S monovette 7.5 ml

After admission to the hospital, but before performing the TAVR procedure, blood samples were obtained from all enrolled patients. The samples were drawn from the central venous catheter and collected in standard tubes (S‐Monovette 7.5 mL, Sarstedt AG & Co. KG, Nürnbrecht, Germany). To separate the serum from corpuscular components, the samples were immediately centrifuged at 3000 rpm (1415 g) for 10 minutes. Subsequently, the samples were aliquoted and stored at −80 °C in the BioBank Bonn.

First blood samples were taken during the preoperative examination. Additional samples were taken postoperatively at standardized intervals, on days 2 and 7 and on 1, 2, 4, 6, and 12 weeks after surgery (Figure 1). The samples were collected between 8 am and 11 am. In all, 3×7.5 mL serum samples (S-Monovette 7.5 mL; Sarstedt AG & Co., Nümbrecht, Germany) and 1×9 mL ethylenediaminetetraacetic acid were taken, centrifuged, aliquoted into Eppendorf tubes and stored at −80°C. Furthermore, C reactive protein (CRP) and leukocyte serum values were assessed during our clinical routine in the first 2 weeks to analyze systemic inflammation. Herewith, we assessed if application of BMP-7 and autologous cancellous bone graft influences systemic CRP and leukocyte levels and thereby a systemic unspecific inflammation that might modulate the cytokine serum values. Furthermore, a possible bias by infection or postoperative ongoing elevated CRP and leukocyte blood levels could be detected. Luminex Performance Human High Sensitivity Assays (Quantikine®,; R&D Systems, Inc., Minneapolis, MN, USA) were used to measure the cytokine serum levels of VEGF, TNF-α, IL-1, IL-6, IL-8, and IL-10 as described in the factory manual. The lab technician performing the Luminex assays was blinded to patient data and kept to manufacturer’s instructions during the measurements.