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Extracorporeal Circulation (extracorporeal + circulation)

Distribution by Scientific Domains

Medical Sciences	95%

Selected Abstracts

Hydrodynamics of Aortic Cannulae During Extracorporeal Circulation in a Mock Aortic Arch Aneurysm Model

ARTIFICIAL ORGANS, Issue 2 2010
Masahito Minakawa
Abstract This study was designed to analyze flow pattern, velocity, and strain on the aortic wall of a glass aortic arch aneurysm model during the extracorporeal circulation, and to elucidate the characteristics of flow pattern in three different aortic cannulae. Different patterns of large vortices and helical flow were made by each cannula. With the curved end-hole cannula, the high velocity flow (,0.6,0.8 m/s) was blowing to the aneurismal wall without attenuating the strain rate tensor (,0.2,0.25/s). With the dispersion cannula and the Soft-Flow cannula, cannular jet was attenuated in the ascending aorta creating a large vortex at a velocity less than 0.5 m/s, and the strain rate tensor on the aneurismal wall was small (less than 0.15/s). In conclusion, end-hole cannula should not be used in the operation of aortic arch aneurysm. Dispersion-type aortic cannulae were less invasive on the aortic arch aneurismal wall, but particular attention to alternative cannulation sites should be paid in cases with severe atherosclerosis on the ascending aortic wall. [source]

Oxygenation,Ozonation of Blood During Extracorporeal Circulation: In Vitro Efficiency of a New Gas Exchange Device

ARTIFICIAL ORGANS, Issue 9 2007
Velio Bocci
Abstract:, We have investigated the performance of a new gas exchange device (GED), named L001, specifically devised for the ozonation of human blood during extracorporeal circulation. This procedure, defined with the acronym "EBOO," means "extracorporeal blood oxygenation,ozonation." The innovative GED is made of microporous, ozone-resistant, polipropylene hollow fibers with an external diameter of 200 µm, a thickness of 50 µm, and a membrane surface area of 0.22 m2. The material is coated with phosphorylcholine on the external side in contact with the circulating blood, while a gas mixture, necessarily composed of medical oxygen and ozone (about 99 and 1%, respectively), flows inside the fibers in opposite direction. The new GED has been tested by using a buffered saline solution containing KI and by varying several parameters, and it has shown to be very versatile and efficient. Its main characteristics are minimal foreign surface contact, high gas transfer, and negligible priming volume. This device appears to be a practical, nontoxic, and rather inexpensive tool for performing ozonation of blood for already defined human diseases. [source]

Experimental Evaluation of the V-Point Heparin-Bonding System Applied to a Dense-Membrane Artificial Lung During 24-Hour Extracorporeal Circulation in Beagles

ARTIFICIAL ORGANS, Issue 8 2001
Masafumi Tashiro
Abstract: Heparin was covalently bonded to a hollow-fiber dense-membrane artificial lung and circuit using a silane coupling agent and polyethyleneimine as a spacer. This study investigated whether the novel artificial lung could sustain prolonged extracorporeal lung assist (ECLA) by venoarterial bypass in beagles using minimal anticoagulants. We maintained ECLA for 24 h in 3 groups of minimal systemic heparinization, heparinization with the new anticoagulant nafamostat mesilate, and without any systemic anticoagulant. The results were assessed from the functional performance of the artificial lung and by macroscopic and microscopic examination after the experiments. Artificial lung function, hemodynamics, hemogram, and platelet aggregation activity were well maintained in all groups. There was no plasma leakage from the artificial lung. Although several clots were observed in stagnant areas of the artificial lungs and circuits, there was no clot formation inside the artificial lung in any group. This highly biocompatible, heparin-bonded dense-membrane artificial lung performed well and safely during prolonged ECLA with blood clotting times less than 120 s. [source]

Are Standard Human Coagulation Tests Suitable in Pigs and Calves During Extracorporeal Circulation?

