Retrospective review of the clinical presentation and outcome of intracranial arteriovenous malformations (AVMs) and aneurysms in the paediatric and infantile populations

An intracranial arteriovenous malformation (AVM) is a web of blood vessels with no intervening capillary bed, arising from a maldevelopment of the embryonic vascular plexus. An aneurysm is a balloon-like dilatation or outpouching of a blood vessel due to disease, defect or injury. Cerebral AVMs and aneurysms often present in a state of medical emergency; approximately one third of AVMs in childhood present acutely [53] and eighty percent of paediatric aneurysms present with SAH [30]. There is a 2-3% per year chance of an unruptured AVM bleeding with a risk of death of about 1% [88] and a 1% per year chance of an unruptured aneurysm 7 to 10mm in diameter bleeding, with this risk increasing with increasing size [55]. Despite the importance of immediate action to address most AVMs and aneurysms, significant delays in diagnosis have been demonstrated and have an influence on the outcome of a patient [69, 86]. It is therefore important for clinicians to have a high index of suspicion regarding these types of conditions.

We conducted a retrospective review of all children admitted to the Royal Children’s Hospital with AVMs or aneurysms during August 1993 until June 2005. There were 79 patients in total - 11 aneurysms, 54 AVMs and 14 Vein of Galen aneurysmal malformations (VGAMs). The latter study group was excluded. The AVM study group consisted of 32 males and 22 females and ages ranged from 2 days to 17 years (mean 8.8 years). The aneurysm study group was much smaller with 9 males and 2 females; ages ranged from 8 months to 16 years (mean 8.2 years). Within the AVM population, the most common presenting problems were haemorrhage (67%), headache (65%), and loss of consciousness (35%). Within the aneurysm population, the most common problems were headache (64%), haemorrhage (55%) and focal neurological deficit (45%). The combined mortality for children presenting at the RCH with either an AVM or aneurysm was 11% (7/65, 95% CI 4% to 21%), comparable with existing literature. Using Fisher’s exact and the Mann-Whitney U (Wilcoxon rank-sum) tests, presentation with coma was associated with death to a high degree (p value = 0.000 6). Glasgow Coma Scale scores were significantly lower in the deceased group than in the live group (p value = 0.004 7). Haemorrhage (p value = 0.21), gender (p value = 0.25), type of vascular malformation (p value = 0.59) and age (p value = 0.50) showed a much weaker correlation with death.

AVMs and aneurysms present in a similar fashion, with headaches and haemorrhage being the most common problems. Presentation with coma is strongly associated with death, but even then, a multi-disciplinary, case-by-case approach ensures that each child receives the appropriate management and hence the highest chance of survival. This study was limited largely by the size of the sample, as is most studies in this field, but movement towards a multi-centre collaborative effort on a global scale will strengthen the existing data.