Intracranial Arteriovenous Malformations Research Articles

Pituitary macroadenoma causing vision loss in Wyburn-Mason syndrome: illustrative case.

Wyburn-Mason syndrome (WMS) is a neurocutaneous disorder consisting of vascular malformations of the brain, eye, and skin. These include characteristically high-flow intracranial and intraorbital arteriovenous malformations (AVMs) that present commonly with visual deterioration, headache, and hemiplegia. Complete removal of these lesions is challenging. Most patients are followed closely, and intervention occurs only in the setting of worsening symptoms secondary to AVM growth or hemorrhage. Here the authors present the first known case of a patient with WMS and a pituitary macroadenoma. A 62-year-old man with a 30-year history of WMS with right basal ganglia and orbital AVMs and right eye blindness presented for new-onset left-sided vision loss. A pituitary adenoma was identified compressing the optic chiasm and left optic nerve. Magnetic resonance imaging and digital subtraction angiography studies were obtained for surgical planning, and the patient underwent an endoscopic transnasal transsphenoidal resection, with significant postoperative vision improvement. Given the variable presentation and poor characterization of this rare syndrome, patients with WMS presenting with new symptoms must undergo evaluation for growth and hemorrhage of known AVMs, as well as new lesions. Further, in patients undergoing intracranial surgery, extensive preoperative imaging and planning are crucial for safe and successful procedures.

Retinal and intracranial arteriovenous malformations in Wyburn–Mason syndrome

A 12-year-old female presented with left exotropia for 1 year. The left eye fundus revealed dilation and tortuosity of the retinal arteries and veins consistent with group 3 retinal arteriovenous malformation (AVM; Fig. 1A). Fundus fluorescein angiography showed AVM filling without leakage but with a temporal nonperfusion area (Fig. 1B). Magnetic resonance angiogram of the head and cerebral angiography showed left orbital and suprasellar AVMs (Fig. 1C, D). The patient was diagnosed with Wyburn–Mason syndrome. No treatment was recommended for the intracranial AVMs because of the associated surgical risk to the perforators and the visual pathway.

Long-term follow-up of an overexposure radiation incident in a cohort treated with linear accelerator-based stereotactic radiosurgery for intracranial arteriovenous malformations.

Dosimetric radiosurgery incidents are rare and probably insufficiently reported in scientific publications. After a long follow-up (FU), the authors studied the outcomes of patients treated with overexposure radiation for arteriovenous malformation (AVM) administered via stereotactic radiosurgery (SRS) at their department. Between May 2006 and June 2007, 22 patients were treated for AVM with SRS. The mean (range) patient age was 43.5 (11.8-78) years. Previous treatments were embolization (n = 10), SRS (1), and surgery (1). The average (range) volume was 2.1 (0.2-6.4) cm3. The median prescribed minimal dose was 18.0 Gy. An initial error in the estimation of scatter factors led to overexposure to radiation. Due to this incident, the median delivered minimum dose was 25.0 Gy. All patients were prospectively followed with clinical examination and imaging. The mean (range) clinical FU was 14.5 (12.0-15.2) years. AVM obliteration after SRS was completed in 90.9% of patients at a mean (range) of 39.4 (24.4-70.4) months. No patient had post-SRS AVM bleeding. Three patients (13.6%) had new permanent deficits due to radiation-induced changes (RICs). Obliteration without new deficits was achieved in 18 patients (81.8%). Two patients had new epilepsy that was probably due to RIC but well controlled. The median (range) MRI FU was 13.8 (2.5-14.9) years. During MRI FU, two RIC periods were observed: one classic period during the first 3 years showed T1-weighted annular irregular enhancement (13%), and the other period between 5 and 15 years after SRS showed the occurrence of cystic and hemorrhagic lesions (22.7%). There were no cases of radiation-induced tumor. The present long-term report showed that this overexposure incident probably increased the AVM obliteration rate. This overexposure seems to have induced RIC and in particular a higher rate of cystic and hemorrhagic late lesions with nevertheless moderate clinical consequences. Long-term FU for AVM is mandatory due to the risk of late RIC.

Surgical management outcomes of intracranial arteriovenous malformations after preoperative embolization: a systematic review and meta-analysis.

