Roller Pump Group Research Articles

P25: Assessment of VentriFlo True Pulse Pump in Cardiopulmonary Bypass Circuit In vivo

Objective: The objective of this study was to evaluate the hemodynamic and laboratory data during the post-cardiopulmonary bypass (CPB) phase in vivo in cardiovascular surgery utilizing the VentriFlo True Pulse Pump, a novel pulsatile extracorporeal blood pump capable of generating a natural-like pulse through standard oxygenators, cannulas, and tubing sets. Methods: The surgical procedure in porcine animal model (n=2, weight 26 and 23 kg) consisted of full median sternotomy access, central aortic cannulation, transatrial venous cannula insertion under general anesthesia. The intended duration of 3 hours has been maintained. In one case, a roller pump (RP) has been instituted. Second case has received the VentriFlo pulsatile pump (VentriFlo Inc., Pelham, NH). Hemodynamics were recorded during the CPB support period and for 3 hours post-CPB, and blood sampling was performed every hour. Results: The aortic pulse pressure was consistently higher with the VentriFlo pump compared to the RP (47 mm Hg vs. 25 mm Hg) (Figure 1). Although the pump flow during CPB was comparable (Both approximately 1.3 L/min), cardiac output was higher in the VentriFlo pig during the post-CPB period (1-3 hours) compared to the RP pig (2.2 L/min vs. 1.1 L/min). Regarding blood tests, the RP group exhibited a higher white blood cell count (21,800/uL vs. 13,150/uL in the VentriFlo pig). Conclusion: The VentriFlo pulsatile pump demonstrated the capability to deliver and maintain normal pulsatile flow and optimal cardiac output during and after CPB. More studies will be necessary to elucidate longer duration postoperative outcomes in cardiovascular surgical setup.Figure 1. Left – Aortic pulse pressure during the study. Middle – cardiac output post CPB. Right – WBC, white blood cell count. CPB, cardiopulmonary bypass.

Coagulation complications after conversion from roller to centrifugal pump in neonatal and pediatric extracorporeal membrane oxygenation

Background/purposeCoagulation complications are frequent, unwanted occurrences in extracorporeal membrane oxygenation (ECMO) treatment, possibly influenced by the pump in the ECMO-circuit. We hypothesized that fewer complications would occur with a smaller, heparin-coated ECMO system with a centrifugal pump (CP) than with one with a roller pump (RP) and that after conversion, complication rates would decrease over time. MethodsThis single-center, retrospective chart study included all first neonatal and pediatric ECMO runs between 2009 and 2015. Differences between groups were assessed with Mann–Whitney U tests and Kruskal–Wallis tests. Determinants of complication rates were evaluated through Poisson regression models. The CP group was divided into three consecutive groups to assess whether complication rates decreased over time. ResultsThe RP group comprised 90 ECMO runs and the CP group 82. Hemorrhagic complication rates were significantly higher with the CP than with the RP, without serious therapeutic consequences, while thrombotic complications rates were unaffected. Intracranial hemorrhage rates and coagulation-related mortality rates were similar. Gained experience with the CP did not improve complication rates or survival over time. ConclusionsAlthough the CP seems safe, it does not seem beneficial over the RP. Further research is warranted on how pump type affects coagulation, taking into account the severity and implications of coagulation complications. Level of EvidenceLevel III.

Outcomes of Infants Supported With Extracorporeal Membrane Oxygenation Using Centrifugal Versus Roller Pumps: An Analysis From the Extracorporeal Life Support Organization Registry