ARTIFICIAL ORGANS, Issue 7 2001
Xavier M. Mueller
Abstract: The thrombogenicity of membrane oxygenators as well as clotting parameters profiles, using standard human clotting tests, was analyzed in calves and pigs during 6 h perfusion. Three calves and 3 pigs were connected to extracorporeal circulation with standard heparinization. Blood samples were taken for coagulation variables throughout perfusion, and oxygenators were examined for clot deposits at the end of the experiment. Two out of 3 oxygenators of the calf group presented clot deposits while none in the pig group did. Baseline coagulation variables of pigs showed values similar to those of humans while neither extrinsic nor intrinsic pathways could be activated in calves with standard human coagulation tests. The calf model, in conclusion, was confirmed to be a difficult model for the testing of extracorporeal circulation device resistance to thrombus formation, which is, however, not reflected by standard human coagulation tests. The pig model is a better model in which both coagulation pathways could be activated with standard human coagulation tests. [source]

Deep Hypothermia and Circulatory Arrest in the Surgical Management of Renal Tumors with Cavoatrial Extension

JOURNAL OF CARDIAC SURGERY, Issue 6 2009
Panagiotis Dedeilias M.D.
Their intraluminar extension to the cardiac cavities occurs with a tumor-thrombus formation at a percentage of 1%. The aim of this study is to present the principles of "radical" management that should be targeted to excision of the kidney together with the cavoatrial tumor-thrombus. Material: From 2003 through 2008, we treated six patients with renal-cell carcinoma involving the IVC and/or the right cardiac chambers. The main symptoms leading to the diagnosis were hematuria, dyspnea, or lower limb edema. The extension of the tumor was type IV in three cases, type III in two, and type II in one case. Method: Extracorporeal circulation combined with a short period of hypothermic circulatory arrest was the method used. Radical nephrectomy combined with cavotomy and atriotomy was performed to an "en-block" extirpation of the tumor-thrombus and allowed oncologic surgical clearance of the disease. Results: There was no operative death. The mean postoperative course duration was 11 days, apart from one obese patient who presented postoperative pancreatitis and died on the 44th postoperative day due to respiratory failure. During the cumulative postoperative follow-up of 171 months the patients remain free of recurrence. Conclusions: The use of extracorporeal circulation and deep hypothermic circulatory arrest provides a good method for radical excision of renal carcinomas involving the IVC with satisfactory morbidity and long-term survival results. Cooperation of urologists and cardiac surgeons is necessary for this type of operation. [source]

Monitoring of monocyte functional state after extracorporeal circulation: A flow cytometry study

CYTOMETRY, Issue 1 2004
Silverio Sbrana
Abstract Background Cardiovascular surgery with cardiopulmonary bypass (CPB) induces systemic inflammation and postoperative complications depending on pro- and anti-inflammatory mechanisms. Activated polymorphonuclear cells and monocytes may be responsible for morbidity associated with CPB. Knowledge of the monocyte functional state in particular may help to develop protective interventions. Methods Samples were drawn from venous peripheral blood (basal condition, at 4 and 24 h after CPB) and coronary blood (before and after cardioplegic arrest) of 14 patients undergoing cardiac surgery. The following phenotypic and functional parameters of the monocyte population were studied by flow cytometry: surface molecules expression (CD18, CD11a, CD11b, CD14, CD15, CD45, HLA-DR, and Toll-like receptor [TLR]-4), myeloperoxidase (MPO) content, and intracellular cytokine production (tumor necrosis factor [TNF]-,, interleukin [IL]-1,, IL-6, and IL-8). Results Cardiac surgery with CPB induced down-modulation of surface molecules expression on peripheral monocytes, especially at 24 h after CPB, for CD18, CD11a, and CD11b (P < 0.003) and for the CD15 adhesive cluster (P = 0.0028) and HLA-DR (P < 0.001). At 4 h after CPB, downregulation was observed for CD14 (P = 0.004), CD45 (P = 0.014), and CD15 (P = 0.0056). A loss of MPO was detected in venous peripheral (at 24 h after CPB, P = 0.01) or coronary (at reperfusion, P < 0.02) blood. The CD15 cluster complex exhibited a down-modulation in coronary blood (at reperfusion, P = 0.0003). Spontaneous intracellular production of IL-1,, IL-6, and IL-8 decreased at 24 h after CPB (P < 0.05). Conclusions The down-modulation of integrins and adhesive receptor expression and the loss of MPO suggest a strong activation and shedding reaction of circulating monocyte after CPB, further exacerbated by contact with coronary ischemic vessels. The changes of differentiation antigens may reflect the appearance of a partially immature population immediately after CPB. The reduced proinflammatory cytokine production, observed at 24 h after CPB, suggests a functional polarization of circulating monocytes. © 2003 Wiley-Liss, Inc. [source]