Preoperative embolization for brain arteriovenous malformations (AVMs) has been shown to mitigate morbidity for high-risk AVMs, chiefly by reducing lesional blood flow before resection. However, associated risks include postembolization AVM rupture, and the effect of preoperative embolization on outcome remains uncertain. We performed a meta-analysis of the literature on preoperative embolization for microsurgically treated AVMs. A systematic review and meta-analysis were conducted of all English-language publications reporting clinical outcomes after combined embolization and surgical resection for AVMs. Single- and 2-arm analyses were performed using random-effects modeling. Thirty-six studies with 2108 patients were included in this analysis. Most patients (90.6%) who underwent embolization had at least a 50% obliteration of AVMs on posttreatment preoperative angiography, with a mean rate of obliteration of approximately 80% (range 28.8-100%). Among patients who had combined treatment, 3.4% (95% confidence interval [CI] 2.1-4.6%) experienced embolization-related hemorrhagic complications before surgery. Both treatment groups achieved excellent postsurgical complete resection rates (odds ratio [OR] 1.05; 95% CI 0.60-1.85). Neither the clinical outcome (OR 1.42; 95% CI 0.84-2.40) nor the total number of hemorrhagic complications (OR 1.84; 95% CI 0.88-3.85) was significantly different between the treatment groups. In this meta-analysis, preoperative embolization appears to have substantially reduced the lesional volume with active AV shunting before AVM resection. Anecdotally, preoperative embolization facilitates safe and efficient resection; however, differences in outcomes were not significant. The decision to pursue preoperative embolization remains a nuanced decision based on individual lesion anatomy and treatment team experience.

Frameless Co-Registration of Biplane 2D Digital Subtraction Angiography Whole Frames and 3D Rotational Angiography-Based Cone-Beam Computed Tomography Angiogram on Dedicated Software for Stereotactic Radiosurgery of Cranial Vascular Malformations.

Purpose: Given its high spatial resolution and vasculature selectivity, the cone-beam computed tomography (CT) angiography (CBCTA) image acquired by selective 3D rotational angiography (3DRA) is the most suitable 3D image for the target definition of stereotactic radiosurgery (SRS) for intracranial arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs). Furthermore, the relatively low temporal resolution of 3DRA-based CBCTA can be complemented by the stereotactic co-registration of orthogonally paired 2D dynamic digital subtraction angiography (2D-DSA). The integration of 2D-DSA, which is usually limited to one or a few frames for each projection, into CBCTA and/or planning CT can be achieved only by catheter-directed angiography on the day of SRS via a dedicated image localizer under rigid frame fixation to the skull, which imposes substantial burdens on patients. This study aimed to demonstrate a novel, convenient, and significantly less invasive method for the frameless co-registration of biplane 2D-DSA whole frames and CBCTA on commercially available dedicated software, namely, Brainlab® Elements (Brainlab AG, Munich, Germany), and present its prerequisite for successful image fusion.Technical Report: Elements have afforded the following functionality: A 3D vasculature image is automatically extracted as a floating image from any 3D image series containing vascular details and then subsequently co-registered manually and automatically to a selected frame pair of 2D-DSA with a six-degree-of-freedom rigid registration. As a preclinical feasibility study, two anonymous image datasets from patients harboring cerebral AVM and transverse-sigmoid (TS) DAVF were used to verify the accuracy and practicality of Elements for the frameless co-registration of 2D/3D vascular images, particularly on the assumption of clinical workflow for the target delineation of SRS planning. The use of ordinary unsubtracted CBCTA resulted in the insufficient extraction of abutting vessels or vessels that are in close proximity to bony structures, particularly in the case of TS-DAVF, where the fistulous pouch and the affected venous sinuses were adjacent to the cranial bone. By contrast, the amount and selectivity of vasculatures and the accuracy of subsequent image fusion were significantly improved from the subtracted CBCTA. The integration of CBCTA into dynamic 2D-DSA allowed the simultaneous review of both image information by sharing any concerning point and 2D or 3D structures under a common 3D coordinate.Conclusions: Elements enable the clinically useful frameless co-registration of biplane 2D-DSA whole frames into CBCTA, for which the routine acquisition of both subtracted and unsubtracted CBCTA axial images for ordinary diagnostic purposes is an indispensable prerequisite for successful image fusion and further widespread application. This frameless integration of the 2D/3D angiogram would dramatically enhance both the frame-based and frameless SRS workflow and circumstances by allowing users to forward SRS planning well in advance before SRS, along with the omission of invasive angiography on the day of SRS, and would broaden the implementation of frameless SRS. Furthermore, the comprehensive alternating interactive review of the 2D/3D integrated angiogram leads to a more in-depth quasi-4D understanding of the affected angioarchitectures compared with the separate viewing of each image.

