Heparin-coated Cardiopulmonary Bypass Research Articles

New hemostatic technique with combined use of Hydrofit® and Surgicel®: an in vitro and in vivo study.

We developed an effective hemostatic technique using Hydrofit® and Surgicel® simultaneously. The aim of this study was to demonstrate the hemostatic efficacy of the Hydrofit® and Surgicel® combination technique through an in vitro experiment and to elucidate mid-term consequences of the combined components through an in vivo experiment. For the in vitro experiment, a closed circuit using a heparin-coated cardiopulmonary bypass circuit and a prosthetic graft was created. The amount of bleeding from the prosthetic graft was measured, and the following three hemostatic methods were applied: only gauze compression in control group, Hydrofit® application in Hydrofit group, Surgicel® spread Hydrofit® application in Hydrofit and Surgicel (HS) group, respectively. In the in vivo experiment, Hydrofit® and/or Surgicel® were implanted under skin on the back of rats (n = 10) at 4 points. In the control group, only an incision was made; in the Hydrofit, Surgicel, and HS groups, Hydrofit® and/or Surgicel® was implanted. One and three months later, each of the five rats were killed and in each section histopathologic examination was carried out. In the in vitro experiment, the amount of bleeding was 7.84 ± 1.08, 2.26 ± 1.02, and 0.87 ± 0.38ml in the control, Hydrofit, and HS groups, respectively. The amount of bleeding in the HS group was more suppressed than in the Hydrofit group (p = 0.012). In the in vivo experiment, the maximal depth diameter of each remaining hemostatic sealant was measured. After 3months, the diameter was 0, 2289.0 ± 768.2, 3850.3 ± 935.8μm in Surgicel, Hydrofit and HS groups, respectively. The diameter was significantly increased in the HS group compared with the Surgicel and Hydrofit groups (p < 0.001, respectively,). In conclusion, the combination of Hydrofit® and Surgicel® was effective in achieving hemostasis. The remnants of Hydrofit® and Surgicel® were present for a long time in the tissues which could compress the surrounding tissue.

Differences of early immunological responses in on-pump versus off-pump cardiac surgery.

Cardiopulmonary bypass surgery is accompanied by an inflammatory response and pulmonary dysfunction that renders patients vulnerable to postoperative complications. The majority of studies investigating the inflammatory response in cardiopulmonary bypass focus on cytokine measurements. This study investigated the early response of peripheral blood cell types and early changes in lung tissue in on-pump versus off-pump cardiopulmonary bypass surgery. Landrace pigs were assigned to the following groups (n = 6 per group): 1. off-pump cardiopulmonary bypass, 2. conventional cardiopulmonary bypass, 3. heparin-coated cardiopulmonary bypass, 4. surface-reduced cardiopulmonary bypass, and 5. surface-reduced cardiopulmonary bypass plus lung perfusion. Surgery was performed under mild hyperthermia (32°C), with 90-minute ischemia and 180-minute reperfusion. Histological and flow cytometric analyses were performed. Lung water content increased during reperfusion in heparin-coated (84.63 ± 2.99%) compared to conventional cardiopulmonary bypass (76.33 ± 4.56%, p = 0.04). Alveolar septal thickness increased during ischemia at heparin-coated (p < 0.01) and surface-reduced cardiopulmonary bypass plus lung perfusion (p = 0.05). Tumor necrosis factor expression increased significantly (p < 0.01) in peribronchial, perivascular, and peripheral lung areas in all on-pump groups, but not in off-pump cardiopulmonary bypass. The usage of heparin-coated cardiopulmonary bypass led to increased percentages of CD3+CD4+ (p = 0.03) and CD3+CD8+ (p = 0.01) T cells compared to an uncoated device. Natural killer and mature B lymphocytes decreased at conventional and surface-reduced cardiopulmonary bypass plus lung perfusion. Activated granulocytes and macrophages increased at conventional cardiopulmonary bypass and heparin-coated cardiopulmonary bypass. Off-pump cardiopulmonary bypass induces less immunological response and lung injury than on-pump surgery. The reduction of cardiopulmonary bypass surface reduces the inflammatory immune response induced by cardiopulmonary bypass. Lung perfusion of surface-reduced cardiopulmonary bypass diminished the extravasation caused by surface reduction of the cardiopulmonary bypass.

Poly-2-methoxyethylacrylate-coated cardiopulmonary bypass circuit can reduce transfusion of platelet products compared to heparin-coated circuit during aortic arch surgery.