History of hemodialyzers' designs

HEMODIALYSIS INTERNATIONAL, Issue 2 2008
Zbylut J. TWARDOWSKI
Abstract Accumulation of knowledge requisite for development of hemodialysis started in antiquity and continued through Middle Ages until the 20th century. Firstly, it was determined that the kidneys produce urine containing toxic substances that accumulate in the body if the kidneys fail to function properly; secondly, it was necessary to discover the process of diffusion and dialysis; thirdly, it was necessary to develop a safe method to prevent clotting in the extracorporeal circulation; and fourthly, it was necessary to develop biocompatible dialyzing membranes. Most of the essential knowledge was acquired by the end of the 19th century. Hemodialysis as a practical means of replacing kidney function started and developed in the 20th century. The original hemodialyzers, using celloidin as a dialyzing membrane and hirudin as an anticoagulant, were used in animal experiments at the beginning of the 20th century, and then there were a few attempts in humans in the 1920s. Rapid progress started with the application of cellophane membranes and heparin as an anticoagulant in the late 1930s and 1940s. The explosion of new dialyzer designs continued in the 1950s and 1960s and ended with the development of capillary dialyzers. Cellophane was replaced by other dialyzing membranes in the 1960s, 1970s, and 1980s. Dialysis solution was originally prepared in the tank from water, electrolytes, and glucose. This solution was recirculated through the dialyzer and back to the tank. In the 1960s, a method of single-pass dialysis solution preparation and delivery system was designed. A large quantity of dialysis solution was used for a single dialysis. Sorbent systems, using a small volume of regenerated dialysis solution, were developed in the mid 1960s, and continue to be used for home hemodialysis and acute renal failure. At the end of the 20th century, a new closed system, which prepared and delivered ultrapure dialysis solution preparation, was developed. This system also had automatic reuse of lines and dialyzers and prepared the machine for the next dialysis. This was specifically designed for quotidian home hemodialysis. Another system for frequent home hemodialysis or acute renal failure was developed at the turn of the 21st century. This system used premanufactured dialysis solution, delivered to the home or dialysis unit, as is done for peritoneal dialysis. [source]

Giant Aneurysm After Aortic Coarctation: Repair without Circulatory Arrest

JOURNAL OF CARDIAC SURGERY, Issue 5 2010
D.E.S.A., Gabor Erdoes M.D.
Using the hemi-clamshell approach, the entire aortic arch was replaced and the supraaortic branches were reimplanted. The applied surgical technique using hypothermic extracorporeal circulation without cardiac arrest allowed an uninterrupted cerebral and spinal cord perfusion due to stepwise clamping of the aortic arch during reconstruction and resulted in an excellent neurologic outcome at six-month follow-up.,(J Card Surg 2010;25:560-562) [source]

Deep Hypothermia and Circulatory Arrest in the Surgical Management of Renal Tumors with Cavoatrial Extension

Transposition of the Left Carotid Artery to the Ascending Aorta to Repair Aortic Arch Injury

JOURNAL OF CARDIAC SURGERY, Issue 1 2009
Salvatore Lentini M.D.
A 52-year-old man presented to our department with a penetrating chest wound by a gunshot in the attempt of suicide. The aortic arch and the insertion of the left carotid artery were involved in the lesion. Through sternotomic approach, the aortic arch was repaired in extracorporeal circulation. Left carotid artery was transected to allow easier repair of the arch posterior wall involved in the lesion, and to reduce the danger of residual stenosis. Then, it was translocated to the ascending aorta by interposing a 7-mm Gore-Tex (W.L. Gore & Associates, Flagstaff, AZ, USA) conduit. The patient complicated renal failure and pneumonia in the postoperative period, but eventually he was discharged in good general conditions. [source]

PEEP Therapy for Patients With Pleurotomy During Coronary Artery Bypass Grafting

JOURNAL OF CARDIAC SURGERY, Issue 3 2000
Susumu Ishikawa M.D.
We studied the efficacy of intraoperative positive end-expiratory airway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. A total of 66 patients with solitary CABG procedure were included in this study. The pleural cavity was intraoperatively opened in 44 patients and not opened in 22. PEEP therapy was not used in any patient before May 1996 (referred to herein as the former period) and was used more recently in eight patients with pleurotomy (referred to herein as the latter period). PEEP was initiated immediately after pleurotomy during the harvest of the internal mammary artery graft. Without PEEP therapy, values of PaO2, A-aDO2, and respiratory index (RI) were worse in patients with pleurotomy than in those without pleurotomy. Meanwhile, there were no major differences in these values between patients with or without pleurotomy after the induction of PEEP therapy. Respiratory insufficiency (A-aDO2 > 400 mmHg and RI > 1.5) was detected in six patients with pleurotomy in the former period. Three of these six patients required over 1 week of long-term mechanical respiratory support. No respiratory insufficiency occurred in patients of the latter period. In conclusion, PEEP therapy, which is initiated just after pleurotomy, may prevent oxygen impairment and pulmonary atelectasis after extracorporeal circulation (ECC) and is recommended for patients with pleurotomy, especially for patients with preoperative low respiratory function. [source]