Reversible cognitive impairment and parkinsonism with leukoencephalopathy due to cranial dural arteriovenous fistula

Parkinsonism and rapid cognitive impairment may have many causes, but only a few have specific treatment. Cranial dural arteriovenous fistula (DAVF) represents 10-15% of intracranial arteriovenous malformations. Clinical manifestations depend on location and venous drainage. It is common the presence of pulsatile tinnitus, bruits and headache or headache and papilledema. Progressive cognitive decline is an unusual presentation due to bilateral thalamic edema or cortical venous hypertension. Endovascular or surgical treatment can reverse disease symptoms.We present a 74-year old man with rapidly progressive cognitive impairment and parkinsonism and a subsequent diagnosis of dural arteriovenous fistula (DAVF). Brain MRI revealed diffuse leukoencephalopathy probably attributable to elevated venous pressure. He was treated with partial embolization with Onix and left transverse sinus angioplasty. Following the procedure, there was a substantial reduction of venous pressure signs and remarkable clinical and imaging improvement, persisting at two years follow-up. This case represents an unusual presentation of DAVF. It is important to suspect the diagnosis of DAVF in cases with rapidly evolving cognitive impairment, parkinsonism and leukoencephalopathy as it can be reversible with early treatment.

A Review of Artificial Intelligence in Cerebrovascular Disease Imaging: Applications and Challenges.

A variety of emerging medical imaging technologies based on artificial intelligence have been widely applied in many diseases, but they are still limitedly used in the cerebrovascular field even though the diseases can lead to catastrophic consequences. This work aims to discuss the current challenges and future directions of artificial intelligence technology in cerebrovascular diseases through reviewing the existing literature related to applications in terms of computer-aided detection, prediction and treatment of cerebrovascular diseases. Based on artificial intelligence applications in four representative cerebrovascular diseases including intracranial aneurysm, arteriovenous malformation, arteriosclerosis and moyamoya disease, this paper systematically reviews studies published between 2006 and 2021 in five databases: National Center for Biotechnology Information, Elsevier Science Direct, IEEE Xplore Digital Library, Web of Science and Springer Link. And three refinement steps were further conducted after identifying relevant literature from these databases. For the popular research topic, most of the included publications involved computer-aided detection and prediction of aneurysms, while studies about arteriovenous malformation, arteriosclerosis and moyamoya disease showed an upward trend in recent years. Both conventional machine learning and deep learning algorithms were utilized in these publications, but machine learning techniques accounted for a larger proportion. Algorithms related to artificial intelligence, especially deep learning, are promising tools for medical imaging analysis and will enhance the performance of computer-aided detection, prediction and treatment of cerebrovascular diseases.

Prophylactic Awake Peripheral VA ECMO TAVI Is Safe and Effective: A Case Series and Patient Management Algorithm

Sylvian arteriovenous malformations (sAVMs) are rare and account for approximately 8%–11% of all intracranial arteriovenous malformations (AVMs).1 Because of their proximity to eloquent structures such as the motor speech center, insular cortex, and internal capsule, microsurgical resection of sAVMs remains a challenge.Several classifications have already been suggested for sAVMs, such as Sugita and Yasargil.1,2 It is well established that for low-grade AVMs, results of the microsurgical resection are excellent and tend to favor surgery,1, 2, 3 but in high-grade AVM, a multimodal assessment is necessary for formulating treatment strategies.1In Video 1, we demonstrate the surgical resection of a ruptured sylvian temporal AVM. This AVM was localized in the superior surface of the temporal lobe, and its nidus was just beneath the cortical surface of this lobe. Because it was 5.1 cm at its largest diameter, had a deep drainage vein, and was localized adjacent to the Wernicke area, we classified it as a Spetzler-Martin grade IV AVM.4Despite the high-grade AVM, microsurgical treatment was the choice in this ruptured AVM and there was no increase in morbidity.

