Introduction
Patients treated with mechanical thrombectomy (MT) for proximal vascular occlusions, frequently present infarct and even hemorrhages in deep grey matter despite angiographically successful recanalization. We described the lenticulostriate artery (LEA) features and associations with lesions in lenticular nucleus (LN) and clinical course in stroke patients treated with MT.
Methods
We studied a prospective cohort of 47 patients with stroke in the anterior circulation treated with stent retrievers that achieved successful recanalization (mTICI=2b/3). In a 3T-MRI study at 48-72h, we assessed the presence of infarct (L-INF) and any hemorrhagic transformation (L-HT) in the LN. We evaluated LEA-vasodilatation (LEA-VD) in TOF-sequences and blood-brain-barrier leakage in LN (LEA-BBBL) was defined as gadolinium enhancement in T1-sequences. The neurological course was assessed as a percentage decrease in the NIHSS from admission to day 7.  
Results
L-INF and L-HT were present in 30 (63.8%) and 13 (27.7%) patients, respectively. LEA-VD and LEA-BBBL were observed in 28 (59.6%) patients each. Patients with LEA-VD and LEA-BBL presented more L-INF (89.3% and 85.7%, respectively) than patients without L-INF (26.3% and 31.6%, respectively; p<0.001 for both signs). Patients with LEA-BBBL presented more L-HT (39.3% vs. 5.3%; p=0.015), and less NIHSS improvement (median, IQR, 93%, 74-100 vs. 100%, 95-100, p=023) than patients without LEA-BBBL, but these associations were not significant in patients with LEA-VD (p=0.087 and p=0.295, respectively). 
Conclusions
Vasodilatation and disruption of perforant vessels were associated with established lesions despite large vessel recanalization. The association of vessel disruption with neurological course suggests that these imaging features may have significant clinical implications.

ESOC-2019