Paediatric intracranial aneurysms are rare, accounting for less than 5% of all age intracranial aneurysms [
1‐
7]. A predilection for males is observed in young children with female preponderance occurring after puberty [
1,
3,
8‐
11]. While a traumatic cause is rare in adult aneurysms (less than 1% of all age aneurysms) [
12], traumatic aneurysms are more frequently observed in children, reported between 5 and 39% in paediatric series [
10,
11,
13‐
16]. Anomalous intracranial arteries seem particularly vulnerable to aneurysm formation in otherwise insignificant trauma and post-traumatic aneurysms seem to be associated with significant morbidity and mortality [
17].
Vertebral artery duplication (VAD) is a rare anomaly, with an incidence of 0.004–1.9%, often regarded as a vascular variant without clinical relevance [
18‐
22]. Complete arterial duplications demonstrate dual origin of the vertebral artery (VA) from the ipsilateral subclavian artery or aortic arch. Vertebral artery fenestration (VAF) describes a partial duplication and are a rare vascular variant and observed in 2% of all intracranial artery fenestrations [
23]. In contrast to true duplication, an anastomotic anomaly occurs during embryonic development resulting in a focal split of a vessel segment into two parallel channels which subsequently reconstitute a single vessel lumen. These anatomical variations have been observed both intra- and extracranially but occur most frequently at the V4 segment [
21] and are frequently associated with other congenital intracranial vascular anomalies such as aneurysms and arteriovenous malformations [
19,
23‐
33]. The mechanism for development of a V4 segment fenestration is the absence or obliteration of 2 intersegmental vessels that have fused [
34], and its morphological changes may be responsible for its vulnerability to formation of aneurysm or development of arterial dissection. Specifically, histopathological examinations of fenestrated vessels have revealed irregularities in wall structure mainly involving the tunica media at the proximal and distal ends of the duplicated segments which can be less developed with an irregular pattern or complete absence of the elastic fibers [
35,
36]. During severe cervical spine trauma involving rapid subluxation, deceleration or flexion through the cervical spine, the VA can be readily injured especially if irregularities in the vessels exist. To date, there have only been a handful of descriptions of this entity in the children (Table
1). However, we are the first to report a child developing a pseudoaneurysm in a VA fenestration after a significant head trauma. This case illustrates a need for special vigilance in managing children with vessel fenestrations or duplications in context of head trauma.
Table 1
Literature review of vertebral artery fenestration incidence and associated vascular anomalies
Wollschlaeger et al. [ 18] | 1967 | 291 | 1 (unknown) | 0.34 | | Autopsy |
| 1972 | 362 | 5 adults 2 children | 1.90 | PComm aneurysm AComm aneurysm ECA-Vert anastomosis | Angiography |
| 1978 | 1290 | 3 adults | 0.23 | Vertebral artery double fenestration |
| 1983 | 500 | 2 adults | 0.40 | |
| 2008 | 504 | 2 (unknown) | 0.40 | Aneurysm in 10.5% of all fenestrations (n = 53) |
| 2011 | 395 | 4 adults (54.32 + 15.3) | 1.01 | Saccular aneurysms in 14 patients |
| 2020 | 44,759 | 67 (2–95 years) | 0.10 | 6 saccular aneurysms (9%) remote from site of fenestration involving ICA |
| 2021 | 554 | 2 (10–99 years) | 0.004 | |