A. Chiti 1, N. Giannini 1, F. De Caro 2, G. Gialdini 1, E. Terni 1, E. Giorli 1, M. Puglioli 3, M. Cosottini 3, A. S. Petronio 2, G. Orlandi 1
1 Neurological Clinic,
2 Cardiothoracic Department, University of Pisa – Pisa,
3 Unit of Neuroradiology, Azienda Ospedaliero-Universitaria Pisana – Pisa, Italy
Objective: The risk of transient ischemic attack and stroke following transfemoral aortic valve implantation (TAVI) is 2-10% and is even higher considering silent ischemic brain injury. Periprocedural microembolic signals (MES) and hemodynamic changes (HC) may be considered physiopathological markers of such events. We show neurosonological and neuroradiological data about a patient submitted to TAVI.
Material and Methods: A 78-year-old man underwent TAVI. During the procedure, continuous monitoring of right middle cerebral artery was performed by transcranial Doppler (TCD), in order to reveal MES and HC (left acoustical temporal bone window was inadequate). Moreover, patient underwent brain magnetic resonance with diffusion-weighted sequences (MR-DWI) before and after TAVI.
Results: 1103 MES were detected: 116 (10.5%) during the crossing of the native valve by guidewire and pigtail catheter, 50 (4.5%) during valve predilatation with balloon, 29 (2.6%) related to passage of device (CoreValve) in the aortic arch and its positioning in the valve, 693 (62.9%) during release of the prosthesis, 215 (19.5%) in the phase of catheter removal. As for HC, peak systolic velocity reduction (from 82 cm/s to 38 cm/s) and heart rate increase (from 66 to 156 beats per minute) were observed in a period of 8 seconds during predilation. Post-procedural brain MR-DWI detected two recent-onset signal abnormalities in the right emisphere. Patient remained asymptomatic during hospital stay.
Discussion: TCD monitoring may provide useful and real-time data on the physiopathological mechanisms underlying the risk of ischemic brain injury during TAVI, identifying phases at higher risk. Further research is needed to validate these findings.
Key words: aortic valve implantation, ischemic brain lesion, transcranial Doppler.