Cerebral arteriovenous malformations in children

Stereotactic radiosurgery treatment of pediatric arteriovenous malformations: a PRISMA systematic review and meta-analysis

BACKGROUND

Stereotactic radiosurgery (SRS) is considered a safe definitive treatment for pediatric arteriovenous malformations (AVMs) upon indicated presentations. There are no published guidelines by the International Stereotactic Radiosurgery Society (ISRS) detailed with indications or characteristics that warrant SRS, other than the guideline that SRS is a safe and efficacious treatment for pediatric AVMs. SRS is performed using either Gamma Knife (GK) or Linear Accelerator (LINAC). This systematic review aims to uncover treatment, differences in GK and LINAC outcomes, and AVM characteristics that lead to high obliteration rates and suggest future studies to determine treatment decisions, raise obliteration rates, and lower complication rates in SRS treatment of pediatric AVMs.

METHODS

We performed a systematic review according to PRISMA guidelines across PubMed, Embase, and SCOPUS utilizing search terms related to pediatric patients, AVMS, and SRS. We collected data from the 32 full-text studies and 4 abstracts that met inclusion criteria. Subsequent pooled analysis was performed on GK vs LINAC obliteration rates, followed by sub-cohort analysis of all SRS patients with hemorrhagic presentation, Spetzler-Martin (SM) Grade, and prior procedure and their effect on obliteration rates.

RESULTS

The 36 studies reported 3425 patients, with a slight male preponderance (1662 patients, 48.5%). The obliteration analysis included 2834 patients that met follow-up criteria and contained obliteration data. The weighted mean age was 12.63 years. Pooled cohort analysis found no significant difference in obliteration proportions when comparing GK to LINAC (P = 0.7449), with an overall obliteration rate of 63% in patients with at least 1 year follow-up. The sub-cohort analysis of all patients treated with SRS revealed that presentation with AVM hemorrhage was associated with increased obliteration (CE: RR = 1.22 [95%CI = 1.09-1.35; RE: RR = 1.22, 95%CI = 10.6-1.40; prediction interval = 1.07-1.38) with low heterogeneity (I2 = 17.1%, τ2 < 0.0001, p = 0.2902). Smaller SM grade was not statistically associated with increased obliteration (CE: RR = 1.25 [95%CI = 0.87-1.81]; RE: RR = 1.84 [95%CI = 0.97-3.50]; prediction interval = 0.38-8.86) and moderate levels of heterogeneity were detected (I2 = 45.2%, τ2 = 0.2668, p = 0.1042). Procedure prior to SRS also had higher obliteration rates than no prior procedure (CE: RR = 0.77 [95%CI = 0.61-0.86]; RE: RR = 0.71 [95%CI = 0.54-0.92]; prediction interval = 0.36-1.39) with low to moderate heterogeneity (I2 = 27.6%, τ2 = 0.0.0264, p = 0.2466).

CONCLUSION

SRS is a safe and effective treatment for pediatric AVMs. This study suggests that there are no differences in obliteration between GK and LINAC, with increased obliteration in patients with hemorrhage at presentation and procedures prior to SRS treatment. Further multicenter, prospective studies are necessary to dictate future treatment decisions.

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).

Hemorrhagic Cerebrovascular Pathology in the Pediatric Population

Hemorrhagic cerebrovascular disease in the pediatric population can have devastating and long-term effects. Progress in the fields of genetics, neuroimaging, pharmacology, and surgical techniques has led to improved diagnosis and management of pediatric cerebrovascular diseases. In this review we discuss the current etiologies and medical and surgical treatments of hemorrhagic cerebrovascular pathology affecting infants and children. A special emphasis is placed on neuroendovascular treatment options. Increased knowledge about this unique pathology and the medical and therapeutic options will empower practitioners to more quickly and accurately identify and accurately treat hemorrhagic diseases in the pediatric population.

Cognitive performance in patients with cerebral arteriovenous malformation

OBJECTIVE

A cerebral arteriovenous malformation (cAVM) can change over time and cause symptoms, but clinical studies tend to define only the patients with ruptured cAVMs as symptomatic and do not consider neurocognitive aspects prior to neurosurgical intervention. The objective of this study was to describe the neurocognitive function of patients with ruptured and unruptured cAVMs according to the Spetzler-Martin (SM) grade, flow status, and anatomical topography.

METHODS

In this blinded cross-sectional study, 70 patients of both sexes and ages 18-60 years were evaluated using the Brazilian Brief Neuropsychological Assessment Battery Neupsilin.

RESULTS

Of the 70 patients with cAVMs, 50 (71.4%) demonstrated deficits in at least one of the eight neurocognitive domains surveyed, although they did not exhibit neurological deficits. cAVMs in the temporal lobe were associated with memory deficits compared with the general population. The SM grade was not significantly associated with the results of patients with unruptured cAVMs. However, among patients with ruptured cAVMs, there were deficits in working memory in those with high-grade (SM grade) cAVMs and deficits in executive function (verbal fluency) in those with low-grade cAVMs (p < 0.001).

