Fibrinolytic response to surgery. Labile and stable patterns and their relevance to post-operative deep venous thrombosis.

Fibrinolytic activity after elective abdominal surgery was studied in 53 middle-aged cancer-free patients. The pattern of their response demonstrated both stable and labile populations. In 10 of the 13 patients in whom fibrinolytic activity fell rapidly to below 5-6 units, deep venous thrombosis (D.V.T.) developed on the first postoperative day. This suggests that reduced fibrinolytic activity after operation is involved in the establishment of postoperative D.V.T. and that the incidence of early thrombosis could be reduced by enhancement of postoperative levels of fibrinolytic activity.