Effect of a Slow-firing Method on Porcine Small Intestine: Evaluation of Staple Malformation by Two Different Methods

Background: In addition to improvement in staplers, surgeons have made some ingenious changes in stapling techniques. There are few reports that have examined in detail the effect of one ingenious change, the slow-firing method, on the malformation of staples. In this study, the malformation of staples was examined from the viewpoint of twisting and wrapping of staple legs. Methods: Fresh porcine small bowel was used for all experiments. The front and rear walls of the small intestine segments were stapled in the longitudinal direction. A powered Echelon Plus stapler with a GST cartridge and an EndGIA tri-stapler with an AMT cartridge were used. After a 1-min pre-compression, firing was done as usual in the normal group. In the slow-firing groups, firing was done over a 1-min period. Malformation of staples was evaluated by the degree of wrapping of the legs to the backspan and the degree of leg twisting. Results: The slow-firing method significantly improved the twist score in Echelon Plus. In contrast, the twist score increased with the slow-firing method in EndGIA. Some staples in Echelon Plus were category Ⅱ or Ⅲ. In addition, all staples on the outside of the tip of stapler were category Ⅱ or Ⅲ. All staples in EndGIA were category Ⅰ. No significant difference in the wrap category was shown by the firing method in both staplers. Conclusion: The slow-firing method contributed to the better formation of staples with Echelon Plus, but the effectiveness was not recognized with EndGIA. B-shaped staples with less twisting and wrapping are important factors to complete a reliable suture. After understanding the characteristics of various staplers and selecting the appropriate staple height, adding techniques, such as pre-compression and slow-firing methods will lead to a reduction in post-operative complications.