Polyvinyl alcohol foam particle sizes and concentrations injectable through microcatheters

Area of Science:

• Interventional Radiology
• Vascular Embolization
• Medical Device Engineering

Background:

• Microcatheters are increasingly used in vascular embolization procedures.
• Polyvinyl alcohol (PVA) foam particles are a common embolic agent.
• Understanding particle size limitations is vital for safe and effective embolization.

Purpose of the Study:

• To determine the optimal and maximum size ranges and concentrations of PVA foam particles for reliable injection through microcatheters.
• To identify potential risks of inadvertent catheter occlusion during embolization.

Main Methods:

• Testing of eight different microcatheters.
• Evaluation of six PVA foam particle size ranges from two manufacturers at three concentrations.
• Continuous pressure monitoring during 60 mL injections per size range and concentration for each catheter.

Main Results:

• Recommended maximum PVA foam particle sizes were determined for each microcatheter.
• Particles up to 1,000–1,500 microm were injectable through catheters used with 0.014–0.016-inch guidewires.
• Smaller particles (300–500 microm) occluded some catheters, while others allowed up to 355–500 microm particles.

Conclusions:

• Knowledge of maximum PVA foam particle size ranges prevents inadvertent catheter occlusion during embolization.
• Results from simulated high-flow lesions may not apply to all clinical scenarios.
• Low-flow lesions may not necessitate the use of maximum particle sizes or concentrations.