CONCLUSIONS

This study indicates that patients with untreated cAVMs, either ruptured or unruptured, already exhibit neurocognitive deficits, even the patients without other neurological symptoms. However, the scales used to evaluate disability in the main clinical studies, such as A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA), do not assess neurocognitive alterations and therefore disregard any deficits that may affect quality of life. The authors' finding raises an important question about the effects of interventional treatment because it reinforces the hypothesis that cognitive alterations may be preexisting and not determined by interventions.

Characteristics and Long-Term Outcome of 127 Children With Cerebral Arteriovenous Malformations

BACKGROUND

Population-based long-term data on pediatric patients with cerebral arteriovenous malformations (AVMs) are limited.

OBJECTIVE

To clarify the characteristics and long-term outcome of pediatric patients with AVM.

METHODS

A retrospective analysis was performed on 805 consecutive brain AVM patients admitted to a single center between 1942 and 2014. The patients were defined as children if they were under 18 yr at admission. Children were compared to an adult cohort. Changing patterns of presentation were also analyzed by decades of admission.

RESULTS

The patients comprised 127 children with a mean age of 12 yr. The mean follow-up time was 21 yr (range 0-62). Children presented more often with intracerebral hemorrhage (ICH) but less often with epilepsy than adults. Basal ganglia, cerebellar, and posterior paracallosal AVMs were more common in pediatric than in adult patients. Frontal and temporal AVMs, in contrast, were more common in adult than in pediatric patients. As the number of incidentally and epilepsy-diagnosed AVMs increased, ICH rates dropped in both cohorts. In total, 22 (82%) pediatric and 108 (39%) adult deaths were assessed as AVM related. After multivariate analysis, small AVM size and surgical treatment correlated with a favorable long-term outcome.

CONCLUSION

Hemorrhagic presentation was more common in children than in adults. This was also reflected as lower prevalence of epileptic presentation in the pediatric cohort. Lobar and cortical AVM locations were less frequent, whereas deep and cerebellar AVMs were more common in children. Hemorrhagic presentation correlated negatively with incidentally and epilepsy-diagnosed AVMs. In children, AVM was a major cause of death, but in adults, other factors contributed more commonly to mortality.

[Arteriovenous malformations and epileptic seizures in children: risk factors of seizures and efficacy of their control depending on the surgical treatment modality]

Epileptic seizures are some of the most frequent manifestations of cerebral AVMs in children. Poor control of seizures can significantly affect patients' quality of life. In this case, factors that are associated with the development of seizures and affect the efficacy of their control upon treatment of cerebral AVMs are not well understood.

PURPOSE

The purpose of this study was to identify risk factors for the development of epileptic seizures as well as factors associated with a seizure-free outcome of AVM treatment in children.

MATERIAL AND METHODS

We analyzed the results of examination and treatment in 89 patients with cerebral AVMs aged 1 to 17 years.

RESULTS

Factors associated with the development of epileptic seizures in cerebral AVMs in children included male gender of the child, a large size of AVM and its superficial location, as well as localization of the pathology in the frontal and temporal lobes of the brain and draining varices. Regression of seizures after surgery was more often observed in the case of microsurgical and/or complex surgical treatment and complete exclusion of the AVM as well as in cases of rare attacks and a short course of the disease.

CONCLUSION

Complex and microsurgical treatment of AVMs in children provides effective control of epileptic seizures, which is obviously associated with complete exclusion of the AVM and removal of the epileptic focus located near the AVM.

An Unusual Presentation of Arteriovenous Malformation in a Pediatric Patient

Arteriovenous malformations (AVMs) are defined as tortuous connections between arteries and veins that bypass the capillary system. Cerebral AVMs are rare with a general prevalence of 0.5%-1% with approximately one-fifth of these being diagnosed in infancy or childhood. Although most AVMs go undetected, the most common presenting symptom is hemorrhage. Despite a broad differential diagnosis for syncope described in the pediatric literature, there has been no report of AVM as the underlying etiology. We present a case of a seven-year-old female who presented with a single syncopal episode and was later found to have a large AVM involving mainly the thalamus on the right side and the basal ganglia with large intraventricular draining veins into the galenic venous system. To our knowledge, this is the only case reported of an AVM presenting as syncope in a pediatric patient.

Case Report of an Obstructive Hydrocephalus Caused by an Unruptured Mesencephalic Arteriovenous Malformation in a Boy and a Review of Literature

Objective

Arteriovenous malformation (AVM) is the most common form of intracranial vascular malformations in adults. Intracranial pediatric AVMs are rare. AVM located in the vicinity of the brain stem in children are even more rare.

