Factors affecting the fibrinolytic response to surgery

Area of Science:

• Biochemistry
• Physiology
• Vascular Biology

Background:

• Surgical stress and injury initially increase blood fibrinolytic activity.
• This is followed by a period of reduced fibrinolytic activity, termed 'fibrinolytic shutdown'.
• This shutdown is pronounced in patients with malignant disease.

Purpose of the Study:

• To investigate the phenomenon of 'fibrinolytic shutdown' after injury and surgery.
• To determine its association with malignant and benign diseases.
• To explore the underlying mechanisms and impact on deep venous thrombosis.

Main Methods:

• Analysis of spontaneous fibrinolytic activity in blood post-injury/surgery.
• Venous occlusion studies to assess endothelial fibrinolytic capacity.
• Measurement of plasma levels of antiplasmins (alpha2-macroglobulin, alpha1-antitrypsin).

Main Results:

• 'Fibrinolytic shutdown' occurs in patients with malignant and benign diseases.
• In benign disease, shutdown is greater on day one in patients who develop deep venous thrombosis (DVT).
• Reduced fibrinolytic capacity of the vascular endothelium, due to plasminogen activator deficiency or release issues, is implicated.
• Changes in antiplasmins (alpha2-macroglobulin decrease, alpha1-antitrypsin increase) occur but do not correlate with DVT development.

Conclusions:

• Post-injury/surgical 'fibrinolytic shutdown' is a significant physiological response.
• The mechanism involves impaired endothelial fibrinolytic capacity.
• While observed in DVT patients, antiplasmin changes do not appear to predict DVT development.