The Influence of Aneurysm Size on the Outcomes of Endovascular Management for Aneurysmal Subarachnoid Hemorrhages: A Comparison of the Treatment Results of Patients with Large and Small Aneurysms.

The influence of aneurysm size on the outcomes of endovascular management (EM) for aneurysmal subarachnoid hemorrhages (aSAH) is poorly understood. To evaluate the outcomes of EM for ruptured large cerebral aneurysms, we retrospectively analyzed the medical records of patients with aSAH that were treated with coiling between 2013 and 2020 and compared the differences in outcomes depending on aneurysm size. A total of 469 patients with aSAH were included; 73 patients had aneurysms measuring ≥10 mm in diameter (group L), and 396 had aneurysms measuring <10 mm in diameter (group S). The median age; the percentage of patients that were classified as World Federation of Neurological Surgeons grade 1, 2, or 3; and the frequency of intracerebral hemorrhages differed significantly between group L and group S (p = 0.0105, p = 0.0075, and p = 0.0458, respectively). There were no significant differences in the frequencies of periprocedural hemorrhagic or ischemic events. Conversely, rebleeding after the initial treatment was significantly more common in group L than in group S (6.8% vs. 2.0%; p = 0.0372). The frequency of a modified Rankin Scale score of 0-2 at discharge was significantly lower (p = 0.0012) and the mortality rate was significantly higher (p = 0.0023) in group L than in group S. After propensity-score matching, there were no significant differences in complications and outcomes between the two groups. Rebleeding was more common in large aneurysm cases. However, propensity-score matching indicated that the outcomes of EM for aSAH may not be affected markedly by aneurysm size.

Comparison of the Clinical Outcome of Carotid Artery Stenting Between Institutions With a Treatment Strategy Based on Risk Factors and Those With First-Line Treatment.

PURPOSE: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended based on certain risk factors. The volume of an institution's treatment experience may be associated with good clinical outcomes. There is a dilemma between the treatment strategy based on risk factors and the experience volume. Therefore, we investigated the clinical outcomes of CAS performed at institutions that selected the treatment strategy based on risk factors and those that performed CAS at the first-line treatment. MATERIALS AND METHODS: Patients who underwent CAS at 5 institutions were included in this retrospective case-control study. We defined CEA/CAS institutions as those that selected the treatment option based on risk factors, and CAS-first institutions as those that performed CAS as the first-line treatment. We investigated cases of ischemic stroke, hemorrhagic stroke, myocardial infarction, and deaths within 30 days of the intervention between the CEA/CAS- and CAS-first institution groups. One-to-one propensity score matching was performed to compare rates of ischemic and hemorrhagic strokes within 30 days of the intervention. RESULTS: A total of 239 and 302 patients underwent CAS at the CEA/CAS institutions and CAS-first institutions, respectively; ischemic stroke occurred in 12 (5.0%) and 7 patients (2.3%), respectively (p=0.09). No differences in major ischemic strokes (0.8% vs 1.3%; p=0.59), hemorrhagic strokes (0.4% vs 0.3%; p=0.87), or deaths (0.0% vs 0.7%; p=0.21) were observed. Myocardial infarction did not occur in either group. Propensity score analysis showed that ischemic stroke (odds ratio: 1.845, 95% confidence interval: 0.601-5.668, p=0.28) and hemorrhagic stroke (odds ratio: 1.000, 95% confidence interval: 0.0061-16.418, p=1.00) were not significantly associated with either institution group. CONCLUSIONS: The CAS-specific treatment strategies for CAS can achieve the same level of outcomes as the treatment strategy based on risk factors. The CAS performed based on risk factors in CEA/CAS institutions and the treatment of more than 30 patients/year/institution in CAS-first institutions were associated with good clinical outcomes.

Perioperative and long-term complications following therapeutic internal carotid artery occlusion.

