Spontaneous thrombosis of type II vein of Galen aneurysmal malformation: a case report.

Vein of Galen malformations (VGAMs) are rare and complex congenital brain vascular anomalies that pose significant diagnostic and treatment challenges. The natural history of this type of vascular anomaly is very poor, with many patients succumbing to complications such as congestive heart failure, hydrocephalus, and brain parenchymal injury. Although the clinical course of most VGAMs was considered unfortunate, with meticulous imaging, a group of lesions with a more placid presentation and course can be identified.

Monopolar stereoelectroencephalography-guided radiofrequency thermocoagulation.

OBJECTIVE: Stereoelectroencephalography (SEEG)-guided radiofrequency thermocoagulation (RFTC) has the advantage of producing a lesion in the epileptogenic zone (EZ) at the end of SEEG. The majority of published SEEG-guided RFTCs have been bipolar and usually performed between contiguous contacts of the same electrode. In the present study, the authors evaluate the safety, efficacy, and benefits of monopolar RFTC at the end of SEEG. METHODS: This study included a series of 31 consecutive patients who had undergone RFTC at the end of SEEG for drug-resistant focal epilepsy in the period of January 2013-December 2019. Post-RFTC seizure control was assessed after 2 months and at the last follow-up visit. Twenty-one patients underwent resective epilepsy surgery after the SEEG-guided RFTC, and the postoperative seizure outcome among these patients was compared with the post-RFTC seizure outcome. RESULTS: Four hundred forty-six monopolar RFTCs were done in the 31 patients. Monopolar RFTCs were performed in all cortical areas, including the insular cortex in 11 patients (56 insular RFTCs). There were 31 noncontiguous lesions (7.0%) because of vascular constraints. The volume of one monopolar RFTC, as measured on T2-weighted MRI immediately after the procedure, was between 44 and 56 mm3 (mean 50 mm3). The 2-month post-RFTC seizure outcomes were as follows: seizure freedom in 13 patients (41.9%), ≥ 50% reduced seizure frequency in 11 (35.5%), and no significant change in 7 (22.6%). Seizure outcome at the last follow-up visit (mean 18 months, range 2-54 months) showed seizure freedom in 2 patients (6.5%) and ≥ 50% reduced seizure frequency in 20 patients (64.5%). Seizure freedom after monopolar RFTC was not significantly associated with the number or location of coagulated contacts. Seizure response after monopolar RFTC had a high positive predictive value (93.8%) but a low negative predictive value (40%) for seizure outcome after subsequent resective surgery. In this series, the only complication (3.2%) was a limited intraventricular hematoma following RFTC performed in the hippocampal head, with spontaneous resolution and no sequelae. CONCLUSIONS: The use of monopolar SEEG-guided RFTC provides more freedom in terms of choosing the SEEG contacts for thermocoagulation and a larger thermolesion volume. Monopolar thermocoagulation seems particularly beneficial in cases with an insular EZ, in which vascular constraints could be partially avoided by making noncontiguous lesions within the EZ.

Comaneci stent-angioplasty for the optimization of inadequately deployed flow diverter stents.

BACKGROUND AND PURPOSE: In endovascular procedures, inadequate deployment of a flow diverter stent is a highly concerning technical complication that can lead to acute parent vessel occlusion and ischaemic events. This study aimed to assess the off-label use of the Comaneci device in managing technical difficulties associated with flow diversion. MATERIALS AND METHODS: We conducted an analysis of all flow diverter procedures documented in our prospectively collected database. Our objective was to identify patients with inadequately deployed implants who underwent Comaneci stent-angioplasty. Both Comaneci 17 and Comaneci 21 devices were utilized to address and remediate technical complications related to stent deployment. We reviewed anatomical features, technical details, intraprocedural complications, as well as clinical and angiographic outcomes. RESULTS: Thirty-one Comaneci devices were employed to remediate 31 inadequately deployed flow diverter stents. Successful resolution of technical complications associated with flow diverter placement was achieved in all attempted cases. No clinically significant complications were attributed to the technique, and no mortality was observed during the study. CONCLUSION: Technical issues arising from flow diverter stent deployment are formidable complications. Familiarity with appropriate corrective manoeuvres is essential to achieve successful outcomes. The Comaneci device can be safely and effectively incorporated into the range of techniques used to rectify inadequately deployed stents.

