Surgical management of pediatric cerebral arteriovenous malformations

Timing of Embolization, Radiosurgery, and Resection of Arteriovenous Malformations in Pediatric Patients: A Retrospective, Descriptive Study

OBJECTIVE

Cerebral arteriovenous malformations (AVMs) are a challenging pathology in pediatric patients, carrying a high risk of morbidity and mortality. Treatment modalities include resection, endovascular embolization, and stereotactic radiosurgery. There is currently no consensus favoring one modality over another. Timing of multimodal therapy with embolization/stereotactic radiosurgery and resection is not well explored in the literature. We present a series of pediatric patients with AVMs, with special attention directed to the timing of treatment.

METHODS

Electronic medical records of all pediatric patients (<18 years old at treatment) with AVMs treated at our institution were retrospectively reviewed after institutional review board approval. Demographic information, AVM characteristics, treatment variables, and outcomes were recorded.

RESULTS

In our cohort of 27 patients, 21 (77.8%) presented with a ruptured AVM. Of these patients, 6 (28.6%) had a Glasgow Coma Scale score of 3-10 and underwent treatment within 24 hours of presentation, and 10 (47.6%) with a Glasgow Coma Scale score of 12-15 were treated between 24 and 120 hours after presentation. The remaining 5 patients (23.8%) were treated 3 weeks to 14 months after AVM rupture. Regardless of rupture status, 96% of our cohort had a modified Rankin Scale score of 1-2 at most recent follow-up.

CONCLUSIONS

We present our institution's experience with pediatric AVMs, focusing on the timing of treatment. Based on our experience, early treatment of AVMs seems to be safe and effective regardless of rupture status.

An "over-fused middle cerebral artery" anomaly: a case report

BACKGROUND

MCA has several anomalies, such as accessory MCA, duplicated MCA and twig-like MCA, up to now all these reported anomalies were hypothesized to due to the failure in fusion of the primitive arterial network. No anomaly of over fused MCA has been reported.

CASE PRESENTATION

A 59- year- old male was hospitalized with a history of paroxysmal slurred speech and left side headache for a week, his blood pressure was 160/80 mmHg and he manifested mild incomplete motor aphasia at the time of admission. The head and neck CTA and DSA all presented a huge and tortuous left MCA, we diagnosed it an anomaly and termed it over-fused MCA. The patient's speech impairment and headache were relieved by controlling his blood pressure.

CONCLUSIONS

Such an anomaly of over-fused MCA is reported for the first time, it's not needed to put special intervention on the anomaly of the patient temporarily, but more observation are needed.

Long-term outcomes in pediatric unruptured brain arteriovenous malformation treated by nonconservative management: a single center analysis

PURPOSE

The best management of pediatric unruptured brain arteriovenous malformations (ubAVM) should be further elucidated.

METHODS

Pediatric patients who presented to our facility with ubAVM and were treated nonconservatively were retrospectively analyzed regarding demographics, presenting symptoms, AVM characteristics, treatment modality, and outcome.

RESULTS

Thirteen patients were included. There were 9 male and 4 female patients with an average age (± SD) of 7.8 ± 4.6 years. The most common presenting symptom was seizure. The mean Spetzler Martin (SM) grade was 3.2. Seven patients were treated by surgical excision, 8 by embolization, 6 by radiosurgery, and during the mean follow-up period of 8.9 years (2.6-14.4 years), there were no hemorrhage. Complete ubAVM obliteration was achieved in all 7 patients (100%) who underwent surgical excision. AVM was obliterated in 5 out of 9 patients whose SM grade was 3 or 4. Modified Rankin scale was good (mRS 0-2) in all 13 patients.

CONCLUSIONS

Since the lifetime hemorrhage rate of pediatric ubAVM is high, it may be better to proceed with nonconservative treatment, especially when surgical excision is amenable. Nonconservative treatment could be an appropriate treatment with acceptable neurological outcome even in those with moderate to high-grade AVMs in selected cases.

