The effect of roller head pump on platelet deterioration during the simulated extracorporeal circulation.

Roller pumping results in hemolysis and adverse effects on coagulation, but there are few reports on the influence of roller heads on platelets. Here, we evaluate the interaction between roller pumping and platelet function using a simulated extracorporeal circuit incorporating a vinyl chloride tube and roller head pump with 30 min recirculation. Platelet aggregation, platelet count, microparticle, P-selectin, Phosphatidylserine (PS) exposure and Ricinus Communis Agglutinin 1 (RCA-1) were measured before, 5, 10, 20, and 30 min after the recirculation using 100 ml of fresh human blood that had obtained from healthy volunteers (n = 9). Platelet aggregation and platelet count gradually decreased but microparticles significantly increased after the recirculation (P < 0.05). P-selectin, PS exposure and RCA-1 were measured using flow cytometry. There were no significant differences in the P-selectin and PS exposure expression during recirculation. RCA-1, a platelet apoptosis markers, significantly increased 30 min after recirculation (P < 0.05). We thus conclude that roller pumping induced platelet apoptosis and caused decreases in platelet count and aggregation after the recirculation.

Right atrial blood cyst in elderly patient: the timing of surgery.

A regular check up on a 59-year-old man showed a high carcinoembryonic antigen level in his blood. A computed tomography scan showed tumors in the right atrium. We performed tumor resection successfully. The resected specimen was found to be blood cysts that had developed from the right atrium to the inferior vena cava. Intracardiac blood cysts are generally observed in infants, spontaneously disappear during the first 6 months of life, and are located in the left side of heart and on atrioventricular valves. Therefore, this case is extremely rare. Also, it is worth considering the timing of this surgery.

Combined treatment for a large primary cardiac sarcoma: a case report.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) as a primary cardiac tumor is rare, with extremely poor prognosis owing to high recurrence and invasion. We encountered a patient who presented with a primary cardiac tumor incarcerating the mitral valve and who was in a shock state. CASE PRESENTATION: A 41-year-old man was transported emergently to our hospital owing to acute respiratory distress and hemoptysis. He was diagnosed with acute left heart failure caused by a large mass in the left atrium (LA) that obstructed cardiac blood flow, as revealed by imaging study findings, and he underwent an emergency open-heart surgery for tumor resection. He was pathologically diagnosed with UPS invading the muscle layer of the LA. However, after receiving combined therapy for local recurrence and distant metastasis, including proton beam radiotherapy and chemotherapy with molecularly targeted drugs, he could return to work for 2 more years after surgery. CONCLUSION: In this study, we reported the case of a patient who was in a state of shock state owing to the presence of UPS in the LA. The patient underwent an emergency surgery and received combined therapy. He survived for 2 more years after an initial diagnosis, without active local recurrence and distant metastasis.

[Acquired Left Ventricular-right Atrial Communication due to Infective Endocarditis;Report of a Case].

A 77-year-old woman presented with a 3-week history of low grade fever, appetite loss and dizziness. An electrocardiogram showed complete heart block. Echocardiography demonstrated severe aortic valve stenosis and a mass of probable vegetation 2 cm in diameter on the atrioventricular septum in the right atrium (RA), but no obvious intra-cardiac fistula. There was no growth of organism in blood cul tures. In the 4th week after admission, a harsh and continuous cardiac murmur was detected for the 1st time. Portable echocardiography revealed disappearance of the mass in the RA, and showed an intra-cardiac shunt from the left ventricle( LV) to RA. The shunt was closed by autologous pericardial patch form LV side and directly with mattress suture form RA side during the emergency operation. The aortic valve was replaced with bio-prosthetic valve (SJM Trifecta 19 mm). No organism was detected in the excised tissue, but antibiotics were continued for 2 months until a permanent pacemaker was inserted.

[Mitral regurgitation and atrial septum aneurysm complicated with osteogenesis imperfecta; report of a case].

A 43-year-old female with a history of osteogenesis imperfecta was admitted to our hospital for congestive heart failure due to mitral valve regurgitation. The patient had suffered from bone fractures 5 times, dislocation of elbow and fingers 3 times since childhood, and subarachnoid hemorrhage 2 years before. She and her son have blue scleras. She was diagnosed with osteogenesis imperfecta type IA clinically. Echocardiography revealed severe mitral regurgitation and aneurysmal formation in the interatrial septum bulging to the right atrium. Mitral valve replacement and repair of the atrial septum were performed without any blood transfusion, but with rib fractures. Echocardiography showed no peri-valvular regurgitation at 1 year after the valve replacement. Cardiovascular disease is rarely associated with osteogenesis imperfecta, but its surgical mortality rate is high due to coagulation abnormality and fragile tissue. To reduce postoperative complications, precise classification of the disease and careful handling of the tissues during operation will be needed.

