Significance of phlebosclerosis in non-healing ischaemic foot ulcers of end-stage renal disease.

OBJECTIVES: To determine the influence of haemodialysis on the poor healing of ischaemic ulcers in end-stage renal failure patients regardless of successful revascularization. MATERIALS AND METHODS: We investigated the microscopic findings of subcutaneous small vessels in the amputated limbs of 78 patients (27 diabetic/haemodialysis, 26 diabetic/non-haemodialysis and 25 non-diabetic/non-haemodialysis patients) who underwent foot/toe or limb amputation because of ischaemic foot ulcers in the period between 1998 and 2006. All the haemodialysis patients were diabetic. Multivariate logistic analysis was conducted to identify important clinical factors related to the histological findings. RESULTS: Marked medial thickening was observed in both small veins and arteries in diabetic patients compared with non-diabetic patients. In diabetics, there was significant medial thickening of small veins, which was greater in haemodialysis patients than in non-haemodialysis patients (Dunnett test, P<0.05). Multivariate analysis indicated that haemodialysis treatment (odds ratio 14.12, P<0.01), ABI value (odds ratio 5.41, P<0.01) and poor stump wound healing (odds ratio 6.19, P=0.03) were important factors related to medial thickening of small veins. CONCLUSIONS: Our data suggest that medial thickening of small veins, or phlebosclerosis, might affect the healing of ischaemic ulcers in end-stage renal failure, although the strong influence of diabetes cannot be ignored.

[Cor triatriatum diagnosed in adulthood; report of a case].

Cor triatriatum is a rare congenital cardiac anomaly especially in adulthood. A 68-year-old female was diagnosed as a cor triatriatum classified to Lucas-Schmidt IA, severe degree of mitral regurgitation and atrial fibrillation. Resection of the abnormal diaphragm in the left atrium and miral valve replacement were performed. Although the reason of sudden death of this patient after discharge is unknown, surgical intervention for atrial fibrillation should have performed to prevent a thromboembolism in such cases.

[Asplenia syndrome with total anomalous pulmonary venous connection].

Three patients of asplenia syndrome with total anomalous pulmonary venous connection (TAPVC) were reported. Case 1 with exceeding pulmonary blood flow, underwent TAPVC repair and pulmonary artery banding as a first palliation before bi-directional Glenn shunt. Case 2 did not require any surgery to control the pulmonary blood flow before the simultaneous procedure of TAPVC repair and bi-directional Glenn shunt. Case 3 with decreased pulmonary blood flow underwent a complicated course with 3 times of Blalock-Taussig shunts and the repair of TAPVC to prepare for bi-directional Glenn shunt. Simultaneous repair of TAPVC with the procedure which aimed to control the pulmonary blood flow at the first palliation surgery will simplify the control of pulmonary blood flow and prepare good condition of the lung for the Fontan operation in the future.

Effect of left ventricular assist device on circulatory autonomic nervous activity.

PURPOSE: For evaluation of the autonomic nervous system (ANS) activity of patients with mechanical circulatory support including LVAD, IABP and PCPS, arterial pressure variability (APV) was examined. APV is the power density values of pressure signals. High frequency (0.15 to 0.4 Hz) and low frequency (0.04 to 0.15 Hz) components of APV are regarded as a function of the autonomic nervous system. METHODS: Arterial pressure signals were acquired every 2 hours at 100 Hz for 6 minutes. Power spectral analysis was carried out, and APV was observed in 18 patients with IABP and/or PCPS. APV was also observed in 3 patients with LVADs (Xemex, Zeon Medical, Japan) before their discharge from ICU for transfer to another hospital for cardiac transplantation. RESULTS: Although the value gradually increased in 18 patients with IABP and/or PCPS, sustained low values of LFAnorm of APV in 6 patients were related to prolonged mechanical support, and 4 patients among them died consequently. The normalized power spectral component with low frequency (LFAnorm) was maintained at relatively high values in 3 patients with LVADs. CONCLUSION: The study results suggest that power spectral analysis of systemic arterial pressure offers a reasonable means for the evaluation of the severity of patient cardiovascular condition and for the prediction of clinical outcome. It also suggested that LVAD support exerts a favorable effect on ANS in patients with severe heart failure before cardiac transplantation.

