Safety and efficacy using a detachable tip microcatheter in the embolization of pediatric arteriovenous malformations

Purpose

The treatment of deep-seeded pediatric brain arteriovenous malformations (AVMs) remains a challenging task. We describe our experience using a new detachable tip microcatheter in the embolization of brain arteriovenous malformations, pial arteriovenous fistulas, and vein of Galen malformations. We describe the safety and efficacy using a new detachable tip microcatheter in the treatment of pediatric deep brain arteriovenous malformations, pial malformations, and vein of Galen malformations.

Methods

During a period of 9 months from March 2013 through January 2014, 11 pediatric patients in 14 procedures with 27 total injections were selected for treatment with a detachable tip under Food and Drug Administration (FDA) compassionate use exemption and were admitted to our department for treatment of their brain AVM using a liquid embolic agent and a detachable tip microcatheter. The ages of the patients ranged from 3 months to 18 years old.

Results

Of the 27 total injections done, the tip detached in seven cases. For the 16 n-BCA injections, the tip detached six times (37.5 %), and for the 11 Onyx injections, the tip detached one time (9 %). There were no cases of premature microcatheter detachment during normal vessel navigation.

Conclusions

The introduction of these detachable tip microcatheters allows for a safe and relaxed injection that permits a true circumferential occlusion, and may further permit filling a larger amount of angioarchitecture without the risk of distal migration, or vessel damage during the usual rapid removal of non detachable micocatheters.     

Clinical features and endovascular treatment of intracranial arteriovenous malformations in pediatric patients

Purpose

The purpose of this study was to characterize clinical features and evaluate the clinical outcome of endovascular embolization treatment intracranial arteriovenous malformations in pediatric patients.

Methods

A cohort of children (age?≤?18 years) with arteriovenous malformations (AVMs) from 2000 to 2012 was included. Predictors studied included patient gender, age, and angioarchitectural features, including AVM location, nidus morphology and size, venous drainage, and associated aneurysms. Treatment method, complications and outcomes were recorded. The features of AVMs were evaluated before the treatment.

Results

One hundred twenty-seven children (77 males, mean age 13.2 years) were included; 90/127 (70.9 %) children were presented with hemorrhage. AVM size and deep venous drainage were independently associated with hemorrhage; 66/127 patients (52 %) treated with endovascular embolization. Complete obliteration at the end of all endovascular procedures was achieved in 14/66 patients (21.2 %), with an average of 78 % (range, 20–100 %) volume reduction. A mean of 2.9 (range, 1–9) feeding pedicles was embolized per patient. Overall, nine complications occurred in a total of 123 procedures (7.3 %). There was no procedure-related death in this study population. There was no significant difference between patients with and without complications in terms of AVM grade, demographic characteristics, or embolization features.

Conclusions

AVM size and deep venous drainage were independently associated with hemorrhage in pediatric patients. Endovascular procedure is feasible and safe for pediatric AVMs, and complete embolization can be achieved in small AVMs, while large AVMs can be adequately reduced in size for additional microsurgery or stereotactic radiosurgery.     

A spectrum of intracranial vascular high-flow arteriovenous shunts in RASA1 mutations

Purpose and background

We describe three paediatric cases with different intracranial fast-flow shunts presenting early in life, all with capillary malformation–arteriovenous malformation syndrome and RASA1 verified mutations. Intracranial arteriovenous fast-flow shunts are rare vascular malformations typically presenting early in life and have been associated with cutaneous capillary malformations, characterized as capillary malformation–arteriovenous malformation syndrome. Heterozygous RASA1 gene mutations have been found to be disease causing with high penetrance for the typical cutaneous findings, but only some individuals with the syndrome have intracranial lesions.

Cases

One infant presented with a vein of Galen malformation responsible for hydrodynamic disorders, one neonate suffered from severe cardiac insufficiency related to a superior sagittal sinus dural malformation with high-flow fistulas, and one baby was treated at infant age of a choroidal arteriovenous fistula discovered antenatally.