To determine whether mortality differs between roller and centrifugal pumps used during extracorporeal membrane oxygenation in infants weighing less than 10 kg. Retrospective propensity-matched cohort study. All extracorporeal membrane oxygenation centers reporting to the Extracorporeal Life Support Organization. All patients less than 10 kg supported on extracorporeal membrane oxygenation during 2011-2016 within Extracorporeal Life Support Organization Registry. Centrifugal and roller pump recipients were propensity matched (1:1) based on predicted probability of receiving a centrifugal pump using demographic variables, indication for extracorporeal membrane oxygenation, central versus peripheral cannulation, and pre-extracorporeal membrane oxygenation patient management. A total of 12,890 patients less than 10 kg were supported with extracorporeal membrane oxygenation within the Extracorporeal Life Support Organization registry during 2011-2016. Patients were propensity matched into a cohort of 8,366. Venoarterial and venovenous extracorporeal membrane oxygenation runs were propensity matched separately. The propensity-matched cohorts were similar except earlier year of extracorporeal membrane oxygenation (standardized mean difference, 0.49) in the roller pump group. Within the propensity-matched cohort, survival to discharge was lower in the centrifugal pump group (57% vs 59%; odds ratio, 0.91; 95% CI, 0.83-0.99; p = 0.04). Hemolytic, infectious, limb injury, mechanical, metabolic, neurologic, pulmonary, and renal complications were more frequent in the centrifugal pump group. Hemorrhagic complications were similar between groups. Hemolysis mediated the relationship between centrifugal pumps and mortality (indirect effect, 0.023; p < 0.001). In this propensity score-matched cohort study of 8,366 extracorporeal membrane oxygenation recipients weighing less than 10 kg, those supported with centrifugal pumps had increased mortality and extracorporeal membrane oxygenation complications. Hemolysis was evaluated as a potential mediator of the relationship between centrifugal pump use and mortality and met criteria for full mediation.

Investigating the effects of two different pump heads (Centrifugal vs. Roller Pump) on hematological and immunological mechanisms.

Technological developments and enhancement of knowledge level enable heart surgery with low mortality rates in most centers. On the other hand, increased systemic inflammatory response against cardiopulmonary bypass (CPB) plays a critical role in the development of postoperative complications. We aimed to compare the effects of centrifugal pump where it is claimed that blood is exposed to minimal trauma and roller pump techniques on inflammatory response and oxidant status during CPB. : A total of 40 patients, who had coronary artery disease and underwent coronary artery bypass graft (CABG) surgery using either roller or centrifugal pump between June 2012 and June 2013 were enrolled in this study. Patients over 40 years old and without any known immunologic, infectious, or inflammatory incidents and hematological problems for the past 6 months were included in the study. Two study groups (Group R: roller pump group and Group C: centrifugal pump group) were created. During CABG surgery tumor necrosis factor (TNF) alpha, interleukin (IL)-6, IL-8, superoxide dismutase (SOD), catalase (CAT), and nitric oxide levels were measured before and after CPB. TNF alpha, IL-6, and IL-8 levels measured before and after CPB were found to be similar between groups. SOD, CAT and Nitric oxide levels were also similar between groups. After the CPB period, glutathione peroxidase enzyme activities in Group R measured after CPB were significantly lower than those measured in Group C. The platelet-activating factor (PAF) levels before CPB usage period were same in both groups, where PAF levels after CPB were found to be significantly higher in roller pump group than centrifugal pump group. At inter-group comparisons, the levels of PAF were same at each group before and after CPB. The study findings indicate that usage of the centrifugal pump does not have a clear superiority in terms of the effects on inflammatory response and oxidant status during CPB when compared to roller pump. Nevertheless, we believe that our results should be supported by further clinical and experimental studies.

Comparison of Warm Blood Cardioplegia Delivery With or Without the Use of a Roller Pump

