Combined application of acellular bovine pericardium and hyaluronic acid in prevention of postoperative pericardial adhesion.

An experiment was designed to find the suitable acellular bovine pericardium (ABP) patch in pericardial cavity reconstruction and to evaluate the effect of sodium hyaluronic acid (NaHA) on inflammatory reaction in prevention of pericardial adhesions. The pericardial adhesion model was established in 20 rabbits, weighing from 3.2 to 3.6 kg. Groups were classified as follows: Group A (n = 5), the control group, the pericardium was directly closed; Group B (n = 5), 0.15% glutaraldehyde-treated ABP (low cross-link degree); Group C, 0.3% glutaraldehyde-treated ABP (middle cross-link degree); Group D, 0.15% glutaraldehyde-treated ABP + NaHA solution. Blood samples were collected at 6 h, 24 h, 3 days, and 5 days, to assay postoperative inflammatory reaction. The tenacity and severity of adhesions were evaluated 2 months after operation, by macroscopic and microscopic examinations, and Q-PCR (real-time quantitative polymerase chain reaction) test was used to quantitatively analyze the associated genes with adhesion. Pericardium regeneration was demonstrated by immunohistochemical technique to identify mesothelial cells. In Group D, the serum concentration of tumor necrosis factor-α (TNF-α) was significantly lower in the early postoperative period, and the mean adhesion score (adhesion between the epicardium and ABP) was significantly lower compared with the control group (Groups D vs. A: 0.20 ± 0.45 vs. 2.00 ± 0.71, P = 0.009*). The signs of degradation of the ABPs were observed 2 months postoperation in Groups D and B. Immunohistochemically, the positive cytokeratin AE1 staining results demonstrated the relatively total regeneration of the pericardium in Group D. Signs of regeneration were observed in Group D. Compared with the control group, the level of TGF-β2 in Group D was significantly lower (0.00132 ± 0.00114, P = 0.022*). The TGF-β3 level was statistically significant, being highest in Group D (0.00805 ± 0.00136, P = 0.029*). The mean quantity of Smad6 in Group D was also lower than the other groups. Low cross-link degree ABP may be an efficient physical block between the epicardium and the sternum and also an ideal scaffold for pericardial tissue regeneration, whereas combined use with NaHA may significantly reduce postoperative pericardial adhesions. The signal transduction pathway of transforming growth factor-β (TGF-β) and Smad6 may play a key role in the formation of pericardial adhesion.