Hemostatic markers before operation in patients with acutely symptomatic nonruptured and ruptured infrarenal abdominal aortic aneurysm

Abstract Background: In patients with acutely symptomatic but nonruptured abdominal aortic aneurysm (AAA), emergent repair is associated with an increased mortality rate as compared with semi-elective repair. Previous results have shown that ruptured but not asymptomatic AAA repair is associated with intense thrombin generation and inhibition of systemic fibrinolysis. The purpose of this study was to determine whether circulating markers of coagulation and fibrinolysis may be used to distinguish acutely symptomatic nonruptured and ruptured AAA. Methods: A prospective study was performed of 44 patients who underwent emergency AAA repair for suspected rupture. Platelet count, fibrinogen level, prothrombin time, activated partial thromboplastin time, tissue plasminogen activator (t-PA) activity, plasminogen activator inhibitor (PAI) activity, prothrombin fragment (PF) 1+2 level, and D dimer level were measured before surgery. Results: When compared with ruptured AAAs (n = 37), acutely symptomatic nonruptured AAAs (n = 7) were associated with increased fibrinogen level ( P =.033), reduced activated partial thromboplastin time ( P =.043), increased t-PA activity ( P =.023), reduced PAI activity ( P =.005), reduced PF 1+2 level ( P =.001), and reduced D dimer level ( P =.005; all P values determined with Mann-Whitney test). The differences in t-PA activity ( P =.01), PAI activity ( P =.004), and PF 1+2 level ( P =.01) persisted in patients whose conditions were normotensive. In all patients, a PF 1+2 level of greater than or equal to 2.5 nmol/L was associated with a sensitivity, specificity, and positive and negative predictive value for rupture of 89%, 86%, 97%, and 60%, respectively. In patients whose conditions were normotensive, PAI activity of greater than or equal to 16 AU/mL was associated with a sensitivity, specificity, and positive and negative predictive value of 83%, 100%, 100%, and 88%, respectively. Conclusion: These data show that acutely symptomatic nonruptured AAA is associated with increased systemic fibrinolysis (caused by reduced fibrinolytic inhibition) and reduced thrombin generation as compared with rupture. Preoperative hemostatic markers, particularly PF 1+2 level and PAI activity, may distinguish acutely symptomatic nonruptured from ruptured AAA. (J Vasc Surg 2002;35:661-5)