De novo cerebral arteriovenous malformation: case report

'De Novo' Brain AVMs-Hypotheses for Development and a Systematic Review of Reported Cases

Background and Objectives: Brain arteriovenous malformations AVMs have been consistently regarded as congenital malformations of the cerebral vasculature. However, recent case reports describing "de novo AVMs" have sparked a growing debate on the nature of these lesions. Materials and Methods: We have performed a systematic review of the literature concerning de novo AVMs utilizing the PubMed and Google Academic databases. Termes used in the search were "AVM," "arteriovenous," "de novo," and "acquired," in all possible combinations. Results: 53 articles including a total of 58 patients harboring allegedly acquired AVMs were identified by researching the literature. Of these, 32 were male (55.17%), and 25 were female (43.10%). Mean age at de novo AVM diagnosis was 27.833 years (standard deviation (SD) of 21.215 years and a 95% confidence interval (CI) of 22.3 to 33.3). Most de novo AVMs were managed via microsurgical resection (20 out of 58, 34.48%), followed by radiosurgery and conservative treatment for 11 patients (18.97%) each, endovascular embolization combined with resection for five patients (8.62%), and embolization alone for three (5.17%), the remaining eight cases (13.79%) having an unspecified therapy. Conclusions: Increasing evidence suggests that some of the AVMs discovered develop some time after birth. We are still a long way from finally elucidating their true nature, though there is reason to believe that they can also appear after birth. Thus, we reason that the de novo AVMs are the result of a 'second hit' of a variable type, such as a previous intracranial hemorrhage or vascular pathology. The congenital or acquired characteristic of AVMs may have a tremendous impact on prognosis, risk of hemorrhage, and short and long-term management.

Review of de novo cerebral arteriovenous malformation: haemorrhage risk, treatment approaches and outcomes

Objective A small number of patients has been reported to develop a completely new or de novo arteriovenous malformation (AVM) after brain surgery, haemorrhage, head trauma or ischaemic stroke. The natural history of these lesions is unknown. In this review, both ruptured and unruptured de novo AVMs and their treatments were reviewed. Methods Published literature in the PubMed database citing 'de novo cerebral arteriovenous malformation' was reviewed. Additional studies were identified through reference searches in each reviewed article. A review was performed using all published cases, the treatment approaches and outcomes. Results A total of 38 patients, including 37 de novo AVMs reported from 1988 to 17 November 2017 and our one patient, was collected. The age at AVM diagnosis was 5-73 years (mean ± SD, 27.6 ± 20.5 years). The duration time, from negative examination to AVM diagnosis, was 2 months to 25 years (mean ± SD, 6.6 ± 4.9 years). The presentation of de novo AVM was headaches in three (7.9%) patients, bleedings in 12 (31.6%), incidental in 14 (36.8%) and seizure in nine (23.7%). The estimated risk of haemorrhage was 4.8% per year. Seventeen (44.7%) patients were treated with surgical resection, 10 (26.3%) were conservatively observed, nine (23.7%) were treated with radiosurgery and two (5.3%) were endovascularly embolised. The morbidity and mortality were reported as 5.3% and 7.9%, respectively. Conclusion Post-natal de novo AVMs have been reported. Their annual haemorrhage risk is 4.8%. Most of them are treated by surgical resection and are associated with morbidity and mortality.

De Novo Arteriovenous Malformation after Aneurysm Clipping

We report a 73-year-old woman with de novo arteriovenous malformations (AVMs) that developed in the ipsilateral parietal lobe after craniotomy and aneurysm clipping. While intracerebral AVMs are considered to be congenital lesions, there have been several reported cases of acquired AVM arising after ischemic or traumatic episodes. We summarize previously reported cases of such acquired 'de novo' AVMs with a discussion of some pathophysiological responses or factors suggested to promote their development.

Progression in size of an arterio-venous malformation

We report a case of a young girl who was admitted with history of sudden onset left hemiplegia, when she was 5 years old. Investigations revealed no vascular malformation or abnormality. On conservative treatment, she progressively improved and had residual hemiparesis. She continued to have intermittent episodes of generalized and focal convulsions. For persistent convulsions, she was investigated again with MRI and angiography after 5 years of first presentation. Investigations at this time revealed a large arteriovenous malformation in the left posterior frontal region. The arteriovenous malformation was resected by surgery. Following surgery, the episodes of convulsions reduced. Arteriovenous malformations are generally considered to be congenital lesions and their size and physical architecture generally remains constant. The presented case clearly demonstrated de novo appearance or growth of the size of the arteriovenous malformation. Such a pattern of development and growth of a arteriovenous malformation is rare and only infrequently reported.

