Formaldehyde is released from cyanoacrylate adhesives used in venous occlusion systems.

ObjectivesCommercially available cyanoacrylates are known to release formaldehyde during degradation. However, it is unknown whether venous adhesive cyanoacrylates used in the treatment of saphenous veins release formaldehyde. Formaldehyde is a known contact allergen, carcinogen and sensitiser.MethodsVenaSeal®, VenaBlock®, Glubran® Tiss 2, Histoacryl®, and Supaglue® were investigated in vitro. All adhesive agents were polymerised in phosphate-buffered saline, sealed in glass bottles and incubated at 37°C for up to 12 weeks. Headspace-gas chromatography mass spectrometry was used to measure formaldehyde release at set time intervals.ResultsPeak levels of formaldehyde were detected in all cyanoacrylate samples within 2 weeks of incubation, with peak levels ranging from 0.05% to 0.17% w/w. These peak concentrations emerged as early as 2 weeks post-polymerisation and remained consistently elevated throughout the 12-week observation period. Glubran Tiss 2 demonstrated the lowest formaldehyde release at 0.05% w/w, while VenaSeal exhibited the highest, reaching a peak of 0.17% w/w at 2 weeks, similar to commercial SupaGlue. Notably, VenaSeal maintained formaldehyde levels above 0.1% w/w for the duration of the 12-week testing period.ConclusionFormaldehyde is released during the post-polymerisation degradation of medical cyanoacrylates. Despite all products containing n-butyl cyanoacrylate (n-BCA), formaldehyde release varied-likely due to undisclosed formulation differences. VenaSeal released the highest level (0.17% w/w) compared to other products tested, suggesting that formulation influences degradation behaviour.