Several coating techniques for extracorporeal circulation have been developed to reduce the systemic inflammatory response during cardiopulmonary bypass (CPB). We compared the clinical effectiveness and biocompatibility of poly-2-methoxyethylacrylate (PMEA)- and heparin-coated CPB circuits in total aortic arch replacement (TAR) with the prolonged use of the bypass technique. Twenty patients who underwent elective TAR were divided randomly into two equal groups: group P (n=10) to use PMEA-coated circuits and group H (n=10) to use heparin-coated circuits. Clinical outcomes, hematological variables, and acute phase inflammatory response were analyzed perioperatively. Demographic, CPB, and clinical outcome data were similar for both groups. Hemoglobin and platelet count showed similar time-course curves. However, the amount of platelet products transfused intraoperatively was significantly larger in group H (group P 26.0±7.0units; group H 33.0±6.7units, p=0.04). Total protein, and albumin levels were significantly higher in group P during and after the operation (total protein, p=0.04; albumin, p=0.02). The use of PMEA-coated circuit is associated with retainment of perioperative plasma proteins levels and may help to reduce transfusion of platelet products in TAR in comparison with the heparin-coated circuit.

Heparin-coated cardiopulmonary bypass circuits selectively deplete the pattern recognition molecule ficolin-2 of the lectin complement pathway in vivo.

The complement system can be activated via the lectin pathway by the recognition molecules mannose-binding lectin (MBL) and the ficolins. Ficolin-2 exhibits binding against a broad range of ligands, including biomaterials in vitro, and low ficolin-2 levels are associated with increased risk of infections. Thus, we investigated the biocompatibility of the recognition molecules of the lectin pathway in two different types of cardiopulmonary bypass circuits. Bloods were drawn at five time-points before, during and postoperatively from 30 patients undergoing elective cardiac surgery. Patients were randomized into two groups using different coatings of cardiopulmonary bypass circuits, Phisio® (phosphorylcholine polymer coating) and Bioline® (albumin-heparin coating). Concentrations of MBL, ficolin-1, -2 and -3 and soluble C3a and terminal complement complex (TCC) in plasma samples were measured. Ficolin-3-mediated complement activation potential was evaluated with C4, C3 and TCC as output. There was no significant difference between the two circuit materials regarding MBL, ficolin-1 and -3. In the Bioline® group the ficolin-2 levels decreased significantly after initiation of surgery (P < 0.0001) and remained reduced throughout the sampling period. This was not seen for Phisio®-coated circuits. Ficolin-3-mediated complement activation potential was reduced significantly in both groups after start of operation (P < 0.0001), whereas soluble C3a and TCC in the samples were increased (P < 0.0001). Ficolin-2 was depleted from plasma during cardiac surgery when using heparin-coated bypass circuits and did not reach baseline level 24 h postoperation. These findings may have implications for the postoperative susceptibility to infections in patients undergoing extracorporeal circulation procedures.

The effect of a cardiopulmonary bypass system with biocompatible coating on fibrinogen levels determined by the TEG – functional fibrinogen method: preliminary results

When cardiopulmonary bypass (CPB) is used, the blood comes into contact with foreign surfaces. To diminish this impact, various types of biocompatibly coated surfaces have been developed. The study assessed the effects of heparin-coated CPB systems on the level and function of fibrinogen as measured by thromboelastography (TEG), as compared with non-coated systems. No statistically significant differences between both groups were revealed by comparing paired data. In our study, heparin-coated CPB circuits had no significant effect on either fibrinogen level or its function.

Increased cerebral blood flow velocities assessed by transcranial Doppler examination is associated with complement activation after cardiopulmonary bypass

The role of complement activation on the cerebral vasculature after cardiopulmonary bypass (CPB) is unclear. The goal of the study was to assess whether heparin-coated CPB reduces complement activation, and influences cerebral blood flow velocities (CBFV). Twenty-four patients undergoing coronary surgery were randomly allocated to non-coated (NC-group) or heparin-coated (HC-group) CPB. Complement activation was assessed by measuring sC5b-9. Transcranial Doppler (TCD) was performed on middle cerebral arteries before and after CPB. Systolic (SV), diastolic (DV) and mean (MV) CBFV were measured. Significant increase of sC5b-9 (p=0.003) was observed in the NC-group and CBFV increased after CPB (SV by 27%, p=0.05; DV by 40%, p=0.06; MV by 33%, p=0.04) whereas no changes were detected in the HC-group. TCD values were higher in the NC-group than in the HC-group (SV, p=0.04; DV, p=0.03; MV, p=0.03) although cardiac index, systemic vascular resistance, haematocrit and pCO(2) were similar. Postoperative SV, DV and MV were significantly correlated with sC5b-9 (r=0.583, p=0.009; r=0.581, p=0.009; r=0.598, p=0.007, respectively). Increased CBFV after CPB are correlated to the level of complement activation and may be controlled by heparin-coated circuits.

