Cerebral arteriovenous malformations in childhood: state of the art with special reference to treatment

Endovascular NBCA treatment of a ruptured arteriovenous malformation with venous pseudoaneurysm in a young child

We reported imaging findings of arterio-venous malformation complicated by hemorrhage and venous pseudoaneurysm in a young child consulting for headache and emesis: to our knowledge venous pseudoaneurysm in association with ruptured arteriovenous malformation is a rare complication reported in the literature. We present the indications for endovascular treatment, especially with NBCA (N-butyl cyanoacrylate).

One-year evaluation of the treatment of hydrocephalus associated with Galen’s vein aneurysm: about 3 cases in a country with limited health resources

Background

Aneurysm of vein of Galen is a rare congenital arteriovenous malformation. Clinical manifestations depend on the age of discovery. Endovascular embolization is currently the treatment of choice. This technique is not always available in developing countries. We report 3 cases treated symptomatically by endoscopic third ventriculostomy and ventriculoperitoneal shunt.

Cases presentation

Three patients, 7 months, 15 years, and 26 years old, received in a table of acute intracranial hypertension, associated for the first one with convulsions and for the second one with moderate heart failure. Bain CT scan revealed triventricular hydrocephalus secondary to sacciform dilatation of the Galen’s vein in all three patients, requiring symptomatic treatment by endoscopic third ventriculostomy for the first patient and ventriculoperitoneal shunt for the other two in the absence of an adequate clinical platform for endovascular embolization. The evolution was favorable at 1 year’s follow-up.

Conclusion

Galen’s vein aneurysm is a rare vascular malformation. It mainly affects newborns and small children but can be discovered in adulthood. Endovascular embolization is its treatment of choice. This technique is not always available in some countries, which makes it necessary to resort to symptomatic treatment by ventricular shunt.

Epidemiology, risk factors and characteristics of pediatric stroke: a nationwide population-based study

BACKGROUND

Stroke, classically characterized as an acute acquired neurological deficit, is an important leading cause of death and chronic morbidity in children.

AIMS

This study reported the period prevalence, incidence and risk factors of pediatric stroke in Taiwan.

METHODS AND PROCEDURES

All Taiwan inhabitants aged 1 month to 18 years registered in the National Health Insurance Research Database between 2010 and 2011 were enrolled in this study. Factors including age, sex, location and household income levels were collected. Incidence, period prevalence, mortality rate and the possible risks were completely evaluated. Outcomes and results: Hemorrhagic stroke has a significantly higher mortality rate than ischemic stroke (27.6% vs. 10.2%, P<0.05). Risk factors or underlying diseases for stroke were identified in 77.8% of the patients and 16.2% had more than one risk factor. The most common risk factors were vascular diseases (26.3%), infection (14.0%) and cardiac disorders (9.1%).

CONCLUSIONS AND IMPLICATIONS

Infants younger than 2 years, boys and children in lower socioeconomic status have a significantly higher risk of stroke. Hemorrhagic stroke has a significantly higher mortality rate than ischemic stroke. More than half of the children with stroke had underlying diseases and the causes of hemorrhagic stroke are significantly different from ischemic stroke.

Clinical outcomes and radiosurgical considerations for pediatric arteriovenous malformation: influence of clinical features on obliteration rate

PURPOSE

Gamma knife radiosurgery (GKRS) is an established treatment modality for brain arteriovenous malformation (AVM), but there have been few published studies examining the relationship between clinical features of AVM and successful obliteration with GKRS in pediatric patients. In the current study, we investigate the outcomes of GKRS for pediatric patients with brain AVM and analyze the variables that influence obliteration.

METHODS

We analyzed 68 pediatric patients (≤ 18 years) with a mean follow-up period of 61.9 months (range 6-215 months). The following parameters were analyzed to determine their influence on obliteration of AVM treated by GKRS: age, sex, target volume, irradiation dose, prior treatment, location of AVM, nidus structure, velocity of AVM, location of venous drainage, number of feeding arteries, and initial presenting symptoms. Also, we estimated clinical factors which should be considered during the follow-up period.