Topical Drug Application to Treat Infective Endocarditis – Preclinical Investigation of Novel Therapeutic Options for an Unmet Medical Need

Sylvian arteriovenous malformations (sAVMs) are rare and account for approximately 8%–11% of all intracranial arteriovenous malformations (AVMs).1 Because of their proximity to eloquent structures such as the motor speech center, insular cortex, and internal capsule, microsurgical resection of sAVMs remains a challenge.Several classifications have already been suggested for sAVMs, such as Sugita and Yasargil.1,2 It is well established that for low-grade AVMs, results of the microsurgical resection are excellent and tend to favor surgery,1, 2, 3 but in high-grade AVM, a multimodal assessment is necessary for formulating treatment strategies.1In Video 1, we demonstrate the surgical resection of a ruptured sylvian temporal AVM. This AVM was localized in the superior surface of the temporal lobe, and its nidus was just beneath the cortical surface of this lobe. Because it was 5.1 cm at its largest diameter, had a deep drainage vein, and was localized adjacent to the Wernicke area, we classified it as a Spetzler-Martin grade IV AVM.4Despite the high-grade AVM, microsurgical treatment was the choice in this ruptured AVM and there was no increase in morbidity.

Prenatal diagnosis of multiple intracranial arteriovenous malformations.

Ultrasound in Obstetrics & GynecologyAccepted Articles Picture of the Month Prenatal diagnosis of multiple intracranial arteriovenous malformations V. Krishnan, Corresponding Author V. Krishnan drvivekkrishnan@gmail.com orcid.org/0000-0003-0767-0982 Fetal Medicine & Perinatology, Amrita Centre of Excellence in Fetal Care, AMRITA Institute of Medical Sciences, Kochi, IndiaCorrespondence to:Dr V. Krishnan MS, DGO, DNB, PDF (Fetal Med.), MNAMS. Clinical Associate Professor & Head, Division of Fetal Medicine & Perinatology, Amrita Institute of Medical Sciences, Ponekkara PO Kochi, Kerala, India Pin: 682 041, Email: drvivekkrishnan@gmail.comSearch for more papers by this authorR. Elayedatt, R. Elayedatt orcid.org/0000-0002-5985-4890 Fetal Medicine & Perinatology, Amrita Centre of Excellence in Fetal Care, AMRITA Institute of Medical Sciences, Kochi, IndiaSearch for more papers by this authorM. Hausman-Kedem, M. Hausman-Kedem orcid.org/0000-0001-5315-3738 Pediatric Neurology Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, IsraelSearch for more papers by this authorK. K. Haratz, K. K. Haratz orcid.org/0000-0001-9868-3548 Senior Consultant, Ultrasound in ObGyn Unit - Lis Maternity Center - Tel Aviv Medical CenterSearch for more papers by this author V. Krishnan, Corresponding Author V. Krishnan drvivekkrishnan@gmail.com orcid.org/0000-0003-0767-0982 Fetal Medicine & Perinatology, Amrita Centre of Excellence in Fetal Care, AMRITA Institute of Medical Sciences, Kochi, IndiaCorrespondence to:Dr V. Krishnan MS, DGO, DNB, PDF (Fetal Med.), MNAMS. Clinical Associate Professor & Head, Division of Fetal Medicine & Perinatology, Amrita Institute of Medical Sciences, Ponekkara PO Kochi, Kerala, India Pin: 682 041, Email: drvivekkrishnan@gmail.comSearch for more papers by this authorR. Elayedatt, R. Elayedatt orcid.org/0000-0002-5985-4890 Fetal Medicine & Perinatology, Amrita Centre of Excellence in Fetal Care, AMRITA Institute of Medical Sciences, Kochi, IndiaSearch for more papers by this authorM. Hausman-Kedem, M. Hausman-Kedem orcid.org/0000-0001-5315-3738 Pediatric Neurology Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, IsraelSearch for more papers by this authorK. K. Haratz, K. K. Haratz orcid.org/0000-0001-9868-3548 Senior Consultant, Ultrasound in ObGyn Unit - Lis Maternity Center - Tel Aviv Medical CenterSearch for more papers by this author First published: 02 February 2022 https://doi.org/10.1002/uog.24871 This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/uog.24871. AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Accepted ArticlesAccepted, unedited articles published online and citable. The final edited and typeset version of record will appear in the future. RelatedInformation