Case report

This study reports a rare case of acute obstructive hydrocephalus following aqueductal stenosis caused by an unruptured grade IV perimesencephalic arteriovenous malformation. An 11-year-old boy admitted to the hospital with progressive headache, nausea and vomiting throughout a month. A Computerized Tomography (CT) showed an obstructive hydrocephaly. A Magnetic Resonance (MR) imaging revealed a mesencephalic AVM compressing the aqueduct. The patient deteriorated in hours and an emergency ventriculoperitoneal shunting was performed. He did well in the early postoperative period. AVM examined with Digital Subtraction Angiography (DSA) in detail for maintaining the definitive treatment by means of endovascular embolization, microsurgery and stereotactic radiosurgery; but the patient was lost to follow up.

Conclusion

A Pubmed search revealed 34 cases of hydrocephalus caused by an unruptured AVM in the literature, and only four cases were less than 18 years old with unruptured AVM locating in brain stem or posterior fossa. Although focal neurologic deficit, seizure and headache are the most common symptoms, acute neurologic deterioration due to hydrocephalus may be the presenting symptom in these cases. The decrease in intracranial pressure by changing the flow of cerebrospinal fluid (CSF) via an emergency ventriculoperitoneal (VP) shunting or Endoscopic Third Ventriculostomy (ETV) can be a lifesaving procedure that gives a chance for further treatment modalities.

Arteriovenous Malformation in a Youth with Atypical Autism Symptoms

Cerebral arteriovenous malformations (AVMs) present a challenge to diagnose in children with developmental disability, because of the overlap in behavioral symptoms and neurologic manifestations. They have been very rarely reported in conjunction with autism spectrum disorder. This case involves a 13 year old male with a history of autism spectrum disorder and significant behavioral issues diagnosed with a thalamic AVM following lateralizing neurologic symptoms. Despite radiosurgical treatment, hemorrhage followed consequently causing extensive neurologic injury and death. This case emphasizes the need for close follow up and coordination within a medical home for children with developmental disabilities. A multidisciplinary team approach is ideal to allow detection of subtle neurologic changes over time that may be masked as behavioral difficulties.

International multicenter cohort study of pediatric brain arteriovenous malformations. Part 1: Predictors of hemorrhagic presentation

OBJECTIVE Brain arteriovenous malformations (AVMs) are the most common cause of spontaneous intracranial hemorrhage in pediatric patients (age < 18 years). Since the cumulative lifetime risk of AVM hemorrhage is considerable in children, an improved understanding of the risk factors influencing hemorrhagic presentation may aid in the management of pediatric AVMs. The aims of this first of a 2-part multicenter, retrospective cohort study are to evaluate the incidence and determine the predictors of hemorrhagic presentation in pediatric AVM patients. METHODS The authors analyzed pooled AVM radiosurgery data from 7 institutions participating in the International Gamma Knife Research Foundation (IGKRF). Patients younger than 18 years at the time of radiosurgery and who had at least 12 months of follow-up were included in the study cohort. Patient and AVM characteristics were compared between unruptured and ruptured pediatric AVMs. RESULTS A total of 357 pediatric patients were eligible for analysis, including 112 patients in the unruptured and 245 patients in the ruptured AVM cohorts (69% incidence of hemorrhagic presentation). The annual hemorrhage rate prior to radiosurgery was 6.3%. Hemorrhagic presentation was significantly more common in deep locations (basal ganglia, thalamus, and brainstem) than in cortical locations (frontal, temporal, parietal, and occipital lobes) (76% vs 62%, p = 0.006). Among the factors found to be significantly associated with hemorrhagic presentation in the multivariate logistic regression analysis, deep venous drainage (OR 3.2, p < 0.001) was the strongest independent predictor, followed by female sex (OR 1.7, p = 0.042) and smaller AVM volume (OR 1.1, p < 0.001). CONCLUSIONS Unruptured and ruptured pediatric AVMs have significantly different patient and nidal features. Pediatric AVM patients who possess 1 or more of these high-risk features may be candidates for relatively more aggressive management strategies.

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.

Arteriovenous Malformations in the Pediatric Population: Review of the Existing Literature

Arteriovenous malformations (AVMs) in the pediatric population are relatively rare but reportedly carry a higher rate of rupture than in adults. This could be due to the fact that most pediatric AVMs are only detected after rupture. We aimed to review the current literature regarding the natural history and the clinical outcome after multimodality AVM treatment in the pediatric population, as optimal management for pediatric AVMs remains controversial. A multidisciplinary approach using multimodality therapy if needed has been proved to be beneficial in approaching these lesions in all age groups. Microsurgical resection remains the gold standard for the treatment of all accessible pediatric AVMs. Embolization and radiosurgery should be considered as an adjunctive therapy. Embolization provides a useful adjunct therapy to microsurgery by preventing significant blood loss and to radiosurgery by decreasing the volume of the AVM. Radiosurgery has been described to provide an alternative treatment approach in certain circumstances either as a primary or adjuvant therapy.

