Temperature-induced configuration changes in hydrogel-coated coils and their relevance in embolization procedures

Area of Science:

• Biomaterials Science
• Medical Device Engineering
• Interventional Radiology

Background:

• Hydrogel-coated coils are utilized in various medical interventions.
• Understanding their configuration changes under thermal stress is crucial for device performance.
• Previous studies have not fully elucidated the temperature-dependent behavior of these coils.

Purpose of the Study:

• To investigate the influence of varying temperature exposures on the configuration of hydrogel-coated coils.
• To classify and quantify the configurational changes observed during thermal immersion.
• To assess the stability of coil configurations under different temperature conditions.

Main Methods:

• Thirty detachable hydrogel-coated coils were subjected to in vitro water immersion tests.
• Coils were exposed to five distinct temperature ranges: 22.6°C, 37°C, 40-50°C, 50-60°C, and 60-70°C.
• Configurational changes were classified (I, II, III) based on curling during 30-minute immersion; stability was tested in a two-step immersion.

Main Results:

• All hydrogel-coated coils exhibited configuration changes upon water immersion.
• A significant negative linear correlation (p < 0.05) was observed between time and temperature for all coil configurations.
• Complete coiling (configuration III) occurred rapidly at higher temperatures: 45.7s at 47.5°C, 20.2s at 57.5°C, and 10.3s at 67.5°C, compared to 160.4s at 37.5°C.

Conclusions:

• Temperatures exceeding 55°C trigger immediate configurational changes, achieving complete curling in under 30 seconds.
• Near-body temperatures (around 36°C) necessitate longer durations for optimal coil curling (configuration III).
• Optimizing HydroCoil preparation can potentially decrease interventional procedure times and enhance clinical outcomes.