Treatment Of Arteriovenous Malformations Research Articles

Treatment of iliac arteriovenous malformation associated with trisomy 21: a case report

Both arteriovenous malformation (AVM) and trisomy 21 are rare diseases. Studies have shown that individuals with trisomy 21 may have potential vascular malformations, with the main site of onset being the portal system. This case involved an adult patient with trisomy 21 who presented with pelvic iliac arteriovenous malformations. The patient underwent interventional treatment, and the prognosis was favorable. It is important to enhance the screening for vascular malformations in patients with trisomy 21 syndrome. At the same time, interventional treatment for AVMs is effective and increasingly important for managing AVMs.

Comparing stand-alone endovascular embolization versus stereotactic radiosurgery in the treatment of arteriovenous malformations with Spetzler-Martin grades I–III: a propensity score matched study

BackgroundArteriovenous malformations (AVMs) are uncommon cerebral lesions that can cause significant neurological complications. Surgical resection is the gold standard for treatment, but endovascular embolization and stereotactic radiosurgery (SRS) are viable...

The role of procedural factors on the outcomes of embolization followed by radiosurgery for the treatment of brain arteriovenous malformations: systematic review and proportional meta-analyses.

Multimodal therapy for brain arteriovenous malformations (bAVM) with embolization followed by stereotactic radiosurgery (E + SRS) has shown varying outcomes. Its benefits over other treatment modalities have been questioned. The goal of this systematic review was to determine the factors associated with cure and complication rates of this treatment strategy. A literature search in Medline and Global Index Medicus, from inception to October 2023, was performed. Studies reporting relevant outcome data from bAVM patients treated with E + SRS were included. Data on several patient, lesion and procedure-related factors were collected. Embolization intent was classified as Targeted (of high-risk features), Devascularizing (feeder embolization/flow reduction) and Occluding (intent-to-cure, nidus embolization). The primary outcome was obliteration rate. Secondary outcomes were post-SRS bleeding (PSB), post-embolization neurological complications (PENC) and post-SRS neurological complications (PSNC). Subgroup analyses included embolic agent, embolization intent and radiosurgery type. Proportional meta-analyses and meta-regressions were performed. Forty-one studies were included in the review. The pooled obliteration rate was 56.45% (95% CI 50.94 to 61.88). Meta-regression analyses showed higher obliteration rates with Copolymers and lower obliteration rates with Devascularizing embolization. The pooled PSB, PENC and PSNC rates were 5.50%, 13.75% and 5.02%, respectively. Meta-regression analyses showed higher rates of PSB, PENC and PSNC with Devascularizing embolization, Liquid & Solid embolic agents and Targeted & Devascularizing intent, respectively. Embolic agent and embolization intent were procedural factors associated with treatment outcomes of E + SRS in the management of bAVM patients. The efficacy and safety profiles favor copolymers as embolic agents and disfavor Devascularizing as embolization intent. The protocol of the systematic review was registered in PROSPERO as CRD42023474171.

Considerations for the Use of Stereotactic Radiosurgery to Treat Large Arteriovenous Malformations.

Stereotactic radiosurgery (SRS) is an effective treatment strategy for cerebral arteriovenous malformations (AVMs). Aggressive treatment achieving complete obliteration is necessary to prevent further intracranial hemorrhage and neurological deficits. However, SRS treatment of large AVMs (>10 cm3) is challenging. To prevent toxicity in the normal brain tissue, it is imperative to reduce the radiation dose as the lesion volume increases; however, this also reduces the rate of obliteration. In this study, we review the various radiosurgical approaches for treating large AVMs and their outcomes, and suggest ways to improve treatment outcomes during SRS for large AVMs.

Surgical treatment and outcome of spinal arteriovenous malformations.

