Prevention of post-operative adhesions: Model development and pilot outcomes of human placental stem cell-based interventions.

BACKGROUND: Abdominal adhesions are the most common surgical complication and without reliable prophylactics. This study presents a novel rat model for abdominal adhesions and reports pilot results of human placental stem cell (hPSC)-based therapies.

METHODS: Forty-four (n = 44) male Sprague-Dawley rats (250-350 g) were used in the experiment. Of these, thirty-eight (n = 38) were included in a preliminary data set to determine a minimum treatment effect. Adhesions were created in a reproducible model to the abdominal wall and between organs. Experimental groups included the control group (Model No Treatment, MNT), Plasmalyte A (Media Alone, MA, 10 mL), hPSC (5 × 106 cells/10 mL Plasmalyte A), hPSC-CM (hPSC secretome, conditioned media) in 10 mL Plasmalyte A, Seprafilm™ (Baxter, Deerfield, IL), and sham animals (laparotomy only). Treatments were inserted intraperitoneally (IP) and the study period was 14 days post-operation. Results are reported as the difference between means of an index statistic (AIS, Animal Index Score) and compared by ANOVA with pairwise comparison.

RESULTS: The overall mean AIS was 23 (SD 6.16) for the MNT group with an average of 75% of ischemic buttons involved in abdominal adhesions. Treatment groups MA (mean overall AIS 17.33 SD 6.4), hPSC (mean overall AIS 13.86 SD 5.01), hPSC-CM (mean overall AIS 13.13 SD 6.15), and Seprafilm (mean overall AIS 13.43 SD 9.11) generated effect sizes of 5.67, 9.14, 9.87, and 9.57 decrease in mean overall AIS, respectively, versus the MNT.

DISCUSSION: The presented rat model and scoring system represent the clinical adhesion disease process. hPSC-based interventions significantly reduce abdominal adhesions in this pilot dataset.