Joeky Senders

80 Chapter 4 hospital. Given our practical research question, the relevance of asymptomatic cases of VTE is questionable, and missed cases due to loss to follow-up are rare because patients were almost invariably followed in our own hospital. We think that the limitations are inherently linked to a retrospective study design and proportionate to the strengths of this study. This study focuses on the incidence of VTE in the short-term postoperative period, thereby reducing bias from either adjuvant therapy or a non-representative group of survivors in the long-term period. To our knowledge, this study presents the largest sample of HGG patients prophylactically treated with LMWH after surgery among all studies that address the effect of prolonged thromboprophylaxis in HGG patients. Lastly, the difference in postoperative management between surgeons allows a relatively unbiased comparison between different postoperative strategies based on the duration of thromboprophylaxis. The results of this study suggest that continuing LMWHbeyond hospitalization is neither safe nor effective in preventing VTE. Therefore, we do not recommend prolongation of thromboprophylaxis up to 21 days after surgery routinely in every patient operated for a HGG. However, effectiveness of prolonged thromboprophylaxis targeted to high-risk patients cannot be excluded. Additionally, LMWH administered up to only 21 days can still be too short to achieve significant differences in VTE outcomes measured at 90 days after surgery. Multicenter prospective studies, preferably in a randomized setting, are needed to validate the findings of the current study, and the development of VTE and ICH prediction models can help tailoring postoperative management to the risk profile of the individual patient. Conclusion LMWH administration continued up to 21 days after craniotomy for a HGG was not significantly associated with a lower VTE rate compared to prophylaxis until discharge (0-7 days). Prolonged prophylaxis was found to be associated with an increased risk of ICH. Based on our results, we do not recommend prolongation of prophylaxis beyond discharge routinely in every patient operated for a HGG. Future studies are needed to clarify the optimal timing of postoperative thromboprophylaxis and identify HGG patients at risk for VTE and ICH.