Topical use of aprotinin in coronary artery bypass surgery

The internal mammary artery (IMA) ranks among excellent, widely used conduits for surgical coronary revascularization. Its harvesting and its using may cause other surgical and technical problems and complications and increase postoperative bleeding from wound surface after the IMA harvesting with significantly greater incidence of blood transfusion. The aim of this study was to get to know how much it increases postoperative bleeding losses and if the local application of aprotinin (to the wound surface after the IMA harvesting and into the pericardial cavity) can reduce them and thus decrease the number of blood transfusions.

In this study there are compared groups of patients (n = 275) operated at the University Department of Cardiac Surgery in Hradec Králové on account of ischemic heart disease. In the first part of this study results of operations of 200 patients were comprised retrospectively. Group A1 comprised 50 patients where for revascularization of the myocardium venous grafts were used. Group B1 comprised 50 patients where also the internal mammary artery was used. Group C1 was formed by 50 patients where after preparation of the IMA aprotinin (100,000 KIU) was administered locally to the wound surface after the IMA harvesting. Group D1 was formed by 50 patients where aprotinin (500,000 KIU) was administered locally to the wound surface and poured into the pericardial cavity before closure of the median sternotomy. The postoperative blood losses and the number of the administered blood transfusions were compared between these groups.

The authors provided evidence that the using of the IMA increases significantly the postoperative blood losses (in group A1 675 ml +/- 352.9, in group B1 1232 ml +/- 336.5) and increases the number of required transfusions (in group A1 2.44 +/- 1.7, in group B1 3.45 +/- 1.0). By local aprotinin application to the wound surface after the IMA harvesting the blood losses and the number of administered transfusions were reduced in group C1 (896 ml (231.9, 2.74 +/- 0.8). In group D1 (local aprotinin application to the wound surface and into the pericardial cavity) the blood losses and the number of transfusions were increasingly reduced than in group C1 (797 ml +/- 280.5, 1.74 +/- 1.3). In the second, prospective randomised part of this study 3 groups of patients were compared. Group A2 comprised 25 patients where venous grafts for revascularization of myocardium were used. Group B2 was formed by 25 patients where also the IMA was used. Group D2 comprised 25 patients where aprotinin (500,000 u.) was administered locally to the wound surface after the IMA harvesting and poured into the pericardial cavity before closure of sternotomy. The postoperative blood losses and the number of administered blood transfusions were again compared between these groups. The total postoperative blood losses were 778 ml +/- 304.2 in group A2, 1072 ml +/- 391.8 in group B2 and 754 ml +/- 197.9 in group D2. There were compared blood losses after 6, 12 and 24 hours, too. There were the statistically significant differences among these groups during the whole postoperative period. The number of blood transfusions were 2.8 +/- 2.3 in group A2 and 2.04 +/- 1.1 in group B2. The use of aprotinin decreased this number in group D2, 1.44 +/- 1.1.

The authors provided evidence that the harvesting and the using of the internal mammary artery for myocardial revascularization increases significantly the postoperative bleeding and increases the number of required transfusions. By local application of aprotinin the author reduced the blood losses and need of transfusions.