The factors associated with hemorrhagic presentation in children with untreated brain arteriovenous malformation: a meta-analysis

OBJECTIVE Rupture of arteriovenous malformations (AVMs) would result in high mortality and prevalence of disability in pediatric patients. Decisions regarding the treatment of AVMs need to weigh the risk of rupture over the course of their natural history against the possibility of creating a lesion during treatment. Multiple factors have been proposed to predict hemorrhagic presentation of pediatric patients with AVMs. The aim of this meta-analysis was to evaluate the predictors of hemorrhagic presentation in pediatric patients with AVMs. METHODS The authors searched the PubMed and EMBASE databases. Studies reporting the predictors of hemorrhagic presentation in children with untreated brain AVMs were included. The predictive ability of identified predictors was assessed by odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS A higher risk of hemorrhagic presentation was found in AVMs with smaller size (< 3 cm, OR 2.97, 95% CI 1.94–4.54, p < 0.00001), deep venous drainage (OR 2.28, 95% CI 1.55–3.36, p < 0.0001), a single draining vein (OR 2.23, 95% CI 1.27–3.92, p = 0.005), a single feeder (OR 3.72, 95% CI 1.31–10.62, p = 0.01), a deep location (OR 1.82, 95% CI 1.22–2.72, p = 0.004), an infratentorial location (OR 2.25, 95% CI 1.19–4.26, p = 0.01), and diffuse morphology (OR 8.94, 95% CI 3.01–26.55, p < 0.0001). In addition, the AVMs with draining vein ectasia (OR 0.35, 95% CI 0.13–0.97, p = 0.04) and high Spetzler-Martin (SM) grade (OR 0.53, 95% CI 0.36–0.78, p = 0.001) had a lower risk of hemorrhagic presentation in pediatric patients. CONCLUSIONS Smaller AVMs, deep venous drainage, a single draining vein, a single feeder, deep/infratentorial location, diffuse morphology, and high SM grade were identified as positive predictors for hemorrhagic presentation. Particularly, patients with diffuse AVMs have a higher risk of hemorrhagic presentation than other factors and may need active treatments. However, factors such as age, sex, draining vein stenosis, and associated aneurysms were not associated with hemorrhagic presentation. ABBREVIATIONS AVM = arteriovenous malformation; CI = confidence interval; NOS = Newcastle-Ottawa Scale; OR = odds ratio; SM = Spetzler-Martin.

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.

Factors associated with seizure occurrence and long-term seizure control in pediatric brain arteriovenous malformation: a retrospective analysis of 89 patients

Background

Few studies have examined seizures in pediatric brain arteriovenous malformation. In our study, risk factors associated with seizure occurrence and long-term seizure control outcomes after different treatments in pediatric arteriovenous malformation patients were investigated.

Methods

A retrospective analysis was conducted with clinical data from a cohort of 89 pediatric brain arteriovenous malformation patients acquired between 2008 and 2013. Univariate and multivariate analyses were used to assess risk factors associated with seizure incidence. Patients who presented with seizure before treatment were evaluated using the Engel classification during the follow-up period.

Results

A higher risk of seizure occurrence was observed in large size and unruptured brain arteriovenous malformations using multivariate logistic regression analysis (p < 0.05). A total of 22 children, who presented with seizure before the interventions, were included in subsequent analysis. During a mean follow-up period of 2.3 years after the intervention, 12 (55 %) of these children were classified as Engel class I after treatment.

Conclusions

Seizures were the most common symptom in unruptured bAVMs. Size of the brain arteriovenous malformation is highly significant to seizure occurrence. Patients with cerebral hemorrhage are prone to having an acute seizure occurrence. The different therapies examined all improved seizure control to varying degrees.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0402-5) contains supplementary material, which is available to authorized users.

Gamma Knife Radiosurgery for Pediatric Arteriovenous Malformations: A Canadian Experience

BACKGROUND

Gamma Knife (GK) radiosurgery for pediatric arteriovenous malformations (AVM) of the brain presents a non-invasive treatment option. We report our institutional experience with GK for pediatric AVMs.

METHODS

We performed a retrospective review of all pediatric patients treated with GK for cerebral AVMs at our institution from November 2003 up to and including September 2014. Patient demographics, AVM characteristics, treatment parameters and AVM responses were recorded.

RESULTS

Nineteen patients were treated, with 4 lost to follow-up. The mean age was 14.2 years (range. 7-18 years), with 10 being males (52.6%). The mean AVM diameter and volume were 2.68 cm and 3.10 cm3 respectively. The mean Spetzler-Martin (SM) and Pollock grades of the treated AVMs were 2.4 and 0.99 respectively. The mean follow-up was 62 months. All AVMs treated demonstrated a response on follow-up imaging. Nine of 15 (60.0%) patients displayed obliteration of their AVMs. Nine of 11 patients with a minimum of 3 years follow-up (81.8%) displayed obliteration, with SM and Pollock grades correlating to the chance of obliteration in this group. Two patients developed post-GK edema requiring short course dexamethasone therapy. No other major complications occurred. No permanent complications occurred.

