Thrombectomy in patients with tandem stenoses.

Abstract

In this issue, Lockau et al. retrospectively analyze different approaches for endovascular recanalization of tandem occlusions in acute stroke [1]. Starting with stent angioplasty of the carotid occlusion as the first step (stent-first group), they reversed the order of their techniques and performed intracranial thrombectomy prior to stenting of the carotid occlusion (thrombectomy-first group, the so-called upside-down approach). They found advantages and disadvantages with both techniques; however, time of intervention was shorter for the thrombectomy-first group. A higher percentage of thrombectomy-first patients had favorable outcomes after 3 months but the difference was not statistically significant. As discussed in this paper, one of the reasons may be that the thrombectomy-first technique allowsmobilization and removal of the intracranial thrombus during flow arrest, whereas the thrombus becomes more compressed due to increased perfusion pressure following stenting of the carotid artery. This is an article from experts for experts that seek to bring researchers and clinicians together and thereby to improve our approach towards treatment of acute internal carotid artery (ICA) occlusion. This goal is equally or even more challenging than other procedures being developed in the emerging field of interventional neuroradiology. Like embolization of an AVM or coiling of an aneurysm, recanalization in acute stroke is an image-guided endovascular microneurosurgical operation that should be navigated using a biplane or 3D roadmap with a spatial resolution of 150 microns and with a time resolution below 100 ms. For treatment of stroke, however, we must navigate our micro-instruments across the occlusion blindly, without a precise radar picture of our roadmap. Knowledge of the neurovascular anatomy and extensive experience with the whole range of neurointerventional instruments and techniques are preconditions for success. Ischemic strokes resulting from occlusion of the ICA are often severe and have a poor prognosis. Predictors of improved outcome are good intracranial collaterals and recanalization. Intravenous thrombolysis in patients with tandem stenoses achieves low rates of recanalization—between 0 and 20 %—which can be increased to more than 80 % by endovascular treatment. A systematic review of 28 studies found significantly higher rates of favorable outcome in the endovascular group (33.6 % of 584 patients with favorable outcome) as compared to the iv thrombolysis group (24.9 % of 385 patients with favorable outcome; p=0.0004) [2]. A recent literature review of 32 studies dealing with endovascular treatment of 1107 patients with acute ischemic stroke and ICA occlusion confirmed these findings [3]. Ten of these studies included patients with tandem occlusions, with an overall favorable clinical outcome in 43 %; however, the mortality rate was 45 %, and 16 % of patients had symptomatic intracranial hemorrhages. Combined analysis of two studies of patients with tandem occlusions showed a significantly lower death rate for the group treated with intra-arterial thrombolysis and a lower rate of recanalization of the extracranial ICA occlusion (61 % for IA thrombolysis versus 99 % with stenting), whereas the rate of recanalization of intracranial occlusion did not differ significantly (60 versus 78 %) [3]. The current situation regarding thrombolysis treatment is reminiscent of the situation of endovascular treatment of stroke in general, where—fortunately—after a promising start followed by a period of prospective and randomized confusion, the fog is starting to lift. This comment refers to the article available at: http://dx.doi.org/10.1007/ s00234-014-1465-5.