Extrinsic Pathway Inhibitor in Elective Surgery: A Comparison with other Coagulation Inhibitors

Abstract

SummaryExtrinsic coagulation pathway inhibitor may be an important regulator of haemostasis to prevent thrombosis after tissue damage. The functional activity of this inhibitor was determined using a chromogenic substrate assay, and compared to the activities of anti thrombin, heparin cofactor II and protein C during the perioperative period of elective hip replacement (n = 28), cholecystectomy (n = 11), and vascular surgery (n = 5). Peroperatively, all the inhibitors decreased rather similarly and to the same degree as the decrease in albumin concentration. The decreases during hip surgery were about 2-fold the decreases observed during cholecystectomy. A significant peroperative increase in extrinsic pathway inhibitor activity was observed in vascular surgery, probably due to a bolus injection of heparin. Antithrombin, heparin cofactor II and protein C levels normalized on days 3-5 postoperatively in all three patient groups. Sustained low levels of extrinsic pathway inhibitor were observed on postoperative days 1 to 7 in hip surgery patients. Apparently, extrinsic pathway inhibitor is not an acute phase reactant. In uncomplicated surgery, the decreases of the coagulation inhibitor levels are mainly due to hemodilution.

Postoperative hypercoagulability and deep-vein thrombosis after laparoscopic cholecystectomy

“…There have been some reports indicating that conventional open cholecystectomy is followed by a postoperative activation of blood coagulation [22,23,27]. The results of the present study clearly demonstrate that LC, despite being considered a minimally invasive procedure, also induces a significant hypercoagulable state, as shown by the modifications in most of the thrombelastographic parameters and PTT.…”

Coagulation modifications after laparoscopic and open cholecystectomy in a swine model

“…Following major surgery, a transient hypercoagulable state ensues that is comparable in magnitude to the degree of surgical trauma [14,20]. Hypercoagulation results from an imbalance between the coagulation and fibrinolytic activities [15,24].…”

“…Postoperative hypercoagulation has been shown to be related to the extent of surgical trauma. Sandset et al demonstrated that postoperative decreases in coagulation inhibitor levels (AT III, heparin cofactor II, extrinsic coagulation pathway inhibitor, and protein C) following hip surgery were two times greater than the decreases occurring after cholecystectomy (open) [20]. Since laparoscopic surgery minimizes surgical trauma compared to open surgery, the postoperative hypercoagulable state after laparoscopic procedures may potentially be diminished.…”

A comparative study of functional assays for tissue factor pathway inhibitor using normal plasma and clinical samples

“…It has previously been reported that TFPI levels are reduced during and after operative procedures [19]. All patients in this study received unfractionated heparin postoperatively.…”