bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation and quantification of the blood trauma caused by the combined dynamic forces experienced during cardiopulmonary bypass
Authors: Mulholland J W , Massey W , Shelton J C
Published: January 2013

Blood is exposed to various dynamic forces during cardiopulmonary bypass (CPB). Understanding the damaging nature of these forces is paramount for research and development of the CPB circuit. The object of this study was to identify the most damaging dynamic non-physiological forces and then quantify this damage.

A series of in vitro experiments simulated the different combinations of dynamic forces experienced during CPB while damage to the blood was closely monitored.

A combination of air interface ( a) and negative pressure ( P) caused the greatest rate of change in plasma Hb (Δp Hb) (4.94 10-3 mg/dl/s) followed by negative pressure and then an air interface. Shear stresses, positive pressures, wall impact forces and a blood-nonendothelial surface caused the least damage (0.26 10-3 mg/dl/s). An air interface showed no threshold value for blood damage, with the relationship between the size of the interface and the blood damage modelled by a second-order polynomial. However, negative pressure did exhibit a threshold value at -120 mmHg, beyond which point there was a linear relationship.

Investigating the reasons for the increased blood trauma caused by the low-pressure suction (LPS) system makes it clear how research into minimizing or completely avoiding certain forces must be the next step to advancing extracorporeal technology.
Anti-inflammatory pre-treatment and the resultant effects of interleukin-10: adjuncts to multi-therapeutical strategies
Authors: Fernando Roldan , Chan Richard
Published: January 2013

With the advent of off-pump coronary bypass surgery, there is increasing demand for research in attenuating the deleterious effects of cardiopulmonary bypass (CPB). An improved understanding of the systemic inflammatory response syndrome (SIRS) has distinguished which areas of components have the most adverse effects and which are, in fact, anti-inflammatory. This classification of inflammatory components allows strategic treatment for those likely to cause the most clinically significant ‘effect’, suitably termed ‘effectors’. This article will identify current methods in treating ‘effectors’, as well as those components having anti-inflammatory effects.

This article selectively features certain inflammatory components by: (1) grouping them as being ‘mediators’ or ‘effectors’; (2) relating them to interleukin-10 (IL-10) and treatments potentiating anti-inflammatory effects; (3) summarizing their mechanisms of action; (4) recognizing the time periods during bypass exhibiting peak levels; and (5) investigating current treatment methods and identifying their significance to ‘effectors’.

A literature search in MEDLINE was performed, featuring articles of the English-language within the past 5 years.

Because of the characteristic of having interlinked multi-component cascades, it is evident that treating SIRS with a one-dimensional method would be inadequate. This article not only confirms the importance of a multi-factorial therapeutic approach, but also targets the inflammatory components having the highest potential for causing direct tissue damage, known as ‘effectors’. In addition, previous studies have found IL-10 to have ‘regulatory effects’ during periods of excessive pro-inflammatory stimuli. These findings may arouse new ideas in exploring the area of anti-inflammatory cytokines. In fact, future treatments may suggest a new classification featuring ‘mediators’, ‘effectors’, and ‘regulators’.
Does heparin pretreatment affect the haemostatic system during and after cardiopulmonary bypass?
Authors: Brinks HJ , Weerwind PW , Bogdan S. , Verbruggen H. , Brouwer Mhj
Published: January 2013

In this clinical pilot study, the influence of heparin pretreatment on the haemostatic system during and after cardiopulmonary bypass (CPB) was investigated. Thirteen patients scheduled for elective coronary artery bypass grafting (CABG) were divided into two groups: heparin pretreated (HP, n = 6) and non-heparin pretreated (NHP, n = 7). Blood samples were taken for measurements of plasma antithrombin-III (AT-III) activity, plasma heparin levels, activated clotting time with (HACT) and without (ACT) heparinase, whole blood platelet function, platelet count, thrombin-antithrombin-III complexes and D-dimer levels. Also, the mediastinal blood loss within the initial 20 h after surgery, and the blood transfusion requirements were monitored. The mean duration of the heparin pretreatment was 55 h (range 24-161 h). There was no significant difference in plasma AT-III activity and platelet count between the groups. Before and after CPB, the platelet responsiveness was better in the NHP group ( p < 0.05). The HACT was prolonged in the NHP group during and after CPB compared to baseline values ( p < 0.05), whereas, in the HP group, no significant changes were found. Plasma heparin levels and ACT values suggested adequate anticoagulation during CPB. However, the extent of thrombin inhibition and fibrinolysis increased with time on CPB, but did not differ between the two groups. Twenty hours after surgery, the thrombin inhibition showed to be significantly higher in the NHP group. Furthermore, mediastinal blood loss showed a tendency to be lower in the HP group ( p = 0.08). However, there was no difference in blood transfusion requirements between the groups. These data suggest that short-term heparin pretreatment affects the perioperative platelet responsiveness and attenuates the consumption of coagulation factors.
Five-year clinical experience with Abiomed BVS 5000 as a ventricular assist device for cardiac failure
Authors: Dekkers Renè J , FitzGerald Daniel J , Couper Gregory S
Published: January 2013

Mechanical support for the failing heart has interested and challenged cardiac specialists for decades. In the United States alone, there are close to 375 000 cardiac surgical procedures performed each year, and, despite the recent advances in myocardial protection, surgical techniques, intra-aortic balloon therapy and maximal pharmacological support, postoperative ventricular dysfunction continues to occur in 0.5-1.0% of all patients undergoing cardiac surgery.