CONCLUSIONS

GK radiosurgery for pediatric AVMs offers a safe and effective treatment option, with low permanent complication rates during early follow-up.

Surgery for a giant arteriovenous malformation without motor deterioration: preoperative transcranial magnetic stimulation in a non-cooperative patient

Transcranial magnetic stimulation (TMS) is a noninvasive activation method that is increasingly used for motor mapping. Preoperative functional mapping in vascular surgery is not routinely performed; however, in cases of high-grade arteriovenous malformations (AVMs), it could play a role in preoperative decision making. A 16-year-old male was suffering from a giant, right-sided insular, Spetzler-Martin Grade V AVM. This patient's history included 3 hemorrhagic strokes in the past 3 years, resulting in Medical Research Council Grade 2-3 (proximal) and 2-4 (distal) paresis of the left side of the body and hydrocephalus requiring a ventriculoperitoneal shunt. Preoperative TMS showed absent contralateral innervation of the remaining left-sided motor functions. Subsequently, the AVM was completely resected without any postoperative increase of the left-sided paresis. This case shows that TMS can support decision making in AVM treatment by mapping motor functions.

Brain arteriovenous malformation modeling, pathogenesis, and novel therapeutic targets

Patients harboring brain arteriovenous malformation (bAVM) are at life-threatening risk of rupture and intracranial hemorrhage (ICH). The pathogenesis of bAVM has not been completely understood. Current treatment options are invasive, and ≈ 20 % of patients are not offered interventional therapy because of excessive treatment risk. There are no specific medical therapies to treat bAVMs. The lack of validated animal models has been an obstacle for testing hypotheses of bAVM pathogenesis and testing new therapies. In this review, we summarize bAVM model development and bAVM pathogenesis and potential therapeutic targets that have been identified during model development.

Safety and Efficacy of Onyx Embolization for Pediatric Cranial and Spinal Vascular Lesions and Tumors

BACKGROUND:

Although Onyx is widely used to embolize vascular lesions in adults, the safety and efficacy of this liquid embolic agent for use in children are not well studied.

OBJECTIVE:

To report our experience using Onyx in pediatric patients for a variety of cranial and spinal vascular lesions and tumors to determine its procedural complication rates, types, and clinical consequences and to highlight the indications for and principles of Onyx embolization in pediatric patients.

METHODS:

All pediatric Onyx embolization cases performed consecutively by the neuroendovascular services at our 2 institutions over a 5-year period were collected retrospectively and analyzed.

RESULTS:

Over the study period, 105 Onyx embolization procedures were performed in 69 pediatric patients with a mean follow-up of 112 days. Fifty-two patients harbored “primary” vascular lesions (malformations, fistulas, etc), whereas 17 patients had tumors. Complications occurred in 25 of 105 procedures (23.8%) and included ischemic infarct (7), asymptomatic nontarget embolization (4), intracerebral hemorrhage (3), microcatheter-related vessel perforation (3), retained microcatheter (2), cerebral edema (2), dimethyl sulfoxide-induced pulmonary edema (2), facial ischemia (1), and contrast-induced bronchospasm (1). Neurological morbidity occurred transiently after 10 procedures (9.5%) and permanently after 2 procedures (1.9%). There were no procedure-related deaths. Statistical analysis revealed no predictors of complications among the multiple potential risk factors evaluated.

CONCLUSION:

Our experience suggests that Onyx can be used effectively for embolization of pediatric cranial and spinal vascular lesions and tumors with low permanent morbidity; however, attention must be paid to the technical nuances of and indications for its use to avoid potential complications.

Recurrence of a paediatric arteriovenous malformation 9 years postcomplete excision: case report and review of literature

Cerebral arteriovenous malformations (AVMs) are a common congenital vascular anomaly, which often present in both children and adults. Surgery is considered curative once postoperative angiography confirms the absence of vessels. We describe a 6-year-old girl, who had a Spetzler-Martin Grade II AVM resected successfully, in which a recurrent AVM was detected on routine follow-up over 9 years post excision. The aetiopathogenesis of this rare occurrence with a review of literature is discussed. Long-term postoperative follow-up in the form of MRI/MR angiogram is recommended for all fully resected AVMs in the paediatric age group, anticipating the possibility of future recurrence.