A rare and diverse set of abnormalities formed by spinal blood arteries known as spinal arteriovenous malformations (AVMs) has a higher risk of hemorrhage and morbidity, causing the shunting of blood from veins with an aberrant capillary bed to arteries. Knowledge of the vascular anatomy of spinal AVMs and the spinal cord's vascular supply is crucial to its therapy. The aim of this study was to report a case of SAVM healing after surgical excision, highlighting the importance of surgical excision in treating these rare lesions. A 56-year-old male with progressive bilateral lower extremity weakness and numbness was diagnosed with spinal cord arteriovenous malformation (SAVM). A thoracolumbar spine MRI was performed, and a vascular lesion was found. The feeding artery was coagulated and incised, and the surrounding hematoma was removed. Spinal cord arteriovenous malformation was diagnosed postoperatively. The Oswestry Disability Index (ODI) and the SF-36 questionnaires assessed functional outcomes and physical functioning in individuals with acute or chronic low back pain. In the reported case, the aneurysm showed spontaneous regression at follow-up after surgical removal of the AVM. Post-surgery rehabilitation improved his motor function. After seven months, he showed 90% physical functioning, 75% emotional well-being, 75% social functioning, 87.5% pain, and 55% general health. He could walk with a walking aid and perform daily activities. Treatment strategies for AVM-related spinal aneurysms should be carefully considered. Surgical treatment in several conditions has advantages and is reported to have good outcomes.

Unforeseen outcomes: Unveiling cyst formation post stereotactic radiosurgery in brain arteriovenous malformations cases

IntroductionCyst formation after stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs) is a rare, delayed but important complication. Prompt recognition and appropriate treatment is essential for good outcome. MethodsWe analysed our institute’s Gamma knife treatment records from 2008 to 2023 and analysed AVM treated patients by gamma knife radiosurgery (GKRS). Patients with cyst formation and with adequate follow up were identified. Clinical details, management and prognosis of these patients was studied in detail along with prior literature review. ResultsA total of 921 AVM patients were treated in the above period and 7 patients were identified with cyst formation. The mean nidus volume was 12.98 ml, the mean radio surgical marginal dose was 23.57 Gy and maximal dose 47.21 Gy. The mean interval gap between SRS and cyst detection was 6.45 years. The mean volume of cyst cavity formed was 47.85 ml. Patients presented either with features of raised intracranial pressure (3) or focal neurological deficits (3) or seizures (1). 3 patients had achieved angiographic nidus obliteration at the time of cyst detection. Treatment was mostly on surgical lines with cyst fenestration(2 patients), excision (3 patients) and emergency decompressive craniectomy (1 patient). 1 patient required additional Ommaya insertion. Conservative management was followed for 1 patient. Residual nidus was treated either by concomitant excision or embolization or redo GKRS.Favourable outcome was seen in 6 out of 7 patients (85.71%) post cyst management with symptomatic and radiological improvement whereas 1 patient (14.28%) died due to refractory status epilepticus secondary to malignant cerebral edema. ConclusionCyst formation after GKRS for AVM treatment is an often-neglected complication due to its low incidence and often long latency period. Long term follow up of patients is hence necessary for prompt recognition. Diagnostic DSA should be done in all patients with cysts to look for residual nidus. Asymptomatic ones can be followed up conservatively while surgical treatment is required for symptomatic cases. Ventricular diversion like Ommaya or cystoperitoneal shunt may be necessary in some cases. Treatment outcome is usually favourable provided timely detection is done.

Influence of preoperative embolisation on resection of brain arteriovenous malformations: cohort study

PurposePreoperative endovascular embolisation is a widely used adjunct for the surgical treatment of brain arteriovenous malformations (AVMs). However, whether this improves completeness of AVM resection is unknown, as previous analyses have not adjusted for potential confounding factors. We aimed to determine if preoperative endovascular embolisation was associated with increased rate of complete AVM resection at first surgery, following adjustment for Spetzler-Martin grade items.MethodsWe identified a cohort of all patients undergoing first ever AVM resection in a specialist neurosciences unit in the NHS Lothian Health Board region of Scotland between June 2004 and June 2022. Data was prospectively extracted from medical records. Our primary outcome was completeness of AVM resection. We determined the odds of complete AVM resection using binomial logistic regression with adjustment for Spetzler-Martin grading system items: maximum nidus diameter, eloquence of adjacent brain and the presence of deep venous drainage.Results88 patients (median age 40y [IQR 19–53], 55% male) underwent AVM resection. 34/88 (39%) patients underwent preoperative embolisation and complete resection was achieved at first surgery in 74/88 (84%). Preoperative embolisation was associated with increased adjusted odds of complete AVM resection (adjusted odds ratio [aOR] 8.6 [95% confidence interval (95% CI) 1.7–67.7]; p = 0.017). The presence of deep venous drainage was associated with reduced chance of complete AVM resection (aOR 0.18 [95% CI 0.04–0.63]; p = 0.009).ConclusionsPreoperative embolisation is associated with improved chances of complete AVM resection following adjustment for Spetzler-Martin grade, and should therefore be considered when planning surgical resection of AVMs.

