Changes in Small Intestine Tissue Compressed by a Linear Stapler Based on Cole _Y Model.

Area of Science:

• Biomedical Engineering
• Gastrointestinal Surgery
• Tissue Mechanics

Background:

• Optimizing surgical stapler design requires understanding gastrointestinal tissue behavior under compression.
• Tissue deformation and fluid shifts significantly impact surgical outcomes and device efficacy.

Purpose of the Study:

• To investigate the multifrequency bioimpedance changes in porcine small intestine tissue compressed by a modified surgical stapler.
• To analyze tissue alterations using the Cole-Cole model parameters (G0, ΔG, CcpeF) under varying compression levels.

Main Methods:

• Modified a surgical stapler for controlled compression of porcine small intestine tissue.
• Measured multifrequency bioimpedance of the compressed tissue.
• Applied the Cole-Cole model to bioimpedance data to extract tissue electrical parameters.

Main Results:

• Two distinct stages of tissue change were observed during compression.
• Initially, all parameters (G0, ΔG, CcpeF) decreased sharply, indicating tissue displacement.
• Subsequently, G0 decreased due to extracellular fluid expulsion, ΔG showed mild changes, and CcpeF remained relatively stable.

Conclusions:

• Stapler closure initially squeezes tissue out of the measurement zone, causing a rapid drop in all electrical parameters.
• Continued compression leads to extracellular fluid expulsion, with intracellular fluid changes potentially related to cell restoration.
• Findings provide a foundation for optimizing surgical stapler design based on tissue response to compression.