[Intraoperative fluid therapy in infants with congestive heart failure due to intracranial pial arteriovenous fistula]

Pial arteriovenous fistula is a rare intracranial congenital malformation (0.1-1: 100,000). It has a high blood flow between one or more pial arteries and drains into the venous circulation. It is usually diagnosed during the childhood by triggering an intracranial hypertension and/or congestive heart failure due to left-right systemic shunt. It is a rare malformation with a complex pathophysiology. The perioperative anaesthetic management is not well established. We present a 6-month-old infant diagnosed with pial arteriovenous fistula with hypertension and congestive heart failure due to left-right shunt. He required a craniotomy and clipping of vascular malformation. Anaesthetic considerations in patients with this condition are a great challenge. It must be performed by multidisciplinary teams with experience in paediatrics. The maintenance of blood volume during the intraoperative course is very important. Excessive fluid therapy can precipitate a congestive heart failure or intracranial hypertension, and a lower fluid therapy may cause a tissue hypoxia due to the bleeding.

Angioarchitectural Risk Factors for Hemorrhage and Clinical Long-Term Outcome in Pediatric Patients with Cerebral Arteriovenous Malformations

BACKGROUND

Intracranial arteriovenous malformation (AVM) in children is a rare diagnosis. Little is known about factors determining AVM rupture and appropriate treatment strategies to prevent hemorrhage and associated disability. Available data suggest that children are subject to an increased risk for AVM rupture compared with adults.

METHODS

In 46 pediatric patients with AVM, demographic factors, clinical presentation, angioarchitectural features, and treatment regimens as well as clinical and radiologic outcomes were retrospectively analyzed. First-line treatment option was microsurgical resection of the disease, with or without preoperative embolization.

RESULTS

Twenty-four boys (52.2%) and 22 girls (47.8%) with a mean age on admission of 12.4 years (4-18 years) were included. Mean follow-up was 4 years (median, 1.5; range, 0.1-16.4). Thirty-one children presented with intracerebral hemorrhage (67.4%). Small AVMs (<3 cm) ruptured in 83.3% (n = 25) and were shown to be more prone to hemorrhage than larger ones (P < 0.01). Small AVM size (P < 0.01; odds ratio [OR], 0.12; 95% confidence interval [CI] 0.02-0.59) and exclusive deep venous drainage (P < 0.01; OR, 29.74; 95% CI, 2.45-4445.34) were independent risk factors for hemorrhage in the presented cohort. Good long-term outcome was associated with a high score on the Glasgow Coma Scale on admittance (P < 0.05; OR, 0.148; 95% CI, 0.03-0.73).

CONCLUSIONS

Two-thirds of children with AVM are admitted with intracerebral hemorrhage. Microsurgical resection was successful as confirmed by radiologic studies in 95%, and 79.5% of patients presented in a good clinical condition on follow-up (modified Rankin Scale 0 or 1). Microsurgical treatment is recommended if the lesion is accessible and angioarchitectural risk factors favor definitive treatment.

Postoperative imaging for detection of recurrent arteriovenous malformations in children

OBJECT The optimal method for detecting recurrent arteriovenous malformations (AVMs) in children is unknown. An inherent preference exists for MR angiography (MRA) surveillance rather than arteriography. The validity of this strategy is uncertain. METHODS A retrospective chart review was performed on pediatric patients treated for cerebral AVMs at a single institution from 1998 to 2012. Patients with complete obliteration of the AVM nidus after treatment and more than 12 months of follow-up were included in the analysis. Data collection focused on recurrence rates, associated risk factors, and surveillance methods. RESULTS A total of 45 patients with a mean age of 11.7 years (range 0.5-18 years) were treated for AVMs via surgical, endovascular, radiosurgical, or combined approaches. Total AVM obliteration on posttreatment digital subtraction angiography (DSA) was confirmed in 27 patients, of whom the 20 with more than 12 months of follow-up were included in subsequent analysis. The mean follow-up duration in this cohort was 5.75 years (median 5.53 years, range 1.11-10.64 years). Recurrence occurred in 3 of 20 patients (15%). Two recurrences were detected by surveillance DSA and 1 at the time of rehemorrhage. No recurrences were detected by MRA. Median time to recurrence was 33.6 months (range 19-71 months). Two patients (10%) underwent follow-up DSA, 5 (25%) had DSA and MRI/MRA, 9 (45%) had MRI/MRA only, 1 (5%) had CT angiography only, and 3 (15%) had no imaging within the first 3 years of follow-up. After 5 years posttreatment, 2 patients (10%) were followed with MRI/MRA only, 2 (10%) with DSA only, and 10 (50%) with continued DSA and MRI/MRA. CONCLUSIONS AVM recurrence in children occurred at a median of 33.6 months, when MRA was more commonly used for surveillance, but failed to detect any recurrences. A recurrence rate of 15% may be an underestimate given the reliance on surveillance MRA over angiography. A new surveillance strategy is proposed, taking into account exposure to diagnostic radiation and the potential for catastrophic rehemorrhage.