Impact of Off-Pump Coronary Artery Bypass Surgery on Systemic Inflammation: Current Best Available Evidence

The systemic inflammatory response after coronary artery bypass grafting using cardiopulmonary bypass (CPB) contributes substantially to postoperative organ dysfunction and coagulation disorders. Important features of this inflammatory reaction include the activation of complement and leukocytes, the release of proinflammatory cytokines, alterations in the metabolism of nitric oxide, and an increase in the production of oxygen-free radicals, which in some cases may lead to oxidant stress injury. Several strategies including the use of steroids, use of aprotinin, heparin-coated CPB circuits, and hemofiltration have been reported to reduce the inflammatory reaction induced by CPB and its consequences. A more radical and effective way of counteracting the effects of the inflammatory reaction and oxidative stress may be the omission of CPB itself. The development and application of off-pump coronary artery bypass (OPCAB) technology has largely been driven by this theme of avoiding systemic inflammatory reaction to decrease the incidence and/or severity of adverse outcomes. This review article discusses the influence of cardiopulmonary bypass on systemic inflammation and attempts to evaluate the current best available evidence on the impact of OPCAB on systemic inflammation.

Biocompatibility of Heparin-Coated Cardiopulmonary Bypass Circuits in Coronary Patients With Left Ventricular Dysfunction Is Superior to PMEA-Coated Circuits

Several coating techniques for extracorporeal circulation have been developed to diminish the systemic inflammatory response during cardiopulmonary bypass (CPB). The aim of this study was to evaluate the clinical effectiveness and biocompatibility of heparin-coated and poly-2-methoxyethylacrylate (PMEA)-coated CPB circuits on coronary patients with left ventricular systolic dysfunction. Thirty-six patients who underwent elective coronary artery bypass grafting were divided into two equal groups: group H (n = 18), heparin-coated; group P (n = 18), PMEA coated. Clinical outcomes, hematologic variables, cardiac enzymes, malondialdehyde (MDA), and acute phase inflammatory response (including myeloperoxidase (MPO), catalase, hsCRP, and IL-8) were analyzed perioperatively. Demographic, CPB, and clinical outcome data were similar for both groups. Plasma fibrinogen, total protein, albumin, and platelet count decreased, neutrophil count, MDA, IL-8, MPO, and catalase levels increased during CPB. During CPB, MPO and catalase values were significantly higher in group P (p = 0.02 and p = 0.01) and postoperative MDA concentration was lower in group H (p = 0.03). Platelet counts were better preserved in group H during and after CPB but neutrophil count and IL-8 level did not differ between the groups. Postoperative total protein, albumin, and fibrinogen levels were higher in group H (p < 0.05). The postoperative first day levels of troponin-I, CK-MB, and CRP increased in both groups without any significant differences between the groups. Heparin-coated circuit provided better suppression of perioperative inflammatory markers and exhibited more favorable effects on hematologic variables than PMEA-coated circuit.

Heparin-Bonded Cardiopulmonary Bypass Circuits Reduce the Rate of Red Blood Cell Transfusion During Elective Coronary Artery Bypass Surgery

This study compared the transfusion rates of patients treated with heparin-bonded circuits with the transfusion rates of patients treated with standard bypass circuits with and without -aminocaproic acid (EACA). Prospective double-blind (drugs), open trial (cardiopulmonary bypass circuits). University medical center. Seventy-one patients undergoing elective am admission coronary artery bypass graft surgery. Patients were randomized to receive either heparin-coated cardiopulmonary bypass circuits (HBCPB), nonheparin-coated cardiopulmonary bypass circuits and EACA (EACPB), or nonheparin-coated bypass circuits and placebo (control). Patients were transfused if their hematocrit was <18% while on cardiopulmonary bypass or <25% at any time after the cardiopulmonary bypass period. The rate and number of transfused packed red blood cells (pRBCs), platelets, fresh frozen plasma, and cryoprecipitate were measured. A Fisher exact test showed that the transfusion rate was as follows: the HBCPB group (5.0%), the EACPB group (18.2%), and the control group (36%), (p = 0.034). The heparin-bonded cardiopulmonary bypass-treated patients in this study received fewer pRBCs than did the control group. A nonsignificant reduction in the pRBC transfusion rate was found between those with heparin-bonded bypass circuits and those with standard circuits who received epsilon-aminocaproic acid.