Various techniques for administration of blood cardioplegia are used worldwide. In this study, the effect of warm blood cardioplegia administration with or without the use of a roller pump on perioperative myocardial injury was studied in patients undergoing coronary artery bypass grafting using minimal extra-corporeal circuits (MECCs). Sixty-eight patients undergoing elective coronary bypass surgery with an MECC system were consecutively enrolled and randomized into a pumpless group (PL group: blood cardioplegia administration without roller pump) or roller pump group (RP group: blood cardioplegia administration with roller pump). No statistically significant differences were found between the PL group and RP group regarding release of cardiac biomarkers. Maximum postoperative biomarker values reached at T1 (after arrival intensive care unit) for heart-type fatty acid binding protein (2.7 [1.5; 6.0] ng/mL PL group vs. 3.2 [1.6; 6.3] ng/mL RP group, p = .63) and at T3 (first postoperative day) for troponin T high-sensitive (22.0 [14.5; 29.3] ng/L PL group vs. 21.1 [15.3; 31.6] ng/L RP group, p = .91), N-terminal pro-brain natriuretic peptide (2.1 [1.7; 2.9] ng/mL PL group vs. 2.6 [1.6; 3.6] ng/mL RP group, p = .48), and C-reactive protein (138 [106; 175] μg/mL PL group vs. 129 [105; 161] μg/mL RP group, p = .65). Besides this, blood cardioplegia flow, blood cardioplegia line pressure, and aortic root pressure during blood cardioplegia administration were similar between the two groups. Administration of warm blood cardioplegia with or without the use of a roller pump results in similar clinically acceptable myocardial protection.

Centrifugal Pump and Roller Pump in Adult Cardiac Surgery: A Meta‐Analysis of Randomized Controlled Trials

Centrifugal pump (CP) and roller pump (RP) designs are the dominant main arterial pumps used in cardiopulmonary bypass (CPB). Trials reporting clinical outcome measures comparing CP and RP are controversial. Therefore, a meta-analysis was undertaken to evaluate clinical variables from randomized controlled trials (RCTs). Keyword searches were performed on Medline (1966-2011), EmBase (1980-2011), and CINAHL (1981-2011) for studies comparing RP and CP as the main arterial pump in adult CPB. Pooled fixed-effects estimates for dichotomous and continuous data were calculated as an odds ratio and weighted-mean difference, respectively. The P value was utilized to assess statistical significance (P < 0.05) between CP and RP groups. Eighteen RCTs met inclusion criteria, which represented 1868 patients (CP = 961, RP = 907). The prevailing operation was isolated coronary artery bypass graft surgery (CP = 88%, RP = 87%). Fixed-effects pooled estimates were performed for end-of-CPB (ECP) and postoperative day one (PDO) for platelet count (ECP: P = 0.51, PDO: P = 0.16), plasma free hemoglobin (ECP: P = 0.36, PDO: P = 0.24), white blood cell count (ECP: P = 0.21, PDO: P = 0.66), and hematocrit (ECP: P = 0.06, PDO: P = 0.51). No difference was demonstrated for postoperative blood loss (P = 0.65) or red blood cell transfusion (P = 0.71). Intensive care unit length of stay (P = 0.30), hospital length of stay (P = 0.33), and mortality (P = 0.91) were similar between the CP and RP groups. Neurologic outcomes were not amenable to pooled analysis; nevertheless, the results were inconclusive. There was no reported pump-related malfunction or mishap. The meta-analysis of RCTs comparing CP and RP in adult cardiac surgery suggests no significant difference for hematological variables, postoperative blood loss, transfusions, neurological outcomes, or mortality.

Increased hemolysis from saline pre-washing RBCs or centrifugal pumps in neonatal ECMO

Hemolysis is a significant complication of extracorporeal membrane oxygenation (ECMO), with a reported incidence of 12.2%. The aims of this study were (1) to investigate hemolysis caused by saline-washed versus unwashed RBCs, (2) to determine in vitro the effects of saline washing on erythrocyte hemolytic markers and (3) to investigate hemolysis by centrifugal versus roller pumps. (1) To evaluate the effect of pre-transfusion saline-washing versus non-washing, the peak plasma-free hemoglobin (FHb) and total bilirubin in the first 3 days versus the next 4 days of ECMO were compared (2) Pre- and postsaline-washed RBCs were analyzed for K+ hemoglobin, mean corpuscular volume, FHb and hemolysis at baseline and after 4 h of storage at 4 degrees C. (3) Over 10 000 neonatal ECMO cases were retrospectively reviewed to study the effect of pump type on hemolysis. (1) The washed blood group had significantly more hemolysis within the first 3 days of ECMO. (2) Immediately after saline washing, the K+ and Hb concentrations were significantly decreased compared with unwashed blood, and these differences were maintained after 4 h. The osmotic fragility of washed RBCs after 4 h of storage at 4 degrees C was significantly higher than at baseline. (3) Hemolysis was reported more often in the centrifugal than in the roller pump group. (1) Using unwashed RBCs decreased hemolysis within the first 3 days of ECMO. (2) Saline washing, while decreasing the concentration of K+ in the plasma, significantly increases RBC membrane osmotic fragility. (3) Hemolysis is linked to the use of centrifugal pumps.

