent-assisted coiling in patients with ruptured aneurysm.

Malignant Glioma in the Cerebellum Presenting as Multiple Small Lesions.

Malignant glioma, the most common malignant primary brain tumor in adults, usually occurs in supratentorial space as a single mass lesion, and cerebellar location and multiple appearance are uncommon. We report a case of a 69-year-old female with three lesions simultaneously found in the cerebellum on magnetic resonance images (MRIs) after suffering from gait disturbance. Two lesions were around 15 mm in size and the other one was observed as a spotty enhancement. Although MRI findings suggested brain metastases, whole body examinations denied any primary malignancies. Biopsy for one lesion in the cerebellum was performed, which resulted in pathological diagnosis of malignant astrocytoma. The lesions were considered multicentric glioma based on MRI definition. The treatment with temozolomide and whole brain radiation was completed. Although the patient was discharged in an independent state with the shrinkage of the tumors, she unexpectedly died following sudden loss of consciousness from an unknown cause one month after discharge. The coincidence of cerebellar location and multicentricity characterized by smallness is quite rare in glioma patients, and such MRI findings might be misleading for the diagnosis. We describe the details of the case and discuss the pathogenesis of this unique presentation of malignant glioma with the literatures.

Long-Lasting Symptomatic Cerebral Hyperperfusion Syndrome following Superficial Temporal Artery-Middle Cerebral Artery Bypass in a Patient with Stenosis of Middle Cerebral Artery.

Cerebral hyperperfusion syndrome (CHPS) is a complication that can occur after cerebral revascularization surgeries such as superficial temporal artery- (STA-) middle cerebral artery (MCA) anastomosis, and it can lead to neurological deteriorations. CHPS is usually temporary and disappears within two weeks. The authors present a case in which speech disturbance due to CHPS lasted unexpectedly long and three months was taken for full recovery. A 40-year-old woman, with a history of medication of quetiapine, dopamine 2 receptor antagonist as an antipsychotics for depression, underwent STA-MCA anastomosis for symptomatic left MCA stenosis. On the second day after surgery, the patient exhibited mild speech disturbance which deteriorated into complete motor aphasia and persisted for one month. SPECT showed the increase of cerebral blood flow (CBF) in left cerebrum, verifying the diagnosis of CHPS. Although CBF increase disappeared one month after surgery, speech disturbance continued for additionally two months with a slow improvement. This case represents a rare clinical course of CHPS. The presumable mechanisms of the prolongation of CHPS are discussed, and the medication of quetiapine might be one possible cause by its effect on cerebral vessels as dopamine 2 receptor antagonist, posing the caution against antipsychotics in cerebrovascular surgeries.

Posterior Meningeal Artery Origin Patterns among 300 Cases and Their Clinical Importance.

BACKGROUND AND PURPOSE: The posterior meningeal artery (PMA) is known as a dura mater-nourishing vessel. We encountered a patient with Wallenberg syndrome during transarterial embolization of the PMA associated with the dural arteriovenous fistula (DAVF). METHODS: After development of Wallenberg syndrome in the patient, we assessed origins of the PMA patterns in 300 cases and divided them into 3 types. CASE PRESENTATION: A 63-year-old man was incidentally diagnosed as having transverse-sigmoid sinus DAVF with a cortical venous reflux. During the transarterial embolization, the patient complained of vertigo and numbness of the right extremities. Postoperatively, the patient exhibited Wallenberg syndrome. Diffusion-weighted magnetic resonance imaging showed a high-intensity area on the lateral side of the right medulla. CONCLUSIONS: While performing arterial embolization of the PMA that directly originates from the intracranial vertebral artery, the possibility of deficient brainstem nourishment must be considered.

Independent Anomalous Origin of the Right Vertebral Artery from the Right Common Carotid Artery.

An anomalous origin of the right vertebral artery is rare. The left vertebral artery from the aortic arch is where most of the anomalies occur. The next is an origin of the right vertebral artery from the right common carotid artery in association with the aberrant right subclavian artery. However, independent anomalous origin of the right vertebral artery from the right common carotid artery has not been well known in the previous literature. We present this anomaly, and able to understand the mechanism of the occurrence by embryological knowledge. Failure of involution of the fourth segmental artery and the ductus caroticus remaining are associated with this anomaly. To understand this, an aberrant may be helpful to avoid injury of the vertebral artery when performing the surgical procedures and catheterization.

A Stent-Retrieving into an Aspiration Catheter with Proximal Balloon (ASAP) Technique: A Technique of Mechanical Thrombectomy.