Surgical management of a penetrated greenfield inferior vena cava filter.

This is a case report of an IVC filter penetration identified during lymph-node dissection for endometrial carcinoma. Although the spread strut put the adjacent abdominal aorta in danger of penetration, surgical removal of the filter could not be performed because there was still an increased risk of pulmonary embolism. Instead of IVC interruption, we used a wrapping technique as a prophylaxis against major bleeding complication due to IVC filter dislocation and recurrent pulmonary embolism.

Evaluation of stress on the autonomic nervous system of patients on mechanical circulatory assist.

PURPOSE: The power density values of high (HF; 0.15 to 0.4 Hz) and low frequency (LF; 0.04 to 0.15 Hz) components of arterial pressure were adopted for evaluation of stress on the autonomic nervous system of patients supported by mechanical circulatory assist. METHODS: Power spectral analysis (PSA) of arterial pressure signals was carried out, and trends in changes in the spectral components were observed in 12 patients on mechanical circulatory support (IABP and/or PCPS) and without the support (n=10). RESULTS: The normalized LF was depressed initially and increased gradually in both groups of patients except for four patients on mechanical circulatory assist. Three patients among them consequently died. CONCLUSIONS: Depressed LF represented marked stress on ANS and prolongation of the depression was related to poor outcome of patients. PSA of systemic blood pressure offers a reasonable tool for evaluation of stress on the ANS and for prediction of the prognosis of patients with circulatory assist devices.

Late aneurysm of the distal aortic arch after repair of aortic interruption. A case report.

Aneurysm formation after aortic coarctation repair is not a rare complication of post-coarctation of aorta repair. We describe the case of a 43-year-old woman who had undergone repair of an isolated interruption of the aortic arch 30 years earlier, who came to our hospital with progressive chest pain, cough and dyspnea. A giant aortic aneurysm was revealed in the distal aortic arch by CT study. The patient underwent aneurysmectomy with total aortic arch replacement using a Dacron graft through redo median sternotomy. An embryologic explanation of this patient's anomaly and the previous surgical procedure are discussed for defining this rare clinical condition.

[A case of lateral femoral circumflex artery as a free graft for coronary artery bypass surgery].

A 46-year-old man had a three-vessel coronary disease. We performed quadruple coronary artery bypass grafting (CABG) with the left internal thoracic artery (LITA), right gastroepiploic artery (RGEA), saphenous vein and lateral femoral circumflex artery (LFCA). Postoperative coronary angiogram showed that the LFCA bypass graft was patent and supplied sufficient blood to the anastomosed vessel. There was no stenosis at the anastomotic site. However, the LFCA graft showed a string sign. Long-term follow-up and angiographic studies is necessary to establish the use of LFCA as an arterial free graft for coronary revascularization.

Upper extremity vein thrombosis: etiologic categories, precipitating causes, and management.

Although an increasing incidence of upper extremity venous thrombosis (U/E-DVT) has been reported, a relative paucity of information regarding the etiologic categories, precipitating causes, and proper management for this disorder is available. To settle on a strategy for the management of U/E-DVT, retrospective analyses were performed using records from the authors' hospital. In 12 patients (seven men, five women), 61 (mean) years of age, diagnosed as having symptomatic venography-proved U/E-DVT and followed up for 41 (mean) months, etiologic factors, precipitating causes, treatments, and outcomes were retrospectively analyzed. As etiologic factors, five of the patients had neoplastic disease, one had hemodialysis, and two had transvenous pacemaker implantations. Among various precipitating causes of U/E-DVT, hypoproteinemia was most frequently noted (67%). Various types of therapeutic management were selected: from thrombolysis with urokinase in six, balloon angioplasty in two, thrombectomy in two, and venous bypass surgery in one patient. Pulmonary embolism did not occur in any of the patients and only three of them complained of mild intermittent arm swelling during the follow-up period. Four patients died of neoplastic disease or heart failure (three within the first 6 months). This study, though limited, suggests that the rate of mortality depends on multiple underlying medical problems in U/E-DVT patients. Low incidences of late postthrombotic sequelae and pulmonary embolism were noted in this series. Symptomatic U/E-DVT patients could be managed conservatively with a revised supplementary therapy for their precipitating causes of U/E-DVT.