[Steroid replacement therapy for shocks after cardiac surgery].

A 63-year-old woman who underwent surgery for valve replacement had shocks 2 times. First, 1 postoperative day (POD), she had dyspnea, high grade fever and tacycardia. Then, she was intubated again, and needed intraaortic ballon pumping (IABP) support. Second, 32 POD, she had dyspnea, loss of consciousness and metabolic acidosis. Then she was intubated and needed continuous hemodiafiltration (CHDF). In both cases, causes were unknown, but she recovered from shocks after steroid therapy. Relative adrenal insufficiency during septic shock has been well known, and it was reported that steroid therapy reduce the risk of death. Also in cardiac surgery, relative adrenal insufficiency and euthyroid sick syndrome due to stress may occur. In a case of shock requiring large amount of catecholamine after cardiac surgery and the reason of the shock is unknown, specimens of adrenocorticotropic hormone (ACTH), cortisol, thyroid-stimulating hormone (TSH), free T3 and free T4 should be taken following by administration of 100 mg hydrocortisone intravenously.

Antithrombogenic properties of a monopivot magnetic suspension centrifugal pump for circulatory assist.

The National Institute of Advanced Industrial Science and Technology (AIST) monopivot magnetic suspension centrifugal pump (MC105) was developed for open-heart surgery and several weeks of circulatory assist. The monopivot centrifugal pump has a closed impeller of 50 mm in diameter, supported by a single pivot bearing, and is driven through a magnetic coupling to widen the fluid gap. Design parameters such as pivot length and tongue radius were determined through flow visualization experiments, and the effectiveness was verified in preliminary animal experiments. The maximum overall pump efficiency reached 18%, and the normalized index of hemolysis tested with bovine blood was as low as 0.0013 g/100 L. Animal experiments with MC105 were conducted in sheep for 3, 15, 29, and 35 days in a configuration of left ventricle bypass. No thrombus was formed around the pivot bearing except when the pump speed was reduced by 20% of normal operational speed, which reduced the pump flow by 40% to avoid inlet suction. Subsequently, the antithrombogenic design was verified in animal experiments for 5 weeks at a minimum rotational speed of greater than 1500 rpm and a minimum pump flow greater than 1.0 L/min; no thrombus formation was observed under these conditions.

Hemocompatibility of a hydrodynamic levitation centrifugal blood pump.

A noncontact type centrifugal pump without any complicated control or sensing modules has been developed as a long-term implantable artificial heart. Centrifugal pumps with impellers levitated by original hydrodynamic bearings were designed and have been modified through numerical analyses and in vitro tests. The hemolysis level was reduced by changing the pressure distribution around the impeller and subsequently expanding the bearing gap. Thrombus formation in the bearing was examined with in vitro thrombogenesis tests and was reduced by changing the groove shapes to increase the bearing-gap flow to 3% of the external flow. Unnecessary vortices around the vanes were also eliminated by changing the number of vanes from four to six.

Cigarette-smoke-induced vasoconstriction of peripheral arteries: evaluation by synchrotron radiation microangiography.

BACKGROUND: Although cigarette smoking is thought to constrict peripheral vessels, details have not been clarified because of the limitation of spatial resolution in conventional X-ray angiography systems. Synchrotron radiation microangiography can identify small arteries down to 50 microm in diameter. METHOD AND RESULTS: Male Wistar rats (n=9) were made to smoke a cigarette using the modified Griffith snout exposure system. Angiography of the rat hind limb was performed before, during, and 15 min after smoking. Arteries were classified into 3 groups based on the pre-smoking diameter: Group S: <100 microm, Group M 100-200 microm, Group L: >200 microm). In Groups M and L, arteries were constricted with smoking (mean diameter 140-106 microm; p<0.001, 260-162 microm; p<0.00001, respectively), whereas no constriction was noted in Group S (82-83 microm). Constricted arteries in Groups M and L returned to pre-smoking levels at 15 min after cessation of smoking. CONCLUSION: The acute changes brought about by cigarette smoking in rat peripheral arteries could be identified by synchrotron radiation microangiography. Cigarette smoking exclusively constricted arteries greater than 100 mum in diameter, which means there is vessel-size dependency of the impairment.