Total temporary occlusion of blood flow for several hours to treat a giant deep arteriovenous malformation: A series of multiple operations to save a young life

Background:

The treatment of giant deep arteriovenous malformations (AVMs) remains challenging.

Case Description:

We report a case of giant deep AVM diagnosed in a 9-year-old girl, for whom the AVM rupture occurred 9 years later. At the age of 9, the girl developed mild left hemiparesis. Magnetic resonance imaging revealed a giant deep AVM. The patient underwent one course of stereotactic radiotherapy followed by serial imaging. At the age of 18, we admitted her to our department with left hemiparesis and a loss of consciousness. Computed tomography showed intracerebral hemorrhage related to AVM. The treatment process proved challenging, with recurrent intracerebral hemorrhages. During the second operation, we used total temporary occlusion for almost 4 hours. Eventually, after 4 rounds of embolizations, 4 microsurgical operations, and a month-and-a-half after admission, AVM was successfully occluded. Five years after this treatment, the patient regained the ability to walk without assistance, although a moderate disability with visual changes remained (Modified Rankin Scale score 3).

Conclusion:

This case illustrates that the cumulative risk of rupture of a high-grade AVM in young patients is evident, while treatment may prove successful with satisfactory results.

Dormant micro arteriovenous malformations lead to recurrent cerebral haemorrhage

Introduction

Some micro arteriovenous malformations (AVMs) located in deep brain are undetectable. How to choose a proper timing to detect these AVMs remains unclear.

Case description

A 21-year-old male patient was admitted to our center for intraventricular haematoma. Digital subtraction angiographies (DSAs) were performed one week and one month respectively after his haemorrhage, but no positive results were obtained. The patient was hospitalized for re-haemorrhage six years later. A micro AVM with two diffused niduses was detected and embolised three months after his re-haemorrhage. The patient recovered without any neurological deficit.

Discussion and evaluation

Compressive effects of haematoma and spontaneous obliteration of AVMs might play pivotal roles in negative DSA results.

Conclusions

Strategic and timely use of DSA could identify some dormant re-haemorrhagic AVMs.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2615-5) contains supplementary material, which is available to authorized users.

De novo arteriovenous malformation in a patient with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant systemic disorder characterized by the enlargement of capillaries, recurrent nosebleeds, and multiple arteriovenous malformations (AVMs). Although cerebral AVMs are traditionally considered to be congenital lesions, some reports have described de novo AVMs, which suggests that the authors believed them to be dynamic conditions. In this article, the authors describe the case of a 5-year-old boy with HHT in whom a de novo cerebral AVM was detected after a negative MRI result at 5 months. To the authors' knowledge, this is the first report of a de novo AVM in a patient with HHT. In patients with a family history of HHT, de novo AVMs are possible, even when no lesions are detected at the first screening. Therefore, regular screenings need to be performed, and the family should be informed that AVMs could still develop despite normal MRI results.

The long-term outcomes of radiosurgery for arteriovenous malformations in pediatric and adolescent populations

OBJECT Although stereotactic radiosurgery (SRS) has been accepted as a therapeutic option for arteriovenous malformations (AVMs) in children and adolescents, substantial data are still lacking regarding the outcomes of SRS for AVMs in this age group, especially long-term complications. This study aimed to clarify the long-term outcomes of SRS for the treatment of AVM in pediatric patients aged ≤ 18 years. METHODS Outcomes of 116 patients who were aged 4-18 years when they underwent SRS between 1990 and 2009 at the study institute were analyzed retrospectively. RESULTS The median follow-up period after SRS was 100 months, with 6 patients followed up for more than 20 years. Actuarial obliteration rates at 3 and 5 years after SRS were 68% and 88%, respectively. Five hemorrhages occurred in 851 patient-years of follow-up. The annual bleeding rate after SRS before obliteration was calculated as 1.3%, which decreased to 0.2% after obliteration. Shorter maximum nidus diameter (p = 0.02) and higher margin dose (p = 0.03) were associated with a higher obliteration rate. Ten patients experienced adverse events after SRS. Of them, 4 patients presented with delayed complications years after SRS (range 9-20 years after SRS). CONCLUSIONS SRS can reduce the risk of hemorrhage in pediatric and adolescent AVMs, with an acceptable risk of complications in the long term. However, adverse events such as expanding hematoma and radiation necrosis that can occur after substantial follow-up should be taken into account at the time that treatment decisions are made and informed consent is obtained.

