Be there or be square: Should we adopt non-rectangular dressing shapes in single-use negative pressure wound therapy?

Area of Science:

• Biomechanics
• Wound Healing
• Medical Device Design

Background:

• Conventional rectangular single-use negative-pressure wound therapy (suNPWT) dressings create stress concentrations at incision sites.
• Optimizing dressing geometry and stiffness can potentially reduce peri-incisional stress and improve wound closure.

Purpose of the Study:

• To investigate the biomechanical effects of suNPWT dressing shape and regional stiffness on peri-wound skin stresses.
• To evaluate the influence of these factors on incision closure under negative pressure.

Main Methods:

• A validated 3D finite element model of a sutured incision was used.
• Five homogeneous dressing shapes were compared for stress reduction.
• The optimal shape was further tested with varying stiffness configurations.
• Lateral skin displacement measured closure work.

Main Results:

• Circular dressings reduced peak lateral skin stresses by 2.9% compared to rectangular ones (0.9%).
• A circular dressing with a stiffer peripheral ring achieved 3.2% stress reduction while maintaining closure support (3.35 mm displacement).
• Fully stiff dressings maximized stress reduction but offered no closure support; fully soft dressings did the opposite.

Conclusions:

• Eliminating sharp geometric features and tuning stiffness attenuates peri-incisional stress without hindering closure.
• Circular suNPWT dressings with a stiffer periphery are a superior alternative to rectangular designs.
• Further pre-clinical and clinical evaluations are warranted.