Left coronary ostial obstruction after aortic valve replacement with a supra-annular aortic valve.

We report a rare case of left coronary ostial obstruction after aortic valve replacement with a Top Hat supra-annular aortic valve, which was diagnosed with intraoperative transesophageal echocardiography and successfully treated with an unplanned coronary bypass. The patient was a 76-year-old woman (height 143 cm, weight 44 kg) with aortic stenosis and regurgitation. A 19-mm Top Hat valve was implanted in the supra-annular position because of a small aortic annulus. There was a possibility that the high profile of this prosthesis might block the left coronary ostium. There may be a problem with the use of this prosthesis in patients with small and rigid aortic roots with little compliance. Although the Top Hat valve has a great advantage for small aortic annuli, care in its use should be taken due to possible interference with the coronary ostia.

Comparison of hydroxyl radical generation in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass.

We measured the hydroxyl radical (.OH) generation in fourteen patients undergoing coronary artery bypass grafting (CABG), of whom seven patients underwent on-pump CABG with cardiopulmonary bypass (CPB) and seven patients underwent off-pump CABG without CPB. To detect .OH generation, we measured the urinary excretion of .OH products of creatinine (Cr), creatol (CTL; 5-hydroxycreatinine) and methylguanidine (MG) with HPLC using the one point sampling and collected urine during and after the operation. The urinary CTL value corrected urinary Cr value of on-pump CABG significantly increased about 3-5 times from the beginning of CPB to 4 h after operation compared to the baseline value before CPB in both the collected urine and the one point sampling urine. The urinary MG/Cr value in both groups did not change significantly. Significantly increased .OH generation was found during and soon after on-pump CABG.

Sivelestat reduces inflammatory mediators and preserves neutrophil deformability during simulated extracorporeal circulation.

BACKGROUND: Neutrophil is a major focus in efforts to ameliorate the systemic inflammatory response associated with cardiopulmonary bypass. Neutrophil elastase is a powerful proteolytic enzyme, and plays a pivotal role in the development of the inflammatory response. This study assesses the inhibitory effects of sivelestat, a highly specific neutrophil elastase inhibitor, on elastase levels, cytokine production, and the functional changes of neutrophils in a simulated extracorporeal circulation model. METHODS: Simulated recirculation was established by recirculating heparinized (3.75 U/mL) human blood for 120 minutes in an oxygenator and a roller pump circuit with and without 100 micromol/L of sivelestat (n = 7 for each group). Neutrophil elastase and interleukin-8 were measured with an enzyme immunoassay. Neutrophil deformability was evaluated by simulated microcapillaries. The neutrophil F-actin and the expression of CD11b and L-selectin were measured by flow cytometry. RESULTS: Sivelestat reduced both neutrophil elastase levels (p = 0.0006) and interleukin-8 production (p < 0.0001) at 120 minutes of recirculation. Sivelestat also significantly preserved neutrophil deformability (p = 0.017) and reduced F-actin expression (p = 0.0037). The drug did not modulate the changes of CD11b or L-selectin. CONCLUSIONS: This study suggests that specific elastase inhibition with sivelestat could be a feasible therapeutic strategy for patients undergoing cardiopulmonary bypass to attenuate neutrophil-derived inflammatory response and organ injuries.

Characterization of a myeloma patient with a life-threatening hemorrhagic diathesis: presence of a lambda dimer protein inhibiting shear-induced platelet aggregation by binding to the A1 domain of von Willebrand factor.

