Coil Summit

December 2022

Coil Summit

In December 2022, The GEST Group conducted a 2-day summit where physicians learned everything they need to know about using coils and how the materials and characteristics translate into clinical use. 

Review of the Coil Summit

Review by Dr. Tom Boeken. Download a copy of the full program here. 
The Coil Summary is available on demand. To access the recorded sessions, click here to login to embolotherapy educational center. 

  • Stainless Steel – early days, not used anymore
  • Tungsten – outdated
  • Polymer – outdated
  • Platinum – main material used for modern coils
  • Inconel – only one coil on the market for peripheral use (MReye, Cook)

Why platinum (92% Platinum, 8% Tungsten)

  • It is highly radiopaque, biocompatible, flexible, malleable with minimal MRI or CT artifact.
  • The primary structure is defined by the raw wire, the secondary structure by the coil diameter, and the tertiary structure by the 3D overall shape.
  • Volume and stiffness can vary independently according to the raw wire structure, which explains why two coils with the same diameter may deploy differently.
  • Small differences in the material will induce differences in softness, pushability, packability, and radial force.

Fibered Coils

  • They are coils enlaced with fibers to promote biological response and support mechanical occlusion.
  • Fibers reduce occlusion time, enhancing the mechanical action of bare coils.
  • Fibers enhance thrombogenicity.
  • They include Concerto, Interlock, Embold, Retracta, Flipper, Nester, Tornado and MReye.

Hydrogel Coating

  •  In contact with blood, hydrogen ions are released and water molecules form with the polymer causing it to expand.
  • It is biologically inert and does not contain or produce biologics.
  • Hydrogels are porous and compliant and allow natural tissue proliferation promoting endothelial formation.
  • They do not rely on thrombus formation and can be used in coagulopathic patients.
  • Azur HydroCoils systems expand 4-5 times when deployed.

Manufacturing Process

  • Coil systems include a delivery wire, a wire / coil connection and a coil.
  • Pusher wires are made of Stainless Steel or Nitinol.
  • The connection has to be predictable, durable, visible, and easy to use.
  • Occlusion characteristics depend on the thrombogenicity and the packability of the coil.
  • Coil manufacturing goes back to the 70’s.
  • It initially started with the idea of mechanical obstruction.
  • The goal of newer coils is also to minimize recanalization.
  • Animal models show that vessels occluded by fibered coils contained 70% of thrombus with fibered coils and 40% with hydrogel-coated coils.
  • Long-term recanalization may be lower if it is less reliant on thrombus-related occlusion.
  • We must keep in mind thrombus resorption when coiling.
  • Oversizing is important in venous coiling (>50%).

 Measuring the Packing Density

  • The goal is to have optimal cross-sectional occlusion to avoid recanalization.
  • Initial aneurysm studies showed a minimal density of 20% to achieve occlusion.
  • There is low level of evidence for a threshold.
  • Coil compaction may be responsible for revascularization.
  • “As much as you can safely deploy”

  • Prime the microcatheter: copious flushing prior to coil insertion.
  • Secure the microcatheter and keep an eye on the diagnostic catheter.
  • Avoid pushing wire into the coil pack.
  • “One more coil”? If hesitant, wait and perform an angio. Occlusion may be delayed.
  • Remove the pusher wire with care under scopic view.
  • Remove the microcatheter with care when in contact with the packing.


Coil Catheter Compatibility at a Glance

During the coil summit, physicians expressed an interest in a quick guide to embolization coil-catheter compatibility. Thanks for Dr. Dania Daye, we are pleased to present the Coil/Catheter Compatibility at a Glance. Fill out the form to the right for immediate access to the guide. 

Coil Catheter compatibility guide

Physician Faculty


Thank you to the following Sponsors for supporting this educational event.