The use of heparin in patients with ruptured abdominal aortic aneurysms.

The use of systemic heparin in patients with ruptured abdominal aortic aneurysms (rAAAs) remains a contentious issue with no clear guidelines. This review reports the current understanding, at a molecular and clinical level, of the possible benefits and risks of heparin in emergency aneurysm repair (both open and endovascular). MEDLINE, EMBASE, AMED, SCOPUS, CINAHL and Cochrane Library were searched for all articles containing the keywords 'rupture', 'abdominal', 'aneurysm' and 'heparin'. Current experience, indications and outcomes were analyzed. Articles were searched for both endovascular and open repair of AAAs. A total of eight studies were included for analysis in the systematic review. Of these, only one paper focused specifically on heparin use in open repair of ruptures and suggested a benefit. Of the remaining seven, two were self-reporting retrospective studies assessing individual surgeons' practice, one was a case report and the remaining four included mention of heparin use but with no outcome data. The evidence available suggests that a pro-coagulable state exists in rAAAs. This may be responsible for the morbidity and mortality postprocedure, which arises predominantly from multiple organ failure and cardiac compromise rather than outright hemorrhage. This diathesis may respond well to heparin administration, suggesting that heparin administration in ruptured aneurysms is appropriate.