OBJECTIVE: The best technique for the first attempt at mechanical thrombectomy for acute ischemic stroke is a still matter of debate. In this study, we evaluate the efficacy of a stent-retrieving into an aspiration catheter with proximal balloon (ASAP) technique that uses a series of thrombus extraction by withdrawing the stent retriever into the aspiration catheter and continuous aspiration from the aspiration catheter at the first attempt. METHODS: We performed a retrospective analysis of 42 consecutive patients with acute ischemic stroke caused by occlusions in the anterior circulation who were treated with the ASAP technique at our institution. Preoperative patient characteristic, including age, thrombus location, Alberta Stroke Program Early CT Score, National Institutions of Health Stroke Scale, and time from onset to puncture; postoperative Thrombolysis in Cerebral Infarction score; modified Rankin Scale score after 3 months; time from puncture to recanalization; the number of passes to achieve recanalization; and procedural complications, including intracranial hemorrhage, embolization to new territory, and distal embolization, were assessed. RESULTS: A Thrombolysis in Cerebral Infarction score of 2B or 3 was achieved in 40/42 patients (95.2%). Average time from puncture to the final recanalization was 21.5 minutes. Recanalization was achieved in a single attempt in 31 patients (77.5%). Embolization to new territory was observed in only 2 patients (4.8%); no patient developed distal embolization or intracranial hemorrhage including asymptomatic subarachnoid hemorrhage. Thirty-two patients (76.2%) achieved modified Rankin Scale scores of 0-2 at 3 months postoperatively. CONCLUSIONS: Our ASAP technique showed fast recanalization, minimal complications, and good clinical outcomes in this case series.

Hemispheric divided coiling technique for coil embolization of middle- and large-sized intracranial aneurysms.

Despite major developments in treating intracranial aneurysms by endovascular coil embolization, complete occlusion of the entire aneurysmal neck remains a problem. We present a novel endovascular strategy for middle- and large sized aneurysms called the "hemispheric divided coiling technique" and compare the short-term follow-up results of this technique with those of conventional coil embolization. Ten patients (mean age, 69.7 ± 9.7 years) with middle- or large-sized ruptured or unruptured intracranial aneurysms (mean maximum aneurysmal diameter, 12.09 ± 3.6 mm) were treated by the hemispheric divided coiling technique, in combination with various adjunctive techniques. We compared the initial occlusion grade, volume embolization ratio, and recurrence rate in this group of patients (hemispheric group) with the results from 20 previous cases (conventional group: mean age, 62.8 ± 9.8 years; mean maximum aneurysmal diameter, 11.43 ± 3.5 mm). The mean volume embolization ratio of the hemispheric group was significantly higher than that of the conventional group (42.3% vs. 31.1%). The hemispheric divided coiling technique achieved a high volume embolization ratio for middle- and large sized intracranial aneurysms, with a low recurrence rate.

Crevice sign as an indicator of plaque laceration associated with postoperative severe thromboembolism after carotid artery stenting: a case report.

Carotid artery stenting (CAS) is increasingly utilized in patients with carotid artery stenosis. Various intraprocedural and postprocedural complications have been reported in the literature. We present a case of symptomatic major thromboembolism after CAS. The intraprocedural angiogram showed extraordinary slow filling of the contrast medium into the plaque, which we named as "crevice sign." An 83-year-old man presented repeat right amaurosis fugax for 6 months. The radiological examinations revealed 85% stenosis of the origin of the right internal carotid artery. The patient underwent right CAS. The procedure was performed without any problems; however, the angiogram showed slow filling of contrast medium into the carotid plaque through the stent (crevice sign). Sixty minutes later in the ward, the patient presented sudden onset of left hemiparesis and aphasia. Emergency catheter angiography did not show in-stent thrombus, major artery occlusion, or the crevice sign. Magnetic resonance imaging on the next day revealed wide acute infarction of the right cerebral hemisphere. Physicians should be aware of the intraprocedural crevice sign so that a subsequent catastrophic ischemic event can be prevented.

Experimental evaluation and training of stent clot retrieval: the confront clot scrambling method.

The introduction of stent retrievers has changed the methods used for acute intracranial thrombectomy, but the training approach has not been discussed enough. We, therefore, aimed to establish a simple skill up method which can be used to train anytime and anywhere with low costs. Also, we introduce our experimental confront clot scrambling method (CCSM) which makes a profitable visualization in how the stent retriever works. The CCSM involved a sham clot set in the middle of a polyvinyl chloride tube, after which two stent retrievers were navigated from each side before being simultaneously withdrawn with the same force. The stent that removes the sham clot is determined to have stronger clot retrieval ability. Several adjunctive techniques were also compared. The push and fluff adjunctive technique was the most effective among all the stents. Generally, the former deployed stent was stronger than later one. Therefore, the later deployed stent with the push and fluff technique lets us know whether the physician's maneuver worked well or not. CCSM could directly evaluate the ability of adjunctive techniques with each stent retriever and demonstrate the physicians' skills. Because the actual endovascular clot retrieval requires extreme fine maneuvers against invisible vessels, repeat training is very important especially in beginners.

