Long-term hemorrhagic risk in pediatric patients with arteriovenous malformations

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Compared with the general population, the specific natural history of arteriovenous malformations (AVMs) in pediatric patients is less well understood. Furthermore, few pediatric studies have compared posttreatment hemorrhagic risk and functional outcome across different treatment modalities. The objective of this study was to elucidate these points.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>The authors retrospectively reviewed all pediatric patients with AVMs evaluated at their institution between 1990 and 2013. The AVM natural history was represented by hemorrhagic risk during the observation period. For treated patients, the observation period was defined as the interval between diagnosis and treatment. Posttreatment hemorrhagic risk and functional outcomes were also assessed.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>A total of 124 pediatric patients with AVMs were evaluated, and 90 patients (72.6%) were retained through follow-up. The average patient age was 13.3 ± 3.8 years, with a mean follow-up period of 9.95 years. The overall AVM obliteration rate was 59.7%. Radiosurgery had an obliteration rate of 49.0%. Thirteen patients were managed conservatively. Four patients under observation hemorrhaged during a total interval of 429.4 patient-years, translating to an annual risk of 0.9%. Posttreatment hemorrhagic risk by treatment modalities were categorized as follows: surgery ± embolization (0.0%), radiosurgery ± embolization (0.8%), embolization alone (2.8%), surgery + radiosurgery ± embolization (3.5%), and observation (0.8%). A significantly higher risk of posttreatment hemorrhage was observed for patients with hemorrhagic presentation (p = 0.043) in multivariate analysis. Seizure presentation, frontal lobe location, nonheadache presentation, and treatment modality were significantly associated with increased risk of poor functional outcomes.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>In this study of pediatric patients with AVMs, the natural history of hemorrhage was relatively low at 0.9%. Resection remained the optimal management for hemorrhage control and functional outcome perseverance in these pediatric patients with AVMs. AVM obliteration is a valid treatment goal, especially for patients with ruptured presentation, to prevent further hemorrhages later in life.</jats:p></jats:sec>

Morbidity after Hemorrhage in Children with Untreated Brain Arteriovenous Malformation

“…During treatment-free follow-up, the annual rate of subsequent severe hemorrhage (overall 1.0%, conservative observation subgroup 0.5%) and annual rupture rate (2.8%) in this pediatric cohort (Table 2) were similar to that quoted in other study of patients of all ages (severe hemorrhage rate of 1.4% and rupture rate of 2–4%) [19–21]. However, the cumulative rupture risk and morbidity could be high, given the long life expectancy of pediatric patients.…”

High-Flow Vascular Malformations in Children

“…The prevalence of brain AVMs is estimated to be 10 to 18 per 100,000 people, 29,30 and although the annual rate of hemorrhage is estimated to be between 2 and 4%, AVMs are the leading cause of nontraumatic intracranial hemorrhage in children. [6][7][8][9]11,[31][32][33][34][35][36] However, for lesions that previously bled and were not treated, the risk of rehemorrhage was estimated to be 11.5% per patient-year. 37 For AVMs harboring multiple high-risk features (such as prior hemorrhage, deep venous drainage, and deep AVM location), the annual hemorrhage rate may be as high as 34.4%.…”

“…33 Recent studies in children and adolescents have reported an annual rate of hemorrhage from 0.9 to 6.3%. 6,7 However, all hemorrhage estimates are inherently limited by selection bias, as lesions with a low treatment risk or high hemorrhage risk are more often selected for treatment. Features such as a deep location, purely deep venous drainage, associated aneurysms, or prior bleeding may substantially increase the risk of bleeding.…”

“…A greater proportion of children present as the result of spontaneous hemorrhage. [6][7][8][9] The exact pattern of neurologic symptoms is dependent on lesion location and size of the hemorrhage, but may include headache, seizure, weakness, numbness, visual disturbances, or cranial neuropathies. With hemorrhage, neurologic findings are often sudden in onset and may be accompanied by clinical signs such as severe headache, nausea, vomiting, and alterations in mental status caused by raised intracranial pressure.…”

“…adults present as the result of rupture, and AVMs are the leading cause of nontraumatic intracerebral hemorrhage in children. [6][7][8][9][10] In patients presenting with spontaneous hemorrhage, treatment is usually considered, since the strongest predictor of a future AVM hemorrhage is a prior hemorrhage. In those patients whose AVM is identified without a prior hemorrhage, the annual likelihood of hemorrhage is low, but the cumulative risk over a child's lifetime is likely to be substantial, and treatment is often favored if the risks are acceptable.…”