An Ex Vivo Study Measuring the Effects of Circumferential and Near-Circumferential Closed Incisional Negative Pressure Wound Therapy Dressings on a Porcine Model.

To investigate the effects of circumferential and near-circumferential closed incisional negative pressure wound therapy (ciNPWT) dressings on compartment pressures within varying tissue levels using an ex vivo porcine model. A deceased swine model was utilized, with bilateral hind legs disarticulated and prepared for experimentation. ciNPWT dressings were applied at 100%, 75%, 50%, and 25% circumferential coverage, with negative pressures set at -200 mmHg, -125 mmHg, and -25 mmHg. A STIC pressure monitor device measured pressures at tissue depths of 10 mm, 20 mm, and 40 mm. Measurements were repeated 3 times for each configuration, and the averages were calculated. Compartment pressures increased with greater magnitudes of negative pressure and were highest at superficial tissue layers. The pressure differences between superficial and deeper layers were most pronounced in 25%-75% circumferential configurations, suggesting that non-circumferential dressings create a pressure gradient. These findings align with a compressive rather than a "lift-off" force mechanism. This study highlights ciNPWT's compressive effects, particularly on superficial tissues, and suggests that pressure gradients in non-circumferential configurations may enhance fluid dynamics and wound healing. The findings also support the potential role of ciNPWT in inducing mechanotransduction and angiogenesis. Limitations include the use of an ex vivo model and variability in measurement accuracy. Especially in superficial layers, ciNPWT exerts a compressive force with non-circumferential dressings allowing greater pressure gradients. Future in vivo studies are needed to confirm these findings and further explore the therapeutic mechanisms and potential applications of ciNPWT.