RESULTS

Of the 68 patients, complete obliteration was confirmed in 26 (38.2%) by cerebral angiography. The response rate of AVM for GKRS was 92.6%. No significant association was observed between any of the parameters investigated and the obliteration of AVM, with the exception of number of feeding arteries, which exhibited a statistically significant difference by univariate analysis (p = 0.003). However, on multivariate analysis, nidus structure (p = 0.007), velocity of the main arterial phase (p = 0.013), velocity of the feeding artery phase (p = 0.004), and the number of feeding arteries (p = 0.018) showed statistical significance.

CONCLUSION

GKRS yielded good long-term clinical outcomes in most pediatric patients. Multiple arterial feeding vessels, diffuse nidus structure, and fast flow of AVM were specific factors associated with a low rate of obliteration in pediatric AVMs.

Multimodality management and outcomes of brain arterio-venous malformations (AVMs) in children: personal experience and review of the literature, with specific emphasis on age at first AVM bleed

PURPOSE

The purpose of this paper is to study the presentation and analyse the results of multimodality treatment of brain arterio-venous malformations (AVMs) in children at our centre and review age at first AVM rupture in the literature.

METHODS

Of 52 patients aged <18 years, 47 with brain AVMs (27 males and 20 females) aged 4-17 years (mean 12.2) were retrospectively reviewed. PubMed search revealed five additional studies including 267 patients where the prevalence of age-related AVMs rupture was analysed.

RESULTS

In our study, 37 patients had bled, 9 were symptomatic without haemorrhage and 1 was incidental. Spetzler-Martin score distribution was 5 cases grade I, 18 grade II, 21 grade III and 3 grade IV. Appropriate imaging was performed, either CT/MRI angiogram only (in emergency cases) or catheter angiogram, prior to definitive treatment. There were 40 supratentorial and 7 infratentorial AVMs. Twenty-nine patients had microsurgery alone and 9 patients were treated by radiosurgery only. Three patients were embolised, all followed by radiosurgery, with one requiring surgery too, while 4 patients had combined surgery and radiosurgery. One patient is awaiting radiosurgery while another was not treated. Good outcomes, classified as modified Rankin score (mRS) 0-2 improved significantly after intervention to 89.4% from 38.3% pre-treatment (p value <0.0001). Angiography confirmed 96.6% obliteration after first planned operation. Repeat cerebral angiogram around age 18 was negative in all previously cured patients. Reviewing the literature, 82.0% (95% CI = [77-87]; N = 267) of children diagnosed with brain AVMs (mean age 11.4 ± 0.4) presented with a bleed in the last 22 years. Males significantly outnumbered females (136 vs 84) (p < 0.001). Ninety-five patients underwent surgical intervention alone when compared to other treatment modalities (p < 0.001).

CONCLUSIONS

Microsurgical excision of surgically accessible intracranial AVMs remains the primary treatment option with very good outcomes. A significant number of patients' AVMs ruptured around puberty; therefore, understanding the pathophysiology of AVM instability at this age may aid future therapy.

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 cm(3). 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.

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.

Evaluation of prognostic factors as predictor of AVMS obliteration after Gamma Knife radiosurgery

BACKGROUND

The reported AVMs obliteration rate after Gamma Knife radiosurgery (GKS) ranges from 70 to 94 %. The objective of the present study was to assess prognostic factors predictive for cerebral AVMs obliteration in 127 patients who underwent GKS.

METHODS

The AVMs were classified according to the Spetzler-Martin classification. Twenty-one cases (16.5 %) were classified as grade I, 46 cases (36.2 %) as grade II, 51 cases (40.1 %) as grade III, and nine cases (7.1 %) as grade IV-V. The AVMs were deeply located in 16.5 % of patients. The peripheral prescription dose ranged from 16 to 30 Gy (mean 22.3 Gy). The AVMs volume ranged from 0.1 to 13 cc (mean 2.7 cc).

RESULTS

In 72 patients out of the 104 (69.2 %) with a radiological follow-up, MRI showed the AVM obliteration; in 54 cases (60 %) out of the 90 that performed a DSA, a complete AVM obliteration was achieved (average closure time 48.5 months). The volume of the nidus (p = 0.001), the prescription dose (p = 0.004), the 2002 Pollock-Flickinger classification (p = 0.031), and their 2008 revised classification (p = 0.025) were found to be statistically significant in predicting the probability of AVM closure. In the multivariate analysis, only the prescription dose was found to be an independent prognostic factor (p = 0.009) for AVM obliteration.

