Intravenous Heparin Reduces The Intra-Operative Mortality In Ruptured AAAs

Objectives: The administration of systemic heparin before aortic clamping in ruptured AAA is inconsistent. The aim of this study was to investigate whether intravenous heparin influenced perioperative mortality rate and the risks of complications including the need for distal thrombectomy in patients with ruptured AAA.
Methods: Prospectively collected data for patients undergoing ruptured AAA repair between January 1999 and June 2004 was analyzed. A multivariate analysis using binary regression was carried out for independent predictive factors.
Results: The thirty day mortality of the series was 25% (n=113). Kaplan-Meier analysis showed that patients who received heparin had a lower perioperative mortality (Log rank test; Chi-square 8.29; p=0.004), Figure1.
Multivariate analysis confirmed heparin administration as an independent predictive factor for survival (p=0.015). Other factors found to affect survival adversely were a low diastolic blood pressure at presentation (p=0.013), male gender (p=0.013), and previous ischaemic heart disease (p=0.05). Age, hypertension, renal failure, chronic obstructive pulmonary disease, stroke, smoking and diabetes had no significant effect on survival. Slightly more patients had a thrombectomy in the heparin group (13% vs. 9%). There was no significant difference in post-operative complications between the two groups.
Conclusions: This study suggests that administration of systemic heparin before clamping is associated with decreased peri-operative mortality and had no effect on limb ischaemia.