We have identified a patient with IgD lambda-type multiple myeloma who was characterized by a severe bleeding tendency, especially after puncture of arterial vessels. Both the bleeding time (>25 min) and activated partial thromboplastin time (APTT) were prolonged. To clarify the underlying pathogenesis, we purified the APTT-prolonging activity from the patient's serum. The purified protein was a highly negatively-charged homodimer of the lambda light chain. The lambda dimer protein (M-protein) inhibited ristocetinand high shear-induced platelet aggregation, dependent on platelet glycoprotein Ibalpha (GPIbalpha), but not epinephrine-, collagen-, ADP-, thrombin-, or botrocetin-induced platelet aggregation. The lambda dimer protein inhibited the binding of platelets to immobilized or ristocetin-treated von Willebrand factor (VWF). Furthermore, a 39/34 kD fragment of VWF encompassing the A1 domain specifically bound to the immobilized lambda dimer protein in the presence of ristocetin, suggesting that the lambda dimer protein directly binds to the A1 domain of VWF. To help elucidate the binding site within the A1 domain, binding of ristocetin-treated VWF to the immobilized lambda dimer protein was assayed in the presence of various anti-A1 domain monoclonal antibodies. Based on these data, we conclude that the lambda dimer protein binds to the region of the A1 domain composed of helices alpha3 and alpha4 and thus interferes with VWF-GPIbalpha interaction. The existence of a protein that inhibits high shear-induced platelet aggregation in acquired von Willebrand disease (VWD) has only rarely been reported. The results suggest that the hemostatic function in arteries with high shear force is profoundly disrupted if the binding of GPIbalpha to VWF is abrogated, supporting the relevance of shear-induced VWF interaction with GPIbalpha in the initiation of the hemostatic process.

Nafamostat preserves neutrophil deformability and reduces microaggregate formation during simulated extracorporeal circulation.

BACKGROUND: Initial sequestration of activated neutrophils and platelet microaggregates in capillaries are responsible for the inflammatory response associated with cardiopulmonary bypass. The study assesses the inhibitory effects of nafamostat mesilate on neutrophil and platelet activation, and on the neutrophil deformability change and microaggregate formation during simulated extracorporeal circulation. METHODS: Fresh heparinized human blood was recirculated for 120 minutes in a membrane oxygenator and a roller pump with and without nafamostat (1.0 mg bolus plus 8.0 mg/h infusion; n = 10 for each group). Neutrophil and platelet counts and platelet aggregation were measured. CD11b, L-selectin, and cytoplasmic F-actin of neutrophils were measured by flow cytometry. The microchannel transit time of whole blood was measured as a marker of neutrophil deformability and microaggregate formation. Neutrophil elastase and complement C4d were measured using enzyme immunoassay. RESULTS: Nafamostat preserved platelet counts and inhibited platelet aggregation. Nafamostat significantly reduced neutrophil elastase release at 120 minutes of recirculation, and F-actin expression at 30 and 60 minutes. The drug did not modulate the changes of CD11b, L-selectin, or C4d. Whole blood filterability was significantly preserved by nafamostat at 30 and 120 minutes. CONCLUSIONS: Nafamostat preserves blood filterability during recirculation, possibly by suppression of F-actin expression and platelet activation. Nafamostat may reduce neutrophil sequestration and microaggregate formation in the microcirculation during cardiopulmonary bypass.

[Reduction of preparatory bank blood requirements in adult cardiac surgery].

The importance of blood conservation to minimize homologous blood use in cardiac surgery is well-accepted. In addition, it is financially important to minimize unnecessary and avoidable bank blood prepared, because once the blood products were taken into a hospital, it could not be returned to the blood bank in Japan. We tried to safely reduce the amount of bank blood products requested in 185 consecutive adult cardiac operations for 18 months. First 6 months' observation revealed that only 2 patients received blood transfusion among 34 patients whose products of weight (kg) and hemoglobin (g/dl) were more than 700. We called the product "a transfusion index", and the amounts of blood prepared were newly set as follows: a transfusion index less than 500; 6 units or more of cross-matched red cell concentrate, 500-700; 2 to 4 units of cross-matched red cell concentrate, more than 700; no cross-matched bank blood. In next 6 months, the amounts of cross-matched blood reduced from 4.8 units to 3.9 units per patient. Last 6 months, we prepared no blood products for the patients whose transfusion indexes were more than 700. The amounts of prepared red cell concentrate reduced to 2.1 units per patient, however, additional blood requirements during the operations did not show significant increase. A transfusion index depends on the patient's weight and preoperative hemoglobin is a simple and useful indicator to anticipate blood requirements.

The most profitable use of flow visualization in the elimination of thrombus from a monopivot magnetic suspension blood pump.

The purpose of this study was to eliminate fluid dynamic causes of thrombus formation for the monopivot magnetic suspension centrifugal pump under development with the aid of flow visualization as an indirect measurement tool for animal experiments. The formation of thrombus observed in early animal experiments was successfully overcome by combining the multiple washout holes at the center into a single hole, optimizing the hole diameter, and eliminating the pivot gap. Flow visualization was used to optimize the washout hole diameter influencing the flow around the pivot. In animal experiments flow visualization showed that the contours of thrombus corresponded to shear rates of 300 s(-1) or 1300-1700 s(-1). It was found that flow visualization is a useful technique to predict locations where low shear thrombi form and to optimize the pump design in the development stage.

