The white-collar sign after Neuroform Atlas stent-assisted coil embolization of unruptured intracranial aneurysms.

PURPOSE: Although stent-assisted technique is expected to help provide a scaffold for neointima formation at the orifice of the aneurysm, not all aneurysms treated with stent-assisted technique develop complete neointima formation. The white-collar sign (WCS) indicates neointimal tissue formation at the aneurysm neck that prevents aneurysm recanalization. The aim of this study was to explore factors related to WCS appearance after stent-assisted coil embolization of unruptured intracranial aneurysms (UIAs). METHODS: A total of 59 UIAs treated with a Neuroform Atlas stent were retrospectively analyzed. The WCS was identified on digital subtraction angiography (DSA) 1 year after coil embolization. The cohort was divided into WCS-positive and WCS-negative groups, and possible predictors of the WCS were explored using logistic regression analysis. RESULTS: The WCS appeared in 20 aneurysms (33.9%). In the WCS-positive group, neck size was significantly smaller (4.2 (interquartile range (IQR): 3.8-4.6) versus 5.4 (IQR: 4.2-6.8) mm, p = .006), the VER was significantly higher (31.8% (IQR: 28.6%-38.4%) versus 27.6% (IQR: 23.6%-33.8%), p = .02), and the rate of RROC class 1 immediately after treatment was significantly higher (70% vs 20.5%, p < .001) than in the WCS-negative group. On multivariate analysis, neck size (odds ratio (OR): 0.542, 95% confidence interval (CI): 0.308-0.954; p = .03) and RROC class 1 immediately after treatment (OR: 6.99, 95% CI: 1.769-27.55; p = .006) were independent predictors of WCS appearance. CONCLUSIONS: Smaller neck size and complete occlusion immediately after treatment were significant factors related to WCS appearance in stent-assisted coil embolization for UIAs using the Neuroform Atlas stent.

Efficacy and safety of fetal posterior cerebral artery stented coil embolization for fetal posterior cerebral aneurysms.

PURPOSE: Aneurysms at the origin of the fetal posterior cerebral artery (fPCA) often show fPCA bifurcation from the aneurysm dome, impeding complete embolization and dense coil packing. The recanalization rate for fPCA aneurysms is therefore high. This study aimed to evaluate the efficacy and safety of stenting into fPCA for aneurysms with fPCA incorporated into the aneurysm to determine whether stenting can provide effective embolization results and prevent recanalization. METHODS: A total of 19 consecutive coil embolization procedures between February 2012 and June 2022 for unruptured fPCA aneurysms with fPCA branching from the dome of the aneurysm were divided into two groups: non-stenting (NS) group (n = 11) and stenting into fPCA (PS) group (n = 8). Data were obtained retrospectively and compared regarding embolization results, complications, and recanalization. RESULTS: Compared with the NS group, the PS group achieved significantly higher complete occlusion rate and packing density (p < 0.001, p = 0.01, respectively). No symptomatic complications were observed in the PS group. Both immediately after stenting and at the 1-year follow-up, no stent kinking, stenosis, occlusion, or malposition were observed in any patients in the PS group. During 1-year follow-up, the cumulative minor and major recanalization-free rate after coil embolization for fPCA aneurysms were significantly higher in the PS group compared with the NS group (p = 0.022, 0.0024, respectively). CONCLUSION: Stenting into fPCA for aneurysms with fPCA incorporated into the aneurysm achieved high-density complete embolization without increasing complications, and prevented recanalization. The fPCA stent-assisted coil embolization can offer an alternative treatment for fPCA aneurysms.

Risk factors for recanalization of dense coil packing for unruptured cerebral aneurysms in endovascular coil embolization: Analysis of a single center's experience.

In coil embolization of cerebral aneurysms, inadequate packing is known to increase the probability of recanalization. Even tightly embolized aneurysms may be recanalized, but predictive factors for recanalization have not been fully investigated. This retrospective study aimed to identify risk factors for recanalization of treated aneurysms with a volume embolization ratio (VER) ≥ 25%. A total of 301 unruptured aneurysms in 248 patients who underwent coil embolization between March 2012 and January 2021 were analyzed. Cases involving dissecting aneurysm, intraluminal thrombosis, parent artery occlusion, intraoperative rupture, re-treatment, rupture the day after surgery, postoperative coil migration, and postoperative parent artery occlusion were excluded due to the inaccuracy of VER. A total of 105 aneurysms (34.9%) treated with VER ≥ 25% were extracted. Clinical features (age, sex, medical history, family history), anatomical features (shape, location, aneurysm size, inflow angle, and volume), procedural features (stent-assisted, Raymond-Roy occlusion classification [RROC] immediately after treatment, re-treatment rate), and follow-up period were compared between Recanalization and Non-recanalization groups. Predictors of recanalization were determined using logistic regression and receiver operating characteristic (ROC) curve analyses. Eleven aneurysms were recanalized. In multivariate analysis, RROC class 3 (odds ratio [OR] 11.0; 95% confidence interval [CI] 2.03-59.4) and aneurysm volume (OR 1.005; 95%CI 1.001-1.008) were independent predictors of recanalization. ROC curve analysis showed optimal cutoff values for aneurysm volume of 69.5 mm3 (sensitivity, 81.8%; specificity, 72.3%). In coil embolization of unruptured aneurysms that VER ≥ 25%, cases with RROC class 3 or high aneurysm volume may be associated with a higher risk of recanalization, and should be carefully followed-up.

