1Elie Lteif,1Emmanuel Chabert, 1Emmanuel Chabert, 1Ricardo Moreno, 1Abderrahim Zerroug

1CHU-Gabriel Montpied


The first pass (FP) recanalization has been highlighted as a strong predictor of good clinical outcome and a benchmark to evaluate mechanical thrombectomy’s efficacy. The thrombus physical characteristics affect the efficacy of recanalization therapies of patients who suffer from an AIS. Some of these characteristics as density, perviousness, and length, can be detected and analyzed on computed tomography (CT). For instance, the thrombi vary in composition and CT characteristics which affect the recanalization rates. Our study primarily aimed to assess whether thrombus CT characteristics could influence the FP recanalization rate of mechanical thrombectomy (MT) with a stent retriever in anterior ischemic stroke (AIS).

Material(s) and Method(s):

We retrospectively studied all patients admitted to the CHU-Clermont Ferrand (France) and who suffered from an anterior acute ischemic stroke due to large vessel occlusion treated by mechanical thrombectomy with a stent retriever starting January 2015 till December 2017.

We registered the following thrombus characteristics by using the mean of three millimeter-sized regions of interest: mean unenhanced thrombus density (MUTD), thrombus attenuation increase (TAI), relative thrombus attenuation increase (rTAI), and the clot burden score. Then, we studied their association with first-pass recanalization, successful recanalization, distal emboli, and clinical outcome.


We included 173 patients. First pass recanalization was achieved in 41.5 %, a successful recanalization was achieved in 73.3 %. MUTD (p = 0.008), TAI (p < 0.001) and rTAI (p < 0.001) were significantly associated with a higher rate of first pass recanalization. These thrombus characteristics were also significantly associated with a higher rate of successful recanalization, (p = 0.002) for MUTD, (p < 0.001) for TAI and (p < 0.001) for rTAI.

Higher TAI (p = 0.02), higher rTAI (p = 0.003) and lower CBS (p = 0.03) were significantly associated with a better clinical outcome at 3 months in contrary of MUTD (p = 0.62).


Higher unenhanced thrombus density and higher thrombus perviousness defined as thrombus attenuation increase on CT angiography are significantly associated with a higher rate of the first-pass recanalization and successful recanalization stent retriever mechanical thrombectomy of AIS.