Strength over time of a resorbable bioscaffold for body wall repair in a dog model

The change in strength over time of a biomaterial derived from the small intestinal submucosa (SIS) was determined in a dog model of body wall repair. Full-thickness body wall defects measuring 8 × 12 cm were surgically created and then repaired with a multilaminate eight-layer form of SIS in 40 dogs. Five dogs were sacrificed at each of the following time points: 1 day, 4 days, 7 days, 10 days, and 1, 3, 6, and 24 months. Ball burst tests that measured biaxial ultimate load-bearing capability were performed on the device prior to implantation and on the device/implant site at the time of sacrifice. The strength of the device at the time of implant was approximately 73 ± 12 pounds. The strength of the implant site diminished to 40 ± 18 pounds at 10 days, and then progressively increased to a value of 156 ± 26 pounds at 24 months (P < 0.05). The clinical utility of a degradable biomaterial such as SIS depends on a balance between the rate of degradation and the rate of host remodeling. Naturally occuring extracellular matrix scaffolds such as SIS show rapid degradation with associated and subsequent remodeling to a tissue with strength that exceeds that of the native tissue when used as a body wall repair device.