Results and conclusions

We report the follow-up of these three cases with RASA1 gene mutation and comment on the possible role of evaluation for vascular lesions and capillary malformation–arteriovenous malformation syndrome in patients and their families, with intracranial fast-flow shunts.

     

Angiographic features help predict outcome after stereotactic radiosurgery for the treatment of pediatric arteriovenous malformations

Purpose

Arteriovenous malformations (AVMs) are a frequent cause of hemorrhagic stroke in children. Stereotactic radiosurgery (SRS) is an established treatment for these lesions, particularly those that are surgically inaccessible. Because only complete AVM obliteration is believed to protect against the future risk of hemorrhage, identifying lesion characteristics that predict response to therapy is an important objective. The goal of this study is to evaluate the influence of angiographic features of AVMs on the rate of obliteration following treatment with SRS.

Methods

This is a retrospective cohort study of pediatric patients (age ≤18 years) treated with Gamma Knife SRS for cerebral AVMs between 2000 and 2012. Detailed angiographic data at the time of initial angiographic evaluation were prospectively recorded by experienced neurointerventional radiologists. The primary outcome was the rate of obliteration on a 3-year follow-up angiogram.

Results

We identified 42 pediatric patients treated with SRS for cerebral AVMs. Twenty-seven patients completed 3-year angiographic follow-ups. Complete obliteration was seen in 30 %, partial response in 67 %, and no response in 4 %. Higher SRS dose was associated with complete obliteration. Larger AVM diameter, presence of multiple draining veins, and presence of multiple draining veins reaching a sinus were associated with partial response. In this small cohort, diffuse AVM borders, presence of aneurysm, and pre-SRS embolization were not associated with obliteration.

Conclusions

Our study identifies AVMs in the pediatric population with a nidus diameter of <2.5 cm and a solitary draining vein as the most likely to undergo complete obliteration after SRS treatment.     

De novo multiple dural arteriovenous fistulas and arteriovenous malformation after embolization of cerebral arteriovenous fistula: case report

Background

A cerebral arteriovenous fistula is a rare neurovascular abnormality. It is very scarce when presenting with other cerebral arteriovenous malformations after embolization.

Method

We reported a case primarily presenting with cerebral arteriovenous fistula. When the fistula was embolized completely, de novo multiple dural arteriovenous fistulas and a small arteriovenous malformation occurred due to the hemodynamic change after the embolization. Embolization of parts of the fistulas for the second time led to an untreatable malformation which became curable. At the third time, the remaining fistula was cured.

Results

The mechanism of the dural arteriovenous fistula and treatment strategy were discussed.

Conclusion

Venous hypertension is the main factor causing a dural arteriovenous fistula. Embolization of the fistulas step by step is recommended.     

Management of cerebral arteriovenous malformations associated with symptomatic congestive intracranial hypertension

We report on management strategies and clinical outcomes in 4 cases of acute symptomatic congestive intracranial hypertension associated with cerebral arteriovenous malformations (AVMs). Congestion resulted from high-volume shunts exhausting the drainage capacity of the cerebral venous system in 3 patients, and from sudden venous outflow obstruction in 1 patient. Two AVMs were suggested to be surgically accessible, whereas two AVMs were deemed to be inoperable. Surgically accessible AVMs were treated with embolization followed by complete surgical resection. Inoperable AVMs were treated with partial embolization. Both AVM embolization followed by surgical resection and partial AVM embolization effectively reduced intracranial pressure and achieved sustained patient recovery. Hence, an endovascular approach may be considered to manage AVM-related congestive intracranial hypertension either in combination with surgical AVM removal, or as a palliative approach in inoperable AVMs.     

Gamma Knife radiosurgery for arteriovenous malformations in pediatric patients

Objective

The authors present the results of Gamma Knife stereotactic radiosurgery performed in a series of children with arteriovenous malformations (AVMs).