This retrospective review describes our 5-year clinical experience at the Brigham and Women's Hospital with the Abiomed BVS 5000 as a means of ventricular support. During the period of 1994 to present, 7428 cardiac surgical operations were performed at our institution. The Abiomed BVS 5000 has been implanted in 47 patients exhibiting ventricular failure. There were 38 patients in the bridge-to-recovery group and nine patients in the bridge-to-transplantation group.

Twenty-five patients (66%) in the bridge-to-recovery group were weaned and 16 patients (42%) went on to discharge. In the bridge-to-transplantation group, one patient actually recovered myocardial function and one expired on the device. The remaining seven patients (77%) underwent cardiac transplantation with post-transplant survival at 66%. Overall, patients were supported in the isolated left ventricular mode (28%), in the biventricular mode (45%) and in the isolated right ventricular mode (28%).

The Abiomed BVS 5000 has been shown to be a safe and simple cardiac support system with no mechanical failure. Our experience shows that a substantial number of patients suffering from ventricular failure will benefit from the use of this device. The results also justify the use of this device in groups of patients other that of postcardiotomy ventricular failure.
Significant reduction of air microbubbles with the dynamic bubble trap during cardiopulmonary bypass
Authors: Schönburg M. , Urbanek P. , Erhardt G. , Kraus B. , Taborski U. , Mühling A. , Hein S. , Roth M. , Tiedtke HJ , Klövekorn WP
Published: January 2013

Air microbubbles mostly occur unnoticed during cardiopulmonary bypass and are predominantly responsible for serious postoperative psycho- neurological dysfunction. A dynamic bubble trap (DBT), which removes air microbubbles from the arterial blood, was tested in a clinical study. The aim was to evaluate the efficiency of microbubble removal under clinical conditions.

As blood passes through the DBT, which is placed in the arterial line between the arterial filter and arterial cannula, it is converted into a rotating stream. The bubbles are directed to the centre of the blood flow and are collected in the distal end of the DBT, from where they are returned to the cardiotomy reservoir. Doppler ultrasonography was used to detect the microbubbles before and after the DBT, and also the number of high- intensity transient signals (HITS) in the right and left middle cerebral artery during extracorporeal circulation. A significant reduction of microbubbles in the arterial line (3990 before DBT, 537 after, p < 0.001) and HITS in the brain (51 in the DBT group, 77 in the placebo group, p = 0.04) was measured.
Inflammo-coagulatory response, extrinsic pathway thrombin generation and a new theory of activated clotting time interpretation
Authors: Gil William
Published: January 2013

When blood is subjected to contact with foreign surfaces, as during cardiopulmonary bypass (CPB), the whole body inflammatory response is initiated, resulting in the expression of procoagulant molecules on the vascular endothelium and white blood cells. These surface bound procoagulants participate in the extrinsic coagulation pathway. It appears that the primary source of thrombin generation during CPB is due to extrinsic pathway activation. Thrombin not only converts fibrinogen to fibrin, it also acts as a proinflammatory agent resulting in a positive feedback loop or the inflammo-coagulatory response.

Extrinsic pathway thrombin generation occurs as a membrane bound event. Membrane bound factors are resistant to heparin/ATIII inhibition. Therefore, the anticoagulant effect of heparin/ATIII is due to thrombin inhibition, not the inhibition of thrombin generation. Interpretation of the activated clotting time (ACT) must take into account the thrombin concentration [T]; this results in the coagulatory ratio, ACT ∝([ Hep- ATIII]/[T]).

Considering this proportionality, it can be seen that the ACT cannot be used to quantitate heparin concentration. Changes in the ACT can reflect changes in [Hep - ATIII], changes in [T], or changes in both concentrations.

Anti-inflammatory agents which suppress or inhibit the extrinsic pathway, such as aprotinin, result in decreased thrombin generation. As thrombin generation decreases, the ACT-heparin dose response curve is warped, resulting in a dose response curve resembling a PTT-heparin dose response curve. We can no longer assume that the disproportionate rise in the ACT relative to the [HEP - ATIII] when aprotinin is used as indicative of failure of the ACT to provide a credible indication of anticoagulation.
Leucodepletion during cardiopulmonary bypass reduces blood transfusion and crystalloid requirements
Authors: Stefanou DC , Gourlay T. , Asimakopoulos G. , Taylor KM
Published: January 2013

Cardiopulmonary bypass (CPB) is associated with the production of inflammatory responses, which can have significant influence on prognosis. We studied the effects of leucocyte-depletion filters on inflammatory parameters and early postoperative prognosis during coronary revascularization. Twenty patients undergoing elective coronary revascularization were randomly divided into two groups. Ten patients had leucocyte-depletion filters added to the CPB circuit (treatment group) and 10 were used as control cases (control group). Expression of CD11 b on neutrophils, and production of myeloperoxidase and lactoferrin, were measured in arterial samples between induction and 3 h postbypass. In addition, clinical parameters were measured during inpatient recovery. CD11b neutrophil expression, and myeloperoxidase and lactoferrin production, were found to be upregulated during CPB and then to decline to preoperative levels by the third postoperative hour. Blood transfusion requirements were reduced in the treatment group, equalling 1.5 ± 1.2 units, compared to 2.7 ± 1.1 units for the control group ( p value = 0.034) and so were the volumes of crystalloid infused during the first 24 h postoperatively, equalling 3.9 ± 1.2 I in the treatment group and 3.3 ± 0.7 I in the control group ( p value = 0.021). Overall, the application of leucocyte depletion produced an early clinical advantage, underlining the need for an improved understanding and manipulation of the inflammatory response to CPB.
Neurological injury during cardiopulmonary bypass in the rat
Authors: Grocott Hilary P , Mackensen G Burkhard , Newman Mark F , Warner David S
Published: January 2013