Management of Mirror Middle Cerebral Artery Aneurysms: Surgical Results and Morphological Parameters.

AIM: To investigate the safety and applicability of two main methods for treating mirror intracranial aneurysms, based on correlations in their geometric characteristics. MATERIAL AND METHODS: We conducted a retrospective analysis on 125 patients who underwent 138 surgical interventions for MCA aneurysms and were treated with microsurgical clipping and endovascular embolization at the Department of Neurosurgery in the University Hospital "St. Iv. Rilski", Sofia, in 2013-2019. In six of these cases, we observed mirror MCA aneurysms. RESULTS: All six patients with "mirror" aneurysms were female. In one case, a third aneurysm was observed on the anterior communicating artery; hence, a total of 13 aneurysms were treated. The average age of the group was 48.16 years. All patients had known risk factors, such as high blood pressure and tobacco smoking. Four patients presented with aneurysmal subarachnoid hemorrhage (aSAH). All patients underwent surgical treatment in two stages-with obliteration of the intracranial aneurysm leading to subarachnoid bleeding in the first stage and planned surgical intervention within a month in the second stage to exclude unruptured aneurysms. During the one-month interval, there were no SAH incidents. However, we observed one patient with a postoperative neurological deficit and one with recanalization of the aneurysm on follow-up at 3 months, requiring re-embolization. In both cases, endovascular treatment was performed despite the unfavorable anatomical features (aspect ratio ≤1.5 and neck size ≥4 mm). The clinical outcome, in all operated patients, for "mirror" aneurysms of the MCA was reasonable (mRS: 0-2). CONCLUSION: The choice of treatment for "mirror" aneurysms should be determined on an individual basis by the clinical manifestations and morphological characteristics of intracranial aneurysms. In cases of aSAH, where "mirror" aneurysms are present, both can be treated safely via microsurgical clipping or endovascular embolization after thorough investigation and ensuring prioritization of the offending lesion.

And don't forget your anti in-stent stenosis pill! Commentary on 'Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device' by Flores-Milan et al.

In their INR study, Flores-Milan et al. present a retrospective single-centre study that aimed to investigate and determine some of the factors associated with in-stent stenosis (ISS) after intracranial aneurysm (IA) embolization using a commercially available flow diverter stent (FD). The retrospective analyses included ruptured and unruptured intracranial aneurysms treated with standalone flow diverter stent implantation or initial coil obliteration with the FD device placed subsequently two weeks after initial treatment. The article's methodology was carefully tailored to demystify the unknown pathophysiological mechanism behind the entity of interest called in-stent stenosis. Study outcomes also included angiographic evaluation of aneurysm occlusion thrombotic and hemorrhagic events. The authors reported excellent technical and clinical results altogether. The achieved angiographic occlusion rates resonate with the current obliteration results reported in the literature. Mortality and morbidity are congruent with previously published results and were 5.3% and 1.1%, respectively.

Endovascular treatment of wide-necked intracranial aneurysms using the Nautilus Intrasaccular System: initial case series of 41 patients at a single center.

BACKGROUND: Endovascular treatment of intracranial wide-necked and bifurcation aneurysms (WNBA) is technically challenging. The Nautilus Intrasaccular System is designed to provide a mechanical barrier at the aneurysm neck to support coil embolization. We report the results of a single-center series of patients treated for intracranial aneurysms with the Nautilus. METHODS: Clinical and radiological data were retrospectively collected for all patients treated with the Nautilus for an unruptured or ruptured intracranial aneurysm at our center between March 2021 and March 2022. Clinical outcomes (modified Rankin Scale (mRS) scores), Raymond-Roy angiographic occlusion, recanalization, and complications were measured immediately post-procedure and at 3-6-month follow-up. RESULTS: A total of 41 patients of mean age 56.7 years (range 37-83 years) were treated with the Nautilus, with 41 saccular aneurysms (18 (43.9%) unruptured and 23 (56.1%) ruptured). The majority of aneurysms (39/41 (95.1%)) were located in the anterior circulation. We experienced no technical complications. One patient had an asymptomatic post-procedural minor stroke related to the procedure. Immediate Class I occlusion was achieved in 30 (73.1%) patients. The rate of all-cause mortality was 7.3% (3/41). One patient was lost to follow-up. At follow-up, 94.5% (35/37) of patients achieved Class I occlusion and 94.5% (35/37) had an mRS score of 0. There were no procedural-related deaths or permanent morbidities at discharge or follow-up. CONCLUSION: This study demonstrates good safety and effectiveness using the Nautilus Intrasaccular System to treat both ruptured and unruptured intracranial aneurysms. Larger studies are needed to confirm these findings.