Hepatocyte dynamics in a three-dimensional rotating bioreactor

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2007
Mitsuo Miyazawa
Abstract Background and Aims:, The use of an artificial liver system with extracorporeal circulation or a three-dimensional bioreactor perfused with liquid culture medium inevitably exposes hepatocytes to fluid mechanical stress (MS). The expression of liver-specific hepatocyte functions seems to be modulated by the magnitude of MS. Nonetheless, few studies have focused on the direct effects of MS on hepatocytes. We subjected hepatocytes to MS using an MS loading device and investigated the effects on the cytoskeleton and hepatocyte dynamics inside three-dimensional scaffolds by monitoring the changes in actin fiber, one of the components of the cytoskeleton. We also assessed the influence of MS on specific hepatocyte functions. Methods:, We subjected hepatocytes to MS by a rotating radial flow bioreactor (RRFB) and examined the effects by comparing the MS-loaded culture cells with cells cultured under stationary conditions without MS loading. The hepatocytes (1 × 106/cm3) were seeded on gauze without collagen coating and examined to determine morphological changes after 60 h incubation. Actin filaments in samples from the MS-loaded hepatocyte culture were stained by fluorescein isothiocyanate-labeled phalloidin. Results:, Hepatocyte aggregation was observed in the MS-loaded culture, but not in the unloaded stationary culture. Better albumin products were observed in the MS-loaded group than in the stationary culture group at all measurement points. Actin filaments extended toward the scaffold after the start of MS loading incubation and polymerized around the hepatocytes. The hepatocyte aggregation eventually advanced to the formation of spheroids. Conclusion:, These results suggest that MS-induced polymerization of actin filaments stimulate hepatocyte aggregation and thereby improve hepatocyte-specific function. [source]

Extended right hemihepatectomy with extracorporeal circulation for liver mestastases invading the inferior vena cava and right atrium

JOURNAL OF SURGICAL ONCOLOGY, Issue 5 2006
E. Usta
No abstract is available for this article. [source]

Cardiopulmonary resuscitation after near drowning and hypothermia: restoration of spontaneous circulation after vasopressin

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2003
G. Sumann
Recent animal data have challenged the common clinical practice to avoid vasopressor drugs during hypothermic cardiopulmonary resuscitation (CPR) when core temperature is below 30°C. In this report, we describe the case of a 19-year-old-female patient with prolonged, hypothermic, out-of-hospital cardiopulmonary arrest after near drowning (core temperature, 27°C) in whom cardiocirculatory arrest persisted despite 2 mg of intravenous epinephrine; but, immediate return of spontaneous circulation occurred after a single dose (40 IU) of intravenous vasopressin. The patient was subsequently admitted to a hospital with stable haemodynamics, and was successfully rewarmed with convective rewarming, but died of multiorgan failure 15 h later. To the best of our knowledge, this is the first report about the use of vasopressin during hypothermic CPR in humans. This case report adds to the growing evidence that vasopressors may be useful to restore spontaneous circulation in hypothermic cardiac arrest patients prior to rewarming, thus avoiding prolonged mechanical CPR efforts, or usage of extracorporeal circulation. It may also support previous experience that the combination of both epinephrine and vasopressin may be necessary to achieve the vasopressor response needed for restoration of spontaneous circulation, especially after asphyxial cardiac arrest or during prolonged CPR efforts. [source]

Severe systemic inflammation response syndrome after minimal invasive extracorporeal circulation

ANAESTHESIA, Issue 6 2008
O. Hennes
No abstract is available for this article. [source]

Variations in the Application of Various Perfusion Technologies in Great Britain and Ireland,A National Survey

