Device Specific Aortic Outflow Cannula Jets Studied Using 2D PIV and High-Performance 3D CFD Simulation

Author(s):  
Prahlad G. Menon ◽  
Nikola Teslovich ◽  
Chia-Yuan Chen ◽  
Fotis Sotiropoulos ◽  
Akif Undar ◽  
...  

In the US, approximately 1 in 100 children are born with a clinically significant congenital heart defect (CHD). The palliative repair of these defects requires complex biventricular and univentricular surgical operations in newborns often smaller than 2 kg. However, recovery after neonatal intervention remains suboptimal 1. A major component of these surgeries is the cardiopulmonary by-pass (CPB) procedure which if prolonged can potentially lead to neurological complications and developmental defects in a young patient. During CPB, tiny aortic cannulae (2–3 mm inner diameter), with micro-scale blood-wetting features transport relatively large blood volumes (0.3 to 1.0 L/min) resulting in high blood flow velocities. Our recent 3D computational fluid dynamics (CFD) simulations of jet flows in device specific cannulae 2 have indicated that the turbulent jet wake at high physiological neonatal extracorporeal life support (ECLS) circuit blood flow rates can potentially have damaging hemolytic effects, when evaluated in a cuboidal flow domain, as well as in in-silico aortic insertion configurations. Such severe flow conditions can result in platelet activation, vascular injuries and blood damage. Despite these risks, cannulation methods have received little attention compared to the effort expended to assure the safety and efficacy of the mechanical circulatory support blood pumps. Qui et al 3 report that cannula problems are the second most frequently reported mechanical complication in ECLS therapy for respiratory cases and the third most frequent complication in cardiac cases. The purpose of this study is to quantitatively evaluate the jet wake region of two popular 8FR pediatric cannulae, DLP Medtronic 77008 and RMI FEM II – 008 – AT (inner diameter ∼1850 microns), using stereo particle image velocimetry (PIV) to validate numerically computed flow fields.

2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
SKT Ma ◽  
WC Sin ◽  
CW Ngai ◽  
ASK Wong ◽  
WM Chan ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is an advanced technique in extracorporeal life support (ECLS) used to support extreme circulatory failure including patients with cardiac arrest and cardiogenic shock refractory to conventional support. It is a long-standing belief that peripheral V-A ECMO poses increased afterload to the inured heart, but conventional echocardiographic measurements are often insensitive in detecting subtle changes in loading conditions. Purpose This study aimed to evaluate the effects of varying blood flow during peripheral V-A ECMO on intrinsic myocardial contractility, using detailed echocardiographic assessment including speckle tracking echocardiography (STE). Methods Adult patients with acute cardiogenic shock who were supported by peripheral V-A ECMO from April 2019 to September 2020 were recruited. Serial hemodynamic and cardiac performance parameters were measured by transthoracic echocardiogram (TTE) within 48 hours after implementation of V-A ECMO, at different levels of extracorporeal blood flow – 100%, 120% and 50% of target blood flow (TBF). Results A total of 30 patients were included. 22 (71%) were male, and the mean (SD) age was 54 (13) years. The major indications for V-A ECMO were myocardial infarction (19, 63% patients), and myocarditis (5, 17%). With a decrease in extracorporeal blood flow from 100% to 50% of TBF, mean arterial pressure (MAP) dropped from 76+/-3 to 64+/-3mmHg (p <0.001), and cardiac index (CI) increased from 0.89+/-0.13 to 1.27+/-0.18L/min/m2 (p < 0.001). All indices of left ventricular contractility improved at a lower extracorporeal blood flow: the myocardial contractility measured by global longitudinal peak systolic strain (GLPSS) improved from -3+/-0.7% to -5+/-0.8% (p < 0.001); left ventricular ejection fraction (LVEF) increased from 21.5+/-2.6% to 30.9+/-2.7% (p < 0.001) and 19.7+/-3.1% to 28.4+/-3.2% (p < 0.001) by biplane and linear methods, respectively; left ventricular index of myocardial performance (LIMP) improved from 1.51+/-0.12 to 1.03+/-0.09 (p < 0.001). Similar findings were reproduced when comparing left ventricular contractility at extracorporeal blood flows of 120% and 50% of TBF. Conclusions The ECMO blood flow rate in peripheral V-A ECMO is inversely related to myocardial contractility, and is quantifiable by myocardial strain measured by STE.