Progressive volume reduction and long-term aneurysmal collapse following flow diversion treatment of giant and symptomatic cerebral aneurysms.

Background: The primary goal of conventional endovascular and microvascular approaches is the clinical and radiological resolution of the symptomatic aneurysm-induced mass effect. This study assessed the volume changes and mass effect reduction due to sac shrinkage after treatment with flow diverter stents (FD) for unruptured cerebral aneurysms. Methods: We analyzed retrospectively 36 symptomatic aneurysms that were larger or equal to 25 mm in diameter in patients treated at our center from January 2016 to April 2022. Radiological and clinical outcomes were analyzed, including aneurysmal volume changes and resolution of aneurysm-related symptoms. Results: At 6 months, 25 aneurysms decreased in size, 2 remained unchanged, and 9 aneurysms demonstrated a post-treatment dimensional increase. At 12 months, 30 aneurysms showed a progressive radiological volume reduction. Either no change or negligible shrinkage was observed in the remaining six aneurysms. At 24 months, 32 aneurysms showed aneurysmal shrinkage by a mean 47% volume loss with respect to baseline. At the last follow-up, all 13 patients who had presented with third cranial nerve palsy showed improvements. Complete reversal of the pretreatment edematous changes was confirmed in all cases. The overall post-treatment complication rate was 8.3%, as 3 patients experienced non-fatal delayed rupture of their aneurysm. There was no mortality in this study. Conclusion: Flow diversion could effectively induce progressive aneurysmal shrinkage and resolution of the mass effect associated with giant symptomatic cerebral aneurysms.

Flow Diversion for the Management of Ruptured Intracranial Arterial Infudibular Dilatation: Proof of Principle and Therapeutic Protocol.

Thought to be benign anatomical variants, cerebral infundibular dilatations (ID) are most commonly encountered at the junction of the internal carotid artery (ICA) and the posterior communicating artery (PcomA). The true nature of this entity remains controversial, as some literature reports suggest they should be considered preaneurysmal lesions and a potential source of devastating subarachnoid hemorrhage. This report describes cases of presumably ruptured IDs and their therapeutic endovascular management. We retrospectively reviewed and analyzed patients with isolated subarachnoid hemorrhage (SAH) where the only potential cause was ruptured cerebral IDs, treated or not, between January 2012 and June 2021. Morphological and radiological features, treatment and procedural considerations, clinical and angiographic outcomes were also reviewed. Natural history of the ID is poorly understood, and its relation to SAH remains controversial. Ruptured cerebral IDs can be the suspected cause of bleeding if no other vascular lesion is present during multimodal examinations. Endovascular flow diversion stenting is safe and effective for the proper treatment of ruptured IDs. Pending further validations with longitudinal data are needed to legitimate the natural course of these mysterious lesions.

Critical Angiographic and Sonographic Analysis of Intra Aneurysmal and Downstream Hemodynamic Changes After Flow Diversion.

Introduction: Successful treatment of intracranial aneurysms after flow diversion (FD) is dependent on the flow modulating effect of the device. We aimed to investigate the intra-aneurysmal and parent vessel hemodynamic changes, as well as the incidence of silent emboli following treatment with various FD devices. Methods: We evaluated the appearance of the eclipse sign in nine distinct phases of cerebral angiography before and immediately after FD placement in correlation with aneurysm occlusion. Angiographic and clinical data of consecutive procedures were analyzed retrospectively. Patients who had successful FD procedure without adjunctive coiling, visible eclipse sign on post embolization angiography, and reliable follow-up angiographic data were included in the analysis. Detailed analysis of hemodynamic data from transcranial doppler after FD was performed in selected patients, such as monitoring for silent emboli. Results: Among all patients (N = 65) who met inclusion criteria, complete aneurysm occlusion at 12 months was achieved in 89% (58/65). Eclipse sign prior to FD was observed in 42% (27/65) with unchanged appearance in 4.6% (3/65) of the treated patients. None of these three patients achieved complete aneurysm occlusion. Among all analyzed variables, such as aneurysm size, device type used, age, and appearance of the eclipse sign pre- and post-FD, the most reliable predictor of permanent aneurysm occlusion at 12 months was earlier, prolonged, and sustained eclipse sign visibility in more than three angiographic phases in comparison to the baseline (p < 0.001). Elevation in flow velocities within the ipsilateral vascular territory was noted in 70% (9/13), and bilaterally in 54% (7/13) of the treated patients. None of the patients had silent emboli. Conclusions: Intra-aneurysmal and parent vessel hemodynamic changes after FD can be reliably assessed by the cerebral angiography and transcranial doppler with important implications for the prediction of successful treatment.