Symptomatic de novo arteriovenous malformation in an adult: Case report and review of the literature

BACKGROUND

Cerebral arteriovenous malformations (AVMs) have been long thought to be a congenital anomaly of vasculogenesis in which arteries and veins form direct connections forming a vascular nidus without an intervening capillary bed or neural tissue. Scattered case reports have described that AVMs may form de novo suggesting they can become an acquired lesion.

CASE DESCRIPTION

The current case report describes a patient who presented with new-onset seizures with an initial negative magnetic resonance imaging (MRI) of the brain and subsequently developed an AVM on a MRI 9 years later.

CONCLUSION

This case joins a small, but growing body of literature that challenges the notion that all AVMs are congenital.

Development of a de novo arteriovenous malformation after severe traumatic brain injury

Arteriovenous malformations (AVMs) are typically considered congenital lesions, although there is growing evidence for de novo formation of these lesions as well. The authors present the case of an AVM in the same cerebral cortex that had been affected by a severe traumatic brain injury (TBI) more than 6 years earlier. To the best of the authors' knowledge, this is the first report attributing the formation of an AVM directly to TBI.

Are parenchymal AVMs congenital lesions?

A long-held dogma in neurosurgery is that parenchymal arteriovenous malformations (AVMs) are congenital. However, there is no strong evidence supporting this theory. An increasing number of documented cases of de novo formation of parenchymal AVMs cast doubt on their congenital nature and suggest that indeed the majority of these lesions may form after birth. Further evidence suggesting the postnatal development of parenchymal AVMs comes from the exceedingly rare diagnosis of these lesions in utero despite the widespread availability of high-resolution imaging modalities such as ultrasound and fetal MRI. The exact mechanism of AVM formation has yet to be elucidated, but most likely involves genetic susceptibility and environmental triggering factors. In this review, the authors report 2 cases of de novo AVM formation and analyze the evidence suggesting that they represent an acquired condition.

De novo cerebral arteriovenous malformations: is epileptic seizure a potential trigger?

MATERIAL AND METHODS

The pathogenesis of cerebral arteriovenous malformations (cAVMs) is still not well understood. Generally, cAVMs are thought to be congenital lesions originating prenatally. We report a 7-year-old boy diagnosed with a de novo cAVM after 3 years of recurrent epileptic seizures.

RESULTS

MR imaging at 4 years of age was normal. Follow-up MR imaging 3 years later demonstrated a de novo 2-cm cAVM in the right occipital lobe, confirmed by conventional angiography. We reviewed five previously reported cases of de novo cAVMs who did not have a previous neurovascular abnormality. Including our case, recurrent epileptic seizures are the major presentation (83.3 %) before de novo cAVM occurrence.

CONCLUSION

We suggest that epileptic seizure is a potential trigger of de novo cAVMs.

Notch1 and 4 signaling responds to an increasing vascular wall shear stress in a rat model of arteriovenous malformations

Notch signaling is suggested to promote the development and maintenance of cerebral arteriovenous malformations (AVMs), and an increasing wall shear stress (WSS) contributes to AVM rupture. Little is known about whether WSS impacts Notch signaling, which is important for understanding the angiogenesis of AVMs. WSS was measured in arteriovenous fistulas (AVF) surgically created in 96 rats at different time points over a period of 84 days. The expression of Notch receptors 1 and 4 and their ligands, Delta1 and 4, Jagged1, and Notch downstream gene target Hes1 was quantified in “nidus” vessels. The interaction events between Notch receptors and their ligands were quantified using proximity ligation assay. There was a positive correlation between WSS and time (r = 0.97; P < 0.001). The expression of Notch receptors and their ligands was upregulated following AVF formation. There was a positive correlation between time and the number of interactions between Notch receptors and their ligands aftre AVF formation (r = 0.62, P < 0.05) and a positive correlation between WSS and the number of interactions between Notch receptors and their ligands (r = 0.87, P < 0.005). In conclusion, an increasing WSS may contribute to the angiogenesis of AVMs by activation of Notch signaling.