Midterm Follow-Up of 20 Consecutive Patients with Nonaneurysmal Subarachnoid Hemorrhage of Unknown Origin in a Single-Center: Two Cases of De Novo Development of Dural Arteriovenous Fistula.

BACKGROUND AND PURPOSE: The mechanisms and prognosis of underlying subarachnoid hemorrhage of unknown origin remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic subarachnoid hemorrhage and venous abnormalities like a primitive venous drainage of the basal vein of Rosenthal. We report the outcome of a midterm follow-up of 20 consecutive patients with nonaneurysmal subarachnoid hemorrhage of unknown origin, and 2 patients in whom the development of new dural arteriovenous fistulas after subarachnoid hemorrhage of unknown origin were detected during follow-up. METHODS: All patients who were admitted to our hospital for nontraumatic subarachnoid hemorrhage between April 2008 and March 2016 were retrospectively analyzed. RESULTS: Of 705 patients included in the study, 20 (2.8%) were diagnosed with nontraumatic subarachnoid hemorrhage of unknown origin. During the follow-up periods, there was no rebleeding. Although 18 patients did not show any vascular abnormalities, the other 2 patients were diagnosed with dural arteriovenous fistula. Both fistulas were successfully treated with endovascular embolization. CONCLUSIONS: Subarachnoid hemorrhage of unknown origin had a low incidence rate, and its clinical course was excellent without rebleeding. Although no vascular abnormalities were observed during the patients' initial admission, venous lesions might have been involved in both subarachnoid hemorrhages and delayed dural arteriovenous fistulas. Here, the possible pathogenesis is discussed with a review of the literature.

Relationship Between Clot Quality and Microguidewire Configuration During Endovascular Thrombectomy for Acute Ischemic Stroke.

BACKGROUND: Although endovascular approaches for acute ischemic stroke have been developed, the appropriate selection and sequence of device application or other treatments is unclear. If information about the clot quality can be obtained before the selection of devices, fast recanalization with a suitable device and strategy can be achieved. We studied the relationship between clot quality and the configuration of a microguidewire during endovascular thrombectomy. METHODS: This prospective single-center study included all patients who were admitted for acute ischemic stroke between October 2015 and June 2017 and underwent emergency endovascular thrombectomy. We used a modified pigtail-shaped microguidewire to penetrate clots. The configurations under radiograph were distinguished into 2 types and assessed according to collected clot appearance and quality. RESULTS: A total of 54 patients underwent acute endovascular thrombectomy. When the tip of the microguidewire became stuck against a clot during penetration, the clot was solid and hard, with statistical significance (P = 0.013). CONCLUSIONS: Our results showed that we can select a suitable device and strategy for fast recanalization according to information about clot quality obtained using the modified pigtail-shaped microguidewire.

Parent and Child Balloon Technique for Navigating Guide Catheters During Neurointerventions.

BACKGROUND: The stabilization of a guide catheter is an important factor for performing successful neurointerventional procedures. We present our technique for navigating guide catheters using parent and child balloons. METHODS: In 9 patients with severe atherosclerosis or anatomic variations such as a bovine arch, 8-9-F balloon-mounted guide catheters were navigated using balloon-attached guidewires. Both balloons were used complementarily for flow navigation and vessel fixation at the appropriate positions and times. RESULTS: In all cases, the balloon guide catheter could be inserted up to the required positions, and the procedures were completed without any complications. CONCLUSIONS: The parent and child balloon technique is useful for inserting guide catheters in hostile vascular anatomies.

A Case of Acute Isolated Posterior Cerebral Artery Occlusion Successfully Treated with Endovascular Clot Aspiration.

Posterior cerebral artery (PCA) strokes produce various symptoms. Therefore, the diagnosis is often delayed and patients arrive late for thrombolytic therapy. We report a case of acute isolated PCA occlusion that was successfully treated with endovascular clot aspiration. A 63-year-old man presented with right complete homonymous hemianopia. Diffusion-weighted image (DWI) showed a high-intensity area (HIA) in the occipital lobe, and magnetic resonance angiography (MRA) showed PCA occlusion. Emergency endovascular clot aspiration was performed immediately after the diagnosis. Blood flow in PCA completely recovered 210 min after symptom onset. DWI after surgery showed partial disappearance of HIA, and the patient recovered from the symptom of right complete homonymous hemianopia. Endovascular recanalization is useful for acute PCA occlusion. This is the first reported case of acute isolated PCA occlusion successfully treated with endovascular clot aspiration. Prompt reperfusion results in a good clinical course in patients with PCA stroke. In this case, endovascular clot aspiration resulted in prompt recanalization in a patient with acute isolated PCA occlusion.