Covered stent combined with embolization treatment for complex congenital lower limb arteriovenous malformations: case report and literature review

BackgroundCurrently, the treatment outcomes for complex congenital arteriovenous malformations (AVMs) remain unsatisfactory. This article reports on the utilization of an abdominal aortic stent graft, in conjunction with embolization techniques, for managing acute heart failure triggered by complex congenital arteriovenous malformations in the lower limb.Case PresentationWe present a case involving a patient with congenital AVMs in the lower limb, who had suffered from prolonged swelling in the left lower limb and recently developed symptoms of heart failure. At the age of 67, the patient was definitively diagnosed with a complex congenital AVMs in the lower limb. This article delves into the practical experiences and limitations encountered in employing an abdominal aortic stent graft, coupled with embolization, to address acute heart failure caused by complex congenital AVMs in the lower limb.ConclusionsOur article presents the initial report on the challenges and limitations encountered in treating acute heart failure triggered by complex congenital AVMs in the lower limb, utilizing a combination of abdominal aortic stent graft placement and embolization techniques.

Surgical treatment of small-sized S3 arterio-venous malformations with neo-adjuvant and adjuvant bleomycin

Arteriovenous Malformations are complex and challenging entities, and their treatment is often tailored on the patient. Interstitial sclerosing treatment with bleomycin is promising especially in cases where the aesthetical and/or functional burden of surgical intervention would be impactful as in the S3 AVM according to the SECg classification.We treated 15 patients presenting small (<10cm3) S3 arterio-venous malformations with 3 + 3 sessions of 15.000 IU of interstitial bleomycin. 9 patients presented moderate to good response to the first 3 sessions and thus surgical re-shaping was performed between the two cycles. US examination was done pre-treatment, before each session and every 3 months after the end of the protocol to assess the arterio-venous malformations.Fifteen of the seventeen patients concluded the protocol. 9 patients underwent surgical re-shaping while 6 skipped it because of their excellent response to the first 3 bleomycin injections. Major improvement in terms of appearance and symptoms (pulsations, ulcerations, bleeding or pain) were always achieved. There was a 20% of minor complications.The presented data are encouraging and seem to suggest that this may be a promising protocol to extend the use of bleomycin in arterio-venous malformations and reduce the impact of surgery.

Surgical Results with Low-Grade Arteriovenous Malformations : A Single Center 14-Year Experience.

Advancements in AVM surgical techniques for cerebral arteriovenous malformation (AVM) underscore its efficacy. Our research aims to showcase the positive outcomes of treating low-grade AVMs surgically, focusing on safety and effectiveness. We retrospectively reviewed 55 patients (36 males and 19 females; average age 37.4 years) with Spetzler-Martin (S-M) grade 1 and 2 AVMs who underwent surgical resection between January 2009 and December 2022. In our study, 55 patients with S-M grade 1 and 2 AVMs underwent surgical resection, evenly divided between grades 1 (50.9%) and 2 (49.1%). Intracranial hemorrhage was the primary symptom in 74.5% of cases. Pre-operative Glasgow coma scale (GCS) scores revealed 69.1% of patients scored above 13, with 18% below 8. Successful resection was achieved in 87.3%. Postoperatively, 95.5% of ruptured and 90.9% of unruptured AVM patients showed lower or same modified Rankin scale scores. Poorer outcomes were significantly linked to lower GCS scores and intranidal/flow-related aneurysms through multivariate logistic regression. Postoperative seizures noted in nine patients, were exclusive to the ruptured AVM group. Our findings indicate surgical resection as a beneficial treatment for low-grade AVMs, yielding high cure rates and positive functional outcomes in both ruptured and unruptured cases. Preoperative GCS scores and the presence of associated aneurysms are predictive of postoperative functional status. Additionally, managing postoperative seizures effectively is key to enhancing prognosis.