De novo cerebral arteriovenous malformation in a child with previous cavernous malformation and developmental venous anomaly

Although cerebral vascular malformations are traditionally considered to be congenital lesions, they often become clinically evident in the 3rd to 4th decades of life, leading to the assumption of a long silent clinical period. Unlike vein of Galen malformations, antenatal diagnosis of cerebral arteriovenous malformations (AVMs) is highly uncommon. Postnatal development of an AVM is an emergent concept supported by more clinical observations. Genetic and biological studies demonstrate that an environmental trigger ("second hit") in addition to genetic predisposition may be a key in understanding the pathophysiology of AVMs and other cerebral vascular lesions such as cavernous malformations (CMs). The authors describe a 6-year-old boy in whom a giant CM was diagnosed and a de novo AVM was detected 25 months after initial resection of the CM. This case seems to support the second-hit hypothesis.

De novo arteriovenous malformations: case report and review of the literature

Intracerebral arteriovenous malformations (AVMs) are traditionally recognized as congenital lesions. However, with the advent of frequent, noninvasive imaging of the brain, that notion has been challenged. We describe another patient with a de novo cerebral arteriovenous malformation and evaluate the reported literature for trends in the development of these lesions. Cases were selected from the English literature using the PUBMED database using the search term "acquired or de novo cerebrovascular arteriovenous malformations". A total of seven patients (including the one reported in this study) with de novo arteriovenous malformations are reported. Majority of patients were female, and mostly diagnosed as children. Their mean age at diagnosis was 18 years (6-32), and the mean time from the initial intracranial study to the diagnosis of an AVM was 8 years (3-17). De novo formation of AVMs is being increasingly reported, especially in young females. We present only the seventh such case reported in the literature and challenge the traditional view that all arteriovenous malformations are congenital in nature.

Pathogenesis and radiobiology of brain arteriovenous malformations: implications for risk stratification in natural history and posttreatment course

Brain arteriovenous malformations (BAVMs) are an important cause of intracerebral hemorrhage (ICH) in young adults. Biological predictors of future ICH risk are lacking, and controversy exists over previous studies of natural history risk among predominantly ruptured BAVM cohorts. Recent studies have suggested that the majority of BAVMs are now diagnosed as unruptured lesions, and that the risk according to natural history among these lesions may be less than previously assumed. In the first part of this review, the authors discuss available data on the natural history of BAVMs and highlight the need for future studies that aim to develop surrogate biomarkers of disease progression that accurately predict future risk of ICH in BAVMs. The etiology of BAVM remains unknown. Recent studies have suggested a role for genetic factors in the pathogenesis of sporadic BAVM, which is further supported by reports of familial occurrence of BAVM and association with known systemic genetic disorders (such as Osler-Weber-Rendu disease, Sturge-Weber disease, and Wyburn-Mason syndrome). Molecular characterization of BAVM tissue demonstrates a highly angiogenic milieu with evidence of increased endothelial cell turnover. Taken together with a number of reports of de novo BAVM formation, radiographic growth after initial BAVM diagnosis, and regrowth after successful treatment of BAVM, these findings challenge the long-held assumption that BAVMs are static lesions of congenital origin. In the second part of this review, the authors discuss available data on the origins of BAVM and offer insights into future investigations into genetics and endothelial progenitor cell involvement in the pathogenesis of BAVM. Current treatment options for BAVM focus on removal or obliteration of the lesion in an attempt to protect against future ICH risk, including microsurgical resection, endovascular embolization, and stereotactic radiosurgery (SRS). In the third part of this review, the authors discuss available data on SRS in BAVMs and highlight the need for future studies on the radiobiology of BAVMs, especially in regard to biomarker detection for tracking SRS response during the latency period. Insights from future investigations in BAVM may not only prove important for the development of novel therapies and relevant biomarkers for BAVM, but could also potentially benefit a variety of other disorders involving new vessel formation in the CNS, including stroke, tumors, moyamoya disease, and other cerebrovascular malformations.

