Does the position of the drains after open heart surgery make a difference? A clinical randomized trial

Pericardial effusion remains a common clinical problem after cardiac surgery. Adequate postoperative drainage can be obtained by posterior pericardial drainage through a posterior tube, along with conventional drainage of the anterior mediastinum. Three hundred patients, who underwent cardiac surgery, were enrolled in a prospectively randomized study. Group A (150 patients) had two retrosternal drains and group B (150 patients) had two retrosternal drains, one retrosternal and one retro-cardiac. Early pericardial effusion developed in 5 (3.4%) patients in group A and 2 (2.9%) in group B (P = 0.76). Early posterior pericardial effusion occurred in 5 (3.4%) patients of group A whereas no patients had early posterior pericardial effusion in Group B (P = 0.024). Fourteen (9.5%) patients from group A had late posterior pericardial effusion, compared to 1 (0.7%) patient from group B (P = 0.001). Three patients from group A had late posterior cardiac tamponade whereas no patients from group B had late posterior cardiac tamponade (P = 0.013). The use of a drain placed in the posterior pericardial cavity is simple and safe and appears to be sufficient for posterior drainage. This reduces not only the high incidence of late significant pericardial effusion but also reduce early pericardial effusion and tamponade.