Onyx embolization of intracranial arteriovenous malformations in pediatric patients

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The authors undertook this study to assess the safety and efficacy of Onyx embolization in the treatment of intracranial arteriovenous malformations (AVMs) in pediatric patients.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>All pediatric Onyx embolization of intracranial AVM cases performed consecutively at a single children's hospital over a 5-year period were collected and evaluated.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Twenty-five patients (mean age 10.5 years) underwent a total of 38 procedures. An aggregate of 56 pedicles were embolized (mean 1.47 per session). The Spetzler-Martin grade was determined in all cases. Onyx embolization resulted in complete obliteration of the AVM in 3 cases (12%) and partial obliteration in 22 cases (88%). A total of 23 patients underwent surgical treatment. The mean preoperative AVM devascularization in these cases was 72%. One patient was treated with radiosurgery following Onyx embolization. Overall, 10 complications occurred in a total of 38 procedures (26.3%). None of the complications resulted in permanent neurological morbidity. The rate of transient neurological complications was 10.5% (4 of 38 procedures) and the rate of transient nonneurological complications was 5.3% (2 of 38 procedures). The remaining 4 complications were clinically silent (rate of 10.5%). There were no procedure-related deaths in this study population. There was no significant difference in patients with and without complications in terms of demographic characteristics, AVM grade, or embolization features (p ≥ 0.2). Deep venous drainage was associated with higher complication rates (p <jats:italic>=</jats:italic> 0.03).</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Onyx utilization is feasible for preoperative or primary embolization in the treatment of pediatric intracranial AVMs; however, the spectrum of complications encountered is broad, and attention must be paid to the technical nuances of and indications for its use to avoid many potential dangerous effects. Although the overall complication rates were higher than expected, all were either clinically silent or had only transient clinical effects. Thus, this experience suggests that Onyx embolization can be performed safely with a low rate of permanent morbidity in pediatric patients harboring these difficult lesions.</jats:p></jats:sec>

Safety of neuroangiography and embolization in children: complication analysis of 697 consecutive procedures in 394 patients

“…This type of complication is in no way unique to children, with the adult literature reporting the risk of postembolization hemorrhage after AVM embolization to be 4%-12%. 8,13,21,23,31 Putative causes of postembolization hemorrhage in adults, such as a high volume of embolic agent administered, 23 are likely equally applicable to children. In our experience, several factors contributed to the low complication rate after the neurointerventions we report here.…”

“…Recent reports have described the risks of endovascular embolization in children with specific individual diagnoses, 1,6,10,31 but an overall evaluation of the safety profile of all neurointerventional procedures in children has not been performed. In the present study, we reviewed our experience with diagnostic cerebral angiography and neurointerventions in children to assess whether the aforementioned challenges translate into an elevated morbidity rate in pediatric patients.…”

Microsurgical treatment of arteriovenous malformations in pediatric patients: the Boston Children's Hospital experience

“…A recent study of 25 children undergoing 38 procedures for Onyx embolization of AVMs reported an overall obliteration rate of 12%, with a procedural complication rate of 26.3% and no permanent neurological morbidity. 35 Given the potential for long-term AVM recurrence in children, even if complete angiographically confirmed obliteration is serendipitously achieved, we would proceed to resection, wherever feasible, regardless of the postembolization angiographic appearance. Complete obliteration is not the primary goal of our embolization sessions.…”

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

“…Although AVMs are less common in kids [5], they are still considered the most frequent abnormality of intracranial circulation in childhood [16], and they are the most common cause of spontaneous intraparenchymal hemorrhage in children. Pediatric AVMs could also present with recurrent seizures or headaches [17,18,19,20,21]. The natural history of AVMs in children is not well studied or understood; in part, this might be due to the initial emergent therapy of these lesions.…”

“…The complication rates after endovascular embolization could be as high as 26% (table 3) [18]. None of the cases reported has a permanent neurological deficit or died, and all complications resolved over time [19,53].…”