A PLACENTAL-DERIVED TISSUE MATRIX AS A BOWEL WALL SUBSTITUTE IN RATS - PRELIMINARY-STUDY

Background. Occasionally, conventional closure of an intestinal wall d efect (fistula) is not possible. The development of a biologic materia l that can be used in this setting would solve a significant clinical problem. We hypothesized that a collagen patch (connective tissue matr ix [CTM]) designed to allow tissue regeneration was such a material. M ethods. To test this hypothesis, we performed a laparotomy on 75 mab S prague-Dawley rats (experiment A) and removed 25 % of the anterior cec al wall (1 cm in diameter) to compare intestinal wound healing in four situations: (1) control (no repair), (2) fibrin glue repair, (3) prim ary 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, hist ologic score (0 to 4), and mortality rates. After this, we used the sa me protocol to remove 80 % of the cecal wall (1.5 x 2.0 cm) in 19 anim als (experiment B) to compare (5) fibrin glue repair alone with (6) CT M 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 th e defect is too large for primary repair (experiment B), repair with f ibrin glue also does not work. However, in this same setting, CTM repa ir is successful (p < 0.00001). Conclusions. Intestinal wall defects n ot suitable for conventional closure can be repaired successfully with a collagen patch, with histologic characteristics similar to those se en with primary repair.