Search

Background and purpose This study aimed to use optical coherence tomography (OCT) to evaluate the efficacy of post-dilatation (PD) after stent placement for unstable plaques during carotid artery stenting (CAS) using closed-cell design stent. Materials and methods Twelve unstable carotid plaque lesions diagnosed by magnetic resonance imaging were evaluated by OCT during CAS. Pre-procedural minimum lumen diameter and area were 1.5 ± 0.6 mm and 2.6 ± 1.6 mm2, respectively. The lesion was pre-dilated with balloon catheters (diameter 4.8 ± 0.3 mm), and closed-cell stent was deployed. PD was performed with balloon catheters of the same size as those used for pre-dilatation. Minimum lumen diameter/area and in-stent tissue prolapse volume after stent placement and after PD were calculated by 2-dimensional cross section images. The number of the stent cells showing tissue prolapse and malapposition after stent-placement and after PD were calculated by 3-dimensional analysis. Results Compared to after stent placement, in-stent tissue prolapse volume (0.18 ± 0.10 to 0.22 ± 0.07 mm2/slice, P Conclusions PD after carotid stent placement caused increase in in-stent tissue prolapse volume and small tissue prolapse, however, the in-stent large tissue prolapse decreased, as the in-stent tissue prolapse may have been crushed into debris.

Carotid artery stenting (CAS) with proximal protection can expose occlusion intolerance (OI) due to ipsilateral cerebral hemisphere hypoperfusion. Near-infrared spectroscopy (NIRS) cerebral oximetry can monitor regional cerebral oxygenation (rSO2) in the frontal lobes, and is used during CAS to predict cerebral blood flow insufficiency. The aim of this study was to evaluate rSO2 as a predictor of OI during CAS. We retrospectively examined 146 patients who underwent CAS with proximal protection. An INVOS® NIRS oximeter was used for rSO2 measurement, which was compared with stump pressure (SP) measured by a guiding catheter during occlusion of the common carotid artery (CCA) and external carotid artery. For the lesion with OI, distal filter protection was combined with proximal protection if possible, and CCA was intermittently occluded during the procedure. Twenty-seven patients (18%) developed OI. The relative decrease in NIRS oximeter saturation (ΔrSO2) on the ipsilateral side was significantly lower in the OI group than in the tolerance group (14 ± 5.1% vs. 3.4 ± 3.5, p

Cerebral venous sinus thrombosis (CVST) is generally treated with anticoagulation therapy, however, endovascular therapy is considered for refractory cases. A 42-year-old woman presented with a progressive disturbance in consciousness, and diagnosed CVST in the straight sinus (SS). Recanalization of SS was achieved by emergent thrombectomy using aspiration catheter and stent-retriever system, and her level of consciousness improved immediately. The combined use of them aided the removal of the thrombus located in the SS.

The feature of titanium oxide steel (Ti-O steel) is that heat affected zone (HAZ) toughness is improved due to the refinement of HAZ microstructure through the formation of intragranular ferrite (IGF). This desirable microstructure, IGF, forms radially from titanium oxide particles. Recently, it has been clarified that manganese in Ti-O steel is an indispensable element for the formation of IGF. Therefore, manganese effects on Ti-O steel have been basically studied in this work, and then a new effect has been found. In Ti-O steel, manganese has the effect of suppressing the formation of ferrite side plates (FSP), which are undesirable due to their coarseness. Consequently, HAZ microstructure of Ti-O steel with high manganese content is so refined that HAZ toughness is remarkably improved. Based on the manganese effects, steel plates with excellent HAZ toughness for offshore structures have been developed and commercially mass-produced. The welded joints exhibit excellent toughness.Copyright © 2010 by ASME