Artificial organs
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Cerebral emboli originating in the ascending aorta are a major cause of noncardiac complications following cardiac surgery. The hemodynamics of the aortic cannula has been proven to play a significant role in emboli generation and distribution. The aim of the current study was to perform a thorough numerical investigation in order to examine the effect of the design and orientation of the cannula used during cardiopulmonary bypass on the risk to develop cerebral embolism. ⋯ The TIP2 cannula exhibited a stronger emanating jet, higher shear stress inside the cannula, and highly disturbed flow, which was more stagnant near the clamp region. Current findings support the significant impact of the cannula design and orientation on emboli generation and distribution. Specifically, the straight tip cannula demonstrated a reduced risk of cerebral embolism, which may be pivotal in the clinical setting.
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Comparative Study
Comparison of hemolysis between CentriMag and RotaFlow rotary blood pumps during extracorporeal membrane oxygenation.
The purpose of this investigation was to compare the hemolysis levels for patients on extracorporeal membrane oxygenation (ECMO) incorporating two different rotary blood pumps (CentriMag [CMAG] and RotaFlow [RF]) in identical circuits otherwise. The difference between the two pumps is the cost. One is 20-30 times less expensive than the other. ⋯ There were also no significant differences between the CMAG and RF groups when comparing the mean values for daily pHb levels (5.7 ± 3.6; 5.7 ± 4.2), lactate levels (2.8 ± 1.9; 3.0 ± 2.1), and LDH levels (2656.3 ± 1606.8; 2688.6 ± 1726.1) or daily lactate, LDH, and pHb levels for the first 10 days of support. From our investigation, there is no difference between the CMAG and the RF blood pumps in regard to the creation of hemolysis during ECMO. The difference in cost of the devices does not correlate with the performance and outcomes.
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Comparative Study
Comparison of continuous-flow and pulsatile-flow blood pumps on reducing pulmonary artery pressure in patients with fixed pulmonary hypertension.
Pulmonary hypertension (PH) is considered as a risk factor for morbidity and mortality in patients undergoing heart transplantation. Recently, left ventricular assist device (LVAD) implantation has been increasingly used in reducing pulmonary artery pressure (PAP) in patients with PH unresponsive to medical therapy. Herein, we aimed to compare the efficacy of continuous-flow and pulsatile-flow blood pumps on the improvement of PH in mechanical circulatory support patients. ⋯ A significantly greater decrease in systolic PAP was noticed in patients with continuous-flow blood pumps (P=0.023); however, no statistically significant difference was found when we considered the change in TAPSE between study groups (P=0.112). A statistical significance in the alteration of RVEF, RVSM, and the grade of TI during study visits was not found between the study groups (P=0.472, P=0.887, and P=0.237, respectively). Although the two studied types of LVADs were found to be effective in reducing PAP in heart transplantation candidates with PH, lesser postoperative systolic PAP values were achieved in patients who underwent continuous-flow pump implantation surgery.
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Acquired von Willebrand Syndrome (AvWS) is known as a frequent bleeding complication in patients on ventricular assist device (VAD) support. Clinicians demand that the requirements for VADs with regard to hemocompatibility should also include low susceptibility for AvWS. Clinical AvWS diagnosis is known to be a complex, high-price, and time-consuming analysis. ⋯ Results gained in this study indicate that vWF:Ac/vWF:Ag ratio is sensitive enough for comparative AvWS investigations in vitro with human blood. The applicability of the method suggested in this article for AvWS characterization in porcine blood needs to be investigated in further studies. The selection of analysis kits promises a less cost- and labor-intensive, time-consuming, and complex method for comparative AvWS investigations in vitro compared with AvWS diagnosis in patients.
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Pump thrombosis is one of the major adverse events associated with the use of a left ventricular assist system (LVAS) in patients with advanced heart failure. We investigated the clinical implication of pump replacement because of thrombus formation. This study included 87 patients who underwent implantation of a Nipro (Toyobo) pulsatile extracorporeal LVAS intended as a bridge to transplantation and were alive more than 3 months after implantation. ⋯ Multivariate Cox regression analysis showed that pump replacement within 3 months after implantation was an independent predictor of mortality (HR 2.50, P = 0.03). In conclusion, pump replacement for thrombus formation may have a strong association with worse outcome. Our results reconfirm the clinical importance of device thrombus in the management of LVAS.