High-frequency QRS potentials as a marker of myocardial dysfunction after cardiac surgery.

BACKGROUND: High-frequency QRS potentials are sensitive to myocardial ischemia. The aim of this study was to evaluate the usefulness of high-frequency QRS potentials as a marker of myocardial dysfunction after cardiac surgery. METHODS: Seventy patients undergoing coronary artery bypass grafting or heart valve surgery were involved. High-frequency QRS potentials were measured by signal-averaged electrocardiogram, and calculated as the root-mean-square voltage of the total QRS duration (RMST). The postoperative RMST was expressed as a percentage of the preoperative RMST. The mean RMST at 1 to 2 hours after removing the aortic cross-clamp was compared with the cardiac index, inotropic agents, and aortic cross-clamping time. The occurrence of ventricular tachycardia within 24 hours and the RMST at 2 postoperative days were also evaluated. Patients were divided into quartile groups from highest to lowest at postoperative RMST (groups 1, 2, 3, and 4, respectively, from maximum to minimum). RESULTS: In postoperative states, cardiac index significantly decreased in accordance with the RMST decrease in a stepwise manner, although there were no differences in cardiac index among the four groups preoperatively. Inotropic agents and aortic cross-clamping time increased as RMST decreased. A high rate of ventricular tachycardia within 24 hours and delayed RMST recovery at 2 postoperative days were seen in group 4. The curve of sensitivity and specificity showed that severe reduction (threshold, 35%) of RMST indicated low-output syndrome. CONCLUSIONS: The severe reduction of filtered high-frequency QRS potentials was related to myocardial dysfunction. Measurement of filtered high-frequency QRS potentials could become a useful, noninvasive, real-time monitor of myocardial dysfunction after surgery.

Ventricular fibrillation during anesthesia in association with J waves in the left precordial leads in a child with coarctation of the aorta.

A 14-year-old boy with coarctation of the aorta who showed repeat ventricular fibrillation during anesthesia, and ultimately sudden cardiac death in school, is presented. Electrocardiography showed J waves in the left precordial leads, which became prominent after an episode of ventricular fibrillation. While some of the clinical features and electrophysiological findings were similar to those seen in Brugada syndrome, others were inconsistent. J waves in the left precordial leads should be recognized as a possible waveform change inducing ventricular fibrillation predominantly at rest.

Overproduction of platelet microparticles in cyanotic congenital heart disease with polycythemia.

OBJECTIVES: We sought to clarify the role of platelets in the pathogenesis of abnormal coagulation in patients with cyanotic congenital heart disease (CCHD) with polycythemia; we evaluated the production of platelet microparticles (MPs), platelet degranulation and aggregation response, as well as the correlations of these variables with polycythemia. BACKGROUND: A shortened life span and suppressed aggregability of platelets are well known in patients with CCHD. Although platelet MPs are overproduced and play an important role in the coagulation process in various hematologic and cardiovascular disorders, the production of MPs remains to be elucidated in CCHD. We studied 19 patients who had CCHD with polycythemia and 21 age-matched subjects with acyanotic congenital heart disease (ACHD). Flow cytometry, using monoclonal antibodies, showed the presence of MPs as particles positive for the surface antigen (glycoprotein IIb/IIIa) specific to platelets, and platelet alpha-degranulation was recognized as platelets positive for the surface antigen of P-selectin. Platelet aggregation was assessed as the response to adenosine diphosphate (ADP). Relationships between these indexes and hematocrit (Hct) values were also evaluated. RESULTS: Production of MPs correlated positively with Hct and markedly increased at Hct values above 60% in patients with CCHD. Surface P-selectin and the mean platelet volume in patients with CCHD were comparable with those in patients with ACHD. The platelet aggregation response to ADP significantly and negatively correlated with Hct. In two subjects who showed hemoptysis and underwent phlebotomy, MPs were reduced 6 h after the procedure. CONCLUSIONS: Platelet MPs are overproduced in patients who have CCHD with polycythemia, probably due to a high shear stress derived from blood hyperviscosity. Circulating incompetent platelets, which have already been activated, as well as MPs, might play an important role in the coagulation abnormalities identified in such patients.