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Fibrinolytic activity and calf pump failure
1Department of Surgery, United Medical School, London, UK.
Insights
Impaired fibrinolysis in the legs of patients with varicose veins or healed ulcers suggests reduced clot breakdown. This is linked to poor calf pump function and lower skin oxygen levels, impacting circulation.
Area of Science:
- Vascular Biology
- Physiology
- Dermatology
Background:
- Abnormal calf pump function is associated with venous diseases like varicose veins and ulcers.
- Interstitial fibrinolytic activity plays a role in clot lysis and tissue repair.
Purpose of the Study:
- To investigate interstitial fibrinolytic activity in the limbs of individuals with compromised calf pump function.
- To correlate fibrin clot lysis rates with calf pump efficiency and skin nutritive circulation.
Main Methods:
- Experimentally produced subcutaneous 125I-fibrin clots were used to measure lysis rates.
- Calf pump function was assessed using foot volumetry.
- Skin nutritive circulation was evaluated by measuring transcutaneous oxygen tension (PtcO2).
Main Results:
- Fibrin clearance was significantly prolonged in the legs of subjects with varicose veins and healed venous ulcers compared to controls.
- A negative correlation was observed between fibrin clearance half-life and half-volume refilling time (P < 0.01).
- Fibrin clearance half-life also negatively correlated with transcutaneous oxygen tension (P < 0.01).
Conclusions:
- Reduced interstitial fibrinolytic activity in the lower limbs is associated with abnormal calf pump function.
- Impaired fibrinolysis may contribute to the pathophysiology of venous insufficiency and delayed healing in conditions like varicose veins and ulcers.
Abstract:
The interstitial fibrinolytic activity of the upper and lower limbs was investigated in subjects with abnormal calf pump function by measuring the lysis rate of experimentally produced subcutaneous 125I-fibrin clots. Thirty-three subjects with healed venous ulcers, five with varicose veins and 11 controls were studied. 125I-fibrin clots were produced in the subcutaneous tissue of the forearms and legs and clearance half-life was calculated. Calf pump function was assessed by foot volumetry and the 'gaiter' skin nutritive circulation by measuring the transcutaneous oxygen tension (PtcO2). Fibrin clearance was prolonged from the subcutaneous tissues of the legs of subjects with varicose veins and healed ulcers compared with controls. Negative correlations were found between fibrin clearance half-life and the half-volume refilling time (P less than 0.01) and the PtcO2 (P less than 0.01).