Low-dose protamine based on heparin-protamine titration method reduces platelet dysfunction after cardiopulmonary bypass.

OBJECTIVE: The heparin-protamine titration method that uses the Hepcon hemostasis management system (Medtronic HemoTec Inc, Englewood, Colo) reduced blood loss in cardiac surgery in previous reports, but the mechanism is not fully understood. This study tests the hypothesis that reduced protamine administration preserves platelet function in human cardiac surgery. METHODS: Platelet count, alpha-granule secretion, and aggregation to thrombin before and after cardiopulmonary bypass in human beings were evaluated. In the control group (n = 14), a fixed dose of protamine (3 mg/kg) was administered. In the titration group (n = 20), protamine doses were based on the heparin concentration measured by the Hepcon system. RESULTS: Heparin concentrations before protamine administration were higher in the titration group (P =.0012), but protamine doses of patients in the titration group were markedly lower than those of the control group (P <.0001). During protamine infusion at a rate of 0.3 mg. kg(-1). min(-1), the percentage of granule membrane protein-140-positive platelets significantly increased in the control group compared with the titration group (18.8% +/- 8.6% vs 13.0% +/- 5.3%, P =.0188). After protamine administration, aggregation of washed platelets to thrombin recovered almost to the preoperative level in the titration group; however, it remained lower in the control group (20% +/- 20% vs 55% +/- 18%, P =.0009). CONCLUSION: Low-dose administration of protamine, based on a heparin-protamine titration method, restores not only the blood coagulation but also the platelet responses to thrombin and attenuates platelet alpha-granule secretion during heparin neutralization. Overdose of protamine activates platelets and may predispose patients to excessive bleeding after cardiac surgery.

Lower extremity hematoma as a complication of warfarinization in patients with artificial heart valves.

Four cases of lower extremity hematoma in patients undergoing anticoagulant therapy after heart valve replacement are herein reported, with special emphasis on the comparative diagnostic value of ultrasonography and computerized tomography. Although conservative management is sufficient for patients with no neurological impairment, needle aspiration after autolysis of the hematoma, which can be confirmed by CT study, is also recommended.

Atrial fibrillation after coronary artery bypass grafting. An increase in high-frequency atrial activity in patients with right coronary artery revascularization.

The increase in atrial high-frequency activity has been reported as a marker of the risk of paroxysmal atrial fibrillation. The presence of proximal right coronary artery disease is a predictor of atrial fibrillation after bypass surgery, however, the potential mechanism remains controversial. In this study, high-frequency atrial activity to clarify the electrophysiologic background for the predisposition to have proximal right coronary artery disease leading to atrial fibrillation after coronary revascularization was investigated. Before and soon after coronary revascularization, frequency analyses were performed on the 100 ms segment at the end of signal-averaged P waves in 22 patients with right coronary artery disease as opposed to the 23 patients without disease. Under the spectrum curve, area ratio (AR50) and magnitude ratios (MR) were calculated as follows; AR50 = (area 20-50 Hz/0-20 Hz) x 100, and MR = (magnitude at 20, 30, 40 and 50 Hz, respectively/maximal magnitude) x 100. In patients with proximal right coronary artery disease, high-frequency atrial components increased significantly in the 20 to 50 Hz range after coronary revascularization, and the incidence of postoperative atrial fibrillation was higher than in those without disease. In patients without right coronary artery disease, the frequency distribution of P waves was unchanged. Postoperatively, the two groups showed the same atrial frequency distribution. This data suggests that the increase in high-frequency atrial activity after right coronary artery revascularization might be associated with the pathogenesis of postoperative atrial fibrillation.

