Stroke can have several causes, and one of them is cerebral venous thrombosis (CVT), affecting mostly young adult and middle-aged patients.1 The current standard for CVT is anticoagulation treatment with heparin, independent of the presence of an intracerebral haemorrhage (ICH) which occurs in about half of the patients with CVT.2,3 Advances in treatment are urgently needed – currently 20% of patients treated with heparin still end up with a disability or die.3 Endovascular treatment (EVT) is being increasingly used for CVT. It aims at recanalising sinuses by the local administration of mechanical thrombectomy, a thrombolytic drug, or both.4 So far, prospective clinical studies showing the benefit of EVT were lacking, but Jonathan Coutinho (Department of Neurology, Amsterdam University Medical Centers, the Netherlands) and his colleagues just recently published their multicentre randomised clinical trial assessing the efficacy and safety of EVT in patients with severe CVT.4
A small patient number to show the efficacy of EVT
A total of 67 patients with radiologically confirmed CVT and at least one risk factor predicting a poor outcome were randomised to either receive EVT in addition to standard medical care (n=33), or standard medical care only (n=34).4 In the present study, EVT was performed by mechanical thrombectomy, local intra-sinus application of alteplase or urokinase, or by a combination of both. The primary outcome of the trial was the proportion of patients who recovered without disability at 12 months.
No improved functional outcome with EVT
At the predefined 12-month timepoint, no statistically significant difference could be seen between the two study groups. 67% of patients in the EVT arm recovered without disability, while 68% in the control arm did.4 New symptomatic ICH, the “most feared complication of EVT” according to the authors, occurred less frequently in the EVT group than in the standard treatment group, yet not statistically significant.4 While EVT did not improve outcomes, it also did not show any major side effects. Overall, it was shown that the rate of mortality was not statistically increased by the additional intervention. Given the results, the study was terminated after the first interim analysis due to futility.
No definitive proof that EVT is ineffective
The authors state that the ineffectiveness of EVT should not be concluded prematurely.4 Their main argument is the large confidence interval (CI) range of the primary outcome results (0.71–1.38), as well as the small sample size. The possibility that EVT is effective in a specific subgroup still exists, but could not be shown in such a small trial. Even though the presented trial is one of the largest randomised trials on CVT, it was not large enough to show a favourable effect of EVT. Following the authors’ recommendations, we should still wait for future studies using other patient selection methods and endovascular intervention techniques to draw our final conclusions about EVT in CVT.