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 in testinal submucosa (SIS) was determined in a dog model of body wall repair. Full-thickness body wall defects measuring 8 x 12 cm were surgically creat ed and then repaired with a multilaminate eight-layer form of SIS in 40 dog s. 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 m easured biaxial ultimate load-bearing capability were performed on the devi ce prior to implantation and on the device/implant site at the time of sacr ifice. 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 +/- 2 6 pounds at 24 months (P < 0.05). The clinical utility of a degradable biom aterial such as SIS depends on a balance between the rate of degradation an d the rate of host remodeling. Naturally occuring extracellular matrix scaf folds such as SIS show rapid degradation with associated and subsequent rem odeling to a tissue with strength that exceeds that of the native tissue wh en used as a body wall repair device. (C) 2001 Academic Press.