An assessment of dressing integrity using an ex-vivo porcine model

Introduction:

Gelling dressings used to pack cavity wounds must be able to be removed in one-piece. Clinicians are presented with laboratory data for strength, however, there is little evidence to dictate what value is sufficient for one-piece removal from a cavity wound.

To understand the relationship between numerical and practical data, the strength of eight ribbon dressings was assessed quantitatively, using a Tensiometer, and qualitatively, using a porcine (pork) cavity model.

Method: Tensile strength was determined by using a Tensiometer to measure the force required to break the ribbon, for both wet and dry product.

Simulated ‘cavity wounds’ (0.8” diameter x 2” deep) were created in pork, each filled with 3ml of simulated wound fluid. Ribbons (N=3) were applied and assessed over 3 days. Fluid was added each day to simulate wound exudate. On day 3, ribbons were removed and product integrity noted.

The test was repeated using cavities with slit wound entry (1” long and 1.5” deep) to provide an increased challenge to the dressings. Fluid input was adjusted accordingly to the wound size.

Results:

Tensiometer Data – Tensile strength varied between dressings, with some demonstrating high strength, and others relatively low.

Pork Cavity Model large- Fluid handling varied.  Pooling was noted in dressings B, E and F. Dressing D leaked. Each ribbon was removed from the cavity in one-piece, though dressing C partially tore, and others left fibres in the cavity.

Small cavities: All dressings handled the fluid supplied. One dressing tore completely on removal, with all others allowing for in-tact removal on day three, even when resistance to removal was noted.

Conclusion:

Nearly all ribbons performed effectively in this clinically relevant pork cavity wound model; even ribbons with relatively low tensile strength. With the varying numerical values, this suggests that numerical strength may not translate to clinical efficacy.