Assessing organic material on single-use vessel sealing devices: a comparative study of reprocessed and new LigaSure™ devices

BACKGROUND: Reprocessed devices must be thoroughly cleaned prior to sterilization to ensure efficacy of sterilization agents. Many single-use devices are not designed to be thoroughly cleaned. Interlocking design features inherent to LigaSure™ vessel sealing devices may prevent thorough cleaning and promote accumulation of human tissue that cannot be removed. Thus, the aim of this study was to compare industry reprocessed and new LigaSure™ vessel sealing devices for organic material. METHODS: A total of 168, 84 new and 84 reprocessed, vessel sealing devices were disassembled and inspected for the presence of residual organic matter using visual, microscopic, and chemical analysis. Devices were randomized and test conductors blinded to group membership. Devices were aseptically disassembled and sent through visual inspection. Next, devices were either examined using light microscopy, scanning electron microscopy (SEM) or exposed to a solution that luminesces in the presence of hemoglobin. Additionally, 165 reprocessed devices were sent to a 3rd party lab for sterility testing via direct immersion culture for 14 days. RESULTS: Significant amounts of remnant organic material (C, N, O, S, Na, P) were observed with 81/84 reprocessed and 0/84 new devices failing inspection protocols. When tested for the presence of hemoglobin, only 1/12 reprocessed devices passed inspection. SEM of reprocessed devices revealed residues with liquid patterns and diffuse soiling with foreign material. Sterility testing of reprocessed devices revealed a sterility level < 6(–3). CONCLUSIONS: The abundance of material resembling human tissue observed on reprocessed VSDs suggests inadequate cleaning prior to sterilization. Atomic and morphological analyses of the remnant materials suggest that bacterial biofilms could also be present. Additionally, surface degradation and release of reinforcing glass fibers from the device were observed. Devices designed for single use can harbor significant amounts of remnant material that likely interfere with the sterilization process.