Etiology, clinical characteristics and prognosis of spontaneous intracerebral hemorrhage in children: A prospective cohort study in China

BACKGROUND AND OBJECTIVE

Much is known about spontaneous intracerebral hemorrhage (SICH) in adults, but few studies have examined pediatric SICH, especially in China. The aim of the present study was to describe the etiology, clinical characteristics and prognosis of SICH in children from southwest China.

METHOD

Consecutive patients aged 1-18 years with SICH at our medical center were prospectively enrolled from January 2012 to June 2014. SICH was defined by WHO criteria and confirmed by CT or MRI findings. Demographic and clinical information was collected at baseline, and follow-up assessments were conducted at 3 and 6 months after SICH, when patients were scored on the modified Rankin Scale (mRS) and events of deaths and recurrent hemorrhagic stroke were recorded.

RESULTS

Among the 70 children (43 males; median age, 12.0 years) in the final analysis, 44 patients (62.9%) had SICH due to arteriovenous malformation, and less frequent etiologies were cavernous malformation (n=4), aneurysm (n=2), tumors (n=2), moyamoya (n=2), hemophilia (n=1), hypertension (n=1), while 14 (20.0%) had SICH of unknown etiology. The mortality rate at 3 months and 6 months was equal, which was both 3%. The rate of disability was 12.1% at 3 months and 9.1% at 6 months.

CONCLUSION

The most frequent etiology of pediatric SICH in this Chinese cohort was arteriovenous malformation. SICH of unknown etiology occurred much more often in our cohort than in previously published Caucasian patients in the US and Europe.

Intraoperative cerebral angiography in arteriovenous malformation resection in children: a single institutional experience

OBJECT

The use of cerebral intraoperative angiography has been described in resection of arteriovenous malformations (AVMs) in adults. More recently, studies have described experiences with intraoperative angiography in a small number of children. However, data on the safety and clinical utility of intraoperative angiography in the pediatric population remains limited in comparison with available data in adults. The aim of the study was to evaluate the use of cerebral intraoperative angiography in children undergoing AVM resection. The clinical utility of intraoperative angiography and procedure-related complications were evaluated.

METHODS

A retrospective review was performed for all patients undergoing cerebral AVM resection with intraoperative angiography at The Children's Hospital of Philadelphia between 2008 and 2012. Patient imaging and operative and medical notes were reviewed to evaluate for end points of the study. A total of 17 patients (8 males, 9 females) were identified, with a median age of 12.1 years (range 1.2-17.9 years) and median weight of 45.5 kg (range 12.1-78.9 kg).

RESULTS

A total of 21 intraoperative angiography procedures were performed for 18 AVM resections in 17 patients. The technical success rate was 94%. In 2 cases (11%), intraoperative angiography demonstrated a residual AVM, and repeat resections were performed. In both cases, no recurrent disease was noted on postoperative follow-up. One procedure-related complication (4.8%) occurred in 1 patient who was positioned prone. Recurrence to date was noted in 2 (14%) of the 14 cases with available postoperative follow-up at 3.5 and 4.7 months following resection with intraoperative angiography. The median follow-up time from intraoperative angiography to the most recent postoperative angiography was 1.1 years (range 4.3 months to 3.8 years).

CONCLUSIONS

Intraoperative angiography is an effective and safe adjunct for surgical management of cerebral AVMs in the pediatric population.

Anaesthesia for neurosurgical procedures in paediatric patients

Recent advances in neurosurgery, neuromonitoring and neurointensive care have dramatically improved the outcome in patients affected by surgical lesions of central nervous system (CNS). Although most of these techniques were applied first in the adult population, paediatric patients present a set of inherent challenges because of their developing and maturing neurological and physiological status, apart from the CNS disease process. To provide optimal neuroanaesthesia care, the anaesthesiologist must have the knowledge of basic neurophysiology of developing brain and effects of various drugs on cerebral haemodynamics apart from the specialised training on paediatric neuroanaesthesia. This article highlights on the perioperative management of paediatric neurosurgical patients.

Pediatric patients with poor neurological status and arteriovenous malformation hemorrhage: an outcome analysis

OBJECT

In general, patients who present with low Glasgow Coma Scale (GCS) scores and/or fixed and dilated pupils are not expected to do well following arteriovenous malformation (AVM) hemorrhage. However, there is a sense among neurosurgeons that pediatric patients may make a better recovery than adults following such an event. There have been few studies focusing on the outcome of pediatric patients with poor neurological status following AVM hemorrhage. The purpose of this study was to characterize functional outcome in pediatric patients with severe disability after AVM hemorrhage.

METHODS

This was a retrospective analysis of clinical presentation and outcome in 15 patients seen at the authors' pediatric hospital presenting with low GCS scores (defined as GCS ≤ 8) following AVM hemorrhage.

