The value of extended preoperative thromboprophylaxis with dalteparin in patients with ovarian cancer qualified to surgical treatment.

Aim: Ovarian cancer (OC) is associated with a high risk of venous thromboembolism (VTE) in both, pre- and postoperative period. The aim of the study was to analyse the efficacy and the safety of an early prophylaxis with dalteparin in patients with OC qualified to surgery.
Methods: The prospective, non-randomized study was performed in the group of OC patients qualified to surgical treatment. The study group (SG) consisted of 37 patients with OC in whom thromboprophylaxis was started at the moment of qualification to the surgery (mean 16,1 days ± 11,32 SD before procedure). The control group (CG) consisted of 61 patients with OC qualified to surgery in whom thromboprophylaxis was started 12 hour before surgical treatment. The duration of postoperative prophylaxis was 4 weeks in both groups. Dalteparin 5000 U/day was used in both groups. The primary end points were occurrence of VTE and major bleeding. The patients underwent color Doppler US and D-dimer (DD) assessment at the moment of qualification for surgery, 1 day before and 7, 14, 28 days and 3 months after procedure.
Results: The total duration of thromboprophylaxis was 45.3 ± 10.7 days in SG and 27.9 ± 3.7 days in CG (P < 0.0001). The deep venous thrombosis rate was 2,7% in SG and 16.4% in CG (P = 0.042). Neither pulmonary embolism, nor major bleeding were observed. Median preoperative DD concentration in all patients was 1700 ng/ml and was significantly higher in patients who developed postoperative DVT when compared to those who did not, 2556.8 and 1691.0 ng/mL respectively (P = 0.0009).
Conclusion: Prolonged preoperative thromboprophylaxis with dalteparin in patients with ovarian cancer qualified to the surgical treatment is safe, decreases the risk of thromboembolic complications. To determine indication, dosage and timing of such thromboprophylaxis in this group of patients further studies are required.