Species differences in erythrocyte mechanical fragility: comparison of human, bovine, and ovine cells.

The erythrocyte destruction rate under constant shear stress was measured to clarify species differences in red blood cell (RBC) mechanical fragility between human, bovine, and ovine cells. Blood was collected from healthy donors by venipuncture. RBC age fractionation was performed by high speed centrifugation (20 min at 12,000 g). Relatively young, middle, and old age RBCs was suspended in Dulbecco's phosphate buffered saline to adjust the hematocrit to 35%. Uniform shear stress was applied to each sample contained in a concavo-convex Couette flow testing machine. Young and old aged samples were exposed to 300 dyne-sec-cm2 for 0 and 15 min. Middle aged samples were exposed to 300 dyne-sec-cm2 for 0, 5, 10 and 15 min. Liberated hemoglobin was estimated by tetramethylbenzidine colorimetric measurement and the erythrocyte destruction rate was calculated. Older samples had a higher hemolysis rate than younger samples in every species. The destruction under constant shear stress is approximately linear in time. Mechanical fragility of ovine and bovine RBCs was 1.8 and 0.5 times as large as human RBCs, respectively. These values could serve as universal standards when extrapolating animal hemolysis data for any blood pump to predict its safety and biocompatibility in human clinical trials.

Right thoracotomy as an alternative for redo mitral valve replacement and concomitant repair of the tricuspid valve.

BACKGROUND: We report the results of a right thoracotomy for reoperation on the mitral plus concomitant procedures. Access to aorta or repair of other lesions by this approach is controversial. EXPERIMENTAL DESIGN AND SETTING: Retrospective study. Institutional practice (University of Tsukuba Hospital, Tsukuba Japan). METHODS: Until 1995, 9 patients underwent right thoracotomy for mitral reoperation. The indication for this approach was no retrosternal space with the pericardium left open. Seven patients had deteriorated bioprosthesis, 1 periprosthetic valve leakage, and 1 re-stenosis. Four were associated with moderate tricuspid regurgitation. Operations were performed under fibrillation. Cardioplegia was used in 1. RESULTS: Through thoracotomy, 4 underwent mitral valve re-replacement, and 4 mitral valve re-replacement plus tricuspid annuloplasty. One was abandoned because of severe pleural adhesion. No neurological injury, or perioperative myocardial infarction occurred. CONCLUSIONS: The right thoracotomy was an effective alternative to repeat sternotomy for redo mitral valve operation. Also, concomitant repair of the tricuspid valve could be safely done by this approach.

Method of noninvasive and continuous hemolysis/thrombogenesis measurement by laser photometry during artificial heart development.

The purpose of this research is to propose and develop a method to measure hemolysis and thrombogenesis non invasively and continuously to aid in development of an artificial heart. Generally, the optical absorption rate of hemoglobin is influenced by oxygen saturation except at the isosbestic point, which is not influenced by oxygen saturation. The authors, therefore, used an 805 nm laser diode, an optical spectrum analyzer to obtain greater accuracy. An experimental blood circuit system was constructed using a Bio-Pump, Tygon tubing, a soft shell reservoir, and an optical measurement system. Experimental settings for monitoring hemolysis were as follows; blood volume 200 ml, blood flow 6 L/min, and afterload 200 mmHg. Blood was sampled six times (0, 30, 60, 120, 180, and 240 min), and hemolysis in each sampled was measured using a colorimetric method. Comparing continuous laser measurement data with the sample data, an adequate correlation is obtained, proving that the dynamic trend of hemolysis could be continuously measured. Furthermore, to analyze the process of thrombogenesis, simple experiments were performed using blood neutralized by protamine. As a result, the authors could see the process of thrombogenesis as it occurred and could confirm that this method is able to dynamically detect hemolysis and thrombogenesis.

