Thrombin generation in patients undergoing carotid endarterectomy: implications in acute vessel wall closure and antithrombotic therapy.
We determined the extent and duration of activation of coagulation during the first 24 hours after carotid endarterectomy. Serial blood samples were collected before, during and after surgery from 10 patients with severe stenosis (> 70%) undergoing carotid endarterectomy with heparinization. Platelet poor plasmas prepared from these samples, were analysed for activated prothrombin fragment F1 + 2 and thrombin-antithrombin III (TAT) levels, using commercially available ELISA kits. F1 + 2 and TATs were measured as indices of thrombin generation and inhibition respectively. Baseline F1 + 2 and TAT levels were 1.19 +/- 0.27 nMol/ml and 17 +/- 10 pMol/ml, respectively. Neither the F1 + 2 nor TAT level increased during surgery at a time when the patients were heparinized. However, both the F1 + 2 and TAT levels increased significantly within 3 hours after surgery and after the heparin had been neutralized with protamine, (p < 0.01). Moreover, both the F1 + 2 and TAT levels remained elevated in 75% of the patients for at least 24 hours, p < 0.01. We conclude that i) thrombin generation is significant post surgery in patients undergoing carotid endarterectomy despite their receiving heparin during surgery; ii) heparin may not be the ideal anticoagulant for carotid endarterectomy; and iii) persistent thrombin generation may contribute to early post-endarterectomy ischemic events.
Wells
J
J
McMaster University, Dept of Surgery, Hamilton, Ontario, Canada.
Nicosia
S
S
Wale
C
C
Smith
L J
LJ
Buchanan
M R
MR
D000208:Acute Disease; D016893:Carotid Stenosis / Q000628:therapy*; D016894:Endarterectomy, Carotid; D005260:Female; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D006493:Heparin; D013917:Thrombin