CONCLUSIONS

The volume of the nidus and the prescription dose significantly influence the outcome of radiosurgical treatment. The Pollock-Flickinger classification was found to be a reliable scoring system in predicting the AVM closure and an important tool for selection of patients candidate for GKS.

Management of pediatric intracranial arteriovenous malformations: experience with multimodality therapy

BACKGROUND

Successful management of pediatric arteriovenous malformations (AVMs) often requires a balanced application of embolization, surgery, and radiosurgery.

OBJECTIVE

To describe our experience treating pediatric AVMs.

METHODS

We analyzed 120 pediatric patients (< 18 years of age) with AVMs treated with various combinations of radiosurgery, surgery, and endovascular techniques.

RESULTS

Between 1985 and 2009, 76 children with low Spetzler-Martin grade (1-3) and 44 with high-grade (4-5) AVMs were treated. Annual risk of hemorrhage from presentation to initial treatment was 4.0%, decreasing to 3.2% after treatment initiation until confirmed obliteration. Results for AVM obliteration were available in 101 patients. Initial single-modality therapy led to AVM obliteration in 51 of 67 low-grade (76%) and 3 of 34 high-grade (9%) AVMs, improving to 58 of 67 (87%) and 9 of 34 (26%), respectively, with further treatment. Mean time to obliteration was 1.8 years for low-grade and 6.4 years for high-grade AVMs. Disabling neurological complications occurred in 4 of 77 low-grade (5%) and 12 of 43 high-grade (28%) AVMs. At the final clinical follow-up (mean, 9.2 years), 48 of 67 patients (72%) with low-grade lesions had a modified Rankin Scale score (mRS) of 0 to 1 compared with 12 of 34 patients (35%) with high-grade AVMs. On multivariate analysis, significant risk factors for poor final clinical outcome (mRS ≥ 2) included baseline mRS ≥ 2 (odds ratio, 9.51; 95% confidence interval, 3.31-27.37; P < .01), left-sided location (odds ratio, 3.03; 95% confidence interval, 1.11-8.33; P = .03), and high AVM grade (odds ratio, 4.35; 95% confidence interval, 1.28-14.28; P = .02).

CONCLUSION

Treatment of pediatric AVMs with multimodality therapy can substantially improve obliteration rates and may decrease AVM hemorrhage rates. The poor natural history and risks of intervention must be carefully considered when deciding to treat high-grade pediatric AVMs.

Pediatric stroke

INTRODUCTION

Pediatric stroke, while increasingly recognized among practitioners as a clinically significant, albeit infrequent entity, remains challenging from the viewpoint of clinicians and researchers.

DISCUSSION

Advances in neuroimaging have revealed a higher prevalence of pediatric stroke while also provided a safer method for evaluating the child's nervous system and vasculature. An understanding of pathogenic mechanisms for pediatric stroke requires a division of ages (perinatal and childhood) and a separation of mechanism (ischemic and hemorrhagic). This article presents a review of the current literature with the recommended divisions of age and mechanism.

CONCLUSION

Guidelines for treatment, though limited, are also discussed.

Cavernous malformations of the central nervous system in children: presentation, treatment and outcome of 20 cases

BACKGROUND

Cavernous malformations (CM) of the central nervous system are vascular malformations responsible for symptoms such as seizures, headache, and neurological deficits: 25% of cases already present in childhood.

MATERIAL AND METHODS

Retrospective study including all CMs of the central nervous system in childhood diagnosed in the period 1993-2008 in 3 paediatric hospitals in Switzerland, focusing on clinical manifestations, neuroimaging findings, treatment, and outcome.

RESULTS

20 children (13 females) were diagnosed with CM, with an average age at presentation of 8.5 years (range 7 months-16 years). 17/20 presented with acute haemorrhage, 9/17 with seizures, 5/17 with focal neurological symptoms, and 3/17 with severe headache only. Localisation was supratentorial in 15/20, infratentorial in 2/20, supra- and infratentorial in 2/20, and spinal in 1 child. Five children had multiple CMs. Treatment was conservative in 10 cases and surgery was indicated in 10: for acute haemorrhage in 5; recurrent bleeding in 3; and epilepsy in 2. Follow-up after diagnosis was 0.5 years-10 years (mean 4 years), revealing neurological sequelae in 6 patients. The CM increased in size in 2 cases with an increase in number also in 1 of these.