ARTIFICIAL ORGANS, Issue 3 2010
Oliver J. Warren
Abstract In an attempt to reduce the negative sequelae of cardiopulmonary bypass (CPB), a variety of new technologies have been created. This study investigates variations in the application of these technologies throughout Great Britain and Ireland (GB & I). All perfusion departments within GB & I were surveyed about equipment and technologies used in CPB. Eighty-five percent of units use a standard arterial line filter in all cases. Forty percent of units occasionally use leukocyte-depleting filters in various sites within the circuit. Sixteen percent always use some element of heparin-bonded circuit, but 62% never use them. Twenty-five percent use solely rotary pumps, 18% use solely centrifugal pumps, and 56% use both. Finally, 20% are now using minimal extracorporeal circulation in certain clinical scenarios. These decisions are most frequently affected by clinician preference and cost. This survey has highlighted significant variation in the utilization of various technologies used in CPB. While some variation between centers is to be expected, as innovative technologies are adopted at varying rates, surveys such as this are useful for alerting clinicians to gaps between evidence-based knowledge and clinical practice. [source]

Hydrodynamics of Aortic Cannulae During Extracorporeal Circulation in a Mock Aortic Arch Aneurysm Model

In Vivo Assessment of a New Method of Pulsatile Perfusion Based on a Centrifugal Pump

ARTIFICIAL ORGANS, Issue 2 2010
Jesús Herreros
Abstract The aim of this study was to assess platelet dysfunction and damage to organs after extracorporeal circulation using a pump based on a new method that adds a pulsatile flow to the continuous flow provided by a centrifugal pump. The continuous component of the total flow (2,3 L/min) is created by a Bio-Pump centrifugal pump, while the pulsatile component is created by the pulsating of an inner membrane pneumatically controlled by an intra-aortic counterpulsation balloon console (systolic volume of 37.5 mL in an asynchronous way with a frequency of 60 bpm). Six pigs were subjected to a partial cardiopulmonary bypass lasting 180 min and were sacrificed 60 min after extracorporeal circulation was suspended. The hematological study included the measurement of hematocrit, hemoglobin, leukocytes, and platelet function. The new pump did not significantly alter either platelet count or platelet function. In contrast, hematocrit and hemoglobin were significantly reduced during extracorporeal circulation (approximately 5% P = 0.011, and 2 g/dL P = 0.01, respectively). The leukocyte count during extracorporeal circulation showed a tendency to decrease, but this was not significant. In general, the short-term use of the new pump (4 h) did not cause any serious morphological damage to the heart, lung, kidney, or liver. The results suggest that the hemodynamic performance of the new pump is similar to a conventional centrifugal pump and could therefore be appropriate for use in extracorporeal circulation. [source]

Hemocompatibility of a Miniaturized Extracorporeal Membrane Oxygenation and a Pumpless Interventional Lung Assist in Experimental Lung Injury

ARTIFICIAL ORGANS, Issue 1 2010
Ruedger Kopp
Abstract Extracorporeal membrane oxygenation (ECMO) is used for most severe acute respiratory distress syndrome cases in specialized centers. Hemocompatibility of devices depends on the size and modification of blood contacting surfaces as well as blood flow rates. An interventional lung assist using arteriovenous perfusion of a low-resistance oxygenator without a blood pump (Novalung, Hechingen, Germany) or a miniaturized ECMO with reduced filling volume and a diagonal blood pump (Deltastream, Medos AG, Stolberg, Germany) could optimize hemocompatibility. The aim of the study was to compare hemocompatibility with conventional ECMO. Female pigs were connected to extracorporeal circulation for 24 h after lavage induced lung injury (eight per group). Activation of coagulation and immune system as well as blood cell damage was measured. A P value <0.05 was considered significant. Plasmatic coagulation was slightly activated in all groups demonstrated by increased thrombin-anti-thrombin III-complex. No clinical signs of bleeding or thromboembolism occurred. Thrombelastography revealed decreased clotting capacities after miniaturized ECMO, probably due to significantly reduced platelet count. These resulted in reduced dosage of intravenous heparin. Scanning electron microscopy of oxygenator fibers showed significantly increased binding and shape change of platelets after interventional lung assist. In all groups, hemolysis remained negligible, indicated by low plasma hemoglobin concentration. Interleukin 8 and tumor necrosis factor-, concentration as well as leukocyte count remained unchanged. Both devices demonstrated adequate hemocompatibility for safe clinical application, although a missing blood pump did not increase hemocompatibility. Further studies seem necessary to analyze the influence of different blood pumps on platelet drop systematically. [source]