Cerebral injury is a well-known complication of cardiac surgery. Investigations of both injury mechanisms and neuroprotective strategies have partially been limited by the lack of an adequate preclinical model of small animal cardiopulmonary bypass (CPB). We sought to determine if neurological injury could be demonstrated in a recovery model of complete CPB in the rat. Rats ( n = 5) underwent 45 min of normothermic CPB followed by 24 h of recovery. Compared to sham-operated rats ( n = 5), the CPB group showed a worse neurological outcome score (median, 25-75th percentile) compared to controls (5, 4-7 vs 9, 8-9, p = 0.016). This rat model of CPB may allow for the study of CPB-associated neurological injury.
Cryofibrination: did it really happen?
Authors: Luckraz Heyman , Boolauky Deobrat , Mohangee Ahmad
Published: January 2013

Cryofibrin precipitation is a phenomenon which has only recently been described, although it might have been present since the advent of membraneoxygenators for cardiopulmonary bypass procedures. The deposition of the cold-reactive protein, cryofibrin, causes progressive occlusion of the heat-exchanger part of the cardiopulmonary circuit, thus leading to a high pressure-drop phenomenon. We describe our experience with a few cases in which the cryofibrination phenomenon developed while using the Avecor-Affinity Medtronic' membrane oxygenator.
Is compartment pressure related to plasma colloid osmotic pressure, in patients during and after cardiac surgery?
Authors: Símonardóttir Líney , Torfason Bjarni , Magnússon Jónas
Published: January 2013

Haemodilution is always considerable during cardiopulmonary bypass (CPB). If this extra fluid sits in the muscle compartments then a corresponding rise in the compartment pressure (CP) is to be expected. The aim of this study was to measure pressure changes in a body compartment with new equipment, the MTC® (Microtransducer). Changes in plasma colloid osmotic pressure (COP) were also measured during and after CPB to find a connection, if any, between CP and plasma COP.

Ten elective consecutive CPB patients were studied. A 3-French (3-F) catheter-size electronic MTC® was inserted in an anterior tibial compartment before CPB. The CP was monitored for 48 h. Plasma COP was also measured before, during and after CPB.

CP increased significantly during and after CPB in all patients ( p=0.01). COP decreased significantly in all patients ( p=0.005), but no correlation was found between changes in COP and CP values in this study. Most of the patients reached their highest CP just after weaning off bypass. The CP remained elevated for 48 h, even though it then tended to decrease again. None of the patients reached the starting value within 48 h. COP decreased rapidly after going on bypass, but returned towards its starting value approximately 6 h after bypass.

It is concluded that CP increases considerably during and after CPB and stays increased for at least 2 days after CPB. COP decreases during CPB, but reaches normal values 6 h after the CPB. No correlation was found between changes in CP and COP. The MTC® is a safe and easy way to measure intracompartment pressure.
Transventricular cannulation of the aorta: a useful technique in acute aortic dissection
Authors: Velissaris Theodore J , Tang Augustine TM , Ohri Sunil K
Published: January 2013

A 39-year-old morbidly obese man suffered type-A acute aortic dissection. At operation, both external iliac and common femoral arteries were thrombosed. Transventricular cannulation of the ascending aorta provided the only means of maintaining adequate flow on cardiopulmonary bypass (CPB) to support an unusually high body mass index. This method of arterial cannulation for CPB was initially described in paediatric patients. We review the application of this technique in the adult population.
An update on perfusion safety: does the type of perfusion practice affect the rate of incidents related to cardiopulmonary bypass?
Authors: Stammers Alfred H , Mejak Brian L
Published: January 2013

Cardiopulmonary bypass (CPB) techniques vary among adult and pediatric patients undergoing cardiac surgery. This may result in a differential conduct of CPB between various aged patients. The present study reports on perfusion incidents occurring in hospitals using extracorporeal circulation.

An 80 question survey was mailed to chief perfusionists at all 1030 US cardiac surgical centers. Respondents were asked to report on device use and incidents occurring during a 2-year period from July 1996 to June 1998.

Five hundred and twenty-four completed surveys were returned with the age of surgical patients operated on at each hospital defined as either an adult ( n=407), pediatric ( n=17), or combined-adult and pediatric ( n=100). Centrifugal pumps were used as the primary systemic pumps in 54% of adult, 12% of pediatric, and 36% of combined centers. In-line blood gas monitoring was used in 76% of all pediatric hospitals, but in only 30% of adult facilities. Incident rates occurred once per every 120.9, 83.9, and 220.2 cases in adult, pediatric, and combined centers, respectively. Mortality rates related to CPB occurred 2.7 times higher in adult and pediatric centers as compared to combined hospitals. Arterial dissection was the number one cause of death in both pediatric and combined hospitals, while coagulation disturbances resulted in the highest mortality for adult procedures.

