A placental-derived tissue matrix as a bowel wall substitute in rats: Preliminary study

Background. Occasionally, conventional closure of an intestinal wall defect (fistula) is not possible. The development of a biologic material that can be used in this setting would solve a significant clinical problem. We hypothesized that a collagen patch (connective tissue matrix [CTM]) designed to allow tissue regeneration was such a material. Methods. To test this hypothesis, we performed a laparotomy on 75 mab Sprague-Dawley rats (experiment A) and removed 25 % of the anterior cecal wall (1 cm in diameter) to compare intestinal wound healing in four situations: (1) control (no repair), (2) fibrin glue repair, (3) primary repair, and (4) repair with CTM (human placental bilayer, types I, III, and IV). Animals were killed at 1, 2, 4 and 6 weeks. Healing was graded by bursting pressure expressed in millimeters of mercury, histologic score (0 to 4), and mortality rates. After this, we used the same protocol to remove 80 % of the cecal wall (1.5 x 2.0 cm) in 19 animals (experiment B) to compare (5) fibrin glue repair alone with (6) CTM repair in a situation in which the defect was too large for primary repair Results. CTM repair of a lethal cecal wall defect (experiment A) is equivalent to either primary repair or fibrin glue repair When the defect is too large for primary repair (experiment B), repair with fibrin glue also does not work. However, in this same setting, CTM repair is successful (p < 0.00001). Conclusions. Intestinal wall defects not suitable for conventional closure can be repaired successfully with a collagen patch, with histologic characteristics similar to those seen with primary repair.