This large placebo controlled trial of patients with VTE, already treated with 3 months of anticoagulation, randomized them to dabigatran, warfarin, or placebo; dabigatran and warfarin had similar rates of recurrent VTE, but dabigatran had lower rates of major/minor bleeding (abstract).
In this large statewide registry of bariatric patients, there was no benefit of prophylactic IVC filters, but there was significant harm, including higher rates of PE, DVT, complications, and death. There does not appear to be any benefit of IVC filters for patients undergoing bariatric surgery (abstract).
In this trial of preoperative sickle cell patients, they were randomized to preoperative RBC transfusions or none; those in the non-transfusion group had higher complication rates (39% vs 15%) and serious adverse events (10% vs 1%) compared to those in the transfusion group (the most common was acute chest). Sickle cell patients so appear to benefit from preoperative RBC transfusions (abstract).
For standard duration VTE prophylaxis, rivaroxaban was equivalent to LMWH, but had a higher risk of bleeding. When VTE prophylaxis was extended (from 10 days to 35 days), the risk of VTE was further reduced, but the risk of bleeding still significantly higher (abstract).
In patients with cancer-related VTE, new guidelines recommend the use of LMWH (or UFH/fonda, but not warfarin) for treatment and prophylaxis, and vena cava filters for those who cannot be medically treated for VTE. Post operative prophylaxis should be continued for 4 weeks. Prophylaxis should be considered for patients with locally advanced or metastatic prostate or lung cancer on chemotherapy. For those with venous catheters, they should not be routinely given prophylaxis, but those with a thrombus should receive 3 months of treatment. The full guidelines can be found here (abstract).