Lead paediatric interventional radiologist at Hong Kong Children’s Hospital, Kevin Fung specialises in vascular access, oncologic interventions and lymphatic imaging and interventions. In this article, Fung highlights the distinct clinical obstacles that arise when gaining arterial access in paediatric patients while sharing his best practices.
Obtaining arterial access remains one of the most technically demanding aspects of paediatric angiography and endovascular intervention. Unlike adults, children present unique hurdles: smaller, spasm-prone arteries, higher risk of dissection, and limited availability of paediatric-specific equipment (Figure 1). Notably, the mismatch between small-calibre arteries and adult-sized vascular sheaths can result in arterial occlusion and thrombotic complications—reported in up to 16% of children weighing under 15kg.
Meticulous pre-procedural planning—including careful site selection, periprocedural optimisation, ultrasound-guided puncture, and attentive post-access care—can improve success rates and minimise adverse outcomes.
While transfemoral access remains the standard approach, alternative access routes can be useful in certain clinical scenarios. In neonates, umbilical vessels are often preferred to avoid access-related extremity complications. The umbilical artery provides direct systemic access via the internal iliac system, while the umbilical vein can be utilised if a patent ductus arteriosus or foramen ovale is present (Figure 2).
In cases of steno-occlusive aortoiliac disease or interventions involving steep visceral artery anatomy, upper-extremity access—radial, brachial or axillary—can facilitate cannulation and device delivery. Brachial and axillary access can be considered in younger children when the radial artery calibre remains small. However, the interventionist must bear in mind the potential risk of upper limb ischaemia and compressive neuropathy in case of haemorrhagic complications. Although radial arteries <2mm were traditionally considered a relative contraindication for radial access, new slender sheath technologies and the low incidence of clinically significant radial artery occlusion (RAO) have prompted re-evaluation of these thresholds. Distal radial access at anatomical snuffbox may further reduce RAO risk.
Intraprocedural unfractionated heparin and vasodilators are essential to mitigate vasospasm and thrombosis. When arterial thrombosis occurs, systemic anticoagulation is first-line therapy for children, while catheter-directed thrombolysis or thrombectomy is reserved for chronic limb-threatening ischemia unresponsive to medical management. Fortunately, long-term sequelae are uncommon in children due to rich collaterisation. However, early surgical revascularisation should be considered in symptomatic children with claudication or limb length discrepancy.
Kevin Fung is an interventional radiologist at Hong Kong Children’s Hospital in Hong Kong.