BACKGROUND: Parent artery occlusion (PAO) is an effective treatment for hemorrhagic diseases associated with the internal carotid artery. There are several reports of long-term cerebral infarction or the formation of de novo cerebral aneurysms following PAO. MATERIALS AND METHODS: We retrospectively reviewed these complications in 38 patients who underwent PAO for therapeutic treatment. We investigated perioperative cerebral infarctions, long-term cerebral infarctions, and de novo aneurysms. RESULTS: The mean age of the patients was 64.0 years, and 25 patients (65.8%) were female. The causative diseases were unruptured (n = 19; 50.0%) and ruptured (n = 8; 21.1%) aneurysms. PAO was performed after ischemic tolerance was assessed with balloon test occlusion (BTO), and BTO was performed in 34 patients, of whom 25 (73.5%) had ischemic tolerance. Twenty-six patients (68.4%) were treated with PAO alone, eight (23.5%) with low-flow bypass, and six (17.6%) with high-flow bypass. Perioperative complications occurred in five patients (13.2%): two of the 26 patients (7.7%) who underwent scheduled treatment and three of the 12 patients (25.0%) who underwent emergency treatment. One patient (2.6%) had long-term de novo aneurysm, and none developed cerebral infarction. CONCLUSIONS: These results showed that the assessment of ischemic tolerance by performing BTO and appropriate revascularization in scheduled treatments are important to reduce perioperative and long-term cerebral infarctions. PAO must be performed with greater caution in emergency treatment.

Brainstem anesthesia during removal operation of ventriculoperitoneal shunt - A case report.

Background: Brainstem anesthesia is a transient loss of brainstem function usually associated with retrobulbar block and rarely seen by neurosurgeons. Case Description: Here, we report a case of brainstem anesthesia during shunt revision operation in a 79-year-old woman. Local anesthesia administered at the end of surgery was thought to have infiltrated the subarachnoid space through a burr hole, causing prolonged unconsciousness and cranial nerves' impairment. Spontaneous resolution occurred during systemic support. Conclusion: As brainstem anesthesia may occur by leakage of local anesthetic through small burr holes, timing injections carefully can avoid this rare complication.

Fatal recurrent ischemic stroke caused by vertebral artery stump syndrome.

BACKGROUND: Vertebral artery stump syndrome (VASS) develops into recurrent posterior circulation ischemic stroke after ipsilateral vertebral artery (VA) occlusion at its origin. CASE DESCRIPTION: The patient was a 46-year-old man with the right posterior cerebral artery occlusion. We used a recombinant tissue plasminogen activator (rt-PA) and then performed mechanical thrombectomy using a stent retriever. Angiography revealed left VA occlusion and stagnant flow to the left VA from the right deep cervical artery; therefore, we diagnosed VASS. Within 24 h of the rt-PA injection, the symptoms had dramatically improved, and so we avoided additional antithrombotic agents. Only 13 h later, the patient developed a basilar artery occlusion and died in spite of a repeated mechanical thrombectomy. CONCLUSION: Vigilance against early (and sometimes fatal) recurrent stroke induced by VASS is required.

Emergent carotid artery stenting for cervical internal carotid artery injury during carotid endarterectomy: A case report.

BACKGROUND: Carotid endarterectomy (CEA) has been the standard preventive procedure for cerebral infarction due to cervical internal carotid artery stenosis, and internal shunt insertion during CEA is widely accepted. However, troubleshooting knowledge is essential because potentially life-threatening complications can occur. Herein, we report a case of cervical internal carotid artery injury caused by the insertion of a shunt device during CEA. CASE DESCRIPTION: A 78-year-old man with a history of hypertension, diabetes, and hyperuricemia developed temporary left hemiplegia. A former physician had diagnosed the patient with a transient cerebral ischemic attack. The patient's medical history was significant for the right internal carotid artery stenosis, which was severe due to a vulnerable plaque. We performed CEA to remove the plaque; however, there was active bleeding in the distal carotid artery of the cervical region after we removed the shunt tube. Hemostasis was achieved through compression using a cotton piece. Intraoperative digital subtraction angiography (DSA) revealed severe stenosis at the internal carotid artery distal to the injury site due to hematoma compression. The patient underwent urgent carotid artery stenting and had two carotid artery stents superimposed on the injury site. On DSA, extravascular pooling of contrast media decreased on postoperative day (POD) 1 and then disappeared on POD 14. The patient was discharged home without sequela on POD 21. CONCLUSION: In the case of cervical internal carotid artery injury during CEA, hemostasis can be achieved by superimposing a carotid artery stent on the injury site, which is considered an acceptable troubleshooting technique.

