The Biomechanical Properties of Meshed Versus Perforated Acellular Dermal Matrices: Analysis of Surface Area and Fluid Egress

Abstract

BACKGROUND: Acellular dermal matrices (ADMs) are used for soft tissue augmentation across surgical specialties. The increased use of ADMs has been particularly apparent in the setting of implant-based breast reconstruction, where matrices are used to supplement the thickness of the mastectomy skin flaps and ensure adequate soft tissue coverage of implants. However, long-term review of these devices has indicated that there is a strong correlation between seroma formation and the use of ADM. Since allograft integration and neovascularization is dependent having on direct opposition between the ADM and a vascular bed, the presence of seromas can inhibit the area of the graft which is in contact with the native tissue. As a result, most ADM products are available in a variety of meshed or perforated forms. Because of the lack of consistency between manufacture designs, we set out to determine the fluid egress properties and the increase in surface area resulting from common cut patterns. METHODS: The fluid egress properties were analyzed for three different commonly encountered commercially available ADM cut patterns: 1 meshed design and 2 distinct perforation designs. Mesh Pattern #1 was designed with 1:1 meshed cuts each measuring 1.5 mm in length. Perforation Pattern #1 was designed with 3 mm diameter perforations at a density of 0.128 perforations per cm2. Perforated Pattern #2 was designed with 3 mm diameter perforations at a density of 0.25 perforations per cm2. The surface area of these modified ADM samples was also calculated, accounting for the mesh length or the perforation diameter and frequency. Fluid egress was calculated by passing fluid through each ADM and measuring the amount of time required for complete passage. An analysis of variance was used to determine if there was a significant difference in egress properties across the three patterns. A P value of <0.05 was used to determine statistical significance. RESULTS: Meshing in a 1:1 pattern resulted in a 97.50% increase in surface area compared to the uncut product. In comparison, only a 0.30% increase resulted from Perforation Pattern #1 and a 0.59% increase resulted from Perforation Pattern #2. There was a significant difference in egress properties across the 3 cut patterns (P = 0.000). The average egress time of Mesh Pattern #1 was 1.974 seconds. The average egress time of Perforation Pattern #2 was 6.504 seconds and of Perforation Pattern #1 was 10.369 seconds. Neither donor (P = 0.249) nor graft thickness (P = 0.914) had a significant impact on the results. CONCLUSION: To our knowledge, this study is the first to directly compare clinically applicable properties between different ADM cut patterns. By comparing a variety of common manufacturer designs, ranging from simple punch-shape perforations to a full 1:1 mesh pattern, we were able to demonstrate that meshing ADM tissue significantly improves fluid egress properties and substantially increases the surface area compared to ADM tissue perforated at levels typically available on the market. Therefore, the use of meshed ADM tissue could improve the ability of the product to incorporate with the recipient, resulting in decreased complications and improved patient outcomes.