When rt-PA goes with the flow: role of collateral circuits in concurrent carotid and middle cerebral artery occlusion

Abstract

Background: Patients with internal carotid artery (ICA) occlusion treated with rt-PA have higher rates of unfavorable outcomes.
When a middle cerebral artery (MCA) embolization is also present, it has been hypothesized that the MCA recanalization could
have an important role in clinical recovery.
Aims: Our aim is to illustrate the clinical and prognostic importance of the activation of Willis’ Circle collateral flows, studied by
transcranial colordoppler, in patients with ICA and concurrent MCA embolization.
Patient: A 74-year-old man presented with right facio-brachio-crural hemiplegia, global aphasia and right campimetric deficit.
Emergency CT showed left MCA hyperdensity. The patient was treated with rt-PA, with resolution of the hyperdensity at the
control-CT. Neck vessels and transcranial colordoppler revealed MCA reperfusion and persistent left carotid occlusion with
intracranial hemodynamic compensation ensured by the right anterior cerebral artery (ACA) through the anterior communicating
artery. The patient had a remarkable clinical recovery (three months later modified Rankin Scale 0) and underwent to carotid
endoarterectomy, because of ultrasound finding of carotid late-reperfusion.
Conclusions: The case highlights a possible role of intracranial collateral flows in MCA reperfusion and clinical recovery of rt-PAtreated
patients with concurrent ICA and MCA occlusions and could stimulate an extensive study on this issue.
Acknowledgments: the Authors would like to thank the institute of Radiology of Policlinico Gemelli for the CT and MR images.