Methods: Thirty rabbits were randomly assigned to six groups: control, pericardium, expanded polytetrafluoroethylene, resorbable membrane, expanded polytetrafluoroethylene + resorbable membrane, and pericardium + resorbable membrane. At the postoperative five weeks, the tenacity of the adhesions was evaluated using a qualitative grading system, and histological specimens were examined.
Results: Resorbable membrane group had significantly lower tenacity scores, compared to the control, pericardium, and expanded polytetrafluoroethylene groups (p<0.01). The scores of the expanded polytetrafluoroethylene + resorbable membrane and pericardium + resorbable membrane groups were lower than the control group (p<0.05 and p<0.01 respectively). Combined use of resorbable membrane, compared to the solitary use, did not produce significantly different tenacity scores. Macroscopically, in the resorbable membrane group after sternotomy, there were filmy adhesions over the epicardium which could be easily dissected digitally. In the expanded polytetrafluoroethylene + resorbable membrane and pericardium + resorbable membrane groups, there were also adhesions beneath the sternum.
Conclusion: Resorbable membrane was effective in reducing postoperative pericardial adhesions when used alone or in combination with expanded polytetrafluoroethylene membrane or pericardial closure. Solitary use of resorbable membrane, compared to combined use, can be preferable, since the addition of expanded polytetrafluoroethylene membrane and pericardial closure increase substernal fibrosis.