Stereotactic Radiosurgery Outcomes in Arteriovenous Malformations: A Pediatric-Adult Comparative Meta-Analysis

Stereotactic radiosurgery (SRS) is an established treatment for brain arteriovenous malformations (AVMs), but outcomes between pediatric and adult populations are not well compared. We conducted a systematic review and meta-analysis comparing SRS outcomes for pediatric versus adult AVMs. PubMed was searched for studies reporting SRS outcomes for pediatric or adult AVMs up to January 2024. Primary outcome was obliteration rate, with secondary outcomes including post-SRS hemorrhage, symptomatic radiation-induced changes (RICs), and permanent RICs. Pooled estimates were calculated using random effects models. Analysis included 22 studies with 3469 patients (1316 pediatric, 2153 adult). Pooled obliteration rate was 63% (95% confidence interval: 56%-70%) overall, with no significant difference between pediatric (61%) and adult (67%) cohorts (P= 0.38). Post-SRS hemorrhage rates were similar (5% pediatric, 6% adult, P= 0.60). Symptomatic RICs occurred in 9% (95% confidence interval: 6%-13%) overall, with 10% in both cohorts (P= 0.91). Permanent RIC rates were 4% in pediatric and 3% in adult cohorts (P= 0.43). Cyst formation (0.6%) and radiation-induced tumors (0.2%) were rare. All-cause mortality was significantly lower in the pediatric cohort (2.6% vs. 9.8%, P= 0.003). Hemorrhagic AVM presentation was inversely correlated with symptomatic RICs across both groups. SRS is a reasonable treatment option for appropriately selected AVM patients in both pediatric and adult populations, offering comparable obliteration rates and adverse event profiles. The lower mortality in pediatric patients underscores the importance of early intervention in this population given their high cumulative lifetime rupture risks.

Enhancing cerebral arteriovenous malformation analysis: Development and application of patient-specific lumped parameter models based on 3D imaging data

Objectives:Cerebral arteriovenous malformations (AVMs) present complex neurovascular challenges, characterized by direct arteriovenous connections that disrupt normal brain blood flow dynamics. Traditional lumped parameter models (LPMs) offer a simplified angioarchitectural representation of AVMs, yet often fail to capture the intricate structure within the AVM nidus. This research aims at refining our understanding of AVM hemodynamics through the development of patient-specific LPMs utilizing three-dimensional (3D) medical imaging data for enhanced structural fidelity. Methods:This study commenced with the meticulous delineation of AVM vascular architecture using threshold segmentation and skeletonization techniques. The AVM nidus’s core structure was outlined, facilitating the extraction of vessel connections and the formation of a detailed fistulous vascular tree model. Sampling points, spatially distributed and derived from the pixel intensity in imaging data, guided the construction of a complex plexiform tree within the nidus by generating smaller Y-shaped vascular formations. This model was then integrated with an electrical analog model to enable precise numerical simulations of cerebral hemodynamics with AVMs. Results:The study successfully generated two distinct patient-specific AVM networks, mirroring the unique structural and morphological characteristics of the AVMs as captured in medical imaging. The models effectively represented the intricate fistulous and plexiform vessel structures within the nidus. Numerical analysis of these models revealed that AVMs induce a blood shunt effect, thereby diminishing blood perfusion to adjacent brain tissues. Conclusion:This investigation enhances the theoretical framework for AVM research by constructing patient-specific LPMs that accurately reflect the true vascular structures of AVMs. These models offer profound insights into the hemodynamic behaviors of AVMs, including their impact on cerebral circulation and the blood steal phenomenon. Further incorporation of clinical data into these models holds the promise of deepening the theoretical comprehension of AVMs and fostering advancements in the diagnosis and treatment of AVMs.