Results of this study show that the lowest incident rates occur at hospitals performing combined adult and pediatric CPB.
Light and electron microscopic analyses for ischaemia-reperfusion lung injury in an ovine cardiopulmonary bypass model
Authors: Kim Won Gon , Lee Byeong-Han , Seo Jeong Wook
Published: January 2013

An experiment to study the role of contact-activation leukocyte sequestration in the formation of ischaemia-reperfusion injury (I-R injury) was carried out. The study was conducted using light and electron microscopic analyses in an ovine cardiopulmonary bypass (CPB) model using a membrane oxygenator.

Five adult sheep were used in the study. The CPB circuitry consisted of a roller pump and a membrane oxygenator. During CPB, flow rates ranged from 50 to 60 ml/kg/min with mild hypothermia. The CPB time was fixed at 120 min. Ten minutes after the start of CPB, total CPB was established. Thereafter, total CPB was performed for 100 min, followed by another 10 min of partial CPB. Lung biopsy specimens for light and electron microscopy were obtained from the upper lobe of the right lung before CPB, 109 min after the start of CPB (just before reperfusion) and 30 min after weaning (after reperfusion). A portion of the lung biopsy specimen was taken for a water content measurement at the same time intervals. For measuring the left and right atrial leukocyte counts, blood samples were taken before thoracotomy, 5 and 109 min after the start of CPB, and 30 and 120 min after weaning. C3a was measured before thoracotomy, 109 min after the start of CPB, and 30 and 120 min after weaning. Plasma malondialdehyde (MDA) was checked before thoracotomy, 109 min after the start of CPB and 30 min after weaning.

On both light and electron microscopic examination, mild to moderate acute lung change was observed after ischaemia-reperfusion. Interstitial oedema, leakage of erythrocytes into the alveolar space and endothelial cell swelling were the main findings. However, few neutrophils were seen. Water content of the lung showed a slight increase after the start of CPB, but there was no statistical significance. Neither significant differences in the transpulmonary gradients of leukocytes nor a significant complement activation, expressed by C3a levels, was observed. The MDA level did not display a significant change related to lung reperfusion despite an increase in MDA after the start of CPB.

These findings indicate that I-R injury during CPB may not be from complement-activation leukocyte sequestration, but from another source of oxygen free radicals related to CPB.
A recovery model of partial cardiopulmonary bypass in the rat
Authors: Fabre O , Zegdi R , Vincentelli A , Cambillaud M , Prat A , Carpentier A , Fabiani J N
Published: January 2013

This study was undertaken to develop a recovery model of cardiopulmonary bypass (CPB) in rats. Twenty male Wistar rats (475-550 g) were anaesthetized, mechanically ventilated and the femoral vessels cannulated. The extracorporeal circulation circuit comprised a roller pump, a venous reservoir and a modified Capiox 308 paediatric membrane oxygenator. Priming consisted of 20 ml of fresh homologous blood and 15 ml of colloid. Anticoagulation was achieved with heparin (500 IU/kg). Blood gas analysis, blood pressure monitoring and survival studies were performed in CPB ( n=10) and Sham ( n=10) rats.

Partial CPB was always easily established and was conducted at a flow rate of 100 ml/kg/min for 90 min. Blood gas analysis and blood pressure data did not differ between the two groups. All CPB rats survived and the 3-week follow-up period remained uneventful.

The rat model of CPB was easy to perform and was associated with excellent survival. This recovery model should allow us to study the pathophysiological processes underlying post-CPB multiple organ dysfunction.
Veno-venous perfusion-induced systemic hyperthermia: case report with perfusion considerations
Authors: Vertrees Roger A , Zwischenberger Joseph B , Woodson Lee C , Bedell Eric A , Deyo Donald J , Chernin Jill M
Published: January 2013

Cancer cells are more susceptible to destruction by heat than are their normal counterparts. However, optimization of this hyperthermic susceptibility for selective cancer cell kill has been difficult to define and technically difficult to achieve. A whole-body hyperthermic technique - veno-venous perfusion-induced systemic hyperthermia (VV-PISH) was designed in in vitro and in swine experiments to achieve selective hyperthermic cancer cell destruction. In this case report, VV-PISH is studied for its safety and therapeutic efficiency in a Food and Drug Administration (FDA) approved phase-I study, where hyperthermia is used to treat advanced (Stage III B or IV) lung cancer.

VV-PISH, utilizing the ThermoChem™ HT system in an extracorporeal circuit, was used to induce hyperthermia to 42.5°C sustained for 120 min. Cooling returned the body temperature to 37°C. After completion of the treatment, the patient was transferred to the intensive care unit on a ventilator, norepinephrine and diuretics. The patient remained somnolent for 36 h, developed pulmonary congestion requiring an additional 48 h before extubation, was transferred to the intermediate unit on day 4 and discharged in good condition on day 8. He did experience hyperthermia-related shrinkage of his lung cancer; however, he succumbed 270 days after this treatment from further progression of this disease.