Detection Rate and Radiological Features of Asymptomatic Intracranial Dural Arteriovenous Fistula: Analysis of Magnetic Resonance Imaging Data of 11745 Individuals in the Japanese Brain Check-Up System.

Objective: Asymptomatic intracranial dural arteriovenous fistula (DAVF) is a rare disease that is often undiagnosed before symptom onset. The present study aimed to examine the detection rate and radiological features of asymptomatic intracranial DAVF using brain MRI data obtained from the Japanese brain check-up system. Methods: We retrospectively identified 11745 individuals who underwent brain MRI between January 2010 and December 2014. After a routine brain MRI screening, a definite diagnosis was made based on DSA. Data regarding sex, age, disease location, classification type, and treatment method were extracted from the system database and patients' medical records. Results: Six individuals (0.05%; mean age, 61.0 ± 9.7 years) were diagnosed with definite intracranial DAVF. The intracranial DAVFs were located in the transverse sinus, confluence, and tentorial sinus in 2, 1, and 3 case(s), respectively. Cortical venous reflux was confirmed in four cases (66.7%), and none of the cases had intracranial hemorrhage or venous congestion. All cases had infratentorial lesions and two-thirds were Borden type II/III. Conclusion: The detection rate of asymptomatic intracranial DAVF was 0.05% based on the analysis of MRI data from the brain check-up system. Low-flow shunt and tiny cortical venous reflux were likely missed on MRI.

The Relationships between Anatomical Factors and Treatment Procedures for the Endovascular Treatment of Anterior Communicating Artery Aneurysms.

Objective: Endovascular treatment of anterior communicating artery aneurysms is difficult due to their complex anatomical structure. We retrospectively analyzed the relationships among the anatomical features, initial microcatheter positions, and initial occlusion outcomes. Methods: In all, 66 cases were treated at our hospital. We investigated the relationships among the anatomical features of the aneurysm and A1 segment of the anterior cerebral artery (ACA), treatment procedures, and initial occlusion outcomes. We divided the initial microcatheter positions into greater and lesser curvatures based on the curvature from A1 to the aneurysm, and evaluated the outcomes. Results: In total, 54 out of 66 patients (82%) achieved complete obliteration (CO) or had residual neck (RN) aneurysms, and 12 had residual aneurysms (RAs: 18%). Neck diameters and superior position aneurysms were correlated with initial occlusion outcomes in the multivariate analysis. The relationship between initial occlusion outcomes and initial microcatheter positions in superior position aneurysms (37 patients) was then examined. Eleven out of 26 patients (42.3%) had residual aneurysms at the greater curvature microcatheter position, whereas no residual aneurysms were detected at the lesser curvature microcatheter position. The A1 angle was not correlated with the outcomes. Conclusion: Wide-necked aneurysms and superior position aneurysms were identified as factors leading to incomplete occlusion in the endovascular treatment of anterior communicating artery aneurysms. The microcatheter position at the greater curvature in superior position aneurysms was a factor for incomplete occlusion. This suggests that guiding the microcatheter to the lesser curvature position of A1 is important in the treatment of superior position aneurysms.

High fibrin/fibrinogen degradation product value as a risk factor for progressive remote traumatic intracranial haemorrhage following neurosurgery.