Timing of Embolization, Radiosurgery, and Resection of Arteriovenous Malformations in Pediatric Patients: A Retrospective, Descriptive Study

ObjectiveCerebral arteriovenous malformations (AVMs) are a challenging pathology in pediatric patients, carrying a high risk of morbidity and mortality. Treatment modalities include resection, endovascular embolization and stereotactic radiosurgery (SRS). There is currently no consensus favoring one modality over another. Timing of multimodal therapy with embolization/SRS and resection is not well explored in the literature. Here we present a series of pediatric AVM patients, with special attention paid to the timing of treatment. MethodsElectronic medical records of all pediatric patients (<18 years at treatment) with AVMs treated at our institution were retrospectively reviewed after IRB approval. Demographic information, AVM characteristics, treatment variables and outcomes were recorded. Results27 total patients were included. 21 (77.8%) presented with a ruptured AVM. 6 patients (28.6%) had an GCS of 3 to 10, and underwent treatment within 24 hours of presentation. 10 patients (47.6 %) with a GCS of 12 to 15 were treated between 24 to 120 hours. 5 patients (23.8%) were treated 3 weeks to 14 months after AVM rupture. 96% of our cohort, regardless of rupture status, had mRS of 1-2 at most recent follow-up. ConclusionsWe present our institution’s experience with pediatric AVM’s, focusing on the timing of treatment. Based on our experience, early treatment of AVMs seems to be safe and effective regardless of rupture status.

IhtObtura: A novel liquid embolic agent with post-embolization radiopacity loss, in endovascular treatment of brain arteriovenous malformations, dural arteriovenous fistulas, and tumors: CLARIDAD trial

BackgroundEndovascular embolization is frequently used for vascular lesions of the head and neck. Newer agents may help to enhance visualization and improve treatment outcomes.MethodsThe CLARIDAD clinical trial was a prospective,...

Combined Endovascular-Microsurgical Treatment for a Parietal Brain Arteriovenous Malformation and Neuropsychological Implications: An Operative 2-Dimensional Video Case: 2-Dimensional Operative Video

Brain arteriovenous malformations (AVMs) are complex vascular anomalies characterized by abnormal veins and arteries, lacking capillary beds. With an average 2.4% annual risk of hemorrhage, AVMs pose a significant challenge in treatment, especially in high-grade cases. Risk factors of hemorrhage include young age, previous rupture, and deep or infratentorial locations. 1-10 In this operative video, a 34-year-old man presented with a history of seizures and progressive headaches over 15 years. Clinical examination revealed a Glasgow Coma Scale of 15 and neuropsychological deficits including divided attention, working memory, verbal and semantic memory, and arithmetic skills. Digital subtraction angiography confirmed an AVM Spetzler-Martin III in the right parietal lobe, with venous drainage toward the superior sagittal sinus and involvement of the superior longitudinal fasciculus. After multiple embolizations, microsurgical resection was performed successfully. Postoperatively, the patient experienced no complications, with follow-up angiography demonstrating complete AVM exclusion. The patient consent to the procedure and to the publication of his/her image. This study was approved by the ethics committee of our institution. Despite its size and location in a noneloquent area, the AVM affected neuropsychological function. The combined endovascular-microsurgical approach proved effective, highlighting the importance of considering anatomical, functional, and neuropsychological factors in AVM treatment to maximize success in achieving complete obliteration and curative outcomes.

