Development and Evaluation of a Mesh-Polyvinyl Alcohol Hydrogel Composite Small Bowel for Small Bowel Anastomosis...

In surgeries requiring small bowel anastomosis, postoperative anastomotic leak is an infrequent (3.02%) but devastating complication associated with increased morbidity and mortality. Simulation continues to advance as a method of practicing surgical technique. Given the delicate nature of the small bowel, a high-fidelity simulated model is critical for ensuring skill acquisition and training transfer. However, the most commonly used models-porcine tissue and commercial synthetic analogs-present notable limitations, including environmental concerns, limited longevity, and mechanical properties that do not accurately represent human tissue.

This study aims to characterize and compare the mechanical properties of human, porcine, commercial off-the-shelf (COTS) tissue analogs, and a novel mesh-polyvinyl alcohol (PVA) hydrogel composite small bowel. Mechanical testing was conducted using a custom load frame (DEXTER) and uniaxial tensile tester to evaluate ultimate tensile strength, stretch ratio (SR), elastic modulus (EM), and suture pullout force (SPOF). In addition, 2 surgeons qualitatively evaluated the hydrogel simulant for its suitability for stapling and suturing, patency, and performance in anastomotic leak prevention.

Compared with human tissue, porcine small bowel yielded a significantly different SPOF (P<0.001). The COTS synthetic small bowel exhibited significantly different EM (P<0.001) and SR (P<0.001). The hydrogel simulant tested similarly to human tissue with respect to tensile strength, SR, EM, and SPOF.

The novel hydrogel small bowel simulant exhibited mechanical properties that more closely resembled human small bowel compared with porcine or COTS models.