Table 2. Examples of commonly used detachable coils.

Name	System requirement	Detachment	Sizes and shapes	Comments
Interlock (Boston Scientific)	Diagnostic catheter and microcatheter	Locking mechanism detached by advancing coil past the tip of the catheter Avoid advancing the pusher too deep into the coils package as the notch can become entangled in the coils	2D, cube, and diamond shapes Size: 2–22 mm Length: up to 60 cm	Very thrombogenic, made of platinum, highly visible, relatively rigid, a nonfibered softer version recently available with 2–5 diameter in sizes and up to 12 cm in length
Concerto (Medtronic)	Microcatheter	Bell and socket locking system, released by a separate handle	Helical and 3D Diameter: 2–20 mm Length: up to 50 cm	Extremely soft, allows embolization of very small and tortuous vessels Coils are not very thrombogenic, require dense packing. Available with polymer fibers to increase thrombogenicity
Ruby (Penumbra)	High flow and regular microcatheter	Standard and soft Deployed by a click in a separate handle	Ruby POD for high-flow lesions Packing coil Diameter: 1–40 mm Length: up to 60 cm	Large-volume coil, requires a large lumen microcatheter Low-profile system recently available that allows using a regular 0.021 microcatheter
Azur (Terumo)	Diagnostic catheter and microcatheter	Deployed by a click in a separate handle	Framing for aneurysms Hydrocoil (filling and packing) and CX (anchor) Diameter: 2–20 Length: up to 40 cm	Hydrogel expands 4–5 times the original size in the presence of blood
Retracta (Cook)	Diagnostic catheter	Deployed by manually unscrewing a cable with a torque 8–10 times counter clockwise	Diameter: 4–20 mm Length: up to 14 cm	Test injection is possible before deployment using a Y adaptor