Quantitative Analysis of Penetrating Wound Behavior Under Vacuum-Assisted Closure Therapy.

Through the ages, the methods of wound dressing have been changing to obtain the best therapeutic effect. The driving force of the process is the development of knowledge and tools. One of the state-of-the-art methods is negative pressure wound therapy. The article presents the results of experimental studies on wound models made in ballistic gel casts and dressed with a vacuum dressing. Methods: The experiments were performed on samples made of ballistic gel. In the casts, holes were cut out to simulate a wound. Wounds were closed with a dressing connected to a pump, creating a negative pressure. Every model was photographed in two perpendicular sections before and after applying the negative pressure. The changes in shape and size were compared. The numerical model of the wound was also created to confirm experimental observation. Results: A comparison of wound geometry before and after applying negative pressure reveals a reduction in size in every case. The volume of the wound was reduced by 40%, while its surface area decreased by 27%. This reduction effect was independent of wound size. Furthermore, numerical computations indicate that veins terminating in wounds also reduce in size, with their shape becoming flattened. Conclusion: The results of experiments and numerical analyses reveal that vacuum dressing can effectively reduce the surface area of the wound by shrinking it and decreasing blood vessel outlets, positively influencing the bleeding reduction. An additional effect is compressive stress in the circumferential direction of the wound, which prevents further development of the wound.