A Hemodynamic Evaluation of the Levitronix Pedivas Centrifugal Pump and Jostra Hl-20 Roller Pump Under Pulsatile and Nonpulsatile Perfusion in an Infant CPB Model NOEL RESSLER,* ALAN R. RIDER,* ALLEN R. KUNSELMAN,† J. SCOTT RICHARDSON,‡ KURT A. DASSE,‡ SHIGANG WANG,*§ AND AKIF ¨ UNDAR*§¶ The hemodynamic comparison of the Jostra HL-20 and the Levitro- nix PediVAS blood pumps is the focus this study, where pressure- flow waveforms and hemodynamic energy values are analyzed in the confines of a pediatric cardiopulmonary bypass circuit. The pseudo pediatric patient was perfused with flow rates between 500 and 900 ml/min (100 ml/min increments) under pulsatile and nonpulsatile mode. The Levitronix continuous flow pump utilized a customized controller to engage in pulsatile perfusion with equivalent pulse settings to the Jostra HL-20 roller pump. Hemodynamic measurements and waveforms were recorded at the precannula location, while the mean arterial pressure was maintained at 40 mm Hg for each test. Glycerin water was used as the blood analog circuit perfusate. At each flow rate 24 trials were conducted yielding a total of 120 ex- periments (n  60 pulsatile and n  60 nonpulsatile). Under nonpulsatile perfusion the Jostra roller pump pro- duced small values for surplus hemodynamic energy (SHE) due to its inherent pulsatility, while the Levitronix produced values of essentially zero for SHE. When switching to pulsatile perfusion, the SHE levels for both the Jostra and Levitronix pump made considerable increases. In comparing the two pumps under pulsatile perfusion, the Levitronix PediVAS pro- duced significantly more surplus and total hemodynamic en- ergy than did the Jostra roller pump each pump flow rate. The study suggests that the Levitronix PediVAS centrifugal pump has the capability of achieving quality pulsatile waveforms and delivering more SHE to the pseudo patient than the Jostra HL-20 roller pump. Further studies are warranted to investigate the Levitronix under bovine blood studies and with various pulsatile settings. ASAIO Journal 2009; 55:106 –110. E vidence for the advantages of pulsatile over nonpulsatile perfusion in several clinical circumstances continues to grow. 1–3 Understanding the role that individual components and settings of the cardiopulmonary bypass (CPB) circuit may play in the delivery of hemodynamic energy to the patient is an important next step in providing the best outcomes for patients after CPB procedures. The centrifugal blood pump is one such component that has been developing rapidly, yet few have the option to perfuse in both nonpulsatile and pulsatile modes. As the future turns to new ways to enhance the CPB procedure, innovative centrifugal pumps may hold the key to this chal- lenge by generating quality physiologic pulsatility and im- proved patient outcomes. The Levitronix PediVAS (Levitronix, LLC, Waltham, MA) is a magnetically levitated centrifugal blood pump that employs a bearingless motor. Pumps without mechanical bearings were proposed to avoid the limited reliability of previous pumps due to contact bearing wear. 4 The PediVAS is currently used for applications in extracorporeal circulatory support such as ECMO, uni and biventricular assistance under nonpulsatile perfusion. Its self-bearing design eliminates the potential for problems related to mechanical bearings, and some of its appeal lies with its low hemolysis and minimal thrombus formation. The objective of this investigation was to test the Levitronix PediVAS pump and the Jostra HL-20 roller pump to ascertain and compare their hemodynamic outputs during nonpulsatile and pulsatile perfusion modes in a simulated pediatric CPB circuit. Materials and Methods Simulated Infant Circuit Design The circuit was designed to simulate an infant undergoing a CPB procedure, and the components used have been described in our previous study. 5 In an effort to produce the most clinically relevant data, components of the circuit were used and arranged in accordance with our operating room standards and specifications. The system was driven by either the Jostra HL-20 roller pump or the Levitronix PediVAS centrifugal pump with a customized controller capable of engaging either pulsatile or nonpulsatile modes. The pseudo patient was perfused by a 10 French Terumo aortic cannula (Terumo Corporation, Tokyo, Japan) with aortic compliance, systemic resistance, and venous compli- ance built into the circuit. Mean arterial pressure of the pseudo patient was maintained at 40 mm Hg via a Hoffman clamp. The simulated circuit was primed with a glycerin- based blood analog solution of 40% glycerin and 60% distilled water, and was maintained at room temperature. The circuit From the *Pediatric Cardiac Research Laboratories, †Department of Health Evaluation Sciences, ‡Pediatrics, and §Surgery and Bioengi- neering, Penn State Milton S. Hershey Medical Center, Penn State College Medicine, Penn State Children’s Hospital, Hershey, Pennsylvania; and ¶Levitronix LLC, Waltham, Massachusetts. Submitted for consideration August 2008; accepted for publication in revised form September 2008. Reprint Requests: Akif U ¨ ndar, PhD, Department of Pediatrics, Surgery, and Bioengineering, Penn State College of Medicine, De- partment of Pediatrics—H085, 500 University Drive, PO Box 850; Hershey, PA 17033-0850. Email: aundar@psu.edu. DOI: 10.1097/MAT.0b013e3181904232 ASAIO Journal 2009 106