RESULTS

Initial GCS scores ranged from 3 to 6, and 11 of 14 patients had fixed pupils on clinical examination (data were not available in 1 patient). Eight of 15 patients suffered primarily a lobar hemorrhage, 3 suffered primarily infratentorial bleeding, 2 suffered primarily hemorrhages of the basal ganglia, and 2 suffered intraventricular hemorrhage. The overall mortality rate was 20% (3 of 15 patients). The clinical outcome of survivors was defined by the Pediatric Cerebral Performance Category (PCPC) and Pediatric Overall Performance Category (POPC) scores at follow-up. One year after AVM hemorrhage, 7 (58%) of the 12 surviving patients showed normal or mild disability (PCPC Score 1 or 2), whereas 5 (42%) of 12 patients had moderate or severe disability (PCPC Score 3 or 4). No patients were in a coma or vegetative state, and 11 (92%) of the 12 patients were functioning independently (POPC Score 1, 2, or 3) 1 year after AVM hemorrhage. All patients were functionally independent by last follow-up, with 8 patients (67%) in the normal or mild disability PCPC category, and 4 in the moderate category (PCPC Score 3). All 12 survivors made a meaningful recovery and went on to live independent lives.

CONCLUSIONS

Pediatric patients suffering AVM hemorrhage have a good outcome and are able to function independently, despite a poor neurological state initially.

Diagnosis and management of arteriovenous malformations in children

Arteriovenous malformation (AVM) is the most common cause of spontaneous intraparenchymal hemorrhage in children, excluding hemorrhages of prematurity and early infancy. Because most children diagnosed with an AVM undergo initial treatment emergently, the natural history of AVMs in the pediatric population is not well understood. Most pediatric AVMs do not come to clinical attention unless they hemorrhage. Therefore, their optimal management remains controversial. Children with intracranial AVMs represent a special challenge in that they harbor unacceptable lifelong risks of hemorrhage and potential neurologic deficits. Patients should be evaluated on a case-by-case basis to determine the best multidisciplinary treatment regimen that can be used to preserve neurologic function and eradicate the AVM with the lowest risk of mortality. Successful treatment depends on the location and size of the AVM, its hemodynamic properties, the clinical condition of the patient, and the treatment modality selected. The armamentarium for AVM management has grown with technological advances and now includes microsurgical resection, endovascular embolization, radiosurgery, or any combination of these modalities. Microsurgical resection remains the gold standard for treatment of accessible pediatric AVMs, especially in cases that present with intracranial hemorrhage. Newer modalities, such as embolization and radiosurgery, have provided additional tools to help children with large or deep-seated lesions that would be deemed unresectable with microsurgical techniques alone. Long-term follow-up with repeated diagnostic imaging is important despite complete obliteration of the lesion to rule out the small possibility of AVM recurrence.

Gamma Knife surgery for arteriovenous malformations in children

OBJECT

The aim of this study was to evaluate the long-term imaging and clinical outcomes of intracranial arteriovenous malformations (AVMs) in children treated with Gamma Knife surgery (GKS).

METHODS

Between 1989 and 2007, 200 patients with AVMs who were 18 years of age or younger were treated at the University of Virginia Health System. Excluding 14 patients who had not reached 2-year follow-up, 186 patients comprised this study. Hemorrhage was the most common presenting symptom leading to the diagnosis of AVMs (71.5%). The mean nidus volume was 3.2 cm(3) at the time of GKS, and a mean prescription dose of 21.9 Gy was used.

RESULTS

After initial GKS, 49.5% of patients achieved total angiographic obliteration. Forty-one patients whose AVM nidi remained patent underwent additional GKS. The obliteration rate increased to 58.6% after a second or multiple GKS. Subtotal obliteration was achieved in 9 patients (4.8%). Forty-nine patients (26.3%) still had a patent residual nidus. In 19 patients (10.2%), obliteration was confirmed on MR imaging only. Ten patients had 17 hemorrhages during the follow-up period. The hemorrhage rate was 5.4% within 2 years after GKS and 0.8% between 2 and 5 years. Six patients developed neurological deficits along with the radiation-induced changes. Two patients developed asymptomatic meningiomas 10 and 12 years after GKS. After a mean clinical follow-up of 98 months, less than 4% of patients had difficulty attending school or developing a career.

CONCLUSIONS

Gamma Knife surgery offers a reasonable chance of obliteration of an AVM in pediatric patients. The incidence of symptomatic radiation-induced changes is relatively low; however, long-term clinical and imaging follow-up is required to identify delayed cyst formation and secondary tumors.

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.

Gamma Knife surgery for intracranial arteriovenous malformations in children: a retrospective study in 103 patients

OBJECT

This retrospective study was designed to study the outcome in children with intracranial arteriovenous malformations (AVMs) treated with Gamma Knife surgery (GKS).