CONCLUSIONS

We confirm that CMs in childhood mainly present with seizures, severe headache, or focal symptoms due to acute haemorrhage. During infancy they may appear as dynamic lesions increasing in size and/or number. The regular application of newer neuroimaging techniques such as susceptibility weighted imaging will detect more lesions but not necessarily resolve problems concerning optimum treatment.

Stereotactic radiosurgery for pediatric arteriovenous malformations

Children with intracranial arteriovenous malformations (AVM) have a high cumulative risk of hemorrhage and therefore effective treatment of AVMs in the pediatric population is imperative. Treatment options include microsurgical resection, endovascular embolization, staged or single fraction radiosurgery, or some combination of these treatments, with the ultimate goal of eliminating the risk of hemorrhage. In this article the authors review the current data on the use of radiosurgery for the treatment of childhood AVMs. Factors associated with successful AVM radiosurgery in this population are examined, and comparisons with outcomes in adult patients are reviewed.

Surgical management of pediatric cerebral arteriovenous malformations

BACKGROUND

Arteriovenous malformations (AVMs) are the most common cause of intracerebral hemorrhage in children. Different options exist for their successful management consisting of surgery, endovascular embolization, stereotactic radiosurgery, or a combination of these treatments.

DISCUSSION

In this paper, we discuss the different treatment modalities in the treatment of pediatric cerebral AVMs emphasizing the role of surgery and endovascular embolization as a preoperative strategy.

Multimodality treatment of cerebral AVMs in children: a single-centre 20 years experience

PURPOSE

The purpose of this study was to review our experience with a multimodality treatment approach in the management of cerebral arteriovenous malformation (AVM) in children.

METHODS

We retrospectively analysed a consecutive series of 56 children who harboured a cerebral AVM and were treated at our institution between 1988 and 2008. During the whole treatment period, a combined treatment strategy, including microsurgery, endovascular treatment and gamma knife radiosurgery, was used.

RESULTS

Of the 56 patients (median age, 14.0; range, 3 months-18 years) reported, 36 (64.3%) were admitted after AVM rupture; of these, only one AVM (1.8%) was considered untreatable. In 30.9% (17/55) of the treated patients, a single treatment measure was sufficient to attain angiographic cure of the AVM. Among these, six patients (10.9%) had microsurgical AVM resection, four patients (7.3%) underwent endovascular treatment, and another seven patients (12.7%) underwent radiosurgical management of the AVM. The majority of the population (38/55; 69.1%) underwent combined treatment: 21 patients (38.2%) received embolisation followed by radiosurgery of the remnant nidus, ten patients (18.2%) underwent embolisation with subsequent surgical resection of the residual AVM, three patients (5.5%) had radiosurgery after incomplete surgical AVM nidus resection and another four patients (7.3%) required a combination of all three treatment modalities to achieve permanent angiographic cure of the AVM. We observed good clinical outcomes (Glasgow Outcome Scale 5 and 4) in 94.6% of the children. Complete angiographic obliteration was achieved in 93.3% of the patients treated.

CONCLUSION

A multimodality treatment approach in children harbouring cerebral AVMs leads to excellent angiographic and clinical outcomes.

Pediatric arteriovenous malformation: University of Toronto experience using stereotactic radiosurgery

INTRODUCTION AND BACKGROUND

Arteriovenous malformations (AVMs) are congenital vascular lesions of the brain, which behave differently in pediatric population compared to adults. Treatment of pediatric AVMs includes a combination of microsurgery, embolization and radiation therapies. However, the role of radiosurgery in the treatment of pediatric AVMs is not fully accepted because of concerns regarding the long-term effects of radiation on the pediatric brain.

DISCUSSION

In this study, we review our experience at the University of Toronto with treating pediatric AVMs using linear accelerator-based (LINAC) radiosurgery over the past 15 years. We report our results, obliteration rates, and complications on a total of 40 patients. In addition, we provide a review of series published to date combined with our own results to determine whether radiosurgery is a safe and reasonable treatment modality for pediatric AVMs.