Developmental venous anomaly causing obstructive hydrocephalus due to aqueductal stenosis: а case report.

Cerebral developmental venous anomalies are asymptomatic benign cerebrovascular malformations that are commonly found accidentally on brain magnetic resonance imaging. It is not uncommon for cerebrospinal fluid flow to be obstructed at the level of the aqueduct of Sylvius, causing an obstructive non-communicating hydrocephalus. Most notable reasons for such an obstruction at that level are tumors, congenital etiology, or post-inflammatory gliotic atresia.

Nautilus-assisted coil embolization for a complex AcomA wide-necked aneurysm in the setting of acute subarachnoid hemorrhage.

Numerous devices and sophisticated strategies have been developed to further increase the number of aneurysms amenable to endovascular treatment.1-4 Despite the superfluity of available neurovascular armamentarium, wide-necked bifurcation aneurysms can still pose a significant technical challenge to the treating clinician.5-7 Neck bridging is a conceptually new approach, which provides increased occlusion rates with lower recurrence and complications rates.8-10 The Nautilus (EndoStream Medical) is an intrasaccular bridging device intended to assist in coil embolization of wide-necked cerebral aneurysms. This CE-marked device, available in various sizes, consists of flexible-layers, and is a nitinol-based, detachable implant. The device is delivered through a standard microcatheter with a minimal 0.0165" inner diameter and is fully radiopaque and completely resheathable.Owing to its unique 'tornado' like shape the device entirely reconstructs the aneurysmal neck, which facilitates the following coil embolization. In this video 1, we demonstrate the use of Nautilus - assisted coil embolization for a complex anterior communicating artery (AcomA) wide-necked aneurysm in the setting of acute subarachnoid hemorrhage. neurintsurg;14/3/310/V1F1V1Video 1.

Diversion-p64: results from an international, prospective, multicenter, single-arm post-market study to assess the safety and effectiveness of the p64 flow modulation device.

BACKGROUND: The use of flow diversion to treat intracranial aneurysms has increased in recent years. OBJECTIVE: To assess the safety and angiographic efficacy of the p64 flow modulation device. METHODS: Diversion-p64 is an international, prospective, multicenter, single-arm, study conducted at 26 centers. The p64 flow modulation device was used to treat anterior circulation aneurysms between December 2015 and January 2019. The primary safety endpoint was the incidence of major stroke or neurologic death at 3-6 months, with the primary efficacy endpoint being complete aneurysm occlusion (Raymond-Roy Occlusion Classification 1) on follow-up angiography. RESULTS: A total of 420 patients met the eligibility criteria and underwent treatment with the p64 flow modulation device (mean age 55±12.0 years, 86.2% female). Mean aneurysm dome width was 6.99±5.28 mm and neck width 4.47±2.28 mm. Mean number of devices implanted per patient was 1.06±0.47, with adjunctive coiling performed in 14.0% of the cases. At the second angiographic follow-up (mean 375±73 days), available for 343 patients (81.7%), complete aneurysm occlusion was seen in 287 (83.7%) patients. Safety data were available for 413 patients (98.3%) at the first follow-up (mean 145±43 days) with a composite morbidity/mortality rate of 2.42% (n=10). CONCLUSIONS: Diversion-p64 is the largest prospective study using the p64 flow modulation device. The results of this study demonstrate that the device has a high efficacy and carries a low rate of mortality and permanent morbidity.

Theoretical stereoelectroencephalography density on the brain convexity.

