Autologous or homologous transfusion in aortic surgery: randomized trial

Abstract

Abstract Background Aortic surgery often requires blood transfusion, which may cause complications and postoperative infection. Autologous transfusion was evaluated in a multicentre clinical trial. Methods Some 145 patients undergoing elective aortic surgery in eight hospitals were randomized to either ‘homologous’ or ‘autologous’ transfusion, a combination of acute normovolaemic haemodilution (ANH) and intraoperative cell salvage. Homologous blood was administered when the haemoglobin concentration fell below 8 g dl−1. Results Median (interquartile range (i.q.r.)) blood loss was 668 (400–862) ml or 17 (10–24) per cent of blood volume in aortobifemoral bypass, and 1120 (765–1700) ml or 24 (17–36) per cent in aneurysm repair (P < 0·001). Autologous transfusion reduced homologous blood requirements from a median (i.q.r.) of 2 (0–4) units to 0 (0–2) units (P = 0·008). Independent predictors of blood transfusion were homologous transfusion strategy (odds ratio (OR) 2·3 (95 per cent confidence interval 1·1–5·0); P = 0·03), low preoperative haemoglobin concentration (OR 3·7 (1·7–8·2); P < 0·001), prolonged surgery (OR 2·1 (1·0–4·8); P = 0·05) and blood loss (OR 3·0 (1·4–6·5); P = 0·007). Patients with a preoperative haemoglobin concentration greater than 13·5 g dl−1 and who lost less than 20 per cent of their blood volume rarely required transfusion. There was no significant difference between the groups in terms of morbidity, mortality and postoperative hospital stay. Conclusion Autologous transfusion reduced the need for homologous blood in aortic surgery, but was useful only in patients with low haemoglobin levels or when blood loss exceeded 20 per cent of the blood volume. ANH alone is indicated for patients undergoing aortobifemoral bypass and in those with a higher haemoglobin level and blood volume.