Hemoperfusion using a portable dual pulsatile extracorporeal life support on paraquat intoxication

Study objectives: To remove toxic substances in the blood, nonpulsatile roller pumps usually have been used for hemoperfusion. We develop a portable extracorporeal life support using dual pulsatile electromechanical blood pump (Twin Pulse Life Support: T-PLS). The purpose of this study is to evaluate the efficacy of an alternative hemoperfusion using T-PLS after paraquat intoxication in dogs. Methods: Twelve dogs weighing 30 to 35 kg were randomly assigned to the T-PLS or roller pump group. An 11F double-lumen hemoperfusion catheter was inserted into the right femoral vein in each dog and connected to T-PLS or a roller pump. At 1 hour after the intramuscular administration of paraquat (30 mg/kg), T-PLS or roller pump was started. Hemodynamic and hematologic parameters, including blood pressure, SaO 2 , plasma hemoglobin, and paraquat levels, arterial blood gas, CBC count, electrolytes, blood urea nitrogen and creatinine, aspartate aminotransferase/alanine aminotransferase, and prothrombin time/partial thromboplastin time were measured at baseline and 60 minutes after paraquat administration and 30 minutes, 60 minutes, 120 minutes, 180 minutes, and 240 minutes after T-PLS or roller pumps supports. Results: Compared with the roller pump group, the T-PLS group showed similar or improved effects on hemodynamic and hematologic parameters, including plasma paraquat level. However, there were no significant differences between the groups. Conclusion: We suggest that hemoperfusion using T-PLS may be an alternative method for the removal of toxic substances in blood.

Centrifugal versus roller head pumps for cardiopulmonary bypass: Effect on early neuropsychologic outcomes after coronary artery surgery

Objective: To test the hypothesis that routine use of a centrifugal pump in the cardiopulmonary bypass circuit would result in a lower incidence of early neuropsychologic deficit when compared with conventional roller pumps. Design: Prospective, randomized, double-blind. Setting: University teaching hospital. Participants: Patients (n = 103) scheduled for elective coronary artery surgery. Interventions: Patients were randomized into group C (centrifugal pump for cardiopulmonary bypass; n = 54) and group R (roller pump for cardiopulmonary bypass; n = 49). Measurements and Main Results: A neuropsychologic test battery of 6 standard tests was administered before surgery and 5 days after surgery. An abnormal test result was defined as deterioration by >1 group SD from an individual's preoperative test performance. There were no significant differences between groups in preoperative or surgical parameters, intensive care unit stay, or hospital stay. There were no significant differences in the incidence of neuropsychologic deficit for patients with a deficit in at least 1 test (group C, 33%; group R, 51%; odds ratio, 0.48; 95% confidence interval, 0.22 to 1.06) or patients with a deficit in ≥2 tests (group C, 6%; group R, 18%; odds ratio, 0.26; 95% confidence interval, 0.07 to 1.03). In group R, there were more individual test deficits per patient than in group C (p = 0.04). Conclusion: There was no significant difference in the incidence of neuropsychologic deficit postoperatively with routine use of centrifugal pumps. The larger number of individual test deficits in the roller pump group suggest that further studies to assess the potential neuropsychologic benefits of the use of centrifugal pumps are warranted. Copyright 2002, Elsevier Science (USA). All rights reserved.

