Artificial organs
-
Prior to the widespread adoption of the arterial switch operation, patients with transposition of the great arteries (TGA) commonly underwent atrial switch operation (Mustard or Senning). It is not uncommon for these patients to progress to end stage heart failure and increasingly ventricular assist devices (VADs) are used to support these patients as a bridge to transplantation, though there is limited experience with this worldwide. A retrospective review of our institution's VAD database was undertaken and revealed seven adult patients with a history of TGA and subsequent systemic ventricular failure were implanted with a VAD: four of whom received the VAD as a bridge to transplantation (BTT) at the time of implantation, two who were initially designated as destination therapy secondary to severe pulmonary hypertension, and one who was designated as destination therapy secondary to a high risk of life-threatening non-compliance. ⋯ Four patients remain on VAD support, three of these patients are awaiting transplantation at last follow-up (mean days on support, 513 days). Bridge to transplantation with a durable VAD is technically feasible and relatively safe in patients with TGA. Multiple redo-sternotomies can be avoided with a left posterior thoracotomy approach and outflow graft anastomosis to the descending thoracic aorta after careful anatomic considerations.
-
Translational research is a useful tool to provide scientific evidence for cannula selection during extracorporeal life support (ECLS). The objective of this study was to evaluate four Avalon Elite bi-caval dual lumen cannulas and nine femoral arterial cannulas in terms of flow range, circuit pressure, pressure drop, and hemodynamic energy transmission in a simulated adult ECLS model. A veno-venous ECLS circuit was used to evaluate four Avalon Elite bi-caval dual lumen cannulas (20, 23, 27, and 31 Fr), and a veno-arterial ECLS circuit was used to evaluate nine femoral arterial cannulas (15, 17, 19, 21, and 23 Fr). ⋯ Maquet at 4 L/min: 17 Fr-43.6 vs. 44.4%, 19 Fr-31.0 vs. 31.4%, 21 Fr-20.8 vs. 22.4%) at high flow rates when compared with the Maquet cannulae. The results for this study provided valuable hemodynamic characteristics of all evaluated adult cannulas with human blood in order to guide ECLS cannula selection in clinical practice. Use of larger cannulas are suggested for VV- and VA-ECLS.
-
The objective of this study is to evaluate the hemodynamic characteristics of two femoral arterial cannulae in terms of circuit pressure, pressure drop, and hemodynamic energy transmission under non-pulsatile and pulsatile modes in a simulated adult extracorporeal life support (ECLS) system. The ECLS circuit consisted of i-cor diagonal pump and console (Xenios AG, Heilbronn, Germany), an iLA membrane ventilator (Xenios AG), an 18 Fr or 16 Fr femoral arterial cannula (Xenios AG), and a 23/25 Fr Estech remote access perfusion (RAP) femoral venous cannula (San Ramon, CA, USA). The circuit was primed with lactated Ringer's solution and packed red blood cells to achieve a hematocrit of 35%. ⋯ The pressure drops and percentages of THE loss across two cannulae tested using human blood were higher compared to the manufacturer's data tested using water. The cannula size should be chosen to match the expected flow rate. In addition, this novel i-cor ECLS system can provide non-pulsatile and ECG-synchronized pulsatile flow without significantly increasing the cannula pressure drop and hemodynamic energy loss.
-
Measurement of lactate concentrations during cardiac surgery with cardiopulmonary bypass (CPB) is a reliable monitoring tool for the assessment of the adequacy of perfusion, and a predictor of poor outcome. However, increased lactate production, which is multifactorial (anaerobic metabolism, hyperglycemia), increased lactate load by packed red blood cell (PRBC) transfusions, and decreased lactate clearance may all result in hyperlactatemia. The aim of this study was to estimate the clearance of lactate in infants undergoing surgery with CPB, using the lactate load from the PRBCs transfusions received during CPB. ⋯ Lactate clearance increased significantly with age. The half-life of lactate in infants is comparable with that reported in adults with CPB, and lactate clearance is higher. Knowing the high lactate content of PRBCs, lactate clearance rather than absolute concentration is potentially a better indicator of the adequacy of perfusion during CPB in infants.
-
The objective of this study is to compare hemodynamic performances under different pulsatile control algorithms between Medos DeltaStream DP3 and i-cor diagonal pumps in simulated pediatric and adult ECLS systems. An additional pilot study was designed to test hemolysis using two pumps during 12h-ECLS. The experimental circuit consisted of parallel combined pediatric and adult ECLS circuits using an i-cor pump head and either an i-cor console or Medos DeltaStream MDC console, a Medos Hilite 2400 LT oxygenator for the pediatric ECLS circuit, and a Medos Hilite 7000 LT oxygenator for the adult ECLS circuit. ⋯ Although high pulsatile amplitudes delivered higher levels of hemodynamic energy to the patient, the high rotational speeds increased the risk of hemolysis. Use of proper pulsatile amplitude settings and intermittent pulsatile mode are suggested to achieve better pulsatility and decrease the risk of hemolysis. Further optimized pulsatile control algorithms are needed.