De novo formation of large arteriovenous shunting and a vascular nidus mimicking an arteriovenous malformation within an anaplastic oligodendroglioma: treatment with embolization and resection

The authors report the de novo occurrence and treatment of an arteriovenous lesion within an anaplastic oligodendroglioma in a patient with previously unremarkable brain imaging. Intracranial arteriovenous malformations (AVMs) are believed to be congenitally acquired lesions, and their association with brain neoplasms is extremely rare. Diagnostic imaging revealed a mass lesion with large arteriovenous shunts and a vascular nidus mimicking a true AVM. Histological and immunohistochemical testing showed an anaplastic oligodendroglioma mixed with an AVM. The clinical, radiological, and operative data are reviewed, as are the histopathological findings. To the authors' knowledge this is the first case of de novo occurrence of an arteriovenous lesion with large shunts and a vascular nidus within an anaplastic oligodendroglioma.

De novo cerebral arteriovenous malformation: case report and literature review

We describe a rare case of a de novo cerebral arteriovenous malformation (AVM) in a 9-year-old girl. MR imaging at 6 years of age demonstrated band heterotopia. Follow-up MR imaging 3 years later demonstrated a new 3.5-cm AVM in the left parietol-occipital region, confirmed by conventional angiography. This report, along with limited previous reports, suggests that AVMs can be acquired lesions and that AVM development is a dynamic process extending into the postnatal period.

Growth and regression of arteriovenous malformations in a patient with hereditary hemorrhagic telangiectasia. Case report

Data on the growth, regression, and de novo formation of arteriovenous malformations (AVMs) suggest that some of these lesions are not formed and developed only during embryogenesis. Patients with hereditary hemorrhagic telangiectasia (HHT) have a genetic propensity to form AVMs. The authors report on the growth and regression of AVMs in a single patient with HHT. This 26-day-old boy with a family history of HHT1 and a mutation in ENG on chromosome 9 presented with a generalized seizure. Results of computed tomography revealed a left frontoparietal intraparenchymal hemorrhage. Cerebral angiography revealed multiple AVMs. Follow-up angiograms obtained 5 months later showed both growth and regression of the AVMs. A craniotomy was performed for complete resection of the left parietal AVM. Histopathological features of the surgical specimen were examined. Active angiogenesis, as indicated by increased endothelial proliferation, might be a part of the underlying pathophysiology of the growth and regression of AVMs.

Nestin expression in vascular malformations: a novel marker for proliferative endothelium

Cavernous angiomas (CAs) and arteriovenous malformations (AVMs) sometimes show growth or de novo appearance. Proliferative capacity of the endothelium is evident in such malformations. Intermediate filament nestin is a newly identified marker for proliferative endothelium, which was originally detected in the neuroepithelial stem cells of the embryonal central nervous system. Immunohistochemical analysis of nestin was evaluated as a marker for proliferative capacity of endothelial cells by comparison with proliferating cell nuclear antigen (PCNA). Sixteen of 27 CAs and 13 of 20 AVMs were positive for nestin. Likewise, 12 of 27 CAs and 10 of 20 AVMs were positive for PCNA. Nestin staining was stronger in the typical malformative vessels of CAs than in AVMs, in both the endothelial cells and the interstitial cells. Newly formed endothelial cells expressed nestin strongly in the reactive tissues including organizing or encapsulated hematomas. These results suggest that neovascularization occurs in the process of repeated bleeding and remodeling of hematomas.

Vascular Endothelial Growth Factor Plasma Levels Are Significantly Elevated in Patients with Cerebral Arteriovenous Malformations

BACKGROUND

Since growth and de novo generation of cerebrovascular malformations were demonstrated, a strictly congenital model cannot be further supported as unique factor in the pathogenesis of cerebral arteriovenous malformations (AVMs). Vascular endothelial growth factor (VEGF) has previously been demonstrated to be highly expressed in AVMs by immunohistochemical methods. However, systemic VEGF levels have not been analysed previously. This study aimed to investigate VEGF plasma concentrations as a possible plasma marker for neovascularization in patients with cerebral AVMs compared to healthy controls.

METHODS

The study included 17 patients with cerebral AVMs and 40 healthy controls. VEGF plasma concentrations were measured by a specific enzyme immuno-assay.

RESULTS

VEGF plasma concentrations were significantly higher in patients with cerebral AVMs (mean 140.9 pg/ml, SD 148.5 pg/ml and median 63.0 pg/ml) compared to a healthy control group (mean 44.7 pg/ml, SD 36.4 pg/ml and median 35.0 pg/ml), p = 0.0003.

CONCLUSIONS

Our findings suggest that VEGF plasma concentrations might play a role in the pathogenesis of cerebral AVMs. Further studies are necessary and would contribute to an improved understanding of the pathogenesis of cerebral AVMs.