Awake Surgery for Arteriovenous Malformations in Eloquent Areas Does Not Increase Intraoperative Risks and Allows for Shorter-Term Recovery and Improved Status

Arteriovenous malformations (AVMs) located in eloquent areas are associated with a significant risk of neurologic deterioration. Awake surgery applied to intracranial AVMs could better identify eloquent areas, but its feasibility and application are controversial and limited to small case series. We retrospectively reviewed a group of 59 brain AVMs located in eloquent areas surgically treated with asleep craniotomy and compared it with a combined group of patients treated with awake craniotomy. Patients were stratified into 2 groups: patients who underwent asleep surgery and patients who underwent awake surgery. With this study, we aimed to perform a complete analysis of surgical risks and outcomes for this subgroup of patients in order to provide a basis for a future prospective study. We compared the asleep group of 25 patients and the awake group of 34 patients. No statistically significant differences were identified regarding the risk of postoperative complications, surgical radicality, presence of residual, and need for adjuvant treatment (P= 1.00). The improvement in Karnofsky Performance Status (KPS) was more rapid and effective during follow-up in patients treated with awake surgery compared with asleep surgery (KPS at day 30 >70%-80% versus 87.2%, P= 0.01 and at 1year KPS >70%-80% vs. 96.9%, P= 0.02). In contrast to what is commonly believed, applying awake surgery to this lesion does not involve increased intraoperative risks. Still, it seems to determine a significant improvement in the outcome of patients from postoperative day 30 onwards.

Stereotactic radiosurgery for ruptured versus unruptured intracranial arteriovenous malformations.

Background: There are a limited data examining the effects of prior hemorrhage on outcomes after stereotactic radiosurgery (SRS). The goal of this study was to identify risk factors for arteriovenous malformation (AVM) rupture and compare outcomes, including post-SRS hemorrhage, between patients presenting with ruptured and unruptured AVMs.Methods: A retrospective review of consecutive patients undergoing SRS for intracranial AVMs between 2009 and 2019 at our institution was conducted. Chi-square and multivariable logistic regression analyses were utilized to identify patient and AVM factors associated with AVM rupture at presentation and outcomes after SRS including the development of recurrent hemorrhage in both ruptured and unruptured groups.Results: Of 210 consecutive patients with intracranial AVMs treated with SRS, 73 patients (34.8%) presented with AVM rupture. Factors associated with AVM rupture included smaller AVM diameter, deep venous drainage, cerebellar location, and the presence of intranidal aneurysms (P < 0.05). In 188 patients with adequate follow-up time (mean 42.7 months), the overall post-SRS hemorrhage rate was 8.5% and was not significantly different between ruptured and unruptured groups (10.3 vs. 7.5%, P = 0.51). There were no significant differences in obliteration rate, time to obliteration, or adverse effects requiring surgery or steroids between unruptured and ruptured groups.Conclusion: Smaller AVM size, deep venous drainage, and associated intranidal aneurysms were associated with rupture at presentation. AVM rupture at presentation was not associated with an increased risk of recurrent hemorrhage or other complication after SRS when compared to unruptured AVM presentation. Obliteration rates were similar between ruptured and unruptured groups.

Intracranial pial arteriovenous malformation in an infant treated with endovascular glue embolization

Intracranial pial arteriovenous fistulas (AVFs) are rare vascular malformation in children. Children usually present with macrocrania and localized neurological impairments, whereas infants typically present with congestive heart failure. Congenital pial AVF may have syndromic association with Rendu-Osler-Weber disease and Klippel-Trenaunay-Weber syndrome. Here, we are reporting the case of a 5-month-old child who presented with multiple episodes of seizures and magnetic resonance imaging brain revealed pial AVF from the left middle cerebral artery. Following digital subtraction angiogram, glue embolization was done and achieved complete obliteration of venous sac and flow across fistula. Child had an uneventful postoperative period and developed no complications.

