The effects of barrier materials on reduction of pericardial adhesion formation in rabbits: a comparative study of a hyaluronan-based solution and a temperature sensitive poloxamer solution/gel material.

OBJECTIVE: This study was performed to examine the efficacy and safety of a hyaluronan solution (Guardix-SL) and a temperature sensitive poloxamer solution/gel material (Guardix-SG) on the prevention of pericardial adhesion in rabbits.
METHODS: A total of 60 rabbits were divided into three groups according to material applied after epicardial abrasion: the control group (group CO), the Guardix SL group (group SL), and the Guardix SG group (group SG). The ejection fraction and the presence of pericardial effusion were evaluated by echocardiograms at the immediate postoperative period and 2 wk after the surgery. The adhesion was evaluated macroscopically and microscopically 2 wk after the surgery.
RESULTS: In the group SG, mild pericardial effusions were observed only at the immediate postoperative period in 10 out of 20 rabbits with an insignificant reduction of the ejection fraction. Group CO had a significantly higher macroscopic adhesion and fibrosis score than did groups SL and SG (P < 0.001), and group SL had a significantly higher adhesion score than did group SG (P = 0.045). Inflammation score and the expression of anti-macrophage antibody in group CO were higher than those in groups SL and SG, although the differences were not significant.
CONCLUSIONS: Guardix-SL and Guardix-SG effectively reduced the adhesion formation, and Guardix-SG is more effective than Guardix-SL for preventing adhesion. However, Guardix-SG showed a potential disadvantage of decreasing the ejection fraction, although this was statistically insignificant. Further study to verify the appropriate dosage to maximize the therapeutic effect without decreasing the heart function is needed.