Effect of topical N-acetylcysteine in the prevention of postoperative pericardial adhesion formation in a rabbit model.

Background: N-acetylcysteine (NAC), a precursor of reduced glutathione, has been in clinical use primarily as a mucolytic. In addition, NAC is well known for their free radical scavenging and antioxidant properties. Increasing of reactive oxygen products occurring during cardiac surgery can play an important role in postoperative adhesion formation. We investigated to the efficacy of the NAC for postoperative pericardial adhesions.

Methods: Sixteen New Zealand white rabbits (2.5-3 kg) were used and categorized into two groups including study (use of NAC) and control groups. In both groups, the pericardium was opened longitudinally, and the exposed epicardial surfaces were abraded with dry gauze. The rabbits were divided into two groups: Group 1 was treated with the sponge, which impregnated with NAC solution, (10%, 300 mg/3 ml) and applied over the abraded epicardium for 5 min (n=8). Group 2 was the control, and the sponge, which was impregnated with 3-ml isotonic NaCl solution (0.9%), was applied onto the surface of the abraded epicardium for 5 min (n=8). After a period of 2 weeks, the animals were sacrificed. The scores of adhesion were graded by macroscopic examination, and the pericardial tissues were analyzed microscopically in point of inflammation and fibrosis.

Results: In Group 1, the adhesion scores were significantly lower compared with the control group [Group 1 vs. 2; 1 (1-2) vs. 3 (2-3), P<.001]. No significant difference was found between the groups in terms of the severity of inflammation [Group 1 vs. 2; 1.5 (1-3) vs. 2.5 (1-3), P=.083]. There was a difference between groups in terms of the degree of fibrosis [Group 1 vs. 2; 2 (1-2) vs. 3 (2-3), P=.007].

Conclusions: The use of NAC for preventing postoperative pericardial adhesions was reduced to adhesion and fibrosis scores in an experimental rabbit model. There was no statistically significant difference between groups in terms of inflammatory scores. The NAC effectively prevented the formation of pericardial adhesion.