Objective: To examine bleeding complications and thromboembolic events in relation to timing of heparin prophylaxis after hysterectomy.
Design: Nationwide prospective cohort study with 30 days post-operative follow-up within the Danish Hysterectomy Database (DHD).
Setting: All gynecological departments in Denmark (n=31).
Sample: 9,949 women who had an elective hysterectomy for benign indication between October 2003 and May 2006 and were reported to DHD (national response rate: 88-99% throughout 2004-2005).
Main outcome measures: Odds ratios (OR) of peri-operative bleeding complications (> or =1,000 ml bleeding during surgery or post-operative wound/vaginal-vault/intraabdominal bleeding or hematoma) and number of events of venous thromboembolism. Logistic regression analysis adjusting for: age, body mass index, alcohol, smoking, meno-/metrorrhagia, uterine weight, department volume, surgeon's experience, route and type of hysterectomy and additional surgery, and stratification on assistant's experience, peri-operative pain prophylaxis with NSAID and daily use of Acetyl Salicylic Acid (ASA)/NSAID.
Results: 9,051 women (92%) received thromboprophylaxis with heparin, initiated pre-operatively in 48% and post-operatively in 52%. At least one bleeding complication was noted in 881 women (10%). Post-operative heparin administration was associated with a reduced risk of bleeding complications; OR=0.85 (95% confidence interval 0.73-0.99) compared to pre-operative administration. Excluding cases with potential impaired hemostasis at baseline, the OR was 0.78 (0.64-0.94). There was no fatal embolism. Three of seven pulmonary embolisms and one of three symptomatic deep venous thromboses occurred with the post-operative heparin administration.
Conclusion: Post-operative rather than pre-operative administration of heparin prophylaxis may reduce the risk of bleeding complications after hysterectomy without apparent risk of increased thromboembolic events.