microcatheter

A microcatheter is a small-diameter, highly flexible catheter used to access distal vessels in interventional radiology, neurointerventional procedures, and some cardiology interventions. It is designed to be navigated through tortuous microvasculature and to deliver contrast, embolic agents, or therapies to precise, distal targets. Microcatheters are typically advanced over a guidewire and may require specialized techniques to achieve superselective catheterization.

Construction and features: Microcatheters commonly incorporate a lubricious coating, such as PTFE, and radiopaque markers to aid visualization. They come in single- and dual-lumen configurations and in various shaft stiffness options to balance pushability with trackability. The distal tip is delicate and often shaped (straight, angled, or curved) to facilitate navigation into small branches. Materials such as polyimide or flexible polymers are used for the shaft, and many devices are designed to be compatible with a range of microguidewires and embolic or diagnostic agents.

Types and configurations: The main distinction is lumen design and intended use. Single-lumen microcatheters are used for selective injections, while dual-lumen variants allow simultaneous delivery of contrast and embolic materials or enable contrast injection through one lumen while guiding another device through the second.

Applications: They are central to neurovascular procedures (for selective catheterization and embolization of cerebral vessels), selective angiography, transarterial chemoembolization in oncology, and various peripheral vascular interventions. In cardiology, specialized microcatheters assist in complex CTO techniques and distal vessel access.

Risks and considerations: Potential complications include vessel injury, dissection, perforation, vasospasm, thromboembolism, catheter kinking or fracture, and contrast-related effects. Use requires careful imaging guidance and operator expertise.