Natural History Of Arteriovenous Malformations Research Articles

Transarterial AVM embolization using Tsinghua grading system: Patient selection and complete obliteration

ObjectiveEndovascular embolization has an important role in the management of brain arteriovenous malformations (AVMs). A Tsinghua AVM grading system has been proposed for patient selection and complete obliteration. The authors sought to validate this system in an independent patient cohort and compare it to the Buffalo grading system. MethodsConsecutive 52 patients underwent endovascular AVM embolization between January 2019 and December 2021 according to Tsinghua AVM grading system. Each AVM was also graded using Buffalo grading system. Baseline clinical characteristics, complications, and AVM obliteration were compared between Tsinghua and Buffalo scales. ResultsComplete obliteration of AVM was obtained in 29 patients (55.8%). Three complications were encountered, one bleeding (1.9%) and 2 ischemic (3.8%), in 3(5.7%) patients who recovered completely at follow-up. The Tsinghua scale (p=0.017) was predictor of complete obliteration as well as Buffalo scale (p=0.002) on ROC curve analysis and their AUCs were not significantly different (p=0.672). The Tsinghua scale was also associated with the initial patient status (p=0.003) and injected Onyx volume (p=0.003) on linear regression test. Because of the low complication rate, neither the Tsinghua scale nor the Buffalo scale predicted complication risk related to AVM embolization. ConclusionsThe bleeding complication rate of 1.9% is within the range of rupture risk reported in the natural history of AVMs. In addition to predicting complete AVM obliteration as well as Buffalo scale, the Tsinghua scale can also predict the patients' status and the volume of Onyx avoid over injection. Key messagesThe Tsinghua grading system for endovascular AVM embolization will guide patient selection of AVM embolization.

A comparison of incidental and symptomatic unruptured brain arteriovenous malformations in children.

Patients with unruptured brain arteriovenous malformations (AVMs) may present with headaches, seizures, and/or neurological deficits. A smaller number of cases may be discovered incidentally. These lesions remain incompletely understood due to their sparse reporting. Herein, the authors describe the largest series to date comparing the presentation, angioarchitecture, and management of incidental versus symptomatic unruptured AVMs in children. The authors performed a retrospective analysis of patients who presented with brain AVMs from 1998 to 2022 at the University of California, San Francisco. Inclusion criteria were age ≤ 18 years at the time of presentation and an angiographically proven unruptured AVM that had been diagnosed postnatally. Of 76 children with unruptured AVMs, 66 (86.8%) presented with headaches, seizures, and/or neurological deficit. Ten AVMs (13.1%) were incidentally discovered through unrelated disease workup (50%), cranial trauma (40%), or research study participation (10%). Compared with patients with symptomatic unruptured AVMs, patients with incidental unruptured AVMs had a smaller mean ± SD maximum nidus diameter (2.82 ± 1.1 vs 3.98 ± 1.52 cm, p = 0.025) and fewer had deep venous drainage (20% of patients vs 61%, p = 0.036). They also presented at an earlier age (10 ± 5.2 vs 13.5 ± 4 years, p = 0.043) and with longer duration to first treatment (541 ± 922 vs 196 ± 448 days, p = 0.005). During the observation period, 1 patient developed recurring headaches and demonstrated AVM nidus growth. Four AVMs greater than 3 cm in size or in a deep location were treated with radiosurgery. Six other AVMs were treated with resection, with 2 receiving preoperative embolization. Eight AVMs (80%) were obliterated on last follow-up. Postprocedural complications included 2 transient neurological deficits after resection and 1 case of delayed seizure development after radiosurgery. The mean follow-up period was 5.7 ± 5.7 years without any hemorrhage episodes. A substantial proportion of pediatric patients with unruptured AVMs are discovered incidentally. With earlier presentation and more elementary angioarchitecture than symptomatic unruptured AVMs, these incidental lesions provide a snapshot into the natural history of AVM before symptom development or rupture.