Hyperthermia is not a benign therapy; management techniques have been developed that have ameliorated many of the problems associated with extremely high temperatures, but pathophysiology still exists. Using these techniques, VV-PISH can be safety implemented, albeit not without temporary sequelae and further hospitalization.
Oxygenator thrombosis: worst case after development of an abnormal pressure gradient - incidence and pathway
Authors: Wendel Hans P , Philipp Alois , Weber Norbert , Birnbaum Dietrich E , Ziemer Gerhard
Published: January 2013

The development of an abnormally high pressure gradient (APG) before the membrane oxygenator (MO) is a complication that occurs during some extracorporeal circulation (ECC) procedures. The present study deals with the incidence of an APG and discusses a probable causative pathway by comparing surface-coated and uncoated oxygenation systems. Five thousand six hundred and seventeen adult ECCs were carried out (2581 without and 3036 with surface coatings). The incidence of an APG, therefore, amounted to 0.03% in the group with coated systems and 4.3% in the uncoated group. In addition, an in vitro study demonstrated significantly reduced adhesion and activation of platelets and leucocytes when the surfaces of the MOs were coated with heparin or polypeptides. The advantages of coating surfaces of ECC devices possibly depend on the selective adsorption of particular plasma proteins. These will presumably form a biocompatible membrane on the surface, and minimize pathological deposit of fibrin, platelets and other blood cells, and, therefore, implicate the prevention of an oxygenator failure.
Is postoperative blood loss, loss of blood? A pilot study in cardiac surgical patients
Authors: Fransen Erik J , de Jong Dick S , Hermens Wim Th , Maessen Jos G
Published: January 2013

The effect of estimating the blood balance using changes in erythrocyte volumes (EVs) instead of the routinely used changes in haematocrit values was studied in 20 patients scheduled for cardiac surgery. We determined the mean haematocrit of the effluent from the postoperative thoracic drainage system at various time intervals. These data were used to more accurately calculate the blood balance. From 8 h after surgery onwards, the haematocrit in the thoracic effluent was less than 10%. Total loss of thoracic effluent until 24 h after removal of the aortic crossclamp (ACC) was 1735±803 ml. Calculated blood loss until 24 h after ACC was only 58% of the total thoracic effluent. Plasma volumes in these patients increased from preoperative values of 2505±499 ml at admission to the hospital to maximum levels of 4969±1027 ml at 12 h after ACC ( p<0.05). Blood volume rose to 159% of the preoperative value at 12 h after ACC, whereas the EV remained relatively stable, decreasing to 95% of the preoperative value at 4 h after ACC and increasing to 107% of the baseline value at 24 h after ACC. In the meantime, patient haematocrit decreased to 78% of the reference value at the time of induction of anaesthesia at 4 h after ACC and then increased to 84% at 24 h after ACC. Thus, the use of patient haematocrit considerably overestimates blood loss. The EV appears to be a more appropiate variable than haematocrit in monitoring the blood balance in cardiac surgical patients. Future studies should reveal whether the EV is practicable in daily clinical practice.
Centrifugation of salvaged pump blood is useful in reducing the amount of heparin re-infused into the patient
Authors: Ean Anne Hoo Ean , Yan Teng Siew , Chan Tanee , James Esther , Chi Ong Biauw
Published: January 2013

Conservation of blood and blood products are of major concern in clinical practice today. All blood salvaged from the extracorporeal circuit at the end of cardiopulmonary bypass should be returned to the patient. We propose the use of a simple and inexpensive centrifuge machine to reduce the amount of heparin from the residual pump blood re-infused to the patient. At the same time, the re-infused blood is concentrated. Sixteen patients were prospectively included in this study. The residual pump blood was collected from the bypass circuit and spun at 4000 rpm for 7 min on the Jouan GR 4.22 machine. The clear upper supernatant was discarded and the remaining concentrated red cells re-infused back to the patient. The heparin concentration and full blood counts of both layers were measured. We found that this method was useful in removing excessive heparin and avoiding the need for additional protamine.
Haemolysis due to active venous drainage during cardiopulmonary bypass: comparison of two different techniques
Authors: Cirri Silvia , Negri Luca , Babbini Marco , Latis Giorgio , Khlat Boutros , Tarelli Giuseppe , Panisi Paolo , Mazzaro Enzo , Bellisario Alessandro , Borghetti Bruna , Bordignon Fernanda , Ferrara Mario , Pavan Helga , Meco Massimo
Published: January 2013

To facilitate mini-access for cardiac surgery, two different methods of active venous drainage are used: vacuum assisted drainage and centrifugal pump aspiration on the venous line. The aim of this study was to compare the haemolysis produced using these two techniques.

From June to December 1999, 50 consecutive patients were operated on using a ministernotomy. All of these patients had valvular surgery for either valve repair or valve replacement (9 MVRepair, 11 MVR, 29 AVR, 1 AVR+MVR). They were randomized into two groups: Group A, 25 patients who underwent surgery where vacuum assisted drainage was used, and Group B, 25 patients where kinetic asssisted venous drainage with centrifugal pump venous aspiration was used. Patient characteristics of both groups were similar for age, gender, body weight, body surface area, height, cardiopulmonary bypass (CPB) time, aortic crossclamp time, priming volume, cardioplegia volume, haemoglobin concentration, haematocrit, serum creatinine, bilirubin, lactate dehydrogenase (LDH), serum glutamic oxaloacetic transaminase (sGOT), serum glutamic pyruvic transaminase (sGPT), aptoglobin, reticulocytes, and platelet count. We checked all these laboratory parameters preoperatively, at the end of CPB, and 2 and 24 h after operation. We also checked haemoglobinuria at these same time points. We assessed blood loss at 6, 12, and 24 h after the operation and calculated total postoperative bleeding. There was a tendency towards a greater increase in LDH, sGOT and sGPT in Group A more than in Group B, but these data did not reach statistical significance. Platelet count was always lower in Group A and aptoglobin increased in Group A more than in Group B. More patients in Group A had haemoglobinuria.