Recent Advances in Understanding and Management of Arteriovenous Malformations of the Temporal Skin Area

Context: Arteriovenous malformations (AVMs) of the temporal skin area, though less common than cerebral AVMs, pose significant challenges in terms of cosmetic and functional outcomes. Over the past decade, substantial advancements have been made in the understanding and management of these lesions. This paper aims to review the latest developments in the pathophysiology, diagnosis, and treatment of temporal skin AVMs, and to explore ongoing challenges and emerging research directions. Evidence Acquisition: A comprehensive literature search was conducted using databases such as PubMed, Scopus, and Google Scholar. The focus was on research published in the past ten years related to temporal skin AVMs, including reviews, clinical studies, and advancements in treatment techniques. Results: The review discusses the evolution in understanding the pathophysiology of temporal skin AVMs, improvements in diagnostic imaging techniques, and the refinement of surgical and non-surgical treatment approaches. The outcomes, including cosmetic and functional results, and complications associated with various treatments, are also presented. Conclusions: The management of temporal skin AVMs has benefited from multidisciplinary approaches, combining surgery, interventional radiology, and dermatology. However, challenges remain in achieving optimal cosmetic and functional outcomes, necessitating ongoing research and innovation.

Intracranial Arteriovenous Malformations During Pregnancy and Puerperium-A Retrospective Nationwide Population-Based Cohort Study.

The knowledge about the management of patients with brain arteriovenous malformations (AVM) during pregnancy is limited, owing partly to insufficient evidence about the outcomes of newborns. This study aims to explore symptomatic AVMs and their outcomes during pregnancy, delivery, and the postpartum period. We conducted a retrospective analysis by combining patients with symptomatic AVM from a nationwide population-based cohort of all women with a pregnancy resulting in delivery during 1987 to 2016 (n = 1 773 728 deliveries) and our AVM database (n = 805, 1942-2014). Cerebrovascular events during pregnancy were identified through International Classification of Diseases-9, International Classification of Diseases-10, or surgical procedure codes from the Hospital Discharge and Medical Birth Registers. Our analysis focused on treatment characteristics and outcomes of patients with AVM hemorrhage or symptomatic AVM during pregnancy, delivery, or puerperium. A total of 28 women with symptomatic AVMs during pregnancy, delivery, or postpartum period were followed for an average of 12.8 years (SD = 15.5) after admission. Among them, 21 (75%) experienced AVM hemorrhages during pregnancy, puerperium, or delivery. The mean age of patients was 28.9 years (SD = 5.5). Hemorrhages occurred predominantly during the second (n = 9, 43% of all ruptures) or the third trimester (n = 5, 24%). Two AVM ruptures occurred during labor. Treatment for AVM took place during pregnancy (n = 7, 25%) or puerperium (n = 3, 14%) in 10 patients (35.7%). Only 5 mothers (17.8%) had not been previously pregnant. There was no significant difference in mean Apgar scores between those with AVM hemorrhage (8.3) and those without (8.4). Most mothers in the study had prior pregnancies, suggesting a potentially weaker association between AVM rupture and pregnancy compared to previous reports. Notably, 2 AVM ruptures occurred during spontaneous vaginal deliveries. Outcomes were generally favorable in both mothers and infants. More research is needed to refine our understanding of the optimal timing for invasive treatment during pregnancy.

Three-Pillar Expansive Craniotomy in Children with Acute Ruptured Supratentorial Brain Arteriovenous Malformations

Acute rupture and hemorrhage of pediatric brain arteriovenous malformations (AVMs) may lead to cerebral herniation or intractable intracranial hypertension, necessitating emerging surgical interventions to alleviate intracranial pressure. However, there is still controversy regarding the timing of treatment for ruptured AVMs. This study aimed to assess the feasibility of utilizing three-pillar expansive craniotomy (3PEC) at different times during the treatment of pediatric ruptured supratentorial AVMs. A retrospective analysis was conducted on all consecutive cases of acute rupture in supratentorial AVM children who underwent 3PEC at a single institution from 2020 to 2022. General information, clinical characteristics, radiological data, and prognosis were reviewed and analyzed. Thirteen children were included in the analysis. The intracranial pressure of all patients decreased to below 15mmHg within 10days. The expansion volume of the cranial cavity of the patients increased by 18.3cm3 (95% confidence interval, 10.2-26.3; P<0.001) compared to the hematoma volume. None of the patients required decompressive craniectomy due to intractable intracranial hypertension caused by cerebral swelling. The median waiting period for patients with delayed AVMs treatment was 8days, during which no rebleeding occurred. Emergency intervention with 3PEC in children experiencing acutely ruptured supratentorial AVMs appears to be feasible. For children requiring delayed management of the AVMs, 3PEC may diminish the risk of rebleeding during the waiting period and shorten the waiting period.