Characteristics of Unruptured Intracranial Aneurysms with Delayed Rupture Following Coil Embolization: Case Series and Review of the Literature.

Objective: Long-term clinical outcomes including delayed rupture of unruptured intracranial aneurysms (UIAs) after coil embolization (CE) remain unclear. The purpose of this study was to evaluate the precise timing of re-treatment for recanalized UIAs before rupture. Methods: From February 2012 to June 2020, a total of 197 patients with 207 UIAs underwent CE in our institution and were followed up for more than 6 months. The follow-up period, as well as morphological changes from treatment to recanalization, regrowth, and rupture, was retrospectively analyzed. Delayed rupture was defined as a rupture that occurred more than 1 month after CE. Results: The average length of follow-up was 48.7 months. Three of 207 UIAs (1.45%) ruptured after CE. The aneurysm locations were the middle cerebral artery (MCA), anterior communicating artery (AcomA), and internal carotid artery-posterior communicating artery (ICA-Pcomm). The annual rupture rate after CE was 0.36%. Immediately after the first CE, treated aneurysms were graded according to the Modified Raymond-Roy Classification with class II for MCA aneurysms and class IIIb for AcomA and ICA-Pcomm aneurysms. The ICA-Pcomm aneurysm was treated with two additional CEs and was finally graded as class I. In all cases, DSA or MRA before aneurysm rupture showed recanalization and regrowth of aneurysms. The average periods from final embolization to regrowth and from regrowth to rupture were 54.3 months (±16.8) and 2.3 months (±0.9), respectively. Conclusion: UIAs with recanalization and regrowth after CE should undergo re-treatment as early as possible.

Evaluation of Balloon Test Occlusion Before Therapeutic Carotid Artery Occlusion: Flat Detector Computed Tomography Cerebral Blood Volume Imaging versus Single-Photon Emission Computed Tomography.

OBJECTIVE: We aimed to compare flat detector computed tomography cerebral blood volume (FD-CBV) imaging to single-photon emission computed tomography (SPECT) as an adjunctive technique during balloon test occlusion (BTO) in patients with intracranial aneurysms or tumors. METHODS: Twelve patients who underwent SPECT (99mTc-ethyl cysteinate dimer) and FD-CBV imaging during BTO were enrolled. Color-coded cerebral blood flow (CBF) images and color-coded FD-CBV images were generated and visually inspected whether there were asymmetries between the ipsilateral and contralateral cerebral hemispheres. Region of interest measurements were performed on the color-coded images at the same locations for both modalities. The mean interhemispheric region of interest ratios were calculated, and the ratio between these were estimated using linear regression models. RESULTS: Ten patients had no symptoms during BTO. Two patients developed subtle but inconclusive neurologic changes approximately 10 minutes after balloon inflation; their images showed asymmetric color-coded images with decreased CBF and FD-CBV in the ipsilateral hemisphere. The mean interhemispheric ratio of CBF was significantly smaller in patients with subtle changes than in those without (0.84 vs. 0.98; P < 0.001). Similarly, the mean interhemispheric ratio of FD-CBV was significantly smaller in patients with subtle changes than in those without (0.88 vs. 1.06; P = 0.01). No patient showed increased CBF or FD-CBV in the ipsilateral hemisphere. CONCLUSIONS: The patients with decreased CBF on SPECT also showed decreased FD-CBV in the ipsilateral hemisphere. FD-CBV imaging may be useful as an adjunctive technique for BTO before potential therapeutic carotid artery occlusion.

Refractory De Novo Multiple Cerebral Aneurysms After Radiotherapy and Multistaged "Open" Surgical Treatment for Low-Grade Glioma During Long-Term Follow-Up: A Case Report and Review of the Literature.