Microsurgical resection of high-flow cerebral arteriovenous malformations after recurrent stroke

Arteriovenous malformations (AVMs) are tangled lesions that may digress the blood flow particularly the high flow ones and microsurgical resection is challenging. The natural history of AVM is not completely understood and its management is controversial. Microsurgical resection of cerebral arteriovenous malformation is a challenging procedure, particularly for high-flow type. Embolization, microsurgery, or radiotherapy are treatment options. Preoperative planning to control the feeders, arachnoid dissection around the AVM for identification and control of all arterial feeders around the AVM surfaces, lastly control of draining vein is the principal of microsurgery. The goal of surgery is to remove the AVM completely to eliminate the risk of bleeding avoiding neurological deterioration. In this paper, we reviewed a case of high-flow cerebral AVM in recurrent bleeding with successful microsurgical resection.The patient in this case report significantly improved his neurological condition and demonstrated a good quality of life during long-term follow-up. The results of this study showed that the microsurgical removal of AVMs represents an efficient treatment with good clinical outcomes. In the future, more investigations of the factors that lead to AVM rupture are required for the advancement of effective medical procedures.

Contrast enhancement of vascular walls of intracranial high flow malformations in black blood MRI indicates high inflammatory activity

BackgroundThere are controversies concerning the natural history of arteriovenous malformations (AVMs) in literature and it is not clear which AVMs should be treated and which should be just observed. Objective criteria beyond growth in serial MRIs or angiographies are needed. The use of black blood MRI is currently under investigation for evaluating the rupture risk of cerebral aneurysms, however its use for assessment of AVMs has yet to be evaluated. We therefore conducted a feasibility study on the application of black blood MRI (bbMRI) in AVMs to assess rupture risk.MethodsRetrospective study of 10 patients with intracranial AVMs and 4 patients with arteriovenous fistulas who received a black blood MRI before treatment.ResultsAVM niduses (9/10) show contrast enhancement irrespective of rupture or size. All arteriovenous fistulas (4 / 4) were contrast enhancing irrespective of rupture.ConclusionHigh flow malformations are in a permanent stage of inflammation which does not seem to allow conclusions on their rupture risk at the current stage. BbMRI is a feasible method of identifying inflammation in AVMs and arteriovenous fistulas. However, future prospective studies are needed to evaluate whether bbMRI contrast enhancement correlates with rupture risk.

The Natural History of Brain Arteriovenous Malformations

AbstractBrain arteriovenous malformations (AVMs) are relatively rare lesions with irreversible consequences in the context of hemorrhage. They are characterized by direct connections between arteries and veins without an intervening capillary network. The natural history of brain AVMs is controversial in the literature, with low evidence level gathered in the papers published, and with large divergence of results among them. A detailed understanding of the natural history is critical for treatment decision. The risk of development of deleterious outcomes such as hemorrhage or brain infarction should always be considered when submitting a patient to the risks of treatment. Several factors related to the patient and to the AVMs are determinants in the natural history of this disease. The topography, size, morphology and angioarchitecture of AVMs determine the risk of rupture. Large AVMs, those located in the posterior fossa and with deep venous drainage, have higher risk of rupture. Due to divergence in the literature regarding the natural history of AVMs, the choice of treatment should also consider experiences acquired over the years from reference centers with a high number of AVMs treated per year. We determined 7 variables that should be considered during the decision to treat an AVM: 1) previous hemorrhage; 2) aneurysm associated to the AVM; 3) direct arteriovenous fistula; 4) factors related to the nidus; 5) age and habits (smoking, sedentary lifestyle, diet quality); 6) the functional performance of the patient; 7) psychological factors.

