Haemorrhage associated with large abdominal aortic aneurysms.

Area of Science:

• Vascular Surgery
• Hematology
• Coagulation Science

Background:

• Abdominal aortic aneurysms (AAAs) are associated with bleeding complications.
• The etiology of bleeding in AAA patients, particularly post-operatively, remains incompletely understood.
• Coagulation factor depletion is often considered a primary cause of surgical bleeding.

Observation:

• Two patients with large AAAs experienced significant hemorrhage following minor surgical procedures.
• Standard laboratory tests did not reveal platelet or coagulation factor deficiencies adequate to explain the observed bleeding.
• Both patients exhibited markedly increased fibrinolytic activity, evidenced by plasmin generation in their circulation.

Findings:

• Enhanced fibrinolytic activity, characterized by plasmin generation, was a prominent feature in both patients.
• In one patient, the insertion of an aortic graft led to a rapid normalization of the fibrinolytic abnormalities.
• These findings suggest that overactive fibrinolysis is a potential mechanism for bleeding in AAA patients.

Implications:

• Overactive fibrinolysis should be considered in the differential diagnosis of bleeding syndromes associated with abdominal aortic aneurysms.
• Targeting fibrinolytic pathways may offer therapeutic strategies for managing hemorrhage in this patient population.
• Further research is warranted to elucidate the precise mechanisms linking AAAs and hyperfibrinolysis.