ABSTRACT
AIMS: To report our first-in-man experience with a new cerebral embolic deflection device (SMT Embolic Deflection Device) during transcatheter aortic valve implantation (TAVI). A significant number of strokes and brain infarcts are caused by embolisation of atherosclerotic material, clots and other debris during various phases of invasive cardiac procedures, especially TAVI. The application of a temporary filter in the aortic arch averting dislodged emboli from entering the cerebral circulation might prevent this. METHODS AND RESULTS: In 15 patients (mean age 79 years) with severe aortic stenosis undergoing percutaneous transfemoral or transapical aortic valve implantation, the SMT Embolic Deflection Device was advanced utilising the contralateral femoral artery access using a 9 Fr delivery sheath. Once deployed in the aortic arch, a porous membrane shields the supraaortic-cerebral trunks by deflecting emboli away from the cerebral circulation. Embolic material is not contained or removed by the device. A 6 Fr pigtail catheter can be used through the same sheath throughout the whole procedure. Brain diffusion weighted (DW)-MRI was obtained in 10 patients before and at 4 days after (± 2 days) the procedure and retrospectively compared to 20 patients previously undergoing TAVI without a protection device. Successful placement of the embolic protection device was achieved in all patients. Additional procedural time due to the use of the device was 7 min (± 2 min). There were no procedural complications. No patient developed new neurological symptoms or clinical findings of stroke except one patient who suffered from a transient ischaemic attack (TIA) two days after the procedure. DW-MRI showed 3.2 new cerebral lesions per patient, compared to 7.2 new lesions per patient in the group without SMT filter. CONCLUSIONS: In this first-in-man experience, the feasibility of a new embolic deflection device is demonstrated. Larger randomised, prospective studies are required to confirm these findings and prove safety and efficacy by reducing the incidence of cerebral embolism and stroke after TAVI.
Subject(s)
Aortic Valve Stenosis/therapy , Cardiac Catheterization/instrumentation , Embolic Protection Devices , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis , Intracranial Embolism/prevention & control , Stroke/prevention & control , Aged , Aged, 80 and over , Cardiac Catheterization/adverse effects , Diffusion Magnetic Resonance Imaging , Feasibility Studies , Female , Heart Valve Prosthesis Implantation/adverse effects , Humans , Intracranial Embolism/diagnosis , Intracranial Embolism/etiology , Male , Netherlands , Prosthesis Design , Registries , Retrospective Studies , Stroke/diagnosis , Stroke/etiology , Time Factors , Treatment OutcomeABSTRACT
So far, only seven and five species of Dysdercus from the Old and New Worlds, respectively, have been cytogenetically analysed. They all have holokinetic chromosomes and a pre-reductional type of meiosis. In the present study the chromosome complement, male meiosis and nucleolar meiotic cycle of Dysdercus imitator were analyzed. During male meiosis several cytogenetic features are remarkable, namely the presence of a long diffuse stage after pachytene, the finding of one or two ring bivalents per cell in almost all specimens, and the presence of several prenucleolar bodies lasting up to telophase II. The origin and function of these prenucleolar bodies could be related to a particular physiological cycle of the meiocytes.