Radiosurgery for arteriovenous malformations in children

OBJECT

The authors present the results of stereotactic radiosurgery performed in a consecutive series of children with arteriovenous malformations (AVMs) and analyze factors associated with successful radiosurgery for this condition.

METHODS

Between 1990 and 2001, 38 patients 18 years of age or younger underwent radiosurgery for AVMs. The median patient age was 15 years; 20 patients (53%) had experienced a prior hemorrhage. Twenty-seven AVMs (71%) were Spetzler-Martin Grade III or higher; 16 patients (42%) had AVMs located in the basal ganglia, thalamus, or brainstem. The median AVM volume was 3.4 cm3. The median radiosurgery-based AVM score was 1.08 according to the following formula: AVM score = 0.1 volume (cm3) + 0.02 x age (years) + 0.3 x location (frontal/temporal = 0; parietal/occipital/corpus callosum/cerebellar = 1; basal ganglia/thalamus/brainstem = 2). The median follow-up period was 42 months. One patient (3%) had an intraventricular hemorrhage 26 months after radiosurgery but experienced no new deficit. No patient had a permanent radiation-related complication after radiosurgery. Twenty-six patients (68%) had excellent outcomes (as defined by complete obliteration of the AVM with no new deficit) after radiosurgical treatment (21 cases determined using angiography and five using magnetic resonance imaging). Twelve patients (32%) remained unchanged (incomplete obliteration but no new deficit). Univariate analysis found that patient age, AVM volume, location, or Spetzler-Martin grade did not correlate with excellent outcomes. Patients whose radiosurgery-based AVM scores were 1 or lower experienced an excellent outcome more frequently than patients with an AVM score higher than 1 (88% compared with 52%, p = 0.03).

CONCLUSIONS

Radiosurgery was successful in the treatment of the majority of pediatric patients suffering from AVMs, and morbidity levels were minimal. The radiosurgery-based AVM grading scale accurately predicted these outcomes. Children whose AVMs are obliterated after radiosurgery should undergo repeated angiography after they reach adulthood to rule out the possibility of a recurrent nidus that would expose them to an ongoing risk of hemorrhage.

Managing stroke in children

The incidence of stroke in the pediatric population is estimated at between 2 and 3 per 100,000. Strokes are divided into ischemic or hemmorhagic categories, depending on whether the primary cause is obstruction or bleeding into the brain. Strokes may present with acute, recurrent, or evolving neurological deficits. There is a long and varied list of causes of stroke in children. The major causes of ischemic stroke are cardiac abnormalities and coagulation disorders. Cerebrovascular malformations account for the majority of hemmorhaghic strokes. The workup is guided by the initial history and imaging studies. Treatment is dependent on the specific risk factors identified, and outcome is dependent on the location and extent of the initial insult.

Gamma knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part I: Differences in epidemiologic, morphologic, and clinical characteristics, permanent complications, and bleeding in the latency period

PURPOSE

To compare the epidemiologic, morphologic, and clinical characteristics of 92 children/adolescents (Group A) and 362 adults (Group B) with cerebral arteriovenous malformations (cAVMs) considered suitable for radiosurgery; to correlate radiosurgery-related permanent complication and post-radiosurgery bleeding rates in the 75 children/adolescents and 297 adults available for follow-up.

METHODS AND MATERIALS

Radiosurgery was performed with a model C 201-source Co60 Leksell Gamma Unit (Elekta Instruments, Stockholm, Sweden). Fisher exact two-tailed, Wilcoxon rank-sum, and two-sample binomial exact tests were used for statistical analysis.

RESULTS

There were significant differences between the two populations in sex (p = 0.015), clinical presentation (p = 0.001), and location (p = 0.008). The permanent complication rate was lower in younger (1.3%) than in older patients (5.4%), although the difference was not significant (p = 0.213). The postradiosurgery bleeding rate was lower in Group A (1.3%) than in Group B (2.7%) (p = 0.694), with global actuarial bleeding rates of 0.56% per year and 1.15% per year, respectively.

CONCLUSIONS

The different characteristics of child/adolescent and adult cAVMs suggest that they should be considered two distinct vascular disorders. The similar rates of radiosurgery-related complications and latency period bleeding in the two populations show that gamma knife radiosurgery does not expose young patients to a higher risk of sequelae than that for older patients.

