Comparative study of endoscopic clips: duration of attachment at the site of clip application

Background Several designs of endoscopic clips are now commercially available, and the indications for endoclip application are rapidly expanding. However, very limited data have been published to aid in choosing between the different types of endoclips. Objective To compare the duration of clip attachment between all commercially available endoclips. Setting Long-term experiments on 50-kg pigs under general anesthesia. Design and Interventions Upper endoscope was inserted into the stomach. One clip of each type (Resolution clip, TriClip, and HX-5L clip) was placed along the same gastric fold at a distance of 0.5 to 1 cm from each other. The animals were recovered. In pig nos. 1 and 2, repeat endoscopy was performed after 2 and 4 weeks. In pig nos. 3 to 5, endoscopy was repeated after 1, 2, and 5 weeks. Main Outcome Measurements Duration of clip retention at the site of application. Results In all animals, only the Resolution endoclip remained attached to the site of application for the entire duration of the study (4-5 weeks). No TriClips or HX-5L clips were attached at the 4- to 5-week follow-up endoscopies. Most of the TriClips (67%) detached within the first week after application. Most of the HX-5L clips (80%) dislodged within the first 2 weeks of follow-up. Limitations The study was performed in a porcine model with a small number of animals. Conclusions The Resolution clip has the longest duration of retention at the site of application (more than 4-5 weeks) and should be preferred when long-term attachment of endoclips is necessary.