Thrombolytic therapy with rt-PA and transcranial color Doppler ultrasound (TCCS) combined with microbubbles for embolic thrombus

Abstract

ObjectiveTo investigate the efficacy of transcranial color Doppler ultrasound (TCCS) combined with microbubbles (MBs) and rt-PA (recombinant tissue plasminogen activator) for thrombolysis in vivo. MethodsAn arterial embolization model was established in Sprague-Dawley rats by retrograde placement of autologous thrombi into the common carotid artery followed by ligation of external carotid artery and temporary occlusion of the carotid artery and internal carotid artery by clamping. The animals were divided into 5 groups with 6 rats in each group: ① untreated control group, ② rt-PA group, ③ TCCS+MBs group, ④ TCCS+MBs+rt-PA group, ⑤ TCCS+MBs+1/2 rt-PA+group. Thrombolytic effects including recanalization rate and recanalization grade were evaluated with grayscale and color Doppler ultrasound post treatment. Examination of histological change in the involved vessel was performed at the end of the experiments. ResultsThrombolysis in terms of recanalization rate and recanalization grade was observed in the treated groups in a time-dependent manner, except the TCCS+MBs group. Addition of rt-PA remarkably enhanced the therapeutic lysis in TCCS+MBs group. However, no difference of therapeutic effects existed between TCCS+MBs+rt-PA group and TCCS+MBs+1/2 rt-PA group. ConclusionTCCS+MBs combined with rt-PA is a relatively effective approach for ischemic arterial thrombosis with an additive or synergistic effect.