Sustaining consistent cobalt-60 dose rate enhances radiosurgical outcomes in brain arteriovenous malformation management

Background and purposeThe impact of cobalt-60 dose rate (Co-60 DR) on outcomes of stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs) remains fully elucidated. This study explored the association between Co-60 DR and SRS outcomes in AVM treatment. Materials and methods772 AVM patients from 1990 to 2020 were included. High DR was defined as ≥ 2.4 Gy/min. AVM patients were categorized into 3 cohorts based on the nidus volume: small (<5 mL), medium (≥5 mL and < 10 mL), and large (≥10 mL). The primary endpoint was AVM obliteration; secondary endpoints included post-SRS hemorrhage. ResultsCumulative obliteration rates of the large AVM were significantly increased in the high DR group than those in the low DR group (84 % vs. 45 % at 5 years, log-rank test; p = 0.011). Multivariable analysis showed that the obliteration rate was significantly elevated for the high DR group in the large AVM cohort with an adjusted hazard ratio (HR) of 1.78 (95 % confidence interval [CI]: 1.00–3.17, p = 0.049). Post-SRS hemorrhage rates of the entire cohort were significantly decreased in the high DR group than in the low DR group (2.5 % vs. 5.3 % at 5 years, log-rank test; p = 0.035). Multivariable analysis revealed post–SRS hemorrhage was reduced in the high DR group with an adjusted HR of 0.47 (95 % CI: 0.24–0.92, p = 0.026). ConclusionHigh DR may lead to increased efficiency for large AVMs and decreased post-SRS hemorrhage in all AVM cases. Sustaining a higher Co-60 DR could potentially yield favorable outcomes for SRS for AVMs.

Primary Embolization of Cerebral Arteriovenous Malformations With Intention to Cure: A Systematic Review of Literature and Meta-Analysis.

The treatment of brain arteriovenous malformations (AVMs) involves multiple approaches, including embolization, microsurgical resection, and radiosurgery. With the advent of new embolisates, dual-lumen balloon catheters, detachable tip microcatheters, and transvenous embolization, endovascular AVM obliteration has become more effective. Although adjuvant embolization and embolization are commonly used, the safety and effectiveness of curative embolization remain unclear. We conducted a systematic literature review using PubMed, Ovid Medline, and Web of Science to identify studies reporting outcomes in patients with AVMs who underwent primary embolization with the intention to cure. We collected data on patient characteristics, AVM features, complications, and radiographic and clinical outcomes for meta-analysis. We identified 25 studies with a total of 1425 patients with 1427 AVMs who underwent curative embolization. Of these patients, 70% were low grade (pooled = 61% [39-82]), 67% were <3 cm (pooled = 78% [60-92]), and 75% were in superficial locations (pooled = 80% [72-86]). At last radiographic follow-up (mean, 16.7 ± 10.9 months), the full obliteration rate was 52% (pooled = 61% [43-77]) and retreatment rate was 25% (pooled = 17% [8.3-27]). At last clinical follow-up (mean, 24.2 ± 13.3 months), the poor clinical outcome rate was 7.9% (pooled = 4.4% [1.3-8.7]) and symptomatic complication rate was 13% (pooled = 13% [8-19]). There was no significant difference in the rate of radiographic cure, need for retreatment, and poor outcomes between ruptured and unruptured AVMs. Symptomatic complications were more common in the treatment of unruptured AVMs. The primary outcomes showed high heterogeneity (I2 = 72%-94%). Curative embolization of AVM is primarily reserved for small and low-grade AVMs, with highly variable outcomes. Our findings suggest poor radiographic outcomes and increased risk of complications. Outcomes are highly dependent on patient selection and technique used. Large multicenter prospective studies are required to further guide patient selection, categorize clinical and radiographic outcomes, and identify subgroup of patients that may benefit from curative embolization.