METHODS: Proximal aortic reconstructions performed between December 2008 and April 2011 were identified from prospectively collected data in a tertiary centre database. Retrospective analysis of patient notes was performed. Proximal aortic surgery patients were categorised as low dose (20 mg) enoxaparin and high dose (40 mg) enoxaparin, and compared for confounding variables. In-hospital, early and one-year readmission rates for pericardial effusion were ascertained from echocardiography reports. The primary outcome was total pericardial effusion rate. Secondary outcomes consisted of 30-day and 1-year mortality.
RESULTS: A total of 198 patients underwent proximal thoracic aortic surgery. Nine patients were excluded due to early postoperative death (n=5) and missing patient records (n=4). This left 189 cases for analysis. There were 93 patients in the low dose group and 96 in the high dose group. Groups were comparable for age, cardiopulmonary bypass time, aortic cross-clamp time, postoperative warfarin and antiplatelet agents. Pericardial effusion rates up to one year were comparable (low dose 19% vs high dose 21%). Thirty-day mortality was lower in the low dose group (0 vs 3 deaths). There were four deaths up to one year but these were not attributable to increased enoxaparin.
CONCLUSIONS: Increased perioperative thromboprophylaxis dosage does not increase pericardial effusion rates or mortality in proximal aortic surgery.