INTRODUCTION: Invasive electroencephalography (EEG) remains the "gold standard" for diagnosing the epileptogenic zone in patients with drug-resistant epilepsy and discrepancies between seizure semiology, video-EEG and magnetic resonance imaging (MRI) findings. However, the possibilities of stereoelectroencephalography (SEEG) to explore the brain surface remain a matter of debate and subdural EEG (SDEEG) is still preferred in some centers for cases when the supposed epileptogenic zone is on the brain convexity. The aim of our study was to evaluate the theoretical safe SEEG coverage on the brain convexity and to compare the theoretical SEEG cortical density with the usual SDEEG density. MATERIALS AND METHODS: Our material included 10 hemispheres in 5 patients, who had been already investigated with SEEG for drug-resistant epilepsy. We translated our previously described technique in a theoretical model in an attempt to calculate the maximal number of avascular windows for each cerebral hemisphere. The distance between every entry point and the other entry points for each hemisphere was calculated using a mathematical formula. Subsequently, the theoretical SEEG coverage on the brain convexity was described using the maximal, minimal and average distances between each entry point and the closest 4 neighboring points. This type of measurement allows a direct comparison between SEEG and SDEEG in their ability to explore the brain convexity. RESULTS: Ten hemispheres had 1328 safe entry points with a safety margin of 2.5 mm and a minimal distance of 2.5 mm between 2 entry points (average number of entry points: 132.8 (SD ± 5). The number of entry points in the explored 10 hemispheres varied from 104 to 156. The average distance between each entry point and its 4 neighbors was 11.47 mm. The maximal distance between two entry points in these 10 hemispheres was ranging from 20.28 to 27.23 mm (average: 24.67 mm). The closest entry points for the explored hemispheres were at an average distance of 4.67 mm (range: 2.82 - 5.96 mm). The average convexity surface was 223.68 cm2 (range: 204.63-238.77 cm2). The safe electrode density without electrode collision on the cortical surface was ranging from 0.46 to 0.69 electrodes per cm2 (average: 0.59 electrodes per cm2) (SD ± 0.023). CONCLUSION: The theoretical SEEG cortical density is comparable with the usual SDEEG density. These findings, combined with the better safety profile of SEEG and the possibilities to explore deep cortical structures, explain the progressive shift from SDEEG to SEEG during the last years.

Nautilus-Assisted Coiling of an Unruptured Wide-Necked Aneurysm of the Posterior Communicating Artery.

A variety of recently introduced devices have allowed more complex aneurysms to be rendered for endovascular embolization. Tiny and sophisticated implants are nowadays designed to provide further either temporary or permanent remodeling of the wide-necked aneurysms and improve coil occlusion rates.1-4 Such improvements in the technical armamentarium include the Woven EndoBridge (Sequent Medical, California, USA), the Medina Embolic Device (Medtronic, Irvine, California, USA), The Contour Neurovascular System (Cerus Endovascular, Fremont, California, USA), and pCONUS 2 HPC (Phenox, GmbH, Bohum, Germany).5-7 Intrasaccular neck bridging is a conceptually new technique descending from the theoretical combination of intrasaccular flow diversion and temporary-stent assisted coiling.8 The Nautilus (EndoStream Medical, Tel Aviv, Israel) is an intrasaccular bridging device that offers complete neck reconstruction in coil embolization of wide-neck cerebral aneurysms. It has been granted a CE mark by the European Union. The detachable intrasaccular implant comprises flexible and "tornado-like"-shaped Nitinol-based layers. The device is compatible with a standard microcatheter with minimal 0.0165″ inner diameter and is fully radiopaque and fully resheathable. The device's intrasaccular nature and the fact that it does not harbor any intraluminal satellite parts suggest that the implant can be safely used in both unruptured and ruptured case scenarios without the need for dual antiplatelet therapy. This is what we consider a great advantage of the proposed technique over the alternative options of intrasaccular and intraluminal flow diversion. This technical video (Video 1) demonstrates the successful obliteration of a complex posterior communicating artery aneurysm with Nautilus-assisted endovascular coiling. To our knowledge, this is the first technical video demonstrating an in-vivo and step-by-step implementation of this novel device.

Awake Epilepsy Surgery in Patients with Focal Cortical Dysplasia.