Intensity-modulated radiosurgery for childhood arteriovenous malformations

PURPOSE

Presentation of intensity-modulated radiosurgery (IMRS) for the treatment of inoperable, complex shaped pediatric arterio-venous malformations AVM.

METHOD

Between 03/99 and 11/04, IMRS was delivered to seven children aged six to 18 years. Prescribed minimum doses ranged from 17.5 to 20 Gy (median 18 Gy). Radiosurgery planning and delivery used a serial tomotherapeutic IMRT technique (Peacock IMRT, North American Scientific/Nomos, Cranberry Township, PA) over two to four couch angles. A linear accelerator attached binary multi-leaf collimator was used to generate pencil beams of 10 mm by either 8.5 or 4.0 mm. Treatment planning employed an inverse treatment planning optimization algorithm. Parameters submitted to the treatment planning system were: prescription dose (PD), volume of target allowed to receive less dose (standard 3%), minimum dose (0.5 Gy less than PD), and maximum dose (200% of PD). Planning system specific IMRS target and tissue types were selected to prioritize dose conformality over dose homogeneity. The prescription isodose encompassed at least 95% of the target volume. We calculated conformality (CI) and homogeneity indices (HI) to characterize the quality of IMRS plans, and summarized preliminary clinical outcomes.

FINDINGS

Target volumes ranged from 0.71 to 63.02 cm(3) (median 13.8 cm(3), 6/7 AVM larger than 10 cm(3)). Median CI was 1.07 (range 1.05 to 1.7) according to RTOG criteria. Median HI was 1.12 (range 1.09 to 1.23). During limited follow-up (median 32 months, range 5 to 53 months), two AVM completely obliterated at 19 and 22 months, and partial obliteration (>75%) was observed in three cases. No treatment-related side effects, other than acute nausea and temporary headaches interpreted as being associated with changes in cerebral blood distribution, were observed.

CONCLUSIONS

IMRS can allow for highly conformal planning and delivery of radiosurgery radiation doses even if pediatric AVM target volumes are large and/or highly complex in shape. This technique has been seen to result in favorable preliminary outcomes, thus supporting future exploration of this technique in pediatric and adult patients.

Leksell gamma knife radiosurgery for cerebral arteriovenous malformations in pediatric patients

OBJECTS

The authors report their experience of gamma knife radiosurgery (GKR) in a large series of pediatric cerebral arteriovenous malformations (cAVMs). The advantages, risks and failures of this approach are presented and discussed.

METHODS

Gamma knife radiosurgery was performed on 63 children aged < or =16 years. Haemorrhage was the clinical onset in 50 out of 63 cases. The mean pre-GK cAVM volume was 3.8 cm(3). Fifty-eight out of 63 cAVMs were Spetzler-Martin grades I-III. Most lesions (47 out of 63) were in eloquent or deep-seated brain regions.

CONCLUSION

Gamma knife radiosurgery-related complications occurred in 2 out of 47 cases with an available follow-up (1 had transient and 1 permanent morbidity). No bleeding occurred during the latency period. In 39 children with >36-month follow-up, complete cAVM occlusion was angiographically documented in 31, with a 3- and 4-year actuarial obliteration rate of 72 and 77% respectively. High rates of complete obliteration and very low frequency of permanent morbidity with no bleeding during the latency period encourage widespread application of GKR in the treatment of pediatric cAVMs.

Surgical results in pediatric Spetzler-Martin grades I-III intracranial arteriovenous malformations

OBJECTS

The goal of cerebral arteriovenous malformation (AVM) therapy in pediatric patients should be complete resection or obliteration of the AVM to eliminate subsequent hemorrhage, because of high mortality and morbidity rates related to hemorrhage in addition to the longer life expectation. Despite advances in Gamma knife radiosurgery and in endovascular embolization, surgical resection is still the gold standard for treating cerebral AVMs.

METHODS

Between 1986 and 2003, 20 children were surgically treated for cerebral AVMs. The AVMs were graded I, II, and III using the Spetzler-Martin (S-M) Grading Scale. Good recovery was achieved in 18 out of 20 patients (90%) and only 1 patient was moderately disabled (5%). There was one mortality (5%) related to the preoperative deep comatose state of the patient. The total obliteration rate was 89% (17 out of 19).