Gene Expression Changes in Leukocytes During Cardiopulmonary Bypass Are Dependent on Circuit Coating

Cardiopulmonary bypass (CPB) results in a systemic inflammatory response. Leukocytes play a crucial role in inflammatory reactions. Their gene expression profile in the context of CPB is unknown. In a prospective, randomized, and double-blind clinical trial, 12 male patients underwent elective coronary artery bypass grafting with either heparin-coated (group H) or protein-coated (group P) CPB circuits. Oligonucleotide microarray analyses of 22,283 genes were performed on circulating leukocytes, collected immediately before surgery and 6 hours after CPB. Microarray results were validated with real-time polymerase chain reaction. All patients had uneventful surgery, and no significant differences between groups were observed during the clinical course. Multiple statistical analyses with different methods were performed. Compared with preoperative expression at a threshold value of P<0.01, postoperative expression revealed 814 upregulated and 1187 downregulated genes in group H compared with 99 upregulated and 231 downregulated in group P (P<0.001). Fifty genes exhibited a >4-fold increase and 27 exhibited a >4-fold decrease in group H, whereas only 7 genes exhibited upregulation and 7 revealed downregulation in group P. Microarray-pathway-profile-finder analyses determined 1405 upregulated and 1454 downregulated pathways in group H compared with 552 upregulated and 818 downregulated pathways in group P (P<0.01). Pathways related to inflammatory response exhibited highest z scores in group H, reflecting cellular inflammatory activation. Heparin coating resulted in a more profound alteration in leukocyte gene expression when compared with protein coating. Microarray analyses present an innovative approach for the evaluation and understanding of inflammatory reactions associated with CPB.

Intraoperative Interventions: American College of Chest Physicians Guidelines for the Prevention and Management of Postoperative Atrial Fibrillation After Cardiac Surgery

A comprehensive evidence review was conducted of the medical literature regarding the relationship between intraoperative interventions and the incidence of postoperative atrial arrhythmias, including, most commonly, atrial fibrillation (AF). Fifteen randomized, controlled studies and one large-scale concurrent cohort study were identified that reported on the following issues: systemic temperature during surgery (one report); "beating heart" surgery vs conventional bypass surgery (three reports); type of myocardial protection (five reports); the use of adjunctive posterior pericardiotomy (one report); the use of thoracic epidural anesthesia (TEA) [two reports]; the use of glucose-insulin-potassium (GIK) solutions (two reports); and the use of heparin-coated circuits for cardiopulmonary bypass (CPB) [two reports]. Based on a systematic review of the reported data and an analysis of the quality of the reported data, we recommend the following: (1) that mild hypothermia, rather than moderate hypothermia, may be effective in reducing the frequency of postoperative AF; (2) the use of posterior pericardiotomy may be a useful adjunct to reduce the frequency of postoperative AF; and (3) the use of heparin-coated CPB circuits is associated with less postoperative AF. Because of conflicting or inadequate data, we cannot conclude that the frequency of postoperative AF is affected by (1) the use of beating-heart techniques, (2) the type of myocardial protection strategy used, (3) the use of TEA, or (4) the use of GIK solutions perioperatively.

The Impact of Heparin-Coated Cardiopulmonary Bypass Circuits on Pulmonary Function and the Release of Inflammatory Mediators

The Impact of Heparin-Coated Cardiopulmonary Bypass Circuits on Pulmonary Function and the Release of Inflammatory Mediators

Brain Injury and Neuropsychological Outcome After Coronary Artery Surgery Are Affected by Complement Activation