Development of an Affordable Diaphragmatic Pump for Cardiopulmonary Bypass: An In Vivo Evaluation

A new diaphragmatic pump (L-Y pump) and its drive unit were developed in our institute. The pump has a priming volume of 80 ml. The pump housing is 72 mm in diameter and 42 mm in height. Its total weight is 139 g. To assess and confirm the function and controllability of this pump, comparative studies of cardiopulmonary bypass (CPB) with L-Y pump (group A) and conventional roller pump (Group B) were performed using dogs. Both pumps provided pump flow of 90 to 100 ml/kg/min. The hemodynamics of both groups were stable and within the normal range. No leakage or thrombus formation was observed in the L-Y pump. All biochemistry data showed no significant differences between the 2 groups. This data demonstrated low plasma-free hemoglobin levels in the L-Y pump group; after 120 min of CPB, mean plasma free hemoglobin levels were 48.7 +/- 8.6 mg/dl in the roller pump group and 21.4 +/- 7.1 mg/dl in the L-Y pump group, and minimal hemolysis was indicated. In conclusion, this L-Y pump and its controller system might be useful for CPB in terms of its low hemolysis and good pump quality. This pump demonstrated easy manipulation, good controllability, and provided a sufficient pulsatile flow. This pump is suitable not only for CPB, but also as a long-term circulatory support system.

Neutrophil degranulation and complement activation during fetal cardiac bypass

Background. Fetal cardiac bypass results in dysfunction of the fetoplacental unit (FPU) characterized by increased placental vascular resistance and respiratory acidosis. However the mechanisms of this dysfunction are not completely understood. To test the hypothesis that complement activation and neutrophil degranulation may contribute to the placental dysfunction associated with fetal bypass, we compared placental hemodynamics, complement activation, and neutrophil degranulation among fetuses exposed to cardiac bypass with a miniaturized bypass circuit including an in-line axial flow pump (Hemopump), fetuses undergoing bypass with a conventional roller pump circuit, and control fetuses that were similarly exposed but did not undergo bypass. Methods. Twenty-six Western Cross sheep fetuses (median 122 days gestation) were randomly assigned to undergo cardiac bypass for 30 minutes with the Hemopump circuit (n = 8), to undergo bypass for 30 minutes with the conventional (roller pump) circuit (n = 10), or to undergo identical exposure and cannulation but not bypass (n = 8, controls). Blood samples were collected to measure white cell count and differential, and C3a and lactoferrin levels prior to bypass, at the end of bypass, and 1 and 2 hours after bypass. Hemodynamics and blood gases were also monitored. Results. There was a fall in white cell count over time that continued after bypass in all groups; neutrophils and lymphocytes were affected similarly. C3a levels rose significantly from prebypass to postbypass in the roller pump group ( p < 0.0001) but not in either of the other groups. Lactoferrin levels rose significantly from start of bypass in both bypass groups (Hemopump p = 0.01; roller pump p < 0.0001) but not in controls. The elevation in lactoferrin level coincided with worsening placental gas exchange and deteriorating cardiac function. Conclusions. Complement and neutrophil activation occurred with fetal cardiac bypass but only neutrophil activation mirrored the FPU and cardiac dysfunction, suggesting that products of neutrophil activation may be important contributing factors. Improved FPU function with a bypass circuit that has less extracorporeal surface and does not require a large priming volume may be due in part to a reduction in the magnitude of this inflammatory response.