Methods

Between June 2005 and January 2014, 75 patients 18 years old or younger received Gamma Knife radiosurgery for AVMs. Of these, 58 patients were eligible for further analysis. The median age of the population was 12 years; 41 % presented with hemorrhage, 34 % with neurological insult, and 24 % patients were diagnosed incidentally. The median AVM volume was 3.5 cm³. The median radiosurgery-based AVM score (RSBAVMS) was 0.86. The median follow-up period was 32 months.

Results

Single session Gamma Knife radiosurgery resulted in complete AVM obliteration in 40 (68.9 %) patients. There were 35 (60.3 %) excellent outcome (complete obliteration with no new deficits) in this series. During the follow-up period, nine (15.51 %) patients experienced new deficits and three (5.1 %) patients experienced intracranial hemorrhage. The annual rate of developing new deficits and hemorrhage was calculated as 5.45 and 1.8 %, respectively. Volume, gender, RSBAVMS, and nidus type factor were factors associated with excellent outcome.

Conclusions

Radiosurgery was successful in majority of patients with minimal morbidity. Gamma Knife radiosurgery for AVMs can be a safe and successful method in pediatric patients.     

Pediatric intracranial arteriovenous shunts: a global overview

Introduction

Cerebral arteriovenous shunts (CAVS) in the pediatric population cannot be compared to those in adults as they present different anatomical, physiological, and pathological characteristics concerning the arterial and venous vasculature and the cerebrospinal fluid physiology. These lesions develop in a maturing brain, of which expression is difficult to assess, with a potential for recovery different from that in adults.

Discussion

Their impact on the brain will be different in the antenatal period, in neonates, in infants, and in children, with variable symptoms according to each age group. We review different classifications of pediatric CAVS (according to the anatomical space in which they develop, their type and architecture, and the age at which they reveal), describe their evolution, and discuss the current role of endovascular treatment in the management of these vascular lesions.     

Surgical flow disconnection of cerebral pial dual-channel arteriovenous fistula with a large varix: the role of anti-platelet agent or anti-coagulation therapy

Introduction

Intracranial pial arteriovenous fistula (AVF) is a rare cerebrovascular lesion, and the literature is sparse. Most authors insist that simple disconnection of arteriovenous shunting is enough to treat intracral single-channel pial AVF in most cases, either by microsurgery or endovascular embolization without resection of entire vascular malformation.

Discussion

We report an insidious onset of peri-lesional edema formation after abrupt disconnection of AVF shunting with surgical arterial ligation. Treatment entailed anti-platelet and anti-coagulation agent to slow down thrombus formation in intracranial dual-channel pial AVF. We suggest that slowing down thrombus formation in the large varix with anti-platelet and/or anti-coagulation agents seems to be necessary in case of abrupt disconnection of shunting in intracranial single- or dual-channel pial AVF to prevent postoperative cerebral edema or infarction.     

血管内栓塞术在神经外科的应用

作者对两年多来收治的106例脑、脊髓AVMs、动脉瘤和供血丰富的头、颈、颌面部肿瘤,采用不同的血管内栓塞技术和栓塞材料,进行了153例次的栓塞治疗,取得了满意的效果。治疗结果表明,不同的病变宜采用相应的栓塞技术,有利于提高血管内栓塞治疗成功率。     

Management of midline dural sinus malformations and review of the literature

Purpose

Dural sinus malformations (DSMs) are rare pediatric vascular lesions that have variable presentations and outcomes. We present three cases of midline DSMs and discuss the treatment strategy employed for each lesion. A review of the literature was completed to summarize current literature and treatment practices.

Methods

A retrospective review of the electronic medical record and all available imaging studies was performed for each of our patients.

