Impact of leaflet splitting on coronary access after redo-TAVI for degenerated supra-annular self-expanding platforms.

BACKGROUND: Coronary access (CA) is a major concern in redo-transcatheter aortic valve implantation (TAVI) for failing supra-annular self-expanding transcatheter aortic valves (TAVs). AIMS: This ex vivo study evaluated the benefit of leaflet splitting (LS) on subsequent CA after redo-TAVI in anatomies deemed at high risk of unfeasible CA. METHODS: Ex vivo, patient-specific models were printed three-dimensionally. Index TAVI was performed using ACURATE neo2 or Evolut PRO (TAV-1) at the standard implant depth and with different degrees of commissural misalignment (CMA). Redo-TAVI was performed using the balloon-expandable SAPIEN 3 Ultra (TAV-2) at different implant depths with commissural alignment. Selective CA was attempted for each configuration before and after LS in a pulsatile flow simulator. The leaflet splay area was assessed on the bench. RESULTS: In matched comparisons of 128 coronary cannulations across 64 redo-TAVI configurations, the overall feasibility of CA significantly increased after LS (60.9% vs 18.7%; p<0.001). The effect of LS varied according to the sinotubular junction height, TAV-1 design, TAV-1 CMA, and TAV-2 implant depth, given TAV-2 alignment. LS enabled CA for up to CMA 45° with the ACURATE neo2 TAV-1 and up to CMA 30° with the Evolut PRO TAV-1. The combination of LS and a low TAV-2 implant provided the highest feasibility of CA after redo-TAVI. The leaflet splay area ranged from 25.60 mm2 to 37.86 mm2 depending on the TAV-1 platform and TAV-2 implant depth. CONCLUSIONS: In high-risk anatomies, LS significantly improves CA feasibility after redo-TAVI for degenerated supra-annular self-expanding platforms. Decisions on redo-TAVI feasibility should be carefully individualised, taking into account the expected benefit of LS on CA for each scenario.

The eye lens evaluation of the atorvastatin-treated white rat.

The aim of this study is to determine potential cataractogenic activity of atorvastatin the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. HMG-CoA reductase inhibitors (atorvastatin, lovastatin, simvastatin, pravastatin, fluvastatin, cerivastatin) (statins) are the most potent cholesterol and LDL-C lowering drugs. Statins differ in many aspects e.g. intensity of side-effects. It is possible that some hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) therapy is associated with cataract occurrence. The purpose of these studies was to focus on the potential cataractogenic contribution of atorvastatin. The studies were carried out on white Wistar rats. The animals were given atorvastatin (Sortis--Parke-Davis, USA) in two doses: 1.14 mg/kg mg/day, and 11.4 mg/day. Lens structure was observed in stereoscopic, dark-filed and in optic microscope, the cataract was observed in the examined preparations, specially high doses administered. We concluded that lens turned out to be reacting to atorvastatin. Drug dose corresponded to increase in the number and duration of cataract episodes (changes were more significant in the experimental groups 11.4 mg/kg). Alterations in the examined lens design may be a result of atorvastatin effect.

Does ACE inhibitor modify the morphofunctional state of the nephron?

Captopril, the inhibitor of the angiotensin convertase (ACE) was administered to white rats in two doses: 0.23 mg/day/rat and 0.71 mg/day/rat. The preparation was being applied for the period of 3 weeks. Observations were carried out in a transmission electron microscope. In the kidneys of the animals subjected to the experiment, in the cells of the proximal canaliculi dilution of the cytoplasm, numerous vacuoles in the apical and basal part of the cell, dilation of the intercellular space as well as more numerous lysosomes were observed. The above-described changes were more distinctly marked in animals which were given a higher dose of the drug. The studies in the electron microscope revealed morphofunctional changes of the nephron related to the application of the Captopril. Application of the Captopril may temporarily modulate the morphofunctional status of certain structures of the nephron, which was demonstrated in the foregoing experiment.

Ultrastructural changes of ciliary epithelial nucleus in experimental diabetes--an animal model.

The aim of this study was to observe in electron microscope the New Zealand rabbits ciliary epithelial nucleus structure changes, depending on the duration of experimental diabetes mellitus. The animals were administered alloxan in the form of 10% solution in 0.9% NaCl, at the dose of 100 mg/kg b.m. If the glycemia level was 11 mmol/l or higher the animal was included in the experimental group. 15 eyes of 15 adult New Zealand rabbits were studied. Conventional electron microscopy was used to show ultrastructural changes of ciliary epithelium nucleus. During the study we noticed severe changes in the structure of ciliary epithelial nucleus depending on diabetes mellitus duration. We found: deep indentations of nuclear membrane, open nuclear pores, irregularity in heterochromatin location and small sizes of the epithelial nucleus.