FLOW CYTOMETRIC ASSAY TO QUANTIFY PUMP INDUCED MICROTHROMBI DURING CARDIOPULMONARY BYPASS

Almost 70% of all patients who undergo cardiopulmonary bypass (CPB) surgery suffer from neuropsychological deficits in the first postoperative week. It is speculated that this transient neurological impairment is based on microemboli, mainly due to pump-induced platelet aggregations. The aim of this study is to establish a new method to detect and quantify pump-induced platelet aggregations in an in vitro experiment. Method: Whole blood flow cytometry was used to quantify circulating platelet microaggregates derived from a centrifugal pump (Baylor Gyro C1E3) and a roller pump (Sarns Inc. 2M 6002). Each pump was tested in a mock circuit for four hours (5L/min flow against 100 mm Hg pressure head) using fresh human anti-coagulated blood (1IU heparin /ml, ACT 250 sec.). Platelets were labeled with the CD42b-PE monoclonal antibody. Platelets and platelet microaggregates were differentiated from other blood cells based on their positive PE-fluorescence. Platelet microaggregates were distinguished from single platelet by size related forward scattering. The extent of platelet aggregation was quantified by depletion of single platelets compared to control. Results: Inactivated control samples showed no platelet aggregates and were defined as 0% platelet aggregation. A positive control with ADP activated platelets (20 μM ADP) showed the presence of platelet microaggregates and resulted in >90% platelet aggregation. Extensive platelet aggregation was also observed within the roller pump group. Values for platelet aggregation increased from 0% (0 min), 8.0±3.2% (15 min) to 52.0±14.4% at the end of experiment. The values for the centrifugal pump group were significantly lower (p < 0.01); 2.0±0.9% (15 min) and 9.0 ± 2.4% (4 hours). Conclusion: Flow cytometry is able to detect and quantify platelet aggregation. This is a very useful tool to evaluate the thrombogenic resistance of prototype blood pumps in a fast, inexpensive and reliable in vitro experiment. Based on these results we speculate that the transient neuropsychological deficits after CPB are primarily due to pump derived platelet aggregation. To reduce frequency and severity of neurological complications, the use of centrifugal pumps seems to be beneficial.

Inflammatory response to cardiopulmonary bypass using roller or centrifugal pumps

Background. The inflammatory response in 29 patients undergoing coronary artery bypass grafting using either roller or centrifugal (CFP) pumps was evaluated in a prospective study.Methods. Patients were randomized in roller pump (n = 15) and CFP (n = 14) groups. Terminal complement complex activation (SC5b-9) and neutrophil activation (elastase) were assessed during the operation. Cytokine production (tumor necrosis factor-α, interleukin-6, interleukin-8) and circulating adhesion molecules (soluble endothelial-leukocyte adhesion molecule-1 and intercellular adhesion molecule-1) were assessed after the operation.Results. Release of SC5b-9 after stopping cardiopulmonary bypass and after protamine administration was higher in the CFP group (p = 0.01 and p = 0.004). Elastase level was higher after stopping cardiopulmonary bypass using CFP (p = 0.006). Multivariate analysis confirmed differences between roller pump and CFP groups in complement and neutrophil activation. After the operation, a significant production of cytokines was detected similarly in both groups, with peak values observed within the range of 4 to 6 hours after starting cardiopulmonary bypass. However, interleukin-8 levels were higher using CFP 2 hours after starting cardiopulmonary bypass (p = 0.02). Plasma levels of adhesion molecules were similar in both groups within the investigation period.Conclusions. During the operation, CFP caused greater complement and neutrophil activation. After the operation, the inflammatory response was similar using either roller pump or CFP.

Selective visceral and renal perfusion in thoracoabdominal aneurysm repair.

Whether or not selective visceral and renal perfusion during thoracoabdominal aortic aneurysm (TAAA) repair has a protective effect on visceral and renal function remains unknown. The aim of this study was to clarify if selective perfusion has such an effect. From May 1982 to December 1997, 82 consecutive patients underwent TAAA repair. Patients receiving hypothermic circulatory arrest or cooling of the kidney using Ringer's lactate solution were excluded, thus 73 patients were enrolled into this study. They were divided into three groups: those in whom selective visceral and renal perfusion was performed using a roller pump (n = 41), those in whom it was performed using a centrifugal pump with a reduced heparin regimen (n = 22) and those who underwent simple aortic clamping alone (n = 10). Serum creatinine, total bilirubin and alanine aminotransferase levels were elevated postoperatively in patients undergoing simple cross-clamp repair, but remained almost within normal limits in patients undergoing TAAA repair with selective visceral and renal perfusion. Urine output was more in selective perfused patients than in non-perfused patients. Renal dysfunction, defined by requirement of hemodialysis or by a serum level of creatinine above 3 mg/dl, occurred in four patients (10%) of the roller pump group and in two patients (9%) of the centrifugal pump group, while in four patients (40%) of the simple cross-clamping group. Our experience suggests that selective visceral and renal perfusion has a protective effect on hepato-renal function during TAAA repair.