Chapter 2 - The natural history of cerebral arteriovenous malformations

Cerebral arteriovenous malformations (AVMs) are composed of a complex tangle of abnormal arteries and veins and are a significant source of cerebral hemorrhage and consequent morbidity and mortality in young adults, representing a diagnostic and therapeutic challenge. Current natural-history studies of cerebral AVMs report overall annual rates of 1% and 3% for the risk of epilepsy and hemorrhage, respectively. Unruptured AVMs have an annual hemorrhage rate of 2.2% while ruptured lesions have an annual hemorrhage rate of 4.5%. These hemorrhage rates are can change over time, particularly for hemorrhagic lesions, with the rebleed rate ranging from 6% to 15.8% in the first year after rupture across several studies. Besides hemorrhage, other significant risk factors for AVM hemorrhage include deep location, deep venous drainage, associated aneurysms, and pregnancy. Other factors include patient age, sex, and small AVM size, which are not currently considered significant risk factors for AVM hemorrhage. In addition to hemorrhage risk and seizure risk, the natural history of an AVM also encompasses the daily psychologic burden that a patient must endure knowing that he or she possesses an untreated AVM. This chapter reviews the epidemiology, clinical features, and natural history of cerebral AVMs.

Long-term hemorrhagic risk in pediatric patients with arteriovenous malformations.

OBJECTIVE Compared with the general population, the specific natural history of arteriovenous malformations (AVMs) in pediatric patients is less well understood. Furthermore, few pediatric studies have compared posttreatment hemorrhagic risk and functional outcome across different treatment modalities. The objective of this study was to elucidate these points. METHODS The authors retrospectively reviewed all pediatric patients with AVMs evaluated at their institution between 1990 and 2013. The AVM natural history was represented by hemorrhagic risk during the observation period. For treated patients, the observation period was defined as the interval between diagnosis and treatment. Posttreatment hemorrhagic risk and functional outcomes were also assessed. RESULTS A total of 124 pediatric patients with AVMs were evaluated, and 90 patients (72.6%) were retained through follow-up. The average patient age was 13.3 ± 3.8 years, with a mean follow-up period of 9.95 years. The overall AVM obliteration rate was 59.7%. Radiosurgery had an obliteration rate of 49.0%. Thirteen patients were managed conservatively. Four patients under observation hemorrhaged during a total interval of 429.4 patient-years, translating to an annual risk of 0.9%. Posttreatment hemorrhagic risk by treatment modalities were categorized as follows: surgery ± embolization (0.0%), radiosurgery ± embolization (0.8%), embolization alone (2.8%), surgery + radiosurgery ± embolization (3.5%), and observation (0.8%). A significantly higher risk of posttreatment hemorrhage was observed for patients with hemorrhagic presentation (p = 0.043) in multivariate analysis. Seizure presentation, frontal lobe location, nonheadache presentation, and treatment modality were significantly associated with increased risk of poor functional outcomes. CONCLUSIONS In this study of pediatric patients with AVMs, the natural history of hemorrhage was relatively low at 0.9%. Resection remained the optimal management for hemorrhage control and functional outcome perseverance in these pediatric patients with AVMs. AVM obliteration is a valid treatment goal, especially for patients with ruptured presentation, to prevent further hemorrhages later in life.

Demographic distribution of hospital admissions for brain arteriovenous malformations in Germany--estimation of the natural course with the big-data approach.

Estimation of the natural history of arteriovenous malformations based on short-term observation is potentially biased by multiple factors. Retrieval of demographic information of all AVM patients of national data pools and comparison with the national demographic profile might be another way to approach the natural history. Upon request, the German Federal Statistical Office provided the numbers of patients admitted in Germany from 2009 through 2013 with ICD Q28.2 (brain AVM) as primary discharge diagnosis, and the corresponding age distribution. Age-related admission rates of AVM were calculated by comparison with the German demographic distribution. A total of 6527 patients were hospitalized from 2009-2013 with brain AVM (Q28.2) as the principal diagnosis. Age-specific admission rate during the first year of life was high with 19.0/100,000 during the 5-year study period, corresponding to a yearly admission rate of 3.8 per 100,000 babies. Apart from the high admission rate during the first year of life, the admission rate was low, but steadily increasing during first decades of life reaching a plateau with 11.1/100,000 in the age group 30-34 years, corresponding to an annual admission rate of 2.2/100,000. After the age of 30-34 years, admission rates decreased continuously, reaching 0 in the age group 90-95 years. The lifetime risk of admission in terms of admission per 100,000 age-matched people was calculated by retrograde integration of the admission rates. At the age of 1 year, the cumulative number offuture admissions for AVM during lifetime amounted to 131.3/100,000 children. For the older age groups, the chance of future admission for AVM decreased as expected, reaching 43.8/100,000 by the age of 50 and 0 by the age of 90. Despite some open issues, the current data suggests that achieving old age with an untreated brain AVM is unlikely. Furthermore, the data support the concept that most brain AVMs are not necessarily a congenital entity but develop during the first decades of life.