These findings indicate that haemolysis is increased more in patients treated with vacuum assisted drainage, when compared to the rise in haemolysis in those treated with centrifugal pump venous drainage. Total bleeding is also greater in Group A.
Systemic inflammation and cardiac surgery: an update
Authors: Asimakopoulos George
Published: January 2013

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with the development of a systemic inflammatory response that can often lead to dysfunction of major organs. The systemic inflammation can be assessed intra- and postoperatively by measuring concentrations of inflammatory mediators in plasma and tissues. These concentrations, however, do not always correlate with the degree of observed organ dysfunction.

Various strategies have been used to reduce inflammatory phenomena in patients undergoing CPB. Cardiac surgery without CPB has been performed increasingly with satisfactory results over the past few years. Attenuation of systemic inflammation and improved outcome in high risk patients are potential benefits of this technique.

The emergence and expanding performance of cardiac surgical procedures without the use of CPB has given us an excellent tool to investigate the relative importance of CPB as a cause of systemic inflammation.

Aprotinin is a protease inhibitor which is used in cardiac surgical patients for its haemostatic effects. Aprotinin has anti-inflammatory properties, the nature of which have not been completely clarified.

This article presents a summary of the published literature investigating inflammatory response and organ dysfunction in patients who have cardiac surgery without CPB. It also presents an overview of recent data on the anti-inflammatory action mechanisms of aprotinin.
Alternatives to unfractioned heparin for anticoagulation in cardiopulmonary bypass
Authors: von Segesser Ludwig K , Mueller X , Marty B , Horisberger J , Corno A
Published: January 2013

Despite the progress made in the development of cardiopulmonary bypass (CPB) equipment, systemic anticoagulation with unfractioned heparin and post-bypass neutralization with protamine are still used in most perfusion procedures. However, there are a number of situations where unfractioned heparin, protamine or both cannot be used for various reasons. Intolerance of protamine can be addressed with extracorporeal heparin removal devices, perfusion with (no) low systemic heparinization and, to some degree, by perfusion with alternative anticoagulants. Various alternative anticoagulation regimens have been used in cases of intolerance to unfractioned heparin, including extreme hemodilution, low molecular weight heparins, danaparoid, ancrod, r-hirudin, abciximab, tirofiban, argatoban and others.

In the presence of heparin-induced thrombocytopenia (HIT) and thrombosis, the use of r-hirudin appears to be an acceptable solution which has been well studied. The main issue with r-hirudin is the difficulty in monitoring its activity during CPB, despite the fact that ecarin coagulation time assessment is now available.

A more recent approach is based on selective blockage of platelet aggregation by means of monoclonal antibodies directed to GPIIb/IIIa receptors (abciximab) or the use of a GPIIb/IIIa inhibitor (tirofiban). An 80% blockage of the GPIIb/IIIa receptors and suppression of platelet aggregation to less than 20% allows the giving of unfractioned heparin and running CPB in a standard fashion despite HIT and thrombosis. Likewise, at the end of the procedure, unfractioned heparin is neutralized with protamine as usual and donor platelets are transfused if necessary. GPIIb/IIIa inhibitors are frequently used in interventional cardiology and, therefore, are available in most hospitals.
Heparin-coated cardiopulmonary bypass circuits: current status
Authors: Hsu Li-Chien
Published: January 2013

Heparin-coated circuits have been subjected to vigorous testing, both experimentally and clinically, for the past decade. When the functions of heparin are preserved on the surface, the heparinized surface plays multiple roles in attenuating the systemic inflammatory response. These include the ability to attenuate contact activation, coagulation activation, complement activation and, directly or indirectly, platelet and leukocyte activation. The heparinized surface also renders the cardiopulmonary bypass (CPB) circuits hydrophilic and protein resistant and augments lipoprotein binding. The multifunctional nature of the heparinized surface contributes to the overall biocompatibility of the surface. Clinically, heparin-coated circuits become most effective in reducing systemic inflammatory response and in improving morbidity, mortality, and other patient outcome related parameters when material-independent blood activation is controlled or minimized through a global biocompatibility strategy. Techniques involved in the global biocompatibility strategy are readily available and are being effectively and safely practiced at several centers. With the global biocompatibility strategy, outstanding and reproducible results have been routinely achieved with conventional CPB techniques. Alternative revascularization procedures should equal or surpass conventional CPB, using best clinically proven strategies with respect to patient outcome and long-term graft patency.
The use of leucocyte-depleting and conventional arterial line filters in cardiac surgery: a systematic review of clinical studies
Authors: Whitaker D C , Stygall J A , Newman S P , Harrison M JG
Published: January 2013