2018 ◽  
Vol 67 (03) ◽  
pp. 164-169
Author(s):  
Alexander Assmann ◽  
Udo Boeken ◽  
Stefan Klotz ◽  
Wolfgang Harringer ◽  
Andreas Beckmann

Background In context of the multidisciplinary German scientific guideline “Use of extracorporeal circulation (extracorporeal life support [ECLS]/extracorporeal membrane oxygenation) for cardiac and circulatory failure,” a nationwide survey should depict the status of organization and application of ECLS therapy in Germany. Methods Between June and October 2017, a standardized questionnaire consisting of 30 items related to ECLS therapy was sent to all German cardiosurgical departments, and all returned results were analyzed and evaluated. Results The return rate amounted to 92.9% (78 out of 84 departments). In the participating departments, ECLS therapy is subject to different responsibilities, and exhibits divergent processes and various ways for specialization of the involved personnel. This also concerns local application standards, such as cannulation strategies, anticoagulation management, left ventricular unloading, antiwatershed treatment, and weaning from circulatory support. Conclusion This nationwide survey underlines the necessity of a multidisciplinary guideline concerning ECLS therapy.


2020 ◽  
Vol 4 (2) ◽  
pp. 1-5
Author(s):  
Bebiana Manuela Monteiro Faria ◽  
João Português ◽  
Roberto Roncon-Albuquerque Jr ◽  
Rodrigo Pimentel

Abstract Background Takotsubo syndrome (TS) is characterized by a transient left ventricular (LV) dysfunction and rarely presents with cardiogenic shock (CS). Inverted TS (ITS) is a rare entity associated with the presence of a pheochromocytoma. Case summary We present a case of a young woman was admitted to the emergency department due to intense headache, chest discomfort, palpitations, and breathlessness. An ITS secondary to a pheochromocytoma crisis presenting with CS was diagnosed. The patient was managed with veno-arterial extracorporeal membrane oxygenation, until recovery of LV function. On the 35th day of hospitalization, open bilateral adrenalectomy was performed. Discussion Takotsubo syndrome patients presenting with CS are challenging and clinicians should be aware of underlying causes. Specific triggers such as pheochromocytoma should systematically be considered particularly if ITS was presented. Extracorporeal life support devices could provide temporary mechanical circulatory support in patients with TS on refractory CS and help to manage complex cases with TS due to pheochromocytoma.


2020 ◽  
Vol 68 (04) ◽  
pp. 263-276 ◽  
Author(s):  
Andreas Beckmann ◽  
Renate Meyer ◽  
Jana Lewandowski ◽  
Andreas Markewitz ◽  
Jan Gummert

AbstractBased on a longtime voluntary registry, founded by the German Society for Thoracic and Cardiovascular Surgery (GSTCVS) in 1980, well-defined data of all cardiac, thoracic, and vascular surgery procedures performed in 78 German heart surgery departments during the year 2019 are analyzed. For this period, a total of 175,705 procedures were submitted to the registry, 100,446 summarized as heart surgery procedures in a classical sense. The unadjusted in-hospital survival rate for the 34,224 isolated coronary artery bypass grafting procedures (relationship on-/off-pump 3.8:1) was 97.3%. For the 36,650 isolated heart valve procedures (16,625 transcatheter interventions included), it was 96.4%. Concerning short- and long-term circulatory support, a total of 2,716 extracorporeal life support/extracorporeal membrane oxygenation implantations, resp. 953 assist device implantations (L-/ R-/ BVAD, TAH) were registered. In 2019, the number of isolated heart transplantations increased to 333, a rise of 6.7% compared to the previous year. The isolated lung transplantations amounted to 311, a decrease of 8.5%. This annually updated registry of the GSTCVS represents voluntary public reporting by accumulating actual information for nearly all heart surgical procedures in Germany, constitutes advancements in heart medicine, and represents a basis for quality management for all participating institutions. In addition, the registry demonstrates that the provision of cardiac surgery in Germany is up to date, appropriate, and nationwide patient treatment is guaranteed all the time.


Perfusion ◽  
2010 ◽  
Vol 25 (1) ◽  
pp. 25-29 ◽  
Author(s):  
AP Simons ◽  
KD Reesink ◽  
MD Lancé ◽  
T. van der Nagel ◽  
FH van der Veen ◽  
...  

