Michelle Christina Johansen, MD

Siddiqui FM, Dandapat S, Banerjee C, Zuurbier SM, Johnson M, Stam J, and Coutinho JM. Mechanical Thrombectomy in Cerebral Venous Thrombosis: Systematic Review of 185 Cases. Stroke. 2015

Compared to arterial disease, research targeting the venous system may appear overlooked or disregarded. There is not a lot published on this subject matter although the patient cohort impacted by cerebral venous thrombosis has been well described. How many neurologists experience frustration while looking into the face of a previously healthy twenty some year old female who is not on oral contraception, without an underlying hypercoagulable state and struggled to answer her “Why me” question? While ongoing international studies such as BEAST (Biorepository to Establish the Aetiology of Sinovenous Thrombosis study) may help provide some answers to that question one day in the future, neurologists continue to focus on providing timely therapy with anticoagulation.

What about the patient for whom this is not an option? What about those who do not respond to anticoagulation or present with severe venous infarcts? How aggressive should we be in managing these patients? What about venous thrombectomy?

Dr. Siddiqui et al. performed a systematic review of 185 cases in order to gain a better understanding of the efficacy and safety of mechanical thrombectomy (MT) in patients with cerebral venous thrombosis (CVT). They reviewed studies (1995-2014) and included all cases of CVT in whom MT was performed. They classified intervals from symptom onset to intervention as acute (<21 days) or chronic (>21 days). They also analyzed clinical outcomes based on modified Rankin scale with good defined as 0-2. Recanalization was defined as: no recanalization/technical failure, partial recanalization if there was contrast visible but the lumen was too narrow and complete/near complete recanalization.

Of the studies evaluated, 66% were single case reports and there were no randomized trials. The patients demographically were female (64%) and in their mid-thirties. The population was ill with 86% having rapid clinical deterioration on heparin, 82% having thrombosis of at least two sinuses and 76% presenting acutely. Regarding the procedure, AngioJet was the most frequently used device and 71% also received concurrent intra-sinus thrombolytics.

The authors found 84% to have a good outcome (mRS 0-2) but 22 patients died, majority with worsening hemorrhage and herniation. Recanalization rates were near to complete in 74%. The predominant procedural complication was new or increased ICH which occurred in 18 patients. Subgroup analysis found that use of the AngioJet was associated with a lower chance of good outcomes and higher risk of complications although the authors make note of the insufficient power to adjust for confounders.

So should we consider mechanical thrombectomy for our patients with CVT? This review suggests it is a consideration in patients who present with a severe clinical picture (comatose, rapid deterioration etc.) as the outcome was “good” in 84% but the authors appropriately caution the physician from acting on this information alone. Would those patients with less severe symptoms have done just as well or better on anticoagulation alone? Would adjusting the designated interval from symptom onset to intervention to <1 week (acute), 1 week to 21 days (subacute) and >21 days (chronic) have led to different results? Publication bias may also sway the literature towards those cases with good outcomes further necessitating caution when interpreting these results.

Nevertheless, we should be grateful for literature concerning cerebral venous thrombosis and the results of this review emphasizes that more randomized trials targeting the venous system is needed.