Management of Arteriovenous Malformations Related to Spetzler-Martin Grading System

Advanced technology and improved understanding of the natural history of arteriovenous malformations (AVMs) led to the reconsideration of the management of these lesions, which once comprised purely microsurgical removal. A multidisciplinary approach for both the evaluation and treatment of AVMs has gained acceptance within the past few decades. Treatment options for AVMs include surgical resection, embolization, or stereotactic radiosurgery, or any combination of these procedures. The risk of a chosen management strategy must include the sum of the risk of all the interventions applied to a given lesion, and this should be compared with the natural history of a given lesion in a particular clinical setting. Among all components of the multimodality treatment, however, microsurgical removal remains the definitive form of treatment.

Natural History of Arteriovenous Malformations

Objective 1) To demonstrate the natural history of arteriovenous malformation (AVMs) when left untreated or inadequately managed. 2) To demonstrate the need for major treatment to patients, families, healthcare providers, and insurance companies. Methods Records from 10 of 50 representative patients treated at University of Arkansas for Medical Sciences (UAMS) for advanced AVMs were reviewed for age at presentation, gender, presenting symptoms, previous treatment, disease course, and post-presentation management. Patients were asked if quality of life had improved after treatment at UAMS Facial photos from childhood were obtained and compared with photos taken at time of presentation. Results 10 patients (7 male, 3 female, range 21–46 years) received treatment. All patients presented with bleeding, pain and/or facial destruction. 6 of 10 patients received previous embolization. No patients had undergone previous surgical resection. All were informed by a previous physician that the disease was incurable or treatment options had been exhausted. All patients experienced subsequent worsening of symptoMS All patients were treated at UAMS with preoperative embolization followed by surgical resection and required multiple surgeries to remove persistent AVM. All patients indicated quality of life improved after embolization/surgical resection. Comparison of photos revealed progression of disease in all cases marked by facial destruction and deformity. Conclusions AVMs display a progressive and destructive nature when left untreated or inadequately managed. Natural history can be used to demonstrate to patients, families, and healthcare providers the seriousness of disease and convince insurance companies that radical treatment is typically necessary to obtain control or cure.

Treatment of multiple arteriovenous malformations in pediatric patients with hereditary hemorrhagic telangiectasia and spontaneous hemorrhage

Due to inheritance of an autosomal dominant genetic mutation, patients with hereditary hemorrhagic telangiectasia (HTT) have an increased risk of harboring a cerebral arteriovenous malformation (AVM). They are also significantly more likely to have multiple AVMs. The natural history of AVMs in patients with HHT as well as their rate of hemorrhage is not clearly defined. Furthermore, spontaneous regression of such lesions has been reported. Treatment of cerebral AVMs in patients with HHT presents a particular challenge, especially with detection of incidental lesions following screening of asymptomatic patients. The management of HHT in two pediatric patients in whom hemorrhaging from a cerebral AVM occurred but who also had other lesions is presented here. Both patients were treated with stereotactic radiosurgery.