Suitability of a 7-F ExoSeal Vascular Closure Device for Femoral Artery Punctures Made by 8-F or 9-F Introducer Sheaths.

PURPOSE: To establish the safety and efficacy of the 7-F ExoSeal device for the closure of femoral puncture sites made by 8-F or 9-F introducer sheaths. METHODS: Between January 2013 and December 2016, 332 patients (mean age 68.4±12.1 years; 195 men) underwent neurointerventional procedures via percutaneous puncture of the common femoral artery and an 8-F (n=272, 81.9%) or 9-F (n=60, 18.1%) introducer. The access sites were sealed with a 7-F ExoSeal in all cases. Procedure success and closure-related complication rates were evaluated, and risk factors for complications were analyzed by comparing patient characteristics between those who did and did not experience complications. RESULTS: Procedure success rates were 99.3% in the 8-F group and 100% in the 9-F group. The overall complication rate was 6.3% (n=17; all in the 8-F group), of which 13 (4.8%) were minor sequelae, including access-site hematoma (n=8), oozing (n=3), pseudoaneurysm (n=1), and retroperitoneal bleeding (n=1). Among the 4 (1.5%) major complications were 3 instances of bleeding requiring a blood transfusion and 1 surgical vascular repair. No complications were observed in the 9-F group. Patients who experienced complications had significantly longer activated clotting times (262±46 vs 218±55 seconds; p<0.001) compared with patients without complications. CONCLUSION: A 7-F ExoSeal vascular closure device is safe and effective for the closure of femoral puncture sites made by 8-F or 9-F introducer sheaths.

A case of anterior communicating artery aneurysm successfully treated after a stent migration during stent assisted endovascular coil embolization.

Stent migration is a complication associated with endovascular coil embolization of intracranial aneurysms. We report a case of anterior communicating artery (ACoA) aneurysm that was successfully treated after stent migration during endovascular coil embolization without retrieval of the stent. A 47-year-old man presented with sudden onset severe headache. Patient was noted to have subarachnoid hemorrhage from a ruptured ACoA aneurysm. Emergency endovascular coil embolization was performed. The second coil embolization was scheduled for the neck-remnant portion with a stent after 16 days from the initial operation. At first, a stent was deployed from the right perpendicular division of anterior cerebral artery (A2) to the left horizontal division of anterior cerebral artery (A1) entirely across the aneurysmal neck. Although the stent position looked fine, the stent migrated inferiorly to the proximal A1 portion when its delivery wire was withdrawn. Fortunately, the stent could be pushed into the distal A1 portion, when we trying to re-access the aneurysm thorough the stent with a pig-tail shaped microguidewire. Additional coil embolization was achieved using the assistance of distal tip of the stent as a scaffold of the coil. The patient was discharged without any complication on the postoperative day 6. Although there are various choices of rescue treatment after stent migration, this is the first reported case of stent repositioning with a microguidewire. Our technique may represent an effective option in case of stent migration.

The Feasibility and Safety of Separate Carotid Artery Stenting Using the Restrict Protective Method for Bilateral Carotid Stenosis.

BACKGROUND AND OBJECTIVE: The treatment strategy for bilateral carotid stenosis (BCS) is not clear. We report our experience of treating 12 patients with BCS using separate carotid artery stenting (CAS) using the restrict protective method. The order of treatment site and the protective method are also discussed. METHODS: Between April 2012 and November 2016, 24 lesions in 12 patients (range, 44-83 years; mean, 71 years; 1 woman) underwent CAS at Kariya Toyota General Hospital. These cases were reviewed retrospectively. In all cases, CAS was first performed on the more severely stenosed site. All procedures were performed using the proximal protective method involving balloons and a filter device. We took into consideration adverse events including death from any cause, major stroke within 30 days, and death between 30 days and 1 year later from any stroke. RESULTS: All procedures were successfully performed under local anesthesia. There was not a single case that showed intolerance during flow arrest to prevent distal embolisms. We observed no adverse events, restenosis, or recurrent symptoms during follow-up. CONCLUSIONS: Good outcomes can be achieved in patients with BCS when attempting separate CAS using the restrict protective method.