The impact of the postoperative inflammatory response on the central nervous system after cardiac surgery is uncertain. The goal of the study was to evaluate the role of complement activation on cellular brain injury in patients undergoing coronary artery bypass grafting. In addition, neuropsychological functioning was assessed. We randomly assigned 30 patients to undergo surgery using either standard noncoated or heparin-coated extracorporeal circuits. Closed cardiopulmonary bypass and controlled suctions of pericardial shed blood were standardized in both groups. Complement activation and cellular brain injury were assessed by measuring sC5b-9 and protein s100beta. Neuropsychometric tests were performed at least 2 weeks before operation and at discharge. They served to calculate z scores of cognitive domains and changes in neuropsychological functioning. Peak value of sC5b-9 at the end of cardiopulmonary bypass in the noncoated group was significantly higher than in the heparin-coated group (p = 0.005). Changes in the heparin-coated group were not significant. Glial injury started after initiation of surgery and peaked at the end of cardiopulmonary bypass with significantly higher concentration of s100beta in the noncoated than in the heparin-coated group (p = 0.008). Values of s100beta and of sC5b-9 were significantly correlated (p = 0.03). Although no statistically significant between group difference was detected, z scores of attention and flexibility or executive functions were lowered postoperatively within the noncoated group (p = 0.033 and p = 0.028), whereas z scores were unchanged within the heparin-coated group. Inhibition of complement activation by heparin-coated cardiopulmonary bypass reduced brain cell injury and was associated with preserved neuropsychological functioning after coronary artery bypass grafting.

Evaluation of a new condensed extra-corporeal circuit for cardiac surgery: a prospective randomized clinical pilot study

This prospective randomized clinical pilot study was conducted to evaluate a recently introduced reduced volume CPB system that is coated with the biopassive Xcoating. Twenty-two patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB), either with a fully heparin-coated CPB circuit (control, n=11) or with an Xcoating coated condensed extra-corporeal circuit (CondECC, n=11), were included. We examined activation of the complement system (C3bc and C4bc), activation of neutrophils (BPI), the acute phase response (interleukin (IL)-6, and acute phase proteins (LBP, AGP, and CRP)), myocardial tissue injury (troponin T), hemolysis (free hemoglobin (FHb)), and clinical outcome parameters. Preoperative risk profiles were identical for both patient groups. All patients went through the procedure without major complications and were discharged from the hospital. FHb and BPI levels at the end of pump support (p < 0.01) and at 15 min after the administration of protamine (p < 0.05) were significantly higher in the control group. In addition, FHb levels were still significantly elevated upon arrival on the cardiothoracic intensive care unit (CICU) in the control group (p < 0.05). C3bc and C4bc, acute phase proteins, IL-6, and troponin T concentrations, and clinical outcome variables were identical in both patient groups. In conclusion, the evaluated condensed extracorporeal circuit is a flexible and multifunctional CPB sytem that offers safe procedures. Furthermore, the results indicate improved biocompatibility of this option for extracorporeal circulation.

Invited commentary

The complement system is often most noted for its ability to lyse certain microorganisms. In the intact organism, however, its role in initiating inflammation is probably of greater importance. Being able to react within minutes, the complement system helps alert the other defense systems to threats of damage, whether caused by microorganisms or physiochemical factors–or the artificial surfaces of an extracorporeal circuit. Its central role in the inflammatory response after cardiopulmonary bypass (CPB) has been acknowledged since the early 1980s. Consequently, when heparin-coated CPB equipment became commercially available and was shown to dramatically reduce complement activation, there were great hopes that the risks of postoperative complications would also drop substantially. Why did this to a large extent turn out not to be the case?

Heparin-coated circuits and reduced systemic anticoagulation applied to 2500 consecutive first-time coronary artery bypass grafting procedures

Background In contrast to the widespread popularity of off-pump techniques for coronary artery bypass grafting, our institution has chosen a different strategy, emphasizing improvements in the technology for extracorporeal circulation, as well as simplifying surgical and clinical management. The clinical short-term results of this approach were analyzed. Methods The on-pump strategy includes routine use of heparin-coated circuits combined with low systemic heparinization (activated coagulation time of more than 250 seconds), intention of total revascularization within limited ischemic times and pump times, minimal use of blood transfusions, early extubation, and rapid postoperative recovery. The data from the first 2,500 consecutive first-time coronary artery bypass grafting patients (January 1998 to February 2002) treated with this protocol were retrospectively analyzed. Results There were 487 female (median age 68 years) and 2013 male (median age 64 years) patients. A median of four (one to nine) (mean 4.5 ± 1.2) distal anastomoses were created, and the median aortic cross-clamp time and pump time were 34 and 54 minutes, respectively. At least one internal mammary artery was used in 99.7% of the patients. Blood or bank blood products were given to 118 patients (4.7%). Median extubation time was 1.5 hours. The stroke rate was 0.8%, transient neurologic deficits occurred in 0.6% of the patients, and the incidence of perioperative myocardial infarction was 1.1%. By the fifth day, 91% of the patients were ready for discharge. Seven patients (0.28%) died during their hospital stay. Conclusions Coronary artery bypass grafting with heparin-coated cardiopulmonary bypass circuits and reduced systemic anticoagulation resulted in excellent clinical results, with minimal blood transfusions and rapid postoperative mobilization. The high number of grafted coronary arteries indicates complete revascularization in most patients, which is known to be a significant predictor of long-term event-free survival.

