Does Human Amnion Membrane Prevent Postoperative Abdominal Adhesions?

Adhesions are bands of tissue that form postoperatively after intra-abdominal surgery. Adhesions cause significant morbidity and despite ongoing research no agent or method has been shown to completely prevent adhesions. Human amnion-derived matrix is a complex tissue matrix derived from human placenta and has been used in other areas of surgery to promote healing and decrease scar tissue formation. Our hypothesis was that aerosolized human amnion-derived matrix particulate solution (HAMPS) applied during abdominal surgery would decrease adhesion formation in rats.

Twenty-four Sprague-Dawley rats were divided into 4 different groups. Group 1 was the control group (CG) which had cecal abrasion 20× with a surgical rasp to generate the adhesion model. Groups 2-4 were the treatment groups (TGs) and had cecal abrasion plus application of the HAMPS at concentrations of 6.25, 12.5, and 25 mg/cc, respectively. After 30 days, rats were euthanized and adhesion assessment performed.

In all groups there were minimal adhesions noted at necropsy. Moderate inflammation was 33% in CG versus 11% in combined TGs. Average adhesion was 1.00 in CG versus 0.44 in combined TGs. This indicated an observational improvement in adhesions/inflammation in the TGs, although this did not reach statistical significance. There was a trend toward significance in the 12.5 mg/cc group alone (P = .054).

Overall, HAMPS showed an observational decrease in adhesions in TGs although not statistically significant. There was a trend toward significance in the 12.5 mg group. Additional studies will have to be performed to further evaluate this subgroup.