Aprotinin inhibits plasmin-induced platelet activation during cardiopulmonary bypass.

BACKGROUND: In the past few years, aprotinin has been used in cardiac surgery with impressive results of reducing blood loss, but several adverse effects of aprotinin also have been reported. One of the most likely mechanisms is the inhibition of plasmin by aprotinin, although this indirect effect has not been reproduced in all experimental studies. METHODS AND RESULTS: We evaluated the platelet function and fibrinolytic activity during human cardiac surgery, with or without aprotinin. During cardiopulmonary bypass (CPB) in humans without aprotinin (n=16), decrease of platelet aggregation induced by thrombin, increase of alpha-granule secretion of platelet and microparticle formation, and increase of plasmin/alpha2-antiplasmin complex (PIC) were observed. In contrast, low-dose aprotinin (1.0 x 10(6) KIU), which was administered only into the priming fluid of extracorporeal circuits (n=10), maintained platelet aggregation induced by thrombin and reduced alpha-granule secretion and microparticle formation of platelets during CPB. In vitro, plasmin (0.8 CU/mL) released alpha-granules of washed platelets, and this activation was completely inhibited by aprotinin (10 KIU/mL). CONCLUSIONS: Aprotinin has indirect effects to inhibit platelet activation, and this may partly explain the reduction of blood loss during cardiac surgery. To prevent the adverse effects, a single and minimal use of aprotinin is important. The results of in vivo and in vitro studies suggest that platelet preservation was demonstrated by the lower concentration of aprotinin (1.0 x 10(6) KIU per patient or 10 KIU/mL) compared with the concentration that inhibits plasma fibrinolysis.

Reoperation of coronary artery bypass with right gastroepiploic artery on a beating heart.

The case of a 67-year-old male with double-vessel coronary artery disease combined with a severely calcified ascending aorta, moderate aortic insufficiency, cholecystic stones, and unruptured intracranial aneurysm is presented. Successful coronary artery bypass reoperation is described using the right gastroepiploic artery through an additional left anterior thoracotomy on the beating heart.

[Aortic valve regurgitation due to quadricuspid valve: a report of complicated case].

A 66-year-old male with the congestive heart failure was diagnosed grade 4 aortic valve regurgitation due to quadricuspid valve associated with bacterial endocarditis, widely patent left coronary artery ostium, chronic renal failure, and secondary hyperparathyroidism. Coronary arteriography showed that the size of left coronary ostium was widely patent 10 mm in diameter, and trans-esophageal echo cardiogram revealed perforation and vegetations on the coronary cusps of the aortic valve.

[Management of postoperative pulmonary hypertensive crisis in children--indication and usefulness of inhaled nitric oxide therapy as a pulmonary vasodilator].

Among 176 pediatric patients who underwent open heart surgery from 1990 to 1996, 7 developed severe pulmonary hypertensive crisis (PHC) postoperatively. All patients were treated with conventional medical therapy consisting of hyperventilation and deep sedation. Prostaglandin E1 and/or amrinone were administered initially as a pulmonary vasodilator, and in 3 of the 7 patients this resulted in immediate improvement in hemodynamics. These patients subsequently weaned off ventilatory support and they were discharged from the hospital. In 4 other patients, pulmonary vasodilator therapy with prostaglandin E1 and amrinone had failed and they were treated with inhaled nitric oxide (NO). In all patients, inhalation of NO resulted in immediate decrease in pulmonary pressure without significant change in systemic arterial pressure. Two patients successfully weaned from the ventilator, whereas in 2 patients decrease in pulmonary pressure was transient. They developed airway bleeding and died as a result of respiratory insufficiency. Although inhaled NO effectively reduced pulmonary pressure in patients with PHC, this effect was not maintained over 12 hours in patients associated with bronchopulmonary dysplasia. In patients at risk for severe PHC, rapid treatment with NO inhalation after initial event as well as the prevention of lung injury caused by mechanical ventilation were found to be important in the postoperative management.