The Aachen Miniaturized Heart-Lung Machine,First Results in a Small Animal Model

ARTIFICIAL ORGANS, Issue 11 2009
Heike Schnoering
Abstract Congenital heart surgery most often incorporates extracorporeal circulation. Due to foreign surface contact and the administration of foreign blood in many children, inflammatory response and hemolysis are important matters of debate. This is particularly an issue in premature and low birth-weight newborns. Taking these considerations into account, the Aachen miniaturized heart-lung machine (MiniHLM) with a total static priming volume of 102 mL (including tubing) was developed and tested in a small animal model. Fourteen female Chinchilla Bastard rabbits were operated on using two different kinds of circuits. In eight animals, a conventional HLM with Dideco Kids oxygenator and Stöckert roller pump (Sorin group, Milan, Italy) was used, and the Aachen MiniHLM was employed in six animals. Outcome parameters were hemolysis and blood gas analysis including lactate. The rabbits were anesthetized, and a standard median sternotomy was performed. The ascending aorta and the right atrium were cannulated. After initiating cardiopulmonary bypass, the aorta was cross-clamped, and cardiac arrest was induced by blood cardioplegia. Blood samples for hemolysis and blood gas analysis were drawn before, during, and after cardiopulmonary bypass. After 1 h aortic clamp time, all animals were weaned from cardiopulmonary bypass. Blood gas analysis revealed adequate oxygenation and perfusion during cardiopulmonary bypass, irrespective of the employed perfusion system. The use of the Aachen MiniHLM resulted in a statistically significant reduced decrease in fibrinogen during cardiopulmonary bypass. A trend revealing a reduced increase in free hemoglobin during bypass in the MiniHLM group could also be observed. This newly developed Aachen MiniHLM with low priming volume, reduced hemolysis, and excellent gas transfer (O2 and CO2) may reduce circuit-induced complications during heart surgery in neonates. [source]

Oxygenation,Ozonation of Blood During Extracorporeal Circulation: In Vitro Efficiency of a New Gas Exchange Device

Mesenteric Complications After Hypothermic Cardiopulmonary Bypass with Cardiac Arrest: Underlying Mechanisms

ARTIFICIAL ORGANS, Issue 11 2002
Terézia Bogdana Andrási
Abstract: The aim of this study was to determine the pathophysiological mechanisms of postcardiopulmonary bypass (CPB) intestinal dysfunction using an in vivo canine model of extracorporeal circulation. Six dogs underwent a 90 min hypothermic CPB with continuous monitoring of mean arterial blood pressure (MAP) and mesenteric blood flow (MBF). Reactive hyperemia and vasodilator responses of the superior mesenteric artery to acetylcholine and sodium nitroprusside were determined before and after CPB. Mesenteric lactate production, glucose consumption, creatine kinase (CK) release and venous free radicals were determined. CPB induced a significant fall (p < 0.05) in MAP and MBF. After CPB, reactive hyperemia (,26 ± 15% versus ,53 ± 2%, p < 0.05) and the response to acetylcholine (,42 ± 9 versus ,55 ± 6%, p < 0.05) were significantly decreased. Reperfusion increased lactate production (0.8 ± 0.09 mmol/L versus 0.4 ± 0.18, p < 0.05) and the CK release (446 ± 98 U/L versus 5 ± 19 U/L, p < 0.01). Endothelial dysfunction, conversion from aerobic to anaerobic metabolism, and intestinal cell necrosis seem to be responsible for intestinal complications associated with CPB. [source]

Are Standard Human Coagulation Tests Suitable in Pigs and Calves During Extracorporeal Circulation?

Importance of Uniform Heparin Coating on Biopolymers

ARTIFICIAL ORGANS, Issue 3 2000
Patrícia Da Luz Moreira
Abstract: Cardiopulmonary surgeries need connectors for extracorporeal circulation. The patient's blood in contact with the tube surfaces modifies its plasmatic proteins, promotes platelet aggregation, and activates the complement system, unleashing thrombus formation. Thus, it becomes necessary for an anticoagulant to keep the circuit free from these events. Heparin is the anticoagulant used even after reports about its disadvantages. Platelet adherence seems to be very dependent on the quality from the surfaces that can promote cellular proliferation, aggregation, and thrombosis. In this study, we compare the quality of the heparin-coated and uncoated surfaces. We used a blood cell culture and scanning electron microscopy (SEM) to visualize the platelet aggregation. It was concluded that there are groove areas that permit platelet adherence, and if they are not coated totally by the heparin, aggregation still occurs although in lower scale than on the uncoated tubes. [source]