History of Management of Intracranial Aneurysms in Children

Understanding of Disease

• 19th century — First case reports: In 1871, Eppinger reported on children suffering aneurysm rupture during exercise, confirmed by postmortem examination (14). He also discussed the etiology of pediatric aneurysms and suggested an association with aortic coarctation. In 1887, Eppinger suggested that ruptured saccular aneurysms may explain some cases of cerebral hemorrhage of unknown etiology in children (15).
• Early 20th century — Association with coarctation of the aorta: In the early 20th century, several investigators reported on a connection between coarctation of the aorta and fatal cerebral hemorrhage, which in many cases was linked to a ruptured intracranial aneurysm (16–18).
• Mid-20th century — Larger series: In 1965, Matson published a series of 14 pediatric aneurysms (19). He noted that incidental aneurysms were not found on autopsy or angiography in children. This report also showed that surgical treatment is feasible, and the outcome is better when compared to that of adults. In 1966, Locksley and colleagues published the results of the Cooperative Study on Intracranial Aneurysms and Subarachnoid Hemorrhage, which comprised more than 6,000 cases. Only 4% of patients with ruptured aneurysms were younger than 20 years (20,21).
• Early 21st century — Elucidating the etiology: In the modern era, improvements in molecular biology techniques have improved our understanding of the etiology of some intracranial aneurysms via the identification of genetic and acquired risk factors for aneurysm formation and rupture (22–25).

Technological Development

• Late 20th and early 21st centuries — Advancements in imaging technology: The continuous refinement of CT, MRI, and catheter-based DSA techniques has allowed for improved diagnostic evaluation and contributed significantly to the scientific body of knowledge regarding common locations and configurations (26).
• Mid-20th century — New surgical techniques: The advent of microsurgery in general and the development of instruments and clips for cerebrovascular microsurgery has had a lasting effect on the treatment of pediatric aneurysms, although no tools or clips have been designed specifically for use in children (27). Moreover, the use of less-common techniques—including aneurysm trapping, cerebrovascular bypass, and hypothermic cardiac arrest—have been described in children (7,28,29).
• Early 21st century — Endovascular technique: Minimally invasive endovascular techniques such as coiling and, more recently, stents and flow diverters have been applied in children (12,30,31). Although demonstrated in clinical practice, these devices are not tested and are generally used in an off-label fashion in children.

Surgical Technique

• 1937 — First successful surgical clipping: The first successful clipping of an intracranial aneurysm is attributed to Dandy in 1937 (32). Clips and instruments were modified by various neurosurgeons in the following decades (33,34). Microsurgical techniques were propagated by Yaşargil (33). There have not been specific advances designed for considerations unique to children.
• Late 20th century — Endovascular treatment: Guglielmi established the use of detachable coils for endovascular obliteration of intracranial aneurysms (35). More recently, flow diverters have been introduced and are often used in the treatment of complex aneurysms (30,36–38). While validated in adults (39,40), these treatments have not been prospectively tested in children.