Comparison between Digital Subtraction Angiography and Indocyanine Green Video Angiography in the Operative Management of Aneurysmal Subarachnoid Hemorrhage

Abstract Background Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a “pre-contrast image” or mask from subsequent images, once the contrast medium has been introduced into a structure, hence the term “Digital subtraction angiography.” Indocyanine green video angiography (ICG-VA) is a safe and practical method of real-time delineation of microvasculature used in the surgical management of intracranial aneurysms, arteriovenous malformations, and other vascular lesions. Intraoperative ICG-VA is used as an adjunct in addition to intraoperative or postoperative DSA, and in other cases, it is used as the sole method to confirm the complete obliteration of clipped intracranial aneurysm. The only limitation of ICG-VA is the nonvisibility of vessels that are not in the operative field. Intraoperative ICG is useful in the clipping of intracranial aneurysms to ensure a gross patency of branch vessels; however, the presence of residual aneurysms and subtle changes in flow in branch vessels is best seen by DSA. Methods ICG angiography was done during the surgery and the findings of intraoperative ICG angiography were compared with postoperative DSA that was done between 6 and 12 weeks. DSA was done to see any compromise of lumen of parent vessel by clip, any residual aneurysm. Results In our study, intraoperative ICG complete aneurysm obliteration was present in all 30 (100%) patients, while in postoperative DSA complete aneurysm obliteration was diagnosed in 27 (90.0%) patients. Parent vessel patency was present in all 30 (100.0%) patients in both intraoperative ICG-VA and postoperative DSA. In intraoperative ICG distal branch patency was present in 26 (86.7%) patients, while in postoperative DSA distal branch patency was diagnosed in 27 (90.0%) patients. Conclusion We compared the intraoperative ICG finding and postoperative DSA finding and found that DSA is more sensitive than ICG in depicting residual aneurysm neck, hence reducing the risk of rupture of the aneurysm in future. Intraoperative ICG has high special resolution reflex feedback, intraoperative repositioning time is less and thus critical ischemia time is reduced. In a developing country like ours where DSA facilities are limited, ICG can be optimal investigation to delineate the vascular anatomy and confirmation of clip position thus reducing mortality.

Vein of Galen aneurysmal malformation: rationalizing medical management of neonatal heart failure.

Neonates who present in high output heart failure secondary to vein of Galen aneurysmal malformation can be difficult to manage medically due to the complex physiology that results from the large shunt through the malformation. Though the cardiac function is often normal, right ventricular dilation, severe pulmonary hypertension, and systemic steal can result in inadequate organ perfusion and shock. This report recommends medical management for stabilization of neonates prior to definitive management with endovascular embolization. IMPACT: Vein of Galen aneurysmal malformation (VGAM) is a rare intracranial arteriovenous malformation, which can present in the neonatal period with high output heart failure. Heart failure secondary to VGAM is often difficult to manage and is associated with high mortality and morbidity. Despite optimal medical management, many patients require urgent endovascular embolization for stabilization of their heart failure. This report offers discrete recommendations that can be used by clinicians as guidelines for the medical management of heart failure in newborns with VGAM.

Angiographic predictors of spontaneous obliteration of transarterial partially embolized brain arteriovenous malformations.

Spontaneous obliteration of cerebral arteriovenous malformations is uncommon but could occur after partial embolization. A retrospective study of 140 patients that underwent embolization for cerebral AVMs from 2005 to August 2019 using liquid embolic agents. The angiographic outcome of patients was classified as regard complete embolization, partial embolization, and complete obliteration after partial embolization. The parameters studied included size, location, number of arterial feeders, number of draining veins, rupture status, embolic agent, and patient factors as well. The study patients included 74 (53%) females and 66 (47%) males. Their age ranged from 7 to 43 years old. One hundred and eight patients (77%) presented with hemorrhage. The AVM grades were grade II in 57 (40.7%) patients and grade III in 56 (39.3%) patients. Sixty-one (43.57%) patients were treated by n-Butyl Cyanoacrylate and 71 (50.71%) patients were treated with Onyx, and both materials were used together in 8 cases. Follow-up angiography was done from 6 to 36 months after embolization. The rate of complete occlusion in all patients was 61.43% (86 patients). There were three groups of patients, the first group had complete occlusion of the nidus at the time of embolization and included 68 (48.57%) patients. The second group had partial embolization with partial occlusion of the nidus 54 patients (38.57%). The 3rd group included 18 patients (12.85%) with complete nidal occlusion on follow up after partial embolization. The delay in the venous drainage of the AVM to the late arterial phase or early venous phase with flow stasis was a significant predictor of future obliteration on follow up after partial embolization. Other significant parameters that were associated with the progressive disappearance of the AVM nidus on follow up after partial embolization are presentation with hemorrhage, AVMs size less than 3 cm, the presence of single draining or double draining veins, superficial venous drainage, and one or 2 arterial feeders. Spontaneous closure of intracranial arteriovenous malformations after partial embolization may be encountered in cases of stasis of flow during embolization procedure with a delay of the venous drainage. A long-term follow-up of more cases over many years is required to confirm the validity of this conclusion.

