BackgroundIncreased middle cerebral artery (MCA) blood flow velocities on transcranial duplex sonography (TCD) were recently reported in individual patients after successful mechanical thrombectomy (MT) and were related to intracranial hemorrhage and poor outcome. However, the retrospective study design of prior studies precluded elucidation of the underlying pathomechanisms, and the relationship between TCD and brain parenchymal perfusion still remains to be determined.MethodsWe prospectively investigated consecutive patients with stroke successfully recanalized by MT with TCD and MRI including contrast-enhanced perfusion sequences within 48 hours post-intervention. Increased MCA flow on TCD was defined as >30% mean blood flow velocity in the treated MCA compared with the contralateral MCA. MRI blood flow maps served to assess hyperperfusion rated by neuroradiologists blinded to TCD.ResultsA total of 226 patients recanalized by MT underwent post-interventional TCD and 92 patients additionally had perfusion MRI. 85 patients (38%) had increased post-interventional MCA flow on TCD. Of these, 10 patients (12%) had an underlying focal stenosis. Increased TCD blood flow in the recanalized MCA was associated with larger infarct size, vasogenic edema, intracranial hemorrhage and poor 90-day outcome (all p≤0.005). In the subgroup for which both TCD and perfusion MRI were available, 29 patients (31%) had increased ipsilateral MCA flow velocities on TCD. Of these, 25 patients also showed parenchymal hyperperfusion on MRI (sensitivity 85%; specificity 62%). Hyperperfusion severity on MRI correlated with MCA flow velocities on TCD (rs=0.379, p<0.001).ConclusionsTCD is a reliable bedside tool to identify post-reperfusion hyperperfusion, correlates well with perfusion MRI, and indicates risk of reperfusion injury after MT.

Background Although decompressive hemicraniectomy (DHC) is a lifesaving treatment strategy for patients with malignant middle cerebral artery infarction (mMCAi), only one in four patients achieves low to moderate post-stroke disability according to previous studies. However, the short follow-up periods in prior studies could have overestimated the poor clinical prognosis. This study therefore examined the long-term outcome after DHC for mMCAi. Methods We retrospectively included all patients who had undergone DHC after mMCAi at the University Hospital Graz between 2006 and 2019. Demographics, clinical data and complications were collected from electronic clinical patient records. To investigate long-term prognosis, all patients were followed up to 14 years after stroke including quality of life (QOL) assessment. Post-stroke disability was rated according to the modified Rankin Scale (mRS). Results Of 47 patients that had undergone DHC for mMCAi, follow-up data were available in 40 patients (mean age: 48 years; 40% female). Six months after the mMCAi, 14 patients had died (35%) and nine (23%) had a low to moderate post-stroke disability (mRS 0–3). Of 26 stroke survivors, half (50%) showed further mRS improvement (≥ 1 point) during the long-term follow-up period (mean follow-up time: 8 years). At last follow-up, 17 patients had achieved an mRS score of ≤ 3 (65% versus 35% after 6 months; p = 0.008) and 55% had no signs of depression and anxiety, and 50% no signs of pain or discomfort in QOL assessment. Conclusion This study shows substantial long-term improvement of functional disability and reasonable QOL in mMCAi patients after DHC.