Inflammatory Mediators in Adults Undergoing Cardiopulmonary Bypass: Comparison of Centrifugal and Roller Pumps

Background. The nonocclusive centrifugal pump is used for cardiopulmonary bypass (CPB) and mechanical cardiac assistance. This study examined its impact on proinflammatory cytokine release. Methods. Forty-one patients undergoing elective coronary artery bypass grafting were randomized prospectively to either a standard roller pump group (n = 21) or a centrifugal vortex pump group (n = 20) for CPB. The two groups were well matched in age, sex, severity of disease, and duration of CPB and aortic cross-clamping. Plasma levels of the cytokines tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8, as well as terminal complement, neutrophil counts, and leukocyte elastase, were analyzed before, during, and after CPB. Results. In both groups, traces of tumor necrosis factor-α were observed infrequently and interleukin-1β was not detected. Plasma levels of interleukin-6 and interleukin-8 increased during and after CPB, reaching a peak at 2 hours after protamine administration in both groups before returning toward baseline at 24 hours. The release of interleukin-6 was significantly greater in the centrifugal group ( p < 0.05), whereas the interleukin-8 concentration did not differ between the groups throughout the study period. Levels of terminal complement increased in both groups perioperatively, reaching a peak 30 minutes after protamine administration, whereas neutrophil counts and elastase peaked 2 hours after protamine administration. Plasma terminal complement, neutrophil counts, and elastase release were significantly higher in the centrifugal group ( p < 0.05). Peak terminal complement correlated ( r = 0.64, p < 0.01) with peak elastase in the centrifugal group only. Conclusions. This study confirms the proinflammatory nature of CPB in adults and demonstrates that use of the centrifugal pump induces a greater systemic inflammatory response than use of the standard roller pump.

The Design and Application of a Pediatric Centrifugal Pump

This centrifugal pump (CP) includes two parts: the blood pump and the driving apparatus. They are connected by six twin magnetic disc plates and driven by a magnetic DC motor (120W). The blood pump had six leaves deadlocked between two plastic discs. Six leaves were set at 30° angles, separately. In the lower chamber of the CP, there was an inlay magnetic disc, which is connected with the disc leaves by an axis. This axis was sealed by silicon rubber and a ceramic ring. The priming volume of the blood chamber was 34 ml. In vitro testing showed that the free hemoglobin caused by the CP was much less than that caused by a roller pump after 180 min. The effect of this CP on blood cell damage was also studied in an animal model. Six goats were placed on cardiopulmonary bypass for 180 min. Perfusion flow rates were maintained between 1.5 and 2.5 L/min. The plasma free hemoglobin was lower in the CP group (6.04 mg/dL) than in the roller pump group (32.25 mg/dL), p &lt; 0.01. The CP has been used in ten pediatric patients undergoing cardiopulmonary bypass surgery. The patients' ages were from three to five years, and body weights were from 15 to 20 kg. Perfusion flow rates were maintained between 1.8 and 2.5 L/min, and bypass times were from 30 to 50 min. The rotation speeds were from 2000 to 2500 rpm. All the patients recovered smoothly, and no hemoglobinuria occurred.

Less Blood Damage in the Impeller Centrifugal Pump: A Comparative Study with the Roller Pump in Open Heart Surgery.

A centrifugal pump with an impeller (Nikkiso Centrifugal Pump, Model HPM15; Nikkiso Co. Ltd.) was applied to cardiopulmonary bypass (CPB) in 14 patients who underwent elective coronary artery bypass grafting. Serum hemoglobin level, platelet count, and serum p-thromboglobulin (pTG) level were measured during CPB. The results were compared with those obtained in a comparative roller pump (RP) group (n = 10). There was no difference in the time on CPB between the NP (109 min) and RP (121 min) groups. The serum pTG level (ng/ ml) was lower in the NP group than in the RP group (obtained 90 min after the initiation of CPB). The plasma-free hemoglobin level also was lower in the NP group than in the RP group (obtained 90 min after the initiation of CPB, 120 min after the initiation of CPB, immediately after the termination of CPB, 3 h after termination of CPB; p < 0.01). There was no significant difference in platelet depletion. The HPM15 pump showed excellent hemodynamic performance with less blood trauma compared with the roller pump in its clinical application to open heart surgery.