Results

Patient 1 had a prenatally diagnosed DSM which decreased in size despite no intervention. She was born without complication and continues to do well at 15 months of age. Patient 2 presented 2 weeks after birth with cardiac failure, intracranial hemorrhage, and seizures and imaging showed a large midline DSM with multiple high-flow shunts. She required multiple endovascular embolizations with complete occlusion of the lesion. At her 3-year follow-up, she was neurologically normal. The third patient was diagnosed prenatally with an enlarging DSM. Multiple endovascular embolizations, surgical decompression, cranial expansion, and CSF diversion were required for treatment. At her 2.5-year follow-up, she was meeting developmental milestones, with some motor delay.

Conclusion

Early diagnosis and treatment, if necessary, of DSMs are critical to prevent cardiac failure or parenchymal injury from chronic venous hypertension. Management should be decided on individual case basis depending on the angioarchitecture and progression of the lesion and can involve observation, endovascular embolization, surgical interventions, or a combination of treatments. A personalized approach to treating these variable lesions can be associated with good outcomes.

     

Spontaneous spinal epidural hematoma secondary to extradural arteriovenous malformation in a child: a case-based update

Introduction

The aim of this study was to report a rare pediatric case of spontaneous spinal epidural hematoma (SSEH) mimicking Guillain-Barré syndrome (GBS), secondary to an epidural arteriovenous malformation (AVM). Furthermore, a case-based update and insight into the entity is attempted.

Methods

An 8-year-old male presented with progressing severe lower limb weakness and no traumatic history. Presentation was mimicking GBS with ascending symptoms. Magnetic resonance (MR) scan revealed a dorsal epidural mass, extending from C6–C7 to T2, compressing the spinal cord. Emergency laminoplasties and surgical evacuation of the hematoma were performed. An up-to-date review of reported SSEH cases in children was conducted, with emphasis on underlying vascular malformations (epidural AVMs in particular). Pathogenesis, predisposing factors, imaging, diagnosis, treatment and outcome are discussed.

Results

The hematoma was successfully evacuated. A vascular membrane on the dura was peeled off and sent for histopathology. There was no evidence of intradural vascular penetration. The patient improved postoperatively and was able to walk with support 7 months later. Histology revealed closely packed thin-walled angiomatous structures with wide lumens (filled with red blood cells) with walls composed of collagen and smooth muscle fibers, findings consistent with AVM.

Conclusions

Non-traumatic SSEH is rare in the pediatric population. Although vascular malformations are suspected, they are extremely rarely identified histopathologically. This case represents one of the very few reports of pediatric SSEH caused by a histologically proven, purely epidural AVM. High index of clinical suspicion and low threshold for MR can lead to timely diagnosis and prompt treatment with good functional outcome.     

Multiple cerebral arteriovenous shunts in children: report of 13 cases

The authors present a series of 13 multiple arteriovenous malformations (MAVMs) in the pediatric population (16.9% of their overall series of brain AVMs in this group). Two types of MAVMs can be distinguished: congenital and acquired. Congenital MAVMs may be of the nidus or fistula type. They may be uni- or bilateral, placed in one or several cerebral lobes, separated or close one to another, or even systematized (Wiburn-Mason syndrome). The symptoms created by these MAVMs are the same as those encountered in the presence of other AVMs, with hemorrhage as revealing symptom in 31% of patients. The responsibility of one particular nidus in the onset of clinical signs is often difficult to determine. From an angioarchitectural point of view, it seems that venous drainage changes are mainly responsible for the symptomatology. The natural history of these MAVMs is difficult to assess; spontaneous regression has been noted in 15% of cases. Acquired cerebral MAVMs can be due to angiogenesis (sprouting or non-sprouting) around a true AVM because of previous hemorrhage or ischemia, or to pial shunts associated with dural arteriovenous malformations. The treatment of MAVMs is difficult. Embolization seems to the authors the best therapeutic modality available, as surgery or radiosurgery are often unable to treat these multifocal lesions. Anatomical cure is rarely obtained; the therapeutic strategy has to be targeted on the symptomatic lesions.     