BACKGROUND: Radiation-induced aneurysms have been previously reported; however, multiple and repeated de novo aneurysm formation chronologically and anatomically during long-term follow-up have not yet been observed. The pathogenesis of persistent radiation-induced vasculopathy is not fully understood. CASE DESCRIPTION: A 31-year-old woman presented with intraventricular hemorrhage due to rupture of a right internal carotid artery (ICA) aneurysm that developed 17 years after surgical resection of a low-grade glioma in the right frontal lobe and postoperative radiotherapy (focal, 50 Gy/25 fractions). During glioma follow-up, salvage surgery with adjuvant gamma knife therapy and chemotherapy (ranimustine, vincristine, temozolomide) were performed for recurrence of the glioma. The aneurysm was treated with endovascular coil embolization. However, she experienced repeated intraventricular hemorrhages, and angiography revealed a de novo ICA aneurysm. The de novo aneurysms were treated with endovascular surgery using coil embolization and stenting. At 2 years after the third hemorrhage, the surgical wound became dehiscent, probably due to wound infection, thus epicranial soft tissue reconstruction using vascularized skin flap was performed. Despite multistaged endovascular surgery for the ICA aneurysm, she experienced repeated subarachnoid and intraventricular hemorrhages. Angiography revealed a de novo aneurysm of the right posterior cerebral artery and basilar trunk. She underwent coil embolization and stenting. Despite active management with endovascular surgery and close follow-up, she died after an eighth consecutive intraventricular and intracerebral hemorrhage caused by a de novo large aneurysm of the posterior cerebral artery. CONCLUSIONS: To the best of our knowledge, the present study is the first to report on of refractory and recurring de novo aneurysms treated by multistaged endovascular surgery during a long-term follow-up after radiotherapy and multistaged craniotomy for glioma.

Spinal Extradural Arteriovenous Fistula with Cowden Syndrome: A Case Report and Literature Review Regarding Pathogenesis and Therapeutic Strategy.

We report the case of a patient with a spinal extradural arteriovenous fistula (AVF) associated with Cowden syndrome (CS) that was successfully treated by endovascular surgery. CS is an autosomal dominant disorder associated with diverse symptoms caused by a deleterious mutation in the phosphatase and tensin homolog (PTEN) gene. A 67-year-old woman was diagnosed with CS based on her medical history of multiple cancers for which she underwent abdominal surgery, macrocephaly, Lhermitte-Duclos disease, and facial papules. Her genetic testing demonstrated a PTEN mutation. She presented with progressive paraparesis and her MRI of the thoracolumbar spine showed the spinal cord edema along with flow voids. A spinal angiogram demonstrated a spinal extradural AVF with the perimedullary drainage. The AVF was successfully treated by endovascular surgery. The PTEN mutation can accelerate angiogenesis; thus, vascular anomalies are one of the diagnostic criteria of CS. However, only two cases of vascular anomalies involving the spinal cord in patients with CS have been reported previously. As the present case, both cases had a history of abdominal or retroperitoneal cancer. The PTEN mutation accompanied with abdominal surgery might have caused this vascular anomaly as the consequences of venous congestion around the thoracolumbar spine. A spinal extradural AVF should be considered in patients with CS who present with myelopathy, especially when the patient has a history of abdominal or retroperitoneal surgery. Regarding the treatment strategy, endovascular surgery should be considered because surgical insult could prompt secondary vascular anomalies resulting from neovascularization due to the PTEN mutation.

Concomitant Intracranial and Lumbar Chronic Subdural Hematoma Treated by Fluoroscopic Guided Lumbar Puncture: A Case Report and Literature Review.

A 40-year-old man presented with a severe headache, lower back pain, and lower abdominal pain 1 month after a head injury caused by falling. Computed tomography (CT) of the head demonstrated bilateral chronic subdural hematoma (CSDH) with a significant amount in the left frontoparietal region. At the same time, magnetic resonance imaging (MRI) of the lumbar spine also revealed CSDH from L2 to S1 level. A simple drainage for the intracranial CSDH on the left side was performed. Postoperatively, the headache was improved; however, the lower back and abdominal pain persisted. Aspiration of the liquefied spinal subdural hematoma was performed by a lumbar puncture under fluoroscopic guidance. The clinical symptoms were dramatically improved postoperatively. Concomitant intracranial and spinal CSDH is considerably rare so only 23 cases including the present case have been reported in the literature so far. The etiology and therapeutic strategy were discussed with a review of the literature. Therapeutic strategy is not established for these two concomitant lesions. Conservative follow-up was chosen for 14 cases, resulting in a favorable clinical outcome. Although surgical evacuation of lumbosacral CSDH was performed in seven cases, an alteration of cerebrospinal fluid (CSF) pressure following spinal surgery should be reminded because of the intracranial lesion. Since CSDH is well liquefied in both intracranial and spinal lesion, a less invasive approach is recommended not only for an intracranial lesion but also for spinal lesion. Fluoroscopic-guided lumbar puncture for lumbosacral CSDH following burr hole surgery for intracranial CSDH could be a recommended strategy.

