In the Lübeck study, patients were randomly selected to receive TCCS-guided PW mode US for 1 h. The color duplex mode was used to improve the accuracy of focusing the US on the thrombus. Patients with exclusively proximal MCA main stem occlusions without

residual flow who underwent simultaneously insonation and rtPA standard treatment were included in the study. The homogeneity of the sample was not only a major strength of the study but also its weakness (i.e., only a relatively low number of patients [n = 37] were included in this monocenter study). Similar to the findings of the CLOTBUST IWR-1 cell line trial, continuous insonation for 1 h (instead of 2 h like in the CLOTBUST trial) resulted in significantly

improved recanalization (partial or complete recanalization: 58% in the continuous insonation group vs. 22% in the control group). Additionally, an improvement in neurological deficits after 4 days, and a clear trend toward better functional outcome after 3 months in patients was shown. Tendencies for increased symptomatic cerebral bleeding (3 patients in the sonothrombolysis group vs. 1 patient in the control group) and increased hemorrhagic transformation of infarcts were also found in patients who underwent continuous insonation [2]. A total of 15 patients were randomized in the arm of the trial for patients with contraindications to rtPA. Recanalization (all of them were partial recanalizations) find more after 1 h occurred only in the sonothrombolysis group (62.5% in the sonothrombolysis group vs. 0% in the control group). Significant improvements in clinical course after 4 days and functional independence after 3 months were found in 2 of 8 patients in the sonothrombolysis group (compared with none of the 7 patients Lumacaftor in the control group) [4]. No sICHs occurred in the sonothrombolysis group. At the end of the randomized trial, this treatment principle was

continued in the context of a clinical register. Currently available data (obtained from a total of 116 patients with MCA main stem occlusions, with or without rtPA treatment) confirm these results (unpublished data). For occlusions of the main intracranial arteries, IV thrombolysis alone is probably not adequate to achieve early recanalization, which explains why interventional therapy, either intra-arterial thrombolysis or thrombus extraction, is often regarded as an alternative. However, in addition to the yet unsatisfactory evidence attained from randomized clinical trials for these interventional therapies, there are two important limitations: the time delay to the start of the intra-arterial intervention and the lack of availability of these types of interventional treatment in nonspecialized centers. Sonothrombolysis as a tool to improve the effectiveness of IV thrombolysis may be a promising alternative option.