Neurointerventional procedures in the pediatric age group

Over the past 15 years there have been significant changes in the field of interventional neuroradiology, which have led to the inclusion of this specialty in the management of pediatric patients with vascular disorders of the central nervous system. Miniaturization of the devices and improvements in the embolic materials used have made it possible to perform endovascular therapy safely on neonates, infants and children. The role of endovascular therapy in the management of patients presenting with vein of Galen malformations and dural arteriovenous shunts has become clearly established. Endovascular therapists have also become important members of multidisciplinary teams managing patients with arteriovenous malformations of the brain and spinal cord. The role of endovascular therapy in the management of children with intracranial aneurysms is rapidly evolving, and experience with thrombolytic intra-arterial therapy for acute ischemic stroke is just gaining momentum. It is anticipated that in the future the role of endovascular therapy will continue to grow as part of the multidisciplinary team approach to the management of children presenting with complex vascular diseases of the central nervous system.     

Giant arteriovenous malformation of the vein of Galen in a 50 year old man

True malformations of the vein of Galen are usually diagnosed within the first weeks of life. They represent less than 1 p. 100 of the cerebral arteriovenous malformations. These true malformations are exceptional in adults but should be known as an endovascular treatment could be performed. The most frequent clinical presentation is a severe cardiac failure leading to death. We report a giant arteriovenous malformation of the vein of Galen in a right-handed, 50 year-old man. During childhood, he suffered from a compensated cardiac failure which remained of unknown cause. Neurological examination showed kinetic and static cerebellar syndrome and a Parinaud syndrome. A cerebral MRI scan revealed a giant vascular malformation of the vein of Galen with a normal posterior fossa. The angiography enabled the diagnosis of a true malformation of the vein of Galen in its choroidian form. Its high blood flow entails cardiac failure because of a steal phenomenon. An endovascular treatment was declined because of numerous arterial afferences and the potential risks of peroperative haemorrhage.     

脑动静脉畸形的血管构筑特征与使用Onyx栓塞治疗的体会

目的 探讨脑动静脉畸形的血管构筑特征与使用Onyx进行血管内栓塞治疗的技巧. 方法 选择自2005年3月至2006年12月广州医学院附属第二医院神经外科收治的26例脑动静脉畸形患者,根据脑血管造影和超选择造影后脑动静脉畸形的血管构筑特征,使用Onyx进行血管内栓塞治疗. 结果 脑动静脉畸形栓塞治疗前需分析房隔结构.引流静脉数量,引流是否通畅,供血方式及混合伴有动脉瘤或静脉结构等.粗大、危险性小的供血动脉及伴发动脉瘤的脑动静脉畸形应优先栓塞,对于多支供血的脑动静脉畸形需保护引流静脉.本组栓塞治疗后畸形血管团完全消失7例,消失90%以上10例,消失70%～90%的7例.消失70%以下2例. 结论 全面的脑血管造影可正确指导使用Onyx栓塞治疗脑动静脉畸形,掌握一定的推注技巧可以显著提高脑动静脉畸形血管内治疗的效果.     

Stereotactic linac radiosurgery and hypofractionated stereotactic radiotherapy for pediatric arteriovenous malformations of the brain: experiences of a single institution

Purpose

The aim of our study was to evaluate treatment results and toxicity of stereotactic irradiation for arteriovenous malformations (AVMs) in children.

Methods

A group of ten consecutive children (four boys and six girls) irradiated between 2002 and 2010 at our institution was included into the study. The mean age at the time of treatment was 15.4 and ranged between 8 and 18 years. There were two Spetzler–Martin grade IV, four grade III, and four grade II lesions. Mean AVM volume was 13.2 cm³ and varied from 0.6 to 36.8 cm³. In five patients, the planned dose of 16–20 Gy was delivered in single fraction, in five the total dose of 16–24 Gy was delivered in two to three fractions. One patient was reirradiated with a dose of 15 Gy, 7 years after the initial treatment.