Perioperative Complications of Transvenous Embolization of Ruptured Intracranial Arteriovenous Malformations.

PurposeTo investigate the perioperative complications of transvenous embolization of ruptured intracranial arteriovenous malformations.Materials and MethodsA total of 27 patients with ruptured intracranial arteriovenous malformations underwent transvenous embolization were enrolled from November 2016 to May 2020 in our prospective database. Perioperative complications and angiographic characteristics were analyzed retrospectively.ResultsComplete disappearance of the nidus occured in 22 (88%) of 25 patients with technically feasible AVMs immediately after embolization. Two cases were partially treated by transarterial embolization due to the failure of microcatheter placement into the draining vein. Seven (25.9%, 7/27) patients had perioperative complications, including three cases of intraoperative hemorrhage, three cases of postoperative hemorrhage and one case of ischemic infarction. No significant differences in complication rates between patients with nidus ≥3 cm and <3 cm (P = 0.659), eloquent area and non-eloquent (P = 0.137), deep location and superficial (P = 0.637), deep venous drainage and cortical vein (P = 1.0), the number of venous drainage (P = 0.49), the angle of draining vein entering venous sinus <90° and ≥90° (P = 1.0), aneurysms (P = 0.058) and the time between hemorrhage and TVE (P = 1.0) were found. Three of these patients received ventriculostomy, two of which received lumbar drainage treatments at the same time, and four patients just received conservative management. Good outcomes (mRS ≤ 2) at the 1-month evaluation were achieved in 5 of the patients who had complications, but poor outcome (mRS = 5) at the 1-month evaluation was in 1 patient, and 1 lethal complication occurred.ConclusionThe most common complication of AVMs with transvenous endovascular embolization is cerebral hemorrhage. The prevention of complications may improve the efficacy of AVM embolization, but the current quality of evidence is low and limited in guiding policy development and improving the TVE for AVMs. It is, therefore, necessary to develop clinical research programs in this field.

Chronic encapsulated expanding hematomas after stereotactic radiosurgery for intracranial arteriovenous malformations.

Cerebral arteriovenous malformations (AVMs) are rare cerebral vascular lesions that are associated with high morbidity and mortality from hemorrhage; however, stereotactic radiosurgery (SRS) is a well-validated treatment modality. Few reports have delineated a subgroup of patients who develop delayed chronic encapsulated expanding hematomas (CEEHs) despite angiographic evidence of AVM obliteration following radiosurgery. In this report, the authors performed a retrospective review of more than 1000 radiosurgically treated intracranial AVM cases to delineate the incidence and management of this rare entity. Between 1988 and 2019, 1010 patients with intracranial AVM underwent Gamma Knife SRS at the University of Pittsburgh Medical Center. In addition to a review of a prospective institutional database, the authors performed a retrospective chart review of the departmental AVM database to specifically identify patients with CEEH. Pertinent clinical and radiological characteristics as well as patient outcomes were recorded and analyzed. Nine hundred fifty patients with intracranial AVM (94%) had sufficient clinical follow-up for analysis. Of these, 6 patients with CEEH underwent delayed resection (incidence rate of 0.0045 event per person-year). These patients included 4 males and 2 females with a mean age of 45.3 ± 13.8 years at the time of initial SRS. Four patients had smaller AVM volumes (4.9-10 cm3), and 3 of them were treated with a single SRS procedure. Two patients had larger-volume AVMs (55 and 56 cm3), and both underwent multimodal management that included staged SRS and embolization. Time to initial recognition of the CEEH after initial SRS ranged between 66 and 243 months. The time between CEEH recognition and resection ranged from 2 to 9 months. Resection was required because of progressive neurological symptoms that correlated with imaging evidence of gradual hematoma expansion. All 6 patients had angiographically confirmed obliteration of their AVM. Pathology revealed a mixed chronicity hematoma with areas of fibrosed blood vessels and rare areas of neovascularization with immature blood vessels but no evidence of a persistent AVM. All 6 patients reported persistent clinical improvement after hematoma resection. CEEH after SRS for AVM is a rare complication with an incidence rate of 0.0045 event per person-year over the authors' 30-year experience. When clinical symptoms progress and imaging reveals progressive enlargement over time, complete resection of a CEEH results in significant clinical recovery. Knowledge of this rare entity facilitates timely detection and eventual surgical intervention to achieve optimal outcomes.

