Anticoagulation to prevent venous thromboembolism (VTE) remains an important part of postoperative care. Especially after major surgery, the risk can increase. But for how long should prophylaxis actually be given? Perhaps two weeks is long enough? This question was addressed in a recent meta-analysis in which the authors included studies with data from about 1.8 million people who had previously had a major surgery.
The main question for the researchers was: When VTE occurs postoperatively, when exactly does it happen? To answer this, they analysed how many thrombotic events developed within four weeks in percentage terms.
The found out that almost half of all VTEs occurred within the first week post-op. In week two it was still almost 27%, in the third week just under 16% and in the fourth week still 10%.
This makes it clear that longer-term prophylaxis makes perfect sense. Especially for people with an increased risk of VTE. Although almost half of all thromboses occur in the first or second week after surgery, a non-negligible proportion develop later.
The likelihood of developing a thrombosis decreases the longer it has been since surgery. But a not insignificant proportion of patients still develop VTE up to one month after surgery. It is therefore important to continue prophylaxis for a sufficiently long time - especially if there are other risk factors that can promote thrombosis. If anticoagulation is stopped after two weeks, almost a quarter of all thromboses fall by the wayside.