De novo presentation of an arteriovenous malformation

The authors report the case of a patient with a de novo arteriovenous malformation (AVM), indicating that the origin of these lesions may not always be congenital. A 3-year-old girl who was struck by a car suffered a mild head injury and experienced posttraumatic epilepsy. The initial magnetic resonance (MR) image obtained in this child revealed only a small contusion in the left frontal lobe. Intractable epilepsy subsequently developed. A second MR image obtained almost 4 years after the injury demonstrated an AVM in the right posterior temporal lobe that was verified using angiography. The lesion was classified as a Spetzler-Martin Grade III AVM. The patient underwent embolization of the feeding vessels followed by gamma knife surgery. Fourteen months after treatment she was asymptomatic. Follow-up MR images demonstrate no evidence of an AVM and no changes in the white matter. This case presents a de novo AVM that developed within approximately 4 years. The findings indicate that AVMs may not always be congenital and reinforce the concept that the natural history of AVMs is dynamic. Lesions may appear de novo, grow, and thrombose spontaneously.

Natural history of arteriovenous malformations: analysis of non-radically treated patients

The natural history of cerebral arteriovenous malformations (AVMs) was studied in 115 patients with untreated or incompletely obliterated AVM. Sixty-six patients had histories of hemorrhage, 20 had seizures, 18 had progressive ischemic neurologic deficits and 8 had headache. Three patients had no symptoms attributable to the AVM. Twenty-seven (23%) AVMs rebled or newly bled and the cumulative bleeding or rebleeding rate was 72.5% (4.2% per year). The cumulative bleeding rate of the neurologic deficit group, however, was significantly lower than the cumulative rebleeding rate of the hemorrhagic group ( P < 0.05) and that of the seizure group ( P < 0.05). No significant differences were found in regard to the initial clinical manifestations. The cumulative survival rate was 84% and the average mortality rate was 1.4% per year. Fifty patients (43%) were below 90 in Karnofsky's Index at the end of the follow-up period and the average morbidity rate was 6.0% per year.

Decision analysis: a tool of the future: an application to unruptured arteriovenous malformations.

Overwhelming and confusing data regarding the natural history of arteriovenous malformations can confound physicians attempting to advise patients whether surgery of unruptured arteriovenous malformations is indicated. Decision analysis is a new mathematical tool that allows physicians to compare options in such patients. With the use of a simple office computer, a software program was devised to compare surgical versus conservative options in a hypothetical 25-year-old man. The computer model weighs the important considerations of patient age, mortality and morbidity rates of the physician performing the surgery, rebleeding from the arteriovenous malformation, and patient desires, using the Markov process. When mortality and morbidity rates are reasonable, the mathematical process supports surgical intervention in the hypothetical patient. Patient guidelines for older patients and future plans for the model using grading systems are discussed.

Stereotactic Neutron Radiosurgery for Arteriovenous Malformations of the Brain

A technique employing single fraction neutron radiosurgery for treatment of intracranial vascular malformations has been developed at the University of Washington and is described in this report. The natural history of arteriovenous malformations of the brain is briefly reviewed, along with currently available therapeutic methods for treatment of these lesions. The characteristics of the neutron beam used for radiosurgery are described, along with methods for patient immobilization, radiation treatment planning, dosimetry, and delivery of treatment using this technique.

Appearance of an independent second arteriovenous malformation 3 years after subtotal resection of a first malformation

Cerebral arteriovenous malformations are thought to be congenital lesions consisting of artery-to-vein communications without an intervening capillary bed. They have been shown both to increase and to decrease in size and even to disappear spontaneously. We present a case of angiographic appearance of an independent right Sylvian fissure arteriovenous malformation 3 years after an incomplete resection of a separate right parietal arterio-venous malformation. Both arteriovenous malformations were subsequently totally resected. We propose that alterations in blood flow after manipulation of the first arteriovenous malformation produced conditions favoring enlargement of a previously unseen cryptic arteriovenous malformation. The appearance of a second arteriovenous malformation in the same patient is unique. Theories of origin and the natural history of arteriovenous malformations are discussed.