Vascular abnormalities - a true cause of pulsatile tinnitus?

Pulsatile tinnitus can be a symptom of vascular pathology. However, many of these pathologies present as incidental findings on scanning for unrelated symptoms. This study investigated whether the pathologies attributed to pulsatile tinnitus could instead be considered incidental findings. This retrospective study evaluated imaging results of 272 pulsatile tinnitus cases for clinically relevant pathologies, and examined correlations between the site of symptoms and the imaging findings. Of 272 patients, 238 (88 per cent) had normal scans, 17 (6 per cent) had clinically insignificant incidental findings, and 18 (7 per cent) had findings requiring further investigation or intervention; regarding these latter 18 patients, findings for 8 patients (42 per cent) did not correlate with the symptomatic side. The rates of intracranial aneurysm and arteriovenous malformation in the pulsatile tinnitus group were comparable to those in normal populations. The comparable rates of vascular abnormalities within the symptomatic pulsatile tinnitus group, plus clinically relevant findings contralateral to symptoms, suggest that vascular pathologies could be incidental findings rather than causes of pulsatile tinnitus. Evaluation is recommended of the effectiveness of the new National Institute for Health and Care Excellence guidelines for pulsatile tinnitus investigation.

Complete seizure-free rates following interventional treatment of intracranial arteriovenous malformations: a systematic review and meta-analysis.

Seizures are common presenting symptoms of intracranial arteriovenous malformations (AVMs). This systematic review and meta-analysis aims to assess the current evidence regarding complete seizure freedom rates following surgical resection, stereotactic radiosurgery (SRS), and/or endovascular embolization of intracranial AVMs. A systematic review of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included manuscripts were methodically scrutinized for quality, spontaneous AVM-associated or hemorrhage-associated seizures, complete seizure-free rates following each interventional treatment, follow-up duration; determination methods of seizure outcomes, and average time-to-onset of recurrent seizures after each treatment. Manuscripts that described patients with nondisabling seizures or reduced seizure frequency in their seizure-free calculations were excluded. Seizure freedom rates following surgical resection, SRS, and endovascular embolization were compared via random-effect analysis. Thirty-four studies with a total of 1765 intracranial AVM patients presenting with spontaneous AVM-associated seizures and 408 patients presenting with hemorrhage-associated seizures were qualitatively analyzed. For patients presenting with AVM-associated seizures, the complete seizure-free rates were 73.0% (321/440 patients; 95% CI 68.8-77.1%) following surgical resection, 60.5% (376/622 patients; 95% CI 56.6-64.3%) following SRS, and 44.6% (29/65 patients; 95% CI 32.5-56.7%) following endovascular embolization alone. For patients presenting with either AVM-associated or hemorrhage-associated seizures, the complete seizure-free rates were 73.0% (584/800 patients; 95% CI 69.9-76.1%) following surgical resection, 46.4% (572/1233 patients; 95% CI 43.6-49.2%) following SRS, and 44.6% (29/65 patients; 95% CI 32.5-56.7%) following embolization. For patients presenting with either AVM-associated or hemorrhage-associated seizures, the overall improvements in seizure outcomes regardless of complete seizure freedom were 82.6% (661/800 patients; 95% CI 80.0-85.3%), 70.6% (870/1233 patients; 95% CI 68.0-73.1%), and 70.8% (46/65 patients; 95% CI 59.7-81.1%) following surgical resection, SRS, and embolization, respectively. No study reported information about the time-to-onset for recurrent seizures in any patient following treatment, as seizure outcomes were only described at the last follow-up visit. The available data suggests that surgical resection results in the highest rate of complete seizure freedom. The rate of seizure improvement following surgery increased further to 82.3% when including patients who had improved seizure frequency without achieving true seizure freedom. Complete seizure-free rates following SRS or embolization were more ambiguous and lower when compared to surgical resection. There is a need for high quality studies evaluating AVM treatment modalities and clearly defined seizure outcomes, as the current literature consists mostly of heterogenous patient populations.