METHODS

One hundred and forty-two children were treated with GKS at the authors' institution between April 1997 and March 2006; of these, 103 patients with a mean follow-up of 26.4 months (range 6-96 months) were included. The mean age at presentation was 13.9 years (range 3-18 years). Eighty-six (83%) patients presented with hemorrhage. In 57 children the AVMs were Spetzler-Martin Grade I or II, and in 46 the AVMs were Grades III, IV, or V. The mean volume of the AVMs was 2.4 ml (range 0.04-23.3 ml). The mean marginal dose administered was 24.4 Gy (range 15-27 Gy). Follow-up angiography was advised at 2 years after GKS and yearly thereafter. In patients with residual AVMs, follow-up angiography was advised yearly until 4 years after GKS. If residual AVM was present, even on a follow-up angiogram obtained 4 years postsurgery, the GKS was considered a failure.

RESULTS

Complete obliteration of the AVM was documented in 34 (87%) of the 39 patients with complete angiographic follow-up. The 3- and 4-year actuarial rates of nidus obliteration were 66 and 86% respectively. Three patients (2.9%) experienced bleeding during the latency period, and symptomatic radiation-induced edema was noted in four patients (3.8%). A significantly higher incidence of radiation edema was noted in patients with AVM volumes greater than 3 ml and in patients with Spetzler-Martin Grade IV and V AVMs.

CONCLUSIONS

Gamma Knife radiosurgery is an effective modality for the treatment of intracranial AVMs in children, yielding high obliteration rates and low complication rates.

ROLE OF RADIOSURGERY IN THE MANAGEMENT OF CEREBRAL ARTERIOVENOUS MALFORMATIONS IN THE PEDIATRIC AGE GROUP

OBJECTIVE

To assess the safety and efficacy of radiosurgery for the management of arteriovenous malformations (AVMs) in the pediatric age group.

METHODS

We reviewed data from 100 children (44 girls and 56 boys) presenting a total of 103 AVMs treated by linear accelerator radiosurgery between December 1988 and May 2002. The median patient age was 12 years (range, 2–16 yr). Sixty-seven AVMs (65%) were in functional locations and 30% were inoperable. The mean AVM volume was 2.8 cm3 (range, 0.9–21.3 cm3). The mean marginal dose was 23 Gy (range, 15–25 Gy) and required between one and four isocenters. Fifty patients received multimodal treatments with embolization and/or surgery before and/or after radiosurgery. Given that 16 patients underwent two sessions of radiosurgery and one patient received three sessions, a total of 119 radiosurgical treatments were delivered. We maintained our clinical and angiographic follow-up for at least 36 months after irradiation or until the complete obliteration of the AVM was confirmed by angiography (our sole end point for judging clinical efficacy). Univariate and multivariate analysis were performed to determine predictive factors for obliteration.

RESULTS

Complete obliteration was achieved for 72 AVMs (70%). The permanent neurological deficit rate was 5%. One patient died because of rebleeding. None of our patients presented bleeding after an angiographically verified AVM obliteration. The main predictive factors for obliteration were low AVM volume and no previous embolization. Moreover, the younger the patient, the more effective the radiosurgery seemed to be.

CONCLUSION

Radiosurgery is a safe and effective treatment for AVMs in the pediatric age group. One criterion for success was the use of a prescription dose similar to that used with adult populations.

Transient sixth nerve palsies and torticollis secondary to parietal arteriovenous malformation

Arteriovenous malformations (AVMs) can compress on any intracranial structures, and the presence and nature of ophthalmologic symptoms and signs depend on the size and location of the AVMs. We report an 11-month-old girl with parietal fistulous AVM, transient bilateral sixth nerve palsies and torticollis. The postoperative period was uneventful and she was discharged in a good condition. The patient recovered from transient bilateral abducens nerve palsies and torticollis; she was asymptomatic during the 18-month follow-up period.

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.

Congenital supratentorial meningeal arteriovenous malformation with hemangioma and massive arachnoid cell hyperplasia

CASE REPORT

We describe the clinical, radiological and pathological findings of concurrent, congenital leptomeningeal arteriovenous malformation with hemangioma diagnosed in a newborn by prenatal and immediately postnatal magnetic resonance imaging. Vascular abnormalities were accompanied by massive arachnoidal cell hyperplasia reminiscent of meningioma.

CONCLUSION

To the best of our knowledge, this is the first case of such a lesion reported in the literature.

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.

Spontaneous intracranial haemorrhage in children: aetiology, presentation and outcome

We are aware of only few reports addressing spontaneous intracranial haemorrhage (SICH) in non-selected series of children. This is a retrospective analysis of clinical presentation and outcome in 34 children with SICH seen in the period 1990-2000 in our hospital. Traumatic, neonatal and subdural haemorrhages were excluded. The majority (47%, 16/34) of SICH was caused by an arteriovenous malformation (AVM). SICH was presented as an acute event in 53% (17/32) of patients. Forty-seven percent (15/32) of the cases had protracted courses, which made the diagnosis difficult. In our series, younger children had less specific symptoms. Mortality (25%, 8/32) and morbidity were considerable, particularly in infratentorial haemorrhages, in aneurysms, in children younger than 3 years and in those with underlying haematological disorders.

