Browsing by Author "Koehler, Till"

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    Minor defects of the luminal integrity in arterial introducer eSheaths after transcatheter aortic valve implantation
    Buege, Michael; Koehler, Till; Heiderhoff, Ralf; Papenheim, Marc; Wang, Si; Schleiting, Heinrich; Arnold, Wolfgang H.; Foerst, Jason R.; Seyfarth, Melchior; Tiroch, Klaus; Riedl, Thomas; Vorpahl, Marc (PLOS, 2017-05-08)
    Background Medical devices such as implant delivery systems are commonly used during minimally invasive procedures in the cardiovascular system. These devices often have lubricious polymer coatings to reduce friction between the device and blood vessels but coatings may separate and potentially cause serious injuries to patients. Methods Lubricious coated eSheaths for transcatheter heart valve implantation were assessed for luminal integrity at the proximal, medial and distal part. We assessed the number, depths and area of luminal trails using environmental scanning electron microscope (ESEM), white light interferometry (WLI) and optical profilometry using area scale fractal complexity (asfc) as surface parameters. A total of 15 eSheaths were retrieved and analyzed after successful femoral transcatheter Sapien 3 implantation in patients (23 mm valve– 14F eSheath, 26 mm valve– 14F eSheath and 29 mm valve– 16F eSheath, n = 5 for each group). Unused eSheaths (14F and 16F) served as controls (n = 5 for each group). Results ESEM revealed significantly greater number of trails after TAVR passage with the 23 mm, 26 mm and 29 mm valves compared to unused control 14F and 16F eSheaths (13.9 ± 3.1, 14.2 ± 2.3, 15.8 ± 1.7 vs. 0.08 ± 0.1 and 1.0 ± 0.5 [n]; p ≤ 0.0001 for all comparisons). Similarly, WLI showed minor, but significantly greater areas of luminal defects after 23 mm, 26 mm and 29 mm valve implantation vs. 14F and 16F unused controls (7.5 ± 0.9, 10.3 ± 1.1, 10.4 ± 1.4 vs. 4.1 ± 0.4 and 2.2 ± 0.4 [μm2], p = 0.0081). Likewise, the 3D-surface-measurement showed comparable results after implantation of the 23 mm, 26 mm and 29 mm valves vs. 14F and 16F unused control eSheaths (79.5 ± 6.3, 105.9 ± 5.3, 98.8 ± 4.8 vs. 5.1 ± 2.8 and 5.6 ± 0.5 [asfc] p = 0.0001). Conclusion Measurable defects of the luminal layer occur during balloon expandable TAVR using 14F and 16F eSheaths though this is likely clinically insignificant. Further clinical investigations including a prospective assessment of minor peripheral embolization are needed to fully address the impact of this luminal defects.
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    Single Center Retrospective Analysis of Conventional and Radial TIG Catheters for Transradial Diagnostic Coronary Angiography
    Vorpahl, Marc; Koehler, Till; Foerst, Jason R.; Panagiotopoulos, Spyridon; Schleiting, Heinrich; Koss, Klaus; Ziegler, Gunda; Brinkmann, Hilmar; Seyfarth, Melchior; Tiroch, Klaus (Hindawi, 2015-09-08)
    Current guidelines favor the radial approach for coronary angiography. Therefore, specialty radial diagnostic catheters were designed to engage both coronary arteries with a single device. However, it is unclear if single catheters are superior to conventional catheters. A retrospective analysis was performed of consecutive right radial coronary angiographies to determine catheter use, fluoroscopy time, radiation dosage, and consumption of contrast. Procedures were performed with a single TIG catheter or conventional catheters (CONV). Procedures with coronary artery bypass grafts or ventricular angiographies were excluded. 273 transradial procedures were performed successfully. 95 procedures were performed with CONV and 178 procedures with a TIG. Crossover to additional catheters was higher in TIG (15.2%) compared to CONV (5.3%, ). Fluoroscopy time was comparable between CONV and TIG, without crossover ( min versus  min; n.s.), however, greater in the case of crossover for CONV () and TIG (; ). Radiation dosage was similar in CONV and the TIG, without crossover (, cGycm2 versus ; n.s.), however, greater for CONV () and TIG (, ) with crossover. Overall, the amount of contrast was greater in TIG ( mL) versus CONV ( mL; ). CONV femoral catheters may be the primary choice for radial approach.