A combined approach for improving cardiopulmonary bypass in coronary artery surgery: a pilot study.

This is a pilot study carried out to assess the feasibility and the clinical impact of a combined approach of cardiopulmonary bypass (CPB) with reduced anti-coagulation. We used a retrospective, non-randomized analysis of 45 consecutive patients undergoing coronary artery bypass using standard CPB with full anticoagulation (activated clotting time, ACT, > 450 s) (Group 1; n = 23) or closed, heparin-coated CPB with low anticoagulation (ACT>250 s), precise heparin and protamine titration, controlled suction, and retrograde autologous prime (Group 2; n = 22). Patients were similar except for a higher incidence of three-vessel disease in Group 2 (77.3% versus 47.8%; p < 0.03). Heparin was reduced by 41% in Group 2 and protamine by 56% (p < 0.0001). Total postoperative blood loss was similar between Groups 1 and 2 (429 +/- 149 versus 435+/-168 ml, respectively). However, the operative hematocrit decrease was lower in Group 2 (-1.6 +/- 7.5% versus -6.9 +/- 4.8%; p = 0.007), although hemodilution was similar, as reflected by the blood protein level. The need for postoperative inotropic support was less frequent in Group 2 (36.4% versus 65.2%; p = 0.05). Within the subgroup of patients weaned from CPB without requiring inotropic support (n = 35), the cardiac index dropped significantly in Group 1 (p = 0.003) 6 h after the start of CPB, whereas it remained stable in Group 2 (p = 0.92). Using multivariate analyses, Group 2 was found to be more protected than Group 1 against myocardial cellular injury (p = 0.046) and need for postoperative inotropic support (p = 0.014). The pejorative postoperative outcome in coronary artery surgery was attenuated through a combined approach aimed at improving CPB.

Surgical results of low-dose systemic heparinization (1 mg/kg, 100 IU/kg) in thoracic aortic operation combined with a heparin-coated cardiopulmonary bypass circuit: Is low-dose heparinization safe during deep hypothermic circulatory arrest?

Heparin-coated cardiopulmonary bypass circuits allow a reduction in the use of systemic heparin administered during cardiopulmonary bypass. This study was carried out to investigate safety during deep hypothermic circulatory arrest in this low-dose heparin group during thoracic aortic operation. Heparin-coated cardiopulmonary bypass circuits were used in 30 adult patients who underwent thoracic aortic operations that required deep hypothermic circulatory arrest. The patients were divided into two groups. Six patients received 300 IU/kg of heparin, and the remaining 24 patients received 100 IU/kg. Clinical outcomes (mortality, incidence of stroke, and transfusion volumes during operation) were examined. All devices remained functional throughout the procedures, and no systemic emboli were detected. Two deaths occurred in the high-dose heparin group, but no deaths occurred in the low-dose heparin group (P = 0.03). The percentage of patients requiring transfusion was similar in the two groups (66.7% vs. 70.8%), but the median exposure to allogenic blood products was greater in the high-dose heparin group than in the low-dose heparin group (9.8 ± 9.5 units vs. 5.5 ± 5.2 units; P = 0.09). Reduced systemic heparinization, combined with hepar-in-coated cardiopulmonary bypass circuits during deep hypothermic circulatory arrest, can be performed with acceptably low early mortality in thoracic aortic operations. Patients are not at increased risk for stroke.

Heparin-coated cardiopulmonary bypass circuits: current status.

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.

Low-molecular-weight heparin-coated cardiopulmonary bypass: coagulatory and clinical findings

The aim of the study was to evaluate clinical and coagulatory effects of low-molecular-weight heparin-coated extracorporeal circulation (ECC) in coronary artery bypass grafting (CABG).