Although various forms of arterial line filter have been available for use during cardiopulmonary bypass (CPB) for 30 years, their use is not universal. The aim of this review was to seek evidence of the clinical benefit of using conventional or leucocyte-depleting arterial line filters during bypass. A literature search revealed 28 relevant clinical studies. Despite the wide variety of patient populations, types of filter and outcome measures utilized in studies, a few conclusions are possible. Whereas conventional filtration has the definite effect of reducing neuropsychological deficit post-CPB, the results of studies using the leucocyte-depleting filter are less clear cut. Leucocyte-depleting filters have potential for reducing inflammatory mediated heart and lung injury, however it is recommended that any additional benefit of leucocyte-depleting filters over conventional filters should be further tested by randomized controlled trials of sufficient size.
MAST system: a new condensed cardiopulmonary bypass circuit for adult cardiac surgery
Authors: McCusker K , Vijay V , DeBois W , Helm R , Sisto D
Published: January 2013

There have been many refinements in cardiopulmonary bypass (CPB) techniques over the past few decades specific to design, materials and function. Despite these improvements, use of the standard length circuit tubing and pump oxygenator alter cellular, biochemical and rheological properties by inducing a systemic inflammatory response, persisting well into the early postoperative phase.

We have designed a new condensed CPB circuit, the MAST system, where the oxygenator and the pumps are brought closer to the operating table (within 30 inches) with the help of a series of telescopic swivel steel poles to which they are attached. The control console is retained at the usual remote location of 2 ft behind the MAST system. This configuration accomplishes a decrease in tubing length, priming volume and blood circulatory time within the extracorporeal circuit. Early experience of a hundred consecutive cases utilizing the MAST CPB system is presented along with a comparative analysis of prime volume, hemodilution and transfusion parameters of MAST system vs the low prime system, which is another newly developed CPB circuit utilizing a pediatric oxygenator to reduce prime volume and hemodilution.
A mobile system for the treatment of accidental hypothermia with extracorporeal circulation
Authors: Kjærgaard Benedict , Tølbøll Poul , Lyduch Steffen , Trautner Sven
Published: January 2013

When deep accidental hypothermia causes circulatory failure, the best chance of survival is treatment with extracorporeal circulation (ECC) and warming of the blood. This may be difficult to achieve if the patient is first admitted to a hospital without a department of thoracic surgery. Our aim was to test a lightweight mobile system for ECC. The equipment could be transported almost anywhere, making it possible to start ECC on the spot and during transfer. The system was tested on six hypothermic pigs, two of the pigs at the institute laboratory, two of the pigs in a normal ambulance, and two of the pigs in an air force rescue helicopter. All of the pigs were transported back to the institute for warming to normal temperature. After warming, and the ECC stopped, all the pigs were in sinus rhythm and had an obviously satisfactory circulation. It is possible to bring a lightweight ECC system to the unstable patient. Treatment is possible in any hospital, ambulance or helicopter.
Use of desmopressin and erythropoietin in an anaemic Jehovah’s Witness patient with severely impaired coagulation capacity undergoing stentless aortic valve replacement
Authors: Beholz Sven , Liu Jianshi , Thoelke Ralf , Spiess C , Konertz Wolfgang
Published: January 2013

Cardiac surgery in Jehovah’s Witness patients remains a challenge in the presence of concomitant congenital or acquired coagulation disorders and anaemia. We report a case of a 66-year-old female Jehovah’s Witness suffering from severe calcified aortic valve stenosis requiring aortic valve replacement. The anaemic patient suffered from concomitant platelet dysfunction and deficiency of factors V and VII due to gammopathy of immunoglobulin G. The patient was preoperatively treated with recombinant erythropoietin in combination with folic acid and iron, which resulted in an increase of the haematocrit from 0.335 to 0.416 after 22 days of treatment. Haemostasis was improved by high dose aprotinin and additional desmopressin, which could be demonstrated to be effective by a preoperative test. The patients intra- and postoperative course was uneventful, her total chest tube loss was 130 ml, and she was able to be discharged without the need of any blood transfusions. The beneficial properties of erythropoietin and desmopressin in Jehovah’s Witness patients are discussed.
Global and regional cerebral blood flow in neonatal piglets undergoing pulsatile cardiopulmonary bypass with continuous perfusion at 25°C and circulatory arrest at 18°C
Authors: Ündar Akif , Masai Takafumi , Yang Shuang-Qiang , Eichstaedt Harald C , McGarry Mary Claire , Vaughn William K , Goddard-Finegold Jan , Fraser Charles D
Published: January 2013

To investigate the influence of hypothermic cardiopulmonary bypass (HCPB) at 25°C and circulatory arrest at 18°C on the global and regional cerebral blood flow (CBF) during pulsatile perfusion, we performed the following studies in a neonatal piglet model.

Using a pediatric physiologic pulsatile pump, we subjected six piglets to deep hypothermic circulatory arrest (DHCA) and six other piglets to HCPB. The DHCA group underwent hypothermia for 25 min, DHCA for 60min, cold reperfusion for 10 min, and rewarming for 40 min. The HCPB group underwent 15 min of cooling, followed by 60 min of HCPB, 10min of cold reperfusion, and 30 min of rewarming. The following variables remained constant in both groups: pump flow (150 ml/kg/min), pump rate (150 bpm), and stroke volume (1 ml/kg). During the 60-min aortic crossclamp period, the temperature was kept at 18°C for DHCA and at 25°C for HCPB. The global and regional CBF (ml/100g/min) was assessed with radiolabeled microspheres.

