Effects of precompression time and strength on the physical characteristics of quasi-stapled porcine small intestinal tissue

Abstract

Precompression is vital when performing gastrointestinal anastomosis with staplers. However, research on the internal changes in intestinal tissue under stapling is lacking, and the effects of precompression have not been clarified. In this study, a stapler was modified, and the multifrequency bioimpedance of porcine small intestinal tissue was measured from before clamping the tissue with the stapler until the release of the tissue after precompression without firing. The Cole Y model was fitted to the bioimpedance, and the changes in the tissue were analyzed using the model parameters: G0, extracellular fluid conductance, and Δ G, intracellular fluid conductance. The results show that the changes of G0 and Δ G could be divided into four stages: rapid decrease, slow decrease, intense resilience, and slow recovery. During slow decrease stage, there was a greater decrease of G0 and Δ G (1.02E−05 ± 1.12E−05 S and 1.73E−05 ± 2.12E−05 S in precompression time’s increase, 1.68E−05 ± 8.74E−06 S and 1.20E−05 ± 1.09E−05 S in precompression strength’s increase). On the contrary, during intense resilience stage, there was a less increase of G0 and Δ G (0.88E−05 ± 4.86E−05 S and 9.15E−05 ± 9.37E−05 S in precompression time’s increase, 2.72E−05 ± 3.53E−05 S and 1.02E−04 ± 8.54E−05 S in precompression strength’s increase). In conclusion, the effects of precompression factors on tissue have been preliminary revealed: the tissue under precompression becomes thinner and less resilient. To improve the precompression effects and reduce any excessive pressure exerted on the staples by tissue resilience, the precompression time and strength should be increased appropriately.