Introduction Pediatric pial arteriovenous fistulas (PAVF) are rare malformations consisting of a direct connection between arteries and veins in the subpial space. They are typically identified within the first years of life due to symptomatic presentation. Therefore, the natural history of untreated lesions is incompletely understood. We present our experience to highlight observations on the natural history in the neonatal and infantile period.
Methods A retrospective review of the cerebrovascular database was performed of a tertiary referral children’s institution between 2010 and 2016 to identify patients with PAVF.
Results Four children (50% female, 50% supratentorial location) were identified with PAVF ranging in age from 1 day of life to 7 years of age. All patients had single-hole fistula angioarchitecture. Only one child had a symptomatic presentation with isolated intraventricular hemorrhage due to an anterior choroidal PAVF and was treated surgically in the early infantile period. A second child had a left MCA PAVF discovered after incidental minor head trauma and treated with a combination of surgery and embolization at age 7. Two female newborns were diagnosed with posterior circulation PAVFs - right posterior inferior cerebellar artery (PICA) and left superior cerebellar artery (SCA) during the neonatal period. Both of these children went on to have complete or partial spontaneous resolution of the PAVF. One PAVF was discovered incidentally during workup of optic nerve hypoplasia (right PICA). The other was discovered due to a pre-natal maternal ultrasound that demonstrated a high flow intracranial lesion that was confirmed by MRI after the child’s birth.
Endovascular treatment was deferred in both newborns until the infantile period. The PICA PAVF spontaneously resolved on repeat MRI that was confirmed by diagnostic angiography at 6 months of age (figure 1). The SCA PAVF experienced partial resolution over a 4 month period with significant reduction in the size of the venous varix on the repeat pre-embolization MRI. The residual SCA PAVF was completely embolized using N-BCA. Interestingly, this partial resolution was associated with thrombocytosis noted on serum analysis.
Conclusions These cases illustrate spontaneous resolution of PAVF may occur during the infantile period - an event that has never been described with this type of pediatric vascular lesion. This highlights the value of initial conservative management in asymptomatic patients. We hypothesize that spontaneous resolution may represent a thrombotic event or a delayed maturation of the intracranial vascular system.
Disclosures M. DeCuypere: None. P. Klimo: None. L. Elijovich: 2; C; Stryker, Codman, Medtronic, Microvention, Penumbra.