Open surgery on the abdominal aorta is a high risk procedure associated with an intravascular volume blood loss and thereby, with high requirement for blood and blood product transfusion.

The aim of this study was to establish the rate for allogenic blood transfusion (ABT) during elective open abdominal aortic surgery and find parameters associated with ABT requirements.

Two distinct clinical entities affect the abdominal aorta: abdominal aortic aneurysm (AAA) and aortoiliac occlusive disease (AIOD). These are multifactorial vascular disorders caused by complex genetic and environmental factors. Older patients with more comorbidity are often affected. Open abdominal aortic surgery is associated with high mortality rate. Even in specialised institutions it varies from 2 to 5%. Similar results can be compared to mortality for coronary artery bypass grafting. This reflects the complexity of the surgery and the general health of those patients. It is associated with intravascular volume blood loss and, thereby, with a high requirement for blood and blood products transfusion. Allogenic blood transfusion (ABT) has been associated with an increased risk of tumour recurrence, postoperative infection, acute lung injury, perioperative myocardial infarction, postoperative low-output cardiac failure, and increased mortality.

In the last decades, multiple strategies have been undertaken to prevent massive intraoperative blood loss during elective surgery and allogenic blood transfusion requirement. One of the method advocates a preoperative increase in red blood cells level using B12, folic acid and iron supplements or with erythropoietin usage. Other methods involve the optimisation of surgical technique and the use of a machine for intraoperative blood salvage, known as "cell saver".

The aim of this study was to establish the rate for ABT during elective open abdominal aortic surgery, find parameters associated with ABT requirements, and optimise the investigators hospital's maximum surgical blood ordering schedule (MSBOS).

Inclusion Criteria:

• Patients older than 18 years
• Elective open abdominal aortic surgery
• Abdominal aortic aneurysm repair
• Abdominal aortic bypass grafting for occlusive aortoiliac disease

Exclusion Criteria:

• Patients younger than 18 years
• Patients undergoing cardiac surgery
• Patients with ruptured abdominal aneurysms
• Patients undergoing endovascular aortic repair
• Patients submitted to other types of vascular surgery (i.e., carotid endarterectomy or peripheral bypass surgery)

A retrospective cross-sectional study was conducted using an existing computerised medical records database at the Department of Anaesthesiology and Intensive Care at the Clinic for Cardiovascular Diseases Magdalena. This Clinic is a tertiary hospital in Croatia specialised in cardiac and vascular surgery. This study is a retrospective analysis of consecutive patients undergoing elective major vascular surgery who had been prospectively risk-stratified.