Extracorporeal life support systems lack volume-buffering capacity. Therefore, any decrease in venous intravascular volume available for drainage may result in acutely reduced support flow. We recently developed a method to quantify drainable volume and now conceived a reserve-driven pump control strategy, which is different from existing pressure or flow servo control schemes. Here, we give an outline of the algorithm and present animal experimental data showing proof of principle. With an acute reduction in circulatory volume (10-15%), pump flow immediately dropped from 4.1 to 1.9 l/min. Our pump control algorithm was able to restore bypass flow to 3.2 l/min (about 80% of the original level) and, thereby, reduced the duration of the low-flow condition. This demonstrates that a reserve-driven pump control strategy, based on the continuous monitoring of drainable volume, may maintain extracorporeal circulatory support flow, despite serious changes in filling conditions.


2020 ◽  
Author(s):  
Paolo Meani ◽  
Mikulas Mlcek ◽  
Mariusz Kowalewski ◽  
Giuseppe Maria Raffa ◽  
Federica Jiritano ◽  
...  

Abstract Background The use of peripheral veno-arterial extracorporeal life support (V-A ECLS) as a mechanical circulatory support in cardiogenic shock has increased dramatically over the last years. However, increased afterload may jeopardize left ventricle (LV) recovery and cause blood stasis and pulmonary edema. Therefore, several LV unloading techniques have been developed and used with limited understanding of the actual difference among them. The aim of the present study was to compare a trans-aortic suction device (Impella) and pulmonary artery (PA) drainage, for LV unloading and V-A ECLS management as well as efficacy in a porcine cardiogenic shock (CS) model Methods A dedicated CS model compared included twelve female swine (21± 1,8-weeks old and weighing 54,3 ± 4,6 kg) supported with V-A ECLS and randomized to Impella or PA-related LV drainage. LV unloading and end-organ perfusion were evaluated through the pulmonary artery catheter and the LV pressure/volume analysis. All the variables were collected at baseline, profound CS, V-A ECLS support with maximum flow and when Impella or PA cannula run on top. Results CS was successfully induced in all twelve animals. Impella resulted in a marked drop of LVEDV compared to a slight decrease in the PA cannula group, resulting in an overall stroke work (SW) and Pressure-Volume Area (PVA) reductions with both techniques. However, SW reduction was significant in the Impella CP group (VA ECMO 3998.82027.6 mmHg x mL vs VAECMO + Impella 1796.9±1033.9 mmHg x ml, p value 0,016), leading to a more consistent PVA reduction (Impella reduction 34,7% vs PA cannula reduction 9,7%) In terms of end organ perfusion, central and mixed O 2 saturation improved with V-A ECLS, and subsequently, remaining unchanged with either Impella or PA cannula as unloading strategy Conclusions Trans-aortic suction and PA drainage provided effective LV unloading during V-A ECLS while maintaining adequate end-organ perfusion. Trans-aortic suction device provides a greater LV unloading effect and reduces more effectively the total LV stroke work.


2019 ◽  
Vol 68 (05) ◽  
pp. 425-432
Author(s):  
Marie Thomas ◽  
Maximilian Kreibich ◽  
Friedhelm Beyersdorf ◽  
Christoph Benk ◽  
Sven Maier ◽  
...  

Objectives Separation from extracorporeal life support (ECLS) is often based on individual decisions rather than evaluated standard operating procedures (SOPs). Therefore, we strived to evaluate a SOP, summarizing specific treatment paths for this group of patients. Methods A total of 107 cardiovascular patients were supported with ECLS within a 4-year period. Fifty-three patients were treated before the SOP was introduced (group A) and 54 patients were treated afterward (group B). Patient characteristics and outcomes were analyzed and compared between the two time periods regarding baseline characteristics, compliance with SOP criteria, and the end points successful weaning and 30-day survival. Results Successful weaning rose significantly from 56.6 to 74.1% (p = 0.045) and 30-day survival rate increased from 34.0 to 50.0% (p = 0.069) after implementation of the SOP. Successful weaning was significantly associated with daily echocardiography (p = 0.012) and circulatory support with dobutamine (p = 0.026). The investigated other criteria used in the weaning process did not show a significant correlation with better outcome. Conclusion The SOP for ECLS weaning showed higher weaning rates compared with a weaning based on individual decisions. Although only parts of the SOP were associated with higher weaning and survival rates, the SOP was experienced as a useful guideline for standardized ECLS management.


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