INTRODUCTION: Remote traumatic intracranial haemorrhage (RTIH) may develop after neurosurgery. Recognition of the risk factors for RTIH before surgery might be of great value. The purpose of this study was to verify if the fibrin/fibrinogen degradation product (FDP) value may be a risk factor for RTIH. METHODS: This was a retrospective study of the data of 56 patients with traumatic intracranial hematomas shown on initial computed tomography (CT) who were treated with craniotomy or decompressive craniectomy and underwent a follow-up CT at a single centre over a period of approximately 10.5 years. We divided the patients into 2 groups: those who developed RTIH (Positive: P-group) and those who did not (Negative: N-group). We compared the 2 groups in terms of not only the laboratory data before surgery, but also patient age, sex, antiplatelet/antithrombotic medications received, cause of injury, and GCS score on arrival. RESULTS: RTIH was observed in 22 patients (P-group, 39.3%). The FDP value was the only significant risk factor identified in this study (p = 0.00076). The cut-off value was estimated on the basis of the area under the receiver operating characteristic (ROC) curve. The cut-off FDP value was 120 µg/mL (63.6% sensitivity and 85.3% specificity). CONCLUSIONS: FDP levels over 120 µg/mL were determined to be a risk factor for progressive RTIH after neurosurgery. We suggest the FDP level be checked before surgery for traumatic intracranial haemorrhage and follow-up CT be done as soon as possible after the surgery if the serum FDP level is over 120 µg/mL.

Stent-Jack Technique for Ruptured Vertebral Artery Dissecting Aneurysm Involving the Origin of Posterior Inferior Cerebellar Artery.

We herein report a case of a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery that was treated using the stent-jack technique. After parent artery occlusion of the distal vertebral artery, stenting of the posterior inferior cerebellar artery was performed. Further coiling was needed because distal vertebral artery recanalization occurred due to transformation of the coil mass. The stent-jack technique for a ruptured vertebral artery dissecting aneurysm involving the origin of the posterior inferior cerebellar artery is effective; however, careful attention to recanalization after stenting is needed due to transformation of the coil mass.

Infant Fistula-Type Arteriovenous Malformation with Cerebellar Hemorrhage Developed into Nidus-Type in Adolescence.

BACKGROUND: Although arteriovenous malformation (AVM) has been considered to be a congenital vascular malformation, morphologic differences associated with age have been indicated in the literature. CASE DESCRIPTION: We report a case of infant fistula-type AVM that developed into a nidus-type AVM 15 years later. This is the first report to document morphologic changes of AVM over time in 1 case. CONCLUSIONS: The present case suggests the possibly that AVM morphology may change with age and is an important when considering the history of AVM.

Effectiveness of Low-Dose Intravenous Fentanyl for Postoperative Headache Management After Neck Clipping of Ruptured Intracranial Aneurysms.

BACKGROUND: After subarachnoid hemorrhage (SAH), headache management is often difficult owing to the need to use multiple analgesic drugs. Fentanyl is an opioid we can use after surgery, and it can decrease pain post SAH. The aim of this study was to investigate the effectiveness and safety of fentanyl for management of headache after SAH. METHODS: Twenty-two patients who underwent surgical clipping for ruptured intracranial aneurysms and complained of severe headache after the surgery were enrolled. Among them, 9 patients were given fentanyl combined with other analgesic drugs. The numeric rating scale score and dietary intake were measured in the acute phase after the SAH. RESULTS: The numeric rating scale scores were significantly lower in the fentanyl (+) group. The maximum numeric rating scale decreased to <5 points within 16.5 ± 2.9 days in the fentanyl (-) group and within 12.0 ± 2.6 days in the fentanyl (+) group. The median numeric rating scale decreased to <5 points over 14.0 ± 4.2 days in the fentanyl (-) group and >7.7 ± 3.8 days in the fentanyl (+) group. At day 14, the fentanyl (+) group showed significantly better dietary intake than that of the fentanyl (-) group. CONCLUSIONS: Using fentanyl after surgical clipping for ruptured intracranial aneurysms might decrease headache and produce few adverse effects. Adequate headache control showed improved dietary intake after SAH.

Prediction of the Cerebral Hyperperfusion Phenomenon after Carotid Endarterectomy Using a Transit Time Flowmeter.

