Background. Redo cardiac surgery is considered high-risk surgery as accidental injury to the aorta, the innominate vein, the ventricles and the atria is a possibility. Such accidental injury occurs when the cardiac chamber is adherent to the undersurface of the sternum. Closure of pericardium at the time of primary surgery can prevent adherence of cardiac chambers to the sternum, but may increase the risk of tamponade. This study aimed to show that covering heart with a pedicled pericardial fat pad not only serves the purpose of cover but also avoids the adverse haemodynamic effects of primary pericardial closure.

Methods. Forty patients undergoing elective cardiac surgery were randomised into two groups depending on the way pericardium was managed. Both techniques were already in routine use in our unit and in other units around the country. One method is to leave the pericardium widely open, the other is to loosely oppose the pericardial fat pad over the surface of the aorta and right ventricle. Twenty-three patients had a pedicled pericardial fat pad covering the heart: Closure Group. Seventeen patients had no pericardial fat pad cover over the heart: Open Group. A haemostasis clip was used as a radio-opaque marker over the epicardium in both groups. Post-operation heart rate, central venous pressure, pulmonary artery diastolic pressure, mean arterial pressure and cardiac index were measured and recorded 1, 3 and 8h after surgery. The distance between the haemoclip and the posterior table of the sternum was measured at 6 days and 6 months post-operation. Haemodynamic parameters and the retrosternal space depth were compared between the two groups.

Results. There were no important differences in haemodynamic parameters between the two groups. Post-operative lateral chest Roentgenograms showed that the distance between epicardial surface and the posterior table of sternum was larger in the Closure Group compared to Open Group on post-operative day 6, 17.5±1.0mm versus 13.4±1.3mm (P=0.0013) and 6 months later, 12.3±0.8mm versus 6.0±1.2mm (P<0.001). There was no mortality in either group.

Conclusion. Pedicled pericardial fat pad cover is a good alternative to primary pericardial closure as there are no adverse haemodynamic effects in early post-operative period and the long-term benefit of protection of heart at the time of re-sternotomy can be expected.