Results

The median follow-up was 38.5 months. The treatment resulted in total obliteration in eight patients and partial in one. The median time to obliteration was 22 months; actuarial total obliteration rates were 20, 54, 54, and 83 % after 1, 2, 3, and 4 years of follow-up, respectively. No patient bled after the treatment. In one patient, new epileptic seizures developed after the treatment; in magnetic resonance imaging, focal necrosis was revealed. In five patients, asymptomatic imaging abnormalities were seen during follow-up.

Conclusions

Stereotactic radiotherapy appears to be an effective method of treatment for pediatric AVMs, the patients however require meticulous follow-up because of relative high incidence of radiation-induced imaging abnormalities.     

Diagnosis and treatment of vein of Galen aneurysmal malformations

Introduction

Vein of Galen aneurysmal malformations (VGAM) are rare but clinically significant intracranial arteriovenous shunt lesions that most often present in neonates and infants.

Methods

Retrospective clinical data were collected for patients evaluated with a diagnosis of VGAM from 1994 to 2007.

Results

Thirteen patients with VGAM were evaluated from 1994 to 2007. Seven patients presented emergently with medically intractable cardiac failure, and six were treated in the first 2 weeks of life. Five children treated after this period (1.5–31 months of age) manifested enlarging head circumference, abnormal development, or subarachnoid hemorrhage. Eleven patients were managed endovascularly. Four disease or procedure-related complications occurred. Two complications were associated with poor outcome, both of which occurred in patients treated at less than 2 weeks of age. Two other patients experienced transient neurological deficits with no evidence of permanent sequelae. Outcome in the six patients treated emergently in the first 2 weeks of life included two patients who developed normally, one with mild to moderate neurological deficits, one with severe neurological deficits, and two deaths. Outcome in the five older patients (treated between 1.5 and 31 months) was considerably better than in the group treated early and included three with normal outcome and two with mild neurological deficits.

Conclusions

Contemporary endovascular techniques remain the preferred treatment for VGAM in all age groups. Early diagnosis and multimodality treatment are essential for the best management and treatment of the complex constellation of clinical problems often arising from this disorder.     

Limitations and technical considerations of endovascular treatment in neonates with high-flow arteriovenous shunts presenting with congestive heart failure: report of two cases

Case report We report two neonatal patients with high-flow intracranial or cervical arteriovenous (AV) shunts who presented with congestive heart failure and were successfully managed with endovascular treatment. One with vein of Galen malformation with body weight of only 2.0 kg is, to our knowledge, the smallest neonate successfully treated with endovascular treatment. The other neonate is, to our knowledge, the first vertebro-vertebral fistula patient presenting with heart failure and treated successfully with endovascular treatment.Conclusion Even in neonates, endovascular treatment is the procedure of choice for high-flow AV shunts presenting with progressive congestive heart failure resistant to medical management. We discuss limitations and technical considerations of endovascular treatments in small neonates with high-flow AV shunts and congestive heart failure.     

A sixty-eight-year-old man with giant intracranial arteriovenous malformation and right-sided hemicrania -- a case report

Arteriovenous malformations (AVMs) are the most dangerous congenital vascular malformations. Intracranial AVMs occur in about 0.1 percent of the population and account for 1 to 2 percent of all strokes. The angioarchitecture of AVMs consists of direct arterial to venous connections without an intervening capillary network. The main symptom reported by half of all patients with arteriovenous malformations is an episodic headache. The headache is associated with nausea and vomiting and due to this resembles the hemicrania or cluster headache attacks. Although cerebral angiography is considered as the gold standard for the diagnosis, planned treatment and after treatment observation, AVMs are usually identified with advanced visual imaging techniques such as magnetic resonance imaging, computed tomography, and computed angiotomography. The treatment options consist of surgery, radiosurgery and endovascular embolization. We report a case of a 68-year-old man with giant intracranial arteriovenous malformation and right-sided hemicrania.