CONCLUSION

For S-M grade I-III AVMs, surgical resection is the treatment of choice, considering its high cure rate and low morbidity and mortality rates.

Radiosurgery of cerebral arteriovenous malformations in children: a series of 57 cases

PURPOSE

To evaluate the efficacy and outcome of Linac radiosurgery (RS) as treatment of cerebral arteriovenous malformations (cAVM) in a series of 57 children.

METHODS AND MATERIALS

Between 1984 and 2000, we used Linac radiosurgery to treat 792 patients with cAVM. This series included 57 children (7.2%) under the age of 15 years at the time of RS (range = 7-15 years, median = 12 years). We were able to evaluate 49 of the children (86%) by angiography, 21 boys and 28 girls (sex ratio = 0.75). First symptoms were: hemorrhage, 34 patients (69.4%); seizures, 6 patients (12.5%); headache, 6 patients (12.5%); and progressive neurologic deficit, 1 patient (2.1%). Nidus size ranged from 5 to 50 mm (median = 20 mm). Nidus volume ranged from 0.6 to 16 cc (median = 3.5 cc). Patient distribution according to Spetzler-Martin grade was as follows: Grade 1, n = 5 (11%); Grade 2, n = 18 (35%); Grade 3, n = 21 (40%,); Grade 4, n = 5 (14%); and Grade 5, n = 0%. Twenty-seven patients (55.1%) had other treatment before RS: embolization, n = 14 (31.1%); neurosurgery, n = 9 (20.5%); embolization and neurosurgery, n = 3 (6.1%). RS was performed with the system used for adults. Patients were seated in a Betti armchair. Circular 15 MV X-ray minibeams (6 to 20 mm) were delivered in coronal arcs by a GECGR Saturne 43 Linac. Planification and dosimetry were carried out using the Associated Target Methodology and Dosigray TPS dosimetric systems. The dose at the peripheral isodose (50-70%) ranged from 18 to 28 Gy. Median and mean doses were 25 Gy and 23.8 Gy. Mono-isocentric planification was used in 25 patients (53.2%) and multi-isocentric in 24 patients (2 to 5 isocenters). The overall follow-up ranged from 7 to 172 months (mean 40 months, median 34 months).

RESULTS

The overall rate of obliteration (OR) was 30/49 (61.2%). Mean time to obliteration was 34 months (range = 7 to 172 months). OR varied according to nidus size and volume: OR was 80% for nidus <15 mm, 67% for nidus between 15 and 25 mm, and 42% for nidus >25 mm (p = 0.058). OR was 100% for nidus <1 cc, 73% for nidus between 1 and 4 cc, and 40% for nidus of 4 to 10 cc (p = 0.019). OR according to patient gender was 84.2% for boys and 40% for girls. OR according to minimum dose (Dmin) was 44% for Dmin < 15 Gy (p = 0.01), 89% for D min from 15 to 20 Gy, and 100% for Dmin > 20 Gy (p = 0.01). OR was 62% in nonembolized AVM and 58% in previously embolized AVM (NS). OR according to the number of isocenters was 68.2%, 55.6%, 80%, 50%, and 0% for 1, 2, 3, 4, and 5 isocenters, respectively. After multivariate analysis, only Dmin closely correlated with OR (beta = 0.462; SE = 0.244, p = 0.057). Of the 6 patients with seizures before RS, 5 (80%) were seizure-free without medication after RS. One patient died of pneumonia.

MORBIDITY

Four patients (8.2%) had bleeding after RS at 39, 45, 51, and 59 months. No new neurologic deficit was found during the follow-up period. Twenty-nine patients underwent magnetic resonance imaging. Thirteen patients (44.8%) showed no parenchymal changes. Thirteen patients (44.8%) had Grade 2 changes, that is, T2 hypersignals. Two patients (6.9%) had Grade 3 changes, and 1 patient (3.4%) had Grade 4 "necrosis-like" changes.

CONCLUSION

In our experience, Linac RS has proven to be a safe and effective method to treat cerebral AVM in children <15 years, whether used alone or in association with embolization and/or neurosurgery.

