Peritoneal Reactivity Evaluation in Horses Subjected to Experimental Small Colon Enterotomy and Treated with Subcutaneous Heparin

Heparin is routinely administered in postoperative abdominal surgery aiming to prevent adhesions formation; however, there is no consensus indicating its effectiveness. This study evaluated the effect of heparin on peritoneal reactivity after abdominal surgery, through the association between peritoneal fluid features and ultrasonographic and laparoscopic examination. Ten adult horses were used: control group (CG) and treated group (TG). Both groups underwent laparotomy and small colon enterotomy. TG received subcutaneous heparin at 150 IU/kg every 12 hours for 5 days. The animals underwent ultrasonography and peritoneal fluid examination prior to enterotomy (M0) 12 hours (M1), 1 day (M2), 2 days (M3), 4 days (M4), 6 days (M5), 10 days (M6), and 14 days after enterotomy (M7) with laparoscopic examination being performed on the fifth postoperative day. Peritoneal inflammatory response was observed in both groups. The peritoneal fluid of TG animals showed higher echogenicity during heparin therapy. No inflammatory difference was observed between groups through peritoneal fluid features, except for the higher D-dimer concentration in CG. On laparoscopy, slightly diffuse peritoneal reactivity for both groups was observed, being higher for TG. Laparoscopy and ultrasonography association allowed detailed access to the abdominal cavity. Ultrasonography assessed the diffuse peritoneal inflammation, and laparoscopy allowed the detailed analysis of the segments. No gross beneficial reactions resulting from the use of heparin on peritoneal reactivity were observed; however, it was observed by D-dimer evaluation that the TG had less fibrin deposition, which is directly related to a lower rate of abdominal adhesions formation.