Spontaneous Thrombosis of a Ruptured Brain Arteriovenous Malformation: The Argument for Early Conservative Management

Long-term surveillance in an infant with spontaneous obliteration of pial arteriovenous malformation and large intranidal aneurysm: A unique case observation

Background

Spontaneous obliteration of untreated cerebral arteriovenous malformations (AVMs) is rare, occurring in <1% of cases, and is even less common in pediatric populations. The mechanisms driving spontaneous regression of brain AVMs remain poorly understood, and long-term surveillance in pediatric patients is infrequently documented.

Case Description

The authors reported a remarkably rare instance of spontaneous thrombosis in a pial AVM accompanied by a large intranidal aneurysm in a 10-month-old infant, initially presenting with a nocturnal seizure. Diagnostic imaging revealed a ruptured intranidal aneurysm causing acute hemorrhage in the left anterior interhemispheric subdural space, extending into adjacent areas. Further, magnetic resonance imaging (MRI) and magnetic resonance angiography delineated the AVM in the left superior frontal gyrus, associated with a thrombosed aneurysm and surrounding edema. Cerebral angiography confirmed the AVM's origin from the left anterior cerebral artery, displaying early venous drainage and small, indirect feeders not amenable to endovascular treatment. Over time, serial imaging showed the aneurysm's transition from partial to complete thrombosis. Subsequent MRIs and angiographic assessments up to age 10 confirmed complete resolution of the AVM and aneurysm, with focal hyperemia persisted until age 16, when recurrent AVM was identified.

Conclusion

We document a rare spontaneous regression of a pial AVM with an intranidal aneurysm influenced by specific vascular factors. Despite this, spontaneous thrombosis should not replace vigilant long-term monitoring in pediatric neurovascular care.

A case of spontaneous brain arteriovenous malformation occlusion: Imaging analysis and clinical debate

The spontaneous occlusion of brain arteriovenous malformations (bAVMs) is a rare event, particularly for unruptured ones. Associated factors include single-venous drainage and small nidus size. Most of the previously reported cases were ruptured bAVMs. We report the case of a middle-aged male patient with an unruptured, rolandic, left-sided bAVM associated with a 30-year history of refractory epilepsy. We documented the spontaneous thrombosis of the venous drainage of the AVM without any sign of bleeding. Finally, we underline the difference between ruptured-induced occlusion and truly spontaneous thrombosis of the bAVMs.

Bleeding pediatric AVM with negative pre-operative angiography: the first case report

INTRODUCTION

Pediatric arteriovenous malformation (pAVM) is one of the most common vascular entities in non-traumatic intracerebral hemorrhage (ICH) in children. To diagnose arteriovenous malformation (AVM), digital subtraction angiography (DSA) is the gold standard investigation because it can provide sufficient dynamic information about the AVM. In extremely rare occasions, angiography is unable to detect an AVM because the AVM is spontaneously occluded. All reported cases found by authors in the literature had already been diagnosed with AVM by angiography or other vascular studies before the AVM occlusion.

CASE PRESENTATION

We present a case of a 4-year-old girl who presented with left occipital ICH with atypical calcification. Based on history and investigation, pAVM was the most likely diagnosis. However, preoperative angiography was negative for pAVM and for shunting. Bleeding tumor was then suspected instead. After resection, pathological diagnosis confirmed pAVM.

CONCLUSION

Our case demonstrates that DSA, despite being considered the gold standard, cannot always diagnose pAVM. The mechanism of spontaneous AVM occlusion remains unknown.

Incidence of Spontaneous Obliteration in Untreated Brain Arteriovenous Malformations

BACKGROUND

Spontaneous obliteration (SpO) of untreated arteriovenous malformations (AVMs) is rare with fewer than 100 cases reported. The incidence and predisposing factors of SpO remain unclear, impeding our understanding of lesion progression in untreated patients.

OBJECTIVE

To determine the incidence rate and predisposing factors of SpO in a North American cohort.

METHODS

AVMs were retrospectively evaluated at our institution for over 25 yr. Untreated AVMs were divided into 2 groups: SpO-AVMs and non-SpO-AVMs. All statistical results were based on univariate analyses. Incidence was generated from counts of SpO over the untreated interval in patient years from birth until obliteration, treatment, or last follow-up.

RESULTS

One hundred fifty-four patients had untreated AVMs; SpO was observed in 4. Average ages were 49.0 ± 23.6 and 48.7 ± 20.4 yr in the SpO-AVM and non-SpO-AVM group, respectively (P = .98). Average AVM sizes were 2.0 ± 1.8 cm (SpO-AVMs) and 3.7 ± 2.6 cm (non-SpO-AVMs, P = .25). All SpO-AVMs and 40 (27.0%) non-SpO-AVMs had a ruptured presentation (P = .006). A single draining vein was observed in all SpO-AVMs and 39 (32.8%) non-SpO-AVMs (P = .01). Deep venous drainage was not observed in any SpO-AVMs, but in 81 (57.9%) non-SpO-AVMs (P = .04). Mean follow-up time was 37.0 ± 42.6 and 75.6 ± 161.7 mo in SpO-AVM and non-SpO-AVMs patients, respectively. Of the 2 SpO-AVM patients with postobliteration follow-up, 1 experienced recanalization. From a 672-patient cohort, the incidence of SpO over 28 961 patient years was 0.014%.

CONCLUSION

SpO-AVMs have an annual incidence rate of approximately 0.014% and tend to present with rupture, a single draining vein, and superficial venous drainage. Expectation of SpO for untreated AVMs is not justified, and patients should anticipate life-long hemorrhagic risk for untreated AVMs.

Linking Brain Arteriovenous Malformations With Anorectal Hemorrhoids: A Clinical and Anatomical Review

Patients who harbor brain arteriovenous malformations are at risk for intracranial hemorrhage. These malformations are often seen in inherited vascular diseases such as hereditary hemorrhagic telangiectasia. However, malformations within the brain also sporadically occur without a hereditary-coding component. Here, we review recent insights into the pathophysiology of arteriovenous malformations, in particular, certain signaling pathways that might underlie endothelial cell pathology. To better interpret the origins, determinants and consequences of brain arteriovenous malformations, we present a clinical case to illustrate the phenotypic landscape of the disease. We also propose that brain arteriovenous malformations might share certain signaling dimensions with those of anorectal hemorrhoids. This working hypothesis provides casual anchors from which to understand vascular diseases characterized by arteriovenous lesions with a hemorrhagic- or bleeding-risk component. Anat Rec, 2017. © The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists. Anat Rec, 300:1973-1980, 2017. © 2017 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

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.