Hybrid Operating Room for Combined Neuroendovascular and Endoscopic Treatment of Ruptured Cerebral Aneurysms with Intraventricular Hemorrhage.

BACKGROUND: Intraventricular hemorrhages (IVHs) caused by ruptured cerebral aneurysms often have poor outcomes. Treatment challenges include comorbidities, increased intracranial pressure caused by IVH, and risk of rebleeding. CASE DESCRIPTION: Two cases of severe IVH accompanied by acute hydrocephalus caused by ruptured aneurysm were treated with coil embolization followed by endoscopic hematoma evacuation as a single treatment session in a hybrid operating room (OR) equipped with a multipurpose angio biplane system. The first case was an 84-year-old woman with a ruptured basilar top aneurysm, who presented with Hunt and Hess (H&H) grade 5 subarachnoid hemorrhage (SAH) with packed IVH. The second case was a 43-year-old man with a ruptured anterior communicating artery aneurysm who presented with H&H grade 5 SAH with packed IVH. In both cases, endovascular coil embolization was performed first to prevent intraoperative bleeding. The coiled aneurysms suddenly appeared on the screen of the endoscope during the hematoma removal, which could have led to massive rebleeding if not treated previously. Neither patient needed a reinsertion of the ventricular drainage or developed chronic hydrocephalus during hospitalization. The hybrid OR enabled the 2 treatment approaches to be performed without the need to transfer the patient, thereby minimizing the transition time between the modalities. Intraoperative cone-beam computed tomography contributed to the evaluation of residual clots. CONCLUSIONS: A hybrid OR may contribute to a combined neuroendoscopic and endovascular treatment for ruptured cerebral aneurysms with severe intraventricular hemorrhage.

Combined surgical and endovascular treatment of complex cerebrovascular diseases in the hybrid operating room.

BACKGROUND: Although most neurovascular diseases can be treated either by microsurgical or endovascular means, a subset of patients may require a combined approach. Patient transfer from the operating room (OR) to the angiosuite has been a fundamental drawback of this type of approach. OBJECTIVE: The purpose of this study is to report our clinical experience performing combined surgical and endovascular procedures for neurovascular diseases in the hybrid OR. METHODS: 29 patients with neurovascular diseases underwent combined endovascular and surgical procedures in a single session: 16 were scheduled combined treatment and 13 were emergency combined procedures. Of the emergency cases, three were rescue surgeries after endovascular complications. Three patients had ruptured intracranial aneurysms, eight had unruptured intracranial aneurysms, eight had arteriovenous malformations and eight had arteriovenous fistulae; two patients had either a spinal tumor or dural arteriovenous fistulae. RESULTS: All combined procedures were performed in a single session without changing the patient's surgical position. In cases of ruptured arteriovenous malformations or aneurysms with hematoma, an emergency embolization was performed to assist the surgical procedure. Combined superficial temporal artery-middle cerebral artery (STA-MCA) bypass followed by endovascular parent artery trapping were successfully performed for complex large or giant aneurysms. There were two periprocedural ischemic complications. Of the three patients who underwent surgical rescue after endovascular complications, two remained intact and one died despite immediate surgical procedures. CONCLUSION: A combined endovascular and surgical approach conducted in a hybrid OR provides a new strategy for the treatment of complex neurovascular diseases.

Intracystic hematoma of middle fossa arachnoid cyst caused by rupture of internal carotid-posterior communicating artery aneurysm.

A 46-year-old woman was admitted with generalized convulsion and deep coma which occurred 3 weeks after sudden onset of severe headache and pyrexia. Initial computed tomography did not reveal any abnormal findings except for an arachnoid cyst in the right middle fossa. Three weeks later repeat computed tomography showed intracystic hematoma in the arachnoid cyst with uncal herniation. Angiography revealed a right internal carotid-posterior communicating artery aneurysm. The neck of the aneurysm was clipped successfully, but hemiparesis was persistent postoperatively. Angiography is required for investigation of intracystic hematoma of an arachnoid cyst, especially in the absence of head injury, to avoid delayed diagnosis of any ruptured aneurysm.

[A case of infected subdural hematoma].

A 87-year old male was admitted to our hospital due to generalized convulsion with loss of consiousness. He was afebrile and his blood sampling was not infectious. Computed tomography scan suspected left chronic subdural hematoma. Burr hole drainage was performed to remove the hematoma, but the abscess was aspirated in the subdural space. Infected subdural hematoma is rare. We discuss the clinical presentation, diagnosis and. treatment, and also briefly review the literature.