BACKGROUND: Awake craniotomy (AC) and direct electric stimulation emerged together with epilepsy surgery >80 years ago. The goal of our study was to evaluate the benefits of awake surgery in patients with drug-resistant epilepsy caused by focal cortical dysplasia (FCD) affecting eloquent areas. METHODS: Our material included 95 patients with drug-resistant epilepsy and FCD, who were operated on between January 2009 and December 2018. These 95 patients were assigned into 3 groups: AC; general anesthesia (GA) with intraoperative neuromonitoring; and GA without intraoperative neuromonitoring. We investigated the following variables: age at surgery, lesion side, eloquent cortex involvement, brain mapping success rate, epilepsy surgery success rate, intraoperative complications, postoperative complications, and intraoperative changes of the preoperative resection plan according to results of the brain mapping by direct electric stimulation. RESULTS: We found statistically significant differences between the AC and GA groups in the mean age at operation, lesion side, eloquent localization, and postoperative transient neurologic deficit. Seizure outcome in the AC was satisfactory (71% complete seizure control) and comparable to the seizure outcome in the GA groups. Our preoperative plan was changed because of functional constraints in 6 patients (43%) operated on during AC. CONCLUSIONS: AC during epilepsy surgery for FCD in eloquent areas may change the preoperative plan. The good rate of postoperative seizure control and the absence of permanent postoperative neurologic deficit in our series is the main proof that AC is a useful tool in patients with FCD involving the eloquent cortex.

Acutely ruptured basilar artery bifurcation aneurysm, treated with simultaneous Cascade and Comaneci temporary-assisted coiling.

Temporary stent-assisted coiling is an eligible approach for the treatment of acutely ruptured complex cerebral aneurysms. Improved material properties and industrial advances in braiding technology have led to the introduction of new stent-like devices to augment endovascular coil embolization. Such technology includes the Cascade and Comaneci neck-bridging devices. Both devices are manually controlled, non-occlusive and fully retrievable neck-bridging temporary implants. The braided nature and the ultra-thin wire, compliant structure of their bridging meshes helps maintain target vessel patency during coil embolization. In this video (video 1) we demonstrate the straightforward combination of two temporary neck-bridging devices for the embolization of an acutely ruptured aneurysm of the basilar artery. Technical success and complete embolization of the aneurysm were recorded at the final angiography. In this technical video we discuss the technical nuances of the Comaneci and Cascade coil embolization. neurintsurg;13/2/196/V1F1V1Video 1.

Endovascular treatment of patients with intracranial aneurysms: feasibility and successful employment of a new low profile visible intraluminal support (LVIS) EVO stent.

BACKGROUND AND PURPOSE: Low-profile self-expandable stents have increased the number of intracranial aneurysms treated by endovascular means. The new low-profile visible intraluminal support device LVIS EVO (Microvention), the successor of LVIS Jr, is a self-expandable and retrievable microstent system, designed for implantation into intracranial arteries with a diameter up to 2.0 mm. In this retrospective study we aimed to elucidate the technical feasibility and clinical safety of the novel LVIS EVO stent for stent-assisted coil embolisation of intracranial aneurysms. MATERIALS AND METHODS: A single centre technical report of the first six consecutive cases of stent-assisted coil embolisation with the novel LVIS EVO stent for the treatment of unruptured or recanalised intracranial aneurysms. Records were made of basic demographics, aneurysmal characteristics, device properties and related technical details, adverse events, clinical outcomes and occlusion rates on available radiological follow-up. RESULTS: Six LVIS EVO devices were successfully implanted in all subjects to treat a total number of six intracranial aneurysms. No device-related intraprocedural complications were seen. At early clinical follow-up six out of six (100%) patients had a modified Ranking score of 0-1. Early angiographic and cross-sectional radiological follow-up, available in five out of six (83.3%) of the patients confirmed unchanged aneurysmal occlusion rates. A minor, transitory neurological deficit was recorded in one of the six (16.6%) patients. Mortality was 0%. CONCLUSIONS: Preliminary experience in this subset of our patients confirms a notably improved technical behaviour of the novel LVIS EVO stent system when compared to its ancestor LVIS Jr. The enhanced visibility of the stent and the refined delivery/retrieval capabilities of the stent further increase the safety margins of the devices profile, especially in cases of tortuous anatomy.