Prevention of intestinal adhesions after laparotomy in a rat model--a randomized prospective study

We prospectively studied the effect of a foam composite containing glycerin, propylene glycol, polyol, stearine, stearate and silicone oil, which is known to form a temporary barrier layer when applied to epithelial surface, on adhesion prevention in rats. The small intestine abrasion model was used for creation of adhesions. Sixty male Sabra rats of a mean weight of 295 +/- 23 g were randomly assigned into four groups: group 1 (n = 20) underwent laparotomy and abrasion; group 2 (n = 20) underwent laparotomy, abrasion and intraperitoneal instillation of the foam composite; group 3 (n = 10) underwent laparotomy with abrasion and a second laparotomy with adhesiolysis 2 weeks later; and group 4 (n = 10), was treated in the same way as group 3 but during the second laparotomy the foam composite was instilled intraperitoneally. All animals were relaparotomized 2 weeks (groups 1 and 2) and 4 weeks (groups 3 and 4) after the initial laparotomy for adhesion scoring performed by a blinded independent investigator using the standard 0-3 adhesion grading score. Representative specimens of small intestine and liver from animals in groups 2 and 4 were analyzed. A significantly lower mean adhesion score was noted in group 2 (1.15 +/- 0.3) compared with that of group 1 (2.65 +/- 0.1) or group 3 (2.60 +/- 0.1) (P < 0.01). Group 4 had a significantly lower score (1.4 +/- 0.3) than group 3 or group 1 (P < 0.05). There was no significant difference in the mean adhesion score between groups 1 and 3. Histological examination revealed no evidence of residual foam composite or adverse reaction to its use in the intestine and liver. The foam composite tested may reduce the severity of intestinal adhesions after laparotomy and may also reduce the severity of recurrent adhesions after adhesiolysis. Intraperitoneal use of this composite is safe in rats. The exact mechanism of action is unclear but may be related to the formation of a temporary microlayer that coats the injured surface of the intestine and facilitates healing without adhesion formation. Further investigation is needed to evaluate its full potential.