The purpose of this study was to investigate the relationship between the cerebral hyperperfusion phenomenon (CHP) and carotid artery flow volume as measured by a transit time flowmeter during carotid endarterectomy (CEA). We retrospectively investigated 74 patients who underwent both transit time flowmetry and single photon emission computed tomography (SPECT). The flow volumes of the internal carotid artery (ICA) before and after the endarterectomy were recorded during surgery as the pre- and the post-ICA (mL/min), respectively. We defined the difference between the pre- and the post-ICA as the ΔIC (mL/min). Two independent board-certified neurosurgeons analyzed the asymmetry index (affected side/contralateral side) of regional qualitative cerebral blood flow before and after the CEA respectively. We defined the CHP as an excessive increase in this asymmetry index between preoperative and postoperative SPECT. The CHP was observed in five of the 74 patients (6.8%). The pre-ICA of the CHP cases was significantly lower than that of the non-CHP cases (in mL/min, median 29 vs. 97; P = 0.01). The ΔIC of the CHP cases was significantly higher than that of the non-CHP cases (in mL/min, median 154 vs. 50; P = 0.002). The cut-off value of the ΔIC was 81 mL/min (sensitivity 100%, specificity 78.3%, area under the curve 0.912). The findings of this study suggest that the ΔIC is associated with the CHP. The transit time flowmeter is useful to predict the CHP during surgery.

[Cognitive Dysfunction in Children who Underwent Surgery after a Traumatic Brain Injury:A Single Institute Investigation].

The cognitive function of children who underwent surgical therapy after a traumatic brain injury is poorly studied. In this study, we investigated the characteristics of 27 children who received surgical therapy at our institution. The children were between 1 and 16 years of age, of which 15 had cognitive dysfunction. Their Glasgow Coma Scale score at the acute stage of dysfunction was worse than in children who did not have cognitive dysfunction. Acute subdural hematoma was more frequent in the cognitive dysfunction group. Moreover, all children in this group showed brain injury by imaging analysis. Differences in imaging characteristics and the association with cognitive dysfunction could not be readily associated with a specific injury. Memory and verbal disorder were the most common cognitive dysfunctions:these symptoms were present among children of all ages;conversely, behavior disorder, impaired attention, and infeasibility were limited to the children under 9 years of age. Since the immature brain is developing, the acquisition of new abilities may be blocked by the injury;thus, we speculate that brain injury at a younger age causes greater cognitive dysfunction.

Treatment Outcomes of Cerebral Aneurysms Presenting with Optic Neuropathy: A Retrospective Case Series.

BACKGROUND: Optic neuropathy due to an aneurysm is relatively rare, with only a few small case series on this topic, and no randomized trials having been published until now. As such, the functional prognosis and treatment for aneurysm-induced optic neuropathy remain controversial. OBJECTIVE: We quantified optic nerve injuries using an objective index (the visual impairment score) and evaluated prognostic factors of postoperative visual function. MATERIALS AND METHODS: Of 960 patients treated for an unruptured intracranial aneurysm, 18 (1.9%) patients had optic neuropathy. Visual acuity and visual field were assessed before surgery and 6 months' postoperatively. Cases were classified on the basis of treatment modality (coil embolization or flow alteration [FA]) and prognostic factors of the two treatment groups. RESULTS: Of the 18 patients with an intracranial aneurysm and optic neuropathy, 12 (67%) were treated using coil embolization and 6 (33%) were FA. Visual function improved after surgery in 8 patients (44%), 5 (42%) in the coil embolization group, and 3 (50%) in the FA group. The visual function remained stable after surgery in 6 (33%) patients and worsened in 4 (22%). Patients with an aneurysms <15 mm in size had a favorable outcome (P = 0.05). CONCLUSIONS: Surgical treatment improved vision in 44% of cases, with no difference in the prognosis of coil embolization and FA and no effect of the duration of symptoms on outcomes. Further, the prognosis of visual function recovery was better for aneurysms <15 mm in diameter.

Transvenous Embolization of Dural Arteriovenous Fistula of the Anterior Condylar Confluence via the Intercavernous Sinus Assisted by Bone Subtraction Computed Tomography Angiography.