Neuropsychological function and brain arteriovenous malformations: redefining eloquence as a risk for treatment

Arteriovenous malformations (AVMs) of the brain, thought to begin during fetal development and undergo an unclear maturation process; most often do not become symptomatic until the patient reaches adulthood. Authors of recent prospective studies have suggested that relatively few patients present with neuropsychological abnormalities in the absence of hemorrhage. In general, neuropsychological evaluations in patients with AVMs have yielded mixed results with respect to localization of function, and the authors of most cognitive studies have not been able to demonstrate the nature and degree of impairment seen in acute ischemic stroke in comparable brain regions. Superselective Wada testing prior to therapeutic embolization, functional imaging studies, and intrasurgical cortical mapping have shown redistribution of language and memory to unpredictable regions. Developmental cognitive history in these patients indicates that most will have at least some background of learning problems during the school-age years with varying degrees of severity, reflecting a time when brain reorganization may be occurring. These data suggest that traditional assumptions about the eloquence of brain regions may not hold for patients with AVMs and that establishing treatment risk in the individual patient needs to be made on an empirical basis.

Pediatric neurologic emergencies

Neuroemergencies are life-threatening situations in which, whatever the cause, common pathologic phenomena result in secondary brain lesions. The goal of critical care management is to stop these self-aggravating processes as soon as possible. Initial resuscitation is devoted to control of the airway and hemodynamic and hydroelectrolytic stabilization. With mass lesions, minimal computed tomographic exploration immediately precedes surgical decompression. Further critical care adapted to the child's needs requires multimodal monitoring. Normoventilation, deep sedation, osmotherapy with mannitol or hypertonic saline solutions, and optimization of mean arterial pressure are the basis of management. A purely pressure-driven approach aimed at controlling cerebral perfusion pressure could be potentially harmful, and associated measurement of blood flow velocity with transcranial Doppler and jugular bulb oxygen saturation monitoring allows an approach to cerebral blood flow and metabolism. Outcome can be improved in dangerous situations such as severe brain injuries, cerebral arteriovenous malformation rupture, status epilepticus, and acute hydrocephalus, provided that emergency management could be applied efficiently.

Language hemispheric dominance in patients with congenital lesions of eloquent brain

OBJECTIVE

In 90% of normal subjects, the left hemisphere is dominant for language function. We investigated whether congenital lesions of the left perisylvian regions altered cortical language representation in right-handed individuals.

METHODS

Using functional magnetic resonance imaging, we studied language hemispheric dominance in five right-handed adult patients with congenitally acquired arteriovenous malformations (AVMs) originating from left hemispheric cortical language regions. The AVMs had not caused neurological symptoms during early development, but patients presented as adults with migraine, seizure, or minor hemorrhage. Results obtained from the AVM patients were contrasted to those from right-handed brain-injured stroke patients recovering from aphasia and to those from right-handed normal subjects.

RESULTS

During silent picture naming and verb generation tasks, cortical language networks lateralized primarily to the right hemisphere in the AVM group, compared with the left hemisphere in the normal group. This right hemisphere-shifted language network in the AVM group exceeded the shifts toward right hemispheric dominance found in the stroke group.

CONCLUSION

Patients with AVMs affecting the left perisylvian regions recruited the right hemisphere into language processing networks during early development, presumably in response to congenitally aberrant circulation. This early right hemisphere recruitment in the AVM patients exceeded the similar process in the brains of stroke patients whose left cortical language networks were damaged in adulthood. Our data provide evidence of effective plasticity in the developing human brain compared with the mature brain response to injury. Knowledge of cortical language representation should assist presurgical planning in patients with developmental anomalies affecting apparently language-dominant brain regions.

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.

[Focalized multiple beam radiotherapy: an alternative in the treatment of deep cerebral arteriovenous malformations]

BACKGROUND

Cerebral arteriovenous malformations are usually treated by excision or selective embolization. Some untreatable malformations may be presently cured by radiosurgery.

CASE REPORT

A 10-year-old girl without previous illness suffered from a sudden quadriventricular hemorrhage due to arteriovenous malformation. Initially the child recovered with symptomatic treatment. Neurosurgery and arterial embolization being impossible, Gamma-Unit treatment was performed. Treatment was first well tolerated but 8 months later, left hemiparesis and language disorders occurred, due to radionecrosis. These complications were dramatically improved by corticosteroids.

CONCLUSION

Gamma-Unit treatment can be successfully proposed for treating those malformations that are inaccessible to surgery or embolization.