Clinical Use of Centrifugal Pumps and the Roller Pump in Open Heart Surgery: A Comparative Evaluation.

Centrifugal pumps have been used widely as the main pump in open heart surgery to reduce damage to blood elements and to reduce the activation of the coagulation system. The purpose of this study was the evaluation and comparison of the effects of two types of centrifugal pumps and of one type of roller pump on blood elements, the coagulation system, complements, and immunoglobulins. Two types of centrifugal pumps (Lifestream; St. Jude Medical, Chelmsford, Massachusetts; and BP-80; Medtronic, BioMedicus, Inc., Eden Prairie, Minnesota, U.S.A.) and one roller pump (Mera Co.) were used separately as the main pump for cardio-pulmonary bypass (CPB) in 29 patients. Platelet counts, lactate dehydrogenase, antithrombin III, thrombin-antithrombin complex (TAT), complements (C3, C4, and CH50) and immunoglobulins G, A, and M values were measured before and after CPB and compared. Values, except those for TAT, showed no significant difference among the three groups. The TAT values increased less in each of the centrifugal pump groups than in the roller pump group. This finding suggests that thrombin synthesis might be suppressed by the use of a centrifugal pump.

Comparison of the effects of centrifugal versus roller pump on the immune response in open-heart surgery

We compared the effects of a centrifugal pump with those of a roller pump on immune responses in 26 coronary artery bypass surgery patients during cardiopulmonary bypass (CPB). The patients were randomly allocated into a (Biomedicus) centrifugal pump group and a (Stöckert) twin roller pump group. Leucocyte and differential counts; percentages of lymphocyte subpopulations (CD3-, CD4-, CD8-, CD16-, CD20- and CD25-positive lymphocytes) and monocytes (CD14); phytohaemagglutinin-, concanavalin A-, and pokeweed mitogen-induced and unstimulated proliferation of separated lymphocytes; unstimulated and pokeweed mitogen-stimulated production of IgG, IgM, or IgA; and plasma fibronectin, C-reactive protein and serum albumin concentrations were measured preoperatively, immediately before CPB, immediately before aortic declamping and on the first postoperative morning. Significant changes were seen in these variables, but no differences occurred between the groups.

Centrifugal Pumping: The Patient Outcome Benefits Following Coronary Artery Bypass Surgery

The increased use of the centrifugal pump during coronary artery bypass surgery has been based primarily on theoretical data related to patient safety. There is minimal evidence suggesting improved outcome when compared to the traditional roller pump technology. We prospectively randomized 200 patients undergoing elective coronary artery bypass grafting into centrifugal pump (100 patients) and roller pump (100 patients) groups to compare differences in blood product usage, complication rate, length of stay and net hospital financial balance. Moderate hypothermic bypass was employed on all patients. Cardiopulmonary bypass circuits were similar in both groups with the exception of the arterial pump. Both groups were statistically identical in regard to age, sex, surgeon, complications, total pump time, aortic cross clamp time, prebypass hematocrit and platelet count. The twenty-four hour postoperative hematocrits, platelet counts, red blood cell requirements, blood loss and mortality (2%) were identical in both groups. The centrifugal pump patients had less 24 hour weight gain than their peers in the roller pump group (p=0.05) The length of stay and net hospital financial balance were also statistically favored in the centrifugal pump group (p&lt;0.05). These latter findings were significant when studied in all payors and coronary artery bypass diagnostic related group classifications. Although the mechanism for improvement in length of stay and net hospital financial balance cannot fully be explained, the ramifications in an increasingly cost conscious environment are obvious.