BACKGROUND: Dural arteriovenous fistulae (dAVFs) of the anatomically complex anterior condylar confluence (ACC) are often examined by computed tomography (CT) angiography and conventional angiography before treatment. Contrasted vessels often overlap with skull bones in enhanced CT scan and make it difficult to detect the shunt point of the dAVF. Bone subtraction CT angiography (BSCTA) can overcome this limitation and allow for superior imaging of dAVFs that may help to find an alternative access for catheterization. CASE DESCRIPTION: An 80-year-old woman suffered from right ear tinnitus, headache, and an audible bruit. Preoperative imaging showed a dAVF of the ACC. It was fed by the bilateral ascending pharyngeal artery, drained to the internal jugular vein (IJV) via the inferior petrosal sinus, and had an intraosseous shunt pouch. We therefore performed transvenous embolization (TVE) via the intercavernous sinus because the angle between the anterior condylar vein and the IJV was too sharp to catheterize vessels through the ipsilateral IJV. CONCLUSIONS: Understanding the inherently complex and individually unique venous anatomy of the ACC is crucial for treatment of dAVFs. BSCTA is an effective visualization technique for dAVFs of the ACC and allows for precise preoperative vascular structure evaluation. We suggest that in the case of the angle between the ACV and the IJV being too sharp to catheterize vessels through the ipsilateral IJV, TVE via the intercavernous sinus can be efficiently used.

Bleb formation in small unruptured intracranial aneurysm as a predictor of early rupture.

Small unruptured aneurysms are thought to have a low risk of rupture, but the management of such lesions is still controversial. A 73-year-old man with a small anterior communication artery aneurysm, 4 mm in diameter, while on follow-up, developed an aneurysmal subarachnoid hemorrhage 2 weeks after the detection of a newly emerged bleb on the surface of the aneurysm. In conclusion, the formation of a bleb should be considered as a warning sign of an impending rupture, and treatment should be provided even for patients with small aneurysms.

[A Case of Kanji Agraphia Resulting from Intracerebral Hemorrhage on the Left Temporal Lobe Associated with Multiple Dural Arteriovenous Fistulas].

A 60-year-old, right-handed man suffered from mild word finding difficulties and kanji agraphia. Brain computed tomography revealed left temporal lobe hemorrhage, and cerebral angiogram revealed multiple dural arteriovenous fistulas (d-AVFs) in the left anterior cranial fossa and middle cranial fossa. Surgical shunt ablation was performed, and the lesions were obliterated completely. Analysis of the kanji agraphia during neuropsychological rehabilitation showed similar symptoms to those of the left posterior inferior temporal lobe lesion. Re-evaluation of magnetic resonance imaging showed multiple microbleeds on the left inferior temporal lobe, which could be responsible for the kanji agraphia. In this case, analysis of clinical symptoms with careful neuropsychological examination was important for understanding these pathologies. (Received March 21, 2017; Accepted June 21, 2017; Published December 1, 2017).

[A Case of Ruptured Anterior Communicating Artery Aneurysm with Visual Field Defects and Deteriorating to Severe Vision Loss].

Although Terson's syndrome is a well-known cause of vision loss due to intracerebral aneurysm rupture, optic nerve neuropathy can also occur because of other causes. Here, we report such a case, i.e., a ruptured anterior communicating artery aneurysm accompanied by vision loss and visual field disturbances due to a cause other than Terson's syndrome. A 47-year-old man presented with right superior altitudinal hemianopia. Computed tomography (CT) showed subarachnoid hemorrhage (SAH), and three-dimensional CT angiography revealed an anterior communicating artery aneurysm. Coil embolization was performed. Right visual acuity degenerated to blindness in the acute stage. MRI performed on day 7 post-admission revealed that the aneurysm had swollen and made contact with the right optic disk. On the basis of the patient's clinical course, we believe that the deterioration in his visual acuity could have been due to ischemic optic neuropathy (ION) resulting from SAH, and the subsequent edema and poor blood perfusion may be attributed to spasm. In cases of visual disturbance associated with SAH, as in our case, it is important to perform MRI to evaluate the damage or risk to the optic nerve as soon as possible. (Received December 26, 2016; Accepted June 9, 2017; Published October 1, 2017).