INTRODUCTION The discussion over the use of continuous versus pulsatile pumps for extracorporeal circulation during medical procedures has gone on for many years (1, 2). It is still controversial whether to pulse for the creation of ideal extracorporeal perfusion. There is still no conclusive proof as to the value of pulsatile versus continuous flow perfusion. Two major factors are (i) the lack of a clear definition of appropriate pulsatile flow and (ii) the use of roller and peristaltic pumps with relatively low amplitude pulsatility as steady flow pumps (1, 2). Patients with chronic renal failure (CRF) and chronic obstructive pulmonary disease (COPD) have an increased risk of fatal outcome, increased length of hospital stay and increased incidence of organ failure and morbidity after open heart surgery (1, 3). Although non-pulsatile CPB (Cardio- pulmonary Bypass) is used more widely than pulsatile cardiopulmonary bypass, it causes transient dysfunction of many systems (especially renal and pulmonary). This dysfunction is more pronounced in patients who have disordered organ functions preoperatively (4, 5). The use of pulsatile flow for CPB in patients was very popular during the last decade. More recently, its use has declined for several reasons. First, there was a lack of under-standing of the basic mechanical properties of the left ventricle and major arteries and of the interactions among them. Second, there was no satisfactory definition of pulsatile flow; and this led to the use of pumps that deliver different types of flow patterns for experimental purposes. A third reason was a recent development of membrane gas exchange devices that dampen the pulse and that are Artificial Heart and Cardiac Assist Devices The International Journal of Artificial Organs / Vol. 27 / no. 5, 2004 / pp. 433-439 Pulsatile roller pump perfusion is safe in high risk patients M. KOCAKULAK 1 , S. KÜÇÜKAKSU 2 , E. PIS ‚ KIN 3 1 Bas ‚ kent University, Biomedical Engineering Department, Ankara - Turkey 2 TYIH Hospital, Cardiovascular Surgery Clinic, Ankara - Turkey 3 Chemical Engineering Department and Bioengineering Division, and TÜBITAK: Centre of Excellence: BIYOMÜH, Hacettepe University, Ankara - Turkey © Wichtig Editore, 2004 0391-3988/433-07 $15.00/0 ABSTRACT: In this study, controllability, safety, blood cell depletion, and hemolysis of a pulsatile roller pump in high-risk patients was evaluated. Sarns 8000 roller pump (Sarns, Terumo CVS, Ann Arbor, MI, USA) with a pulsatile control module was used as arterial pump in a clinical setting. Forty patients undergoing elective open heart surgery with high-risk either having chronically obstructive pulmonary disease or chronic renal failure were randomly included in the study to be operated on using pulsatile perfusion or non-pulsatile perfusion. Blood samples were withdrawn at induction of anesthesia, at the time of aortic clamping and de-clamping and at 1 hour and 24 hours following cessation of the bypass. Hematocrit and plasma free hemoglobin values were measured. We observed that the pulsatile roller pump perfusion and the extracorporeal circuit used in the clinical study is safe in high-risk patients undergoing cardiopulmonary bypass. We did not face any emboli, hemolysis, or technical problems. Pulsatile roller pump perfusion with Sarns 8000 heart-lung machine is a simple and reliable technique and can be easily applied during open heart surgery. (Int J Artif Organs 2004; 27: 433-9) KEY WORDS: Pulsatile flow, Pulsatile perfusion, Heart-lung machine, Extracorporeal technology, Roller pump, High-risk patients, Heart surgery