Clinical course and medical management of neonates with severe cardiac failure related to vein of Galen malformation

BACKGROUND

Neonatal presentation of vein of Galen aneurysmal malformations (VGAMs) with intractable cardiac failure is considered a poor prognostic sign. Interventional neuroradiology with embolisation has been shown to control cardiac failure, but there is a perception that neurological outcome in survivors is poor.

OBJECTIVE

To determine if aggressive intensive care and anaesthetic management of cardiac failure before urgent embolisation can influence morbidity and mortality.

PATIENTS

Nine newborns (four boys, five girls) were diagnosed with symptomatic vein of Galen malformations in the neonatal period during the period 1996-2001. Eight developed intractable high output cardiac failure requiring initial endovascular treatment in the first week of life.

RESULTS

The immediate outcome after a series of endovascular procedures was control of cardiac failure and normal neurological function in six (66%) patients, one death from intractable cardiac failure in the neonatal period, and two late deaths with severe hypoxic-ischaemic neurological injury (33% mortality). Clinical review at 6 months to 4 years of age showed five infants with no evidence of neurological abnormality or cardiac failure and one child with mild developmental delay (11%).

CONCLUSIONS

Aggressive medical treatment of cardiac failure and early neurointervention combined with modern neuroanaesthetic care results in good survival rates with low morbidity even in cases of high risk VGAM presenting in the immediate perinatal period with cardiac failure. Systemic arterial vasodilators improve outcome in neonates with cardiac failure secondary to VGAM. Excessive beta adrenergic stimulation induced by conventional inotropic agents may exacerbate systemic hypoperfusion.

Report of the National Institute of Neurological Disorders and Stroke workshop on perinatal and childhood stroke

The National Institute of Neurological Disorders and Stroke and the Office of Rare Disorders sponsored a workshop on perinatal and childhood stroke in Bethesda, Maryland, on September 18 and 19, 2000. This was an international workshop to bring together experts in the field of perinatal and childhood stroke. Topics covered included epidemiology, animal models, risk factors, outcome and prognosis, and areas of future research for perinatal and childhood stroke. Stroke in infants and children is an important cause of morbidity and mortality and an emerging area for clinical and translational research. Currently, there is no consensus on the classification, evaluation, outcome measurement, or treatment of perinatal and childhood stroke. Pediatric stroke registries are needed to generate data regarding risk factors, recurrence, and outcome. The impact of maternal and perinatal factors on risk and outcome of neonatal stroke needs to be studied. This information is essential to identifying significant areas for future treatment and prevention.

Emergency management of deeply comatose children with acute rupture of cerebral arteriovenous malformations

PURPOSE

To assess the impact of emergency management on mortality and morbidity of acute rupture of cerebral arteriovenous malformations resulting in deep coma in children, and the factors predicting outcome.

METHODS

Retrospective chart review of 20 children with a Glasgow Coma Scale < or = 8 with acute hemorrhagic stroke from a cerebral arteriovenous malformation rupture was conducted. Protocol included: early resuscitation with tracheal intubation and ventilation after induction of anesthesia with sufentanil, and benzodiazepine, and mannitol 20% or hypertonic saline 7.5% infusion for life-threatening brain herniation. Radiological exploration was limited to contrast-enhanced CT scan preceding immediate surgical decompression. Postoperatively, children were deeply sedated and intracranial pressure monitoring allowed titration with osmotherapy, vasopressors, hyperventilation or barbiturate coma to control cerebral perfusion pressure. Analysis used stratification of the type of hemorrhage (supra or infra tentorial), location (intraparenchymal and subarachnoid, intraparenchymal and intraventricular or intraventricular alone) and relationship between presentation, evolution with resuscitation, type of cerebral lesion, and outcome.

RESULTS

Patients had a severe initial presentation (median Glasgow Coma Scale five), eight had unilateral and eight bilateral third nerve palsy. Compressive hematoma in supratentorial localisation represented 75% of the cases. Global mortality was 40%. Persistence of mydriasis after resuscitation increased mortality to 75%. Massive intraventricular flooding was associated with increased mortality. Good functional outcome was achieved in survivors.

CONCLUSION

Acute rupture of an AVM can result in rapidly progressing coma. Emergency management with early resuscitation, minimal radiological exploration before rapid surgical decompression results in a mortality rate of 40%, but a good functional outcome can be expected in the survivors.