The CBF was 48% lower during deep hypothermia at 18°C (before DHCA) than during hypothermia at 25°C (55.2± 14.3 ml/100 g/min vs 106.4±19.7 ml/100 g/min; p < 0.05). After rewarming, the global CBF was 45% lower in the DHCA group than in the HCPB group 48.3±18.1 ml/100 g/min vs (87±35.9 ml/100 g/min; p<0.05). Fifteen minutes after the termination of CPB, the global CBF was only 25% lower in the DHCA group than in the HCPB group (42.2±20.7 ml/100 g/min vs 56.4±25.8 ml/100 g/min; p=NS). In the right and left hemispheres, cerebellum, basal ganglia, and brain stem, blood flow resembled the global CBF.

In conclusion, both HCPB and DHCA significantly decrease the regional and global CBF during CPB. Unlike HCPB, DHCA has a continued negative impact on the CBF after rewarming. However, 15 min after the end of CPB, there are no significant intergroup differences in the CBF.
Haemolysis during cardiopulmonary bypass: how to reduce the free haemoglobin by managing the suctioned blood separately
Authors: Pierangeli A , Masieri V , Bruzzi F , De Toni E , Grillone G , Boni P , Delnevo A
Published: January 2013

During cardiopulmonary bypass (CPB) the collection of the patient’s blood from the operating area is of fundamental importance. This blood is collected in the cardiotomy reservoir using field suckers and can be managed in different ways. It can be filtered in the cardiotomy reservoir and redirected to the venous reservoir, then oxygenated and returned to the patient, or it can be managed separately: collected in the cardiotomy reservoir, treated at the end of the operation and only after this, returned to the patient. The aim of this study is to determine in vivo the effect of a separate management of the suction blood from the operative field, using the Avant D903 oxygenator (Dideco, Mirandola, Italy). Twenty-one patients undergoing coronary artery bypass graft surgery with CPB were selected and put into two groups at random. In the control group ( n 10) the suction blood in the cardiotomy reservoir was filtered and immediately redirected into the venous reservoir, oxygenated and returned to the patient. In the study group ( n 11) the suctioned blood was collected in the D903 Avant’s (Dideco) cardiotomy reservoir and returned to the patient only after having been washed at the end of the operation, using a Compact Advanced (Dideco), as required. Clinical data demonstrated that while in the study group it was possible to keep the free plasma haemoglobin (FPH) concentrations the same as at the beginning, in the control group there was a significant increase in FPH from 5.0 3.5 mg/dl (baseline) to 37 16.7 mg/dl (120 min after CPB).
Clinical experience with the Diametrics IRMA (Immediate Response Mobile Analysis) blood analysis system
Authors: Hedlund Kelly D , Oen Scott , LaFauce Leo , Sanford D Michael
Published: January 2013

The Immediate Response Mobile Analysis (IRMA) blood analysis system (Diametrics Medical Incorporated, St Paul, MN, USA) is a new point-of-care testing device that uses technology similar to the Gem Premier (Mallinckrodt Sensor Systems Incorporated, Ann Arbor, MI, USA), which are ion-specific electrodes. We compared these two analysers using both patient blood samples ( n = 50) and aqueous quality control solutions ( n = 45). Linear regression (Pearson product-moment correlation coefficient) was performed to quantify the strength of the association between results. In addition, bias and precision were determined in accordance with the method described by Bland and Altman.1 The results demonstrated excellent correlation between the IRMA and the Gem Premier, and bias and precision were acceptable for both patient and quality control samples. Reproducibility of results was also assessed using one level of aqueous quality control solution ( n = 50). The IRMA demonstrated very little variance in parameter readings over a five-day study period.
Extracorporeal circulation for port-access cardiac surgery
Authors: Toomasian John M , Peters William S , Siegel Lawrence C , Stevens John H
Published: January 2013

Minimally invasive techniques for cardiac surgery are a new approach in performing some cardiac operations. Minimally invasive surgery may minimize patient discomfort, length of stay in the hospital and postoperative rehabilitation. These procedures utilize a small thoracotomy for direct visualization of the heart. However, without the use of cardiopulmonary bypass, this approach is limited to some epicardial procedures such as coronary bypass grafting, where the heart rate is pharmacologically reduced.

Port-access cardiac surgery is a new approach which provides all the benefits of minimally invasive surgery without sacrificing the advantages of cardiopulmonary bypass and myocardial preservation. Port-access cardiac surgery uses an anterior mediastinotomy and thoracic ports in conjunction with a specially designed set of endovascular catheters. These catheters provide a mode to arrest, preserve and vent the heart through an endoaortic occlusion balloon positioned in the ascending aorta, A pulmonary artery vent and coronary sinus cardioplegia catheter can also be used. These endovascular catheters, integrated with a modified heart-lung machine, provide complete cardiopulmonary support through extrathoracic cannulae inserted in a femoral artery and vein. Maintenance and monitoring of this endovascular cardiopulmonary bypass system requires the use of a kinetic pump in the venous drainage line to augment return to the heart-lung machine. Special guidelines and management parameters exist to optimize bypass with this catheter system. Using this system, port-access, minimally invasive surgery can be applied to a wider range of both epicardial and intracardiac procedures.