[Zasshi] [Journal]. Nihon Kyobu Geka Gakkai最新文献

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are homeostatic hormones secreted from the human heart which protect both cardiac and the renal function. It is well known that these hormones increase in patients along with increases in the severity of congestive heart failure or acute myocardial infarction. However, as yet there are no reports in the literature on changes of the secreted level of ANP or BNP in surgical patients undergoing cardiopulmonary bypass (CPB). We evaluated the relationship between ANP, BNP, and perioperative cardiac and renal functions in patients with heart failure caused by CPB. We selected 45 patients of elective open heart surgery. We measured plasma level of ANP in all 45 cases, and BNP in 18 cases at preoperation, postoperation, and postoperatively three days after, respectively. At the same time, the cardiac index (CI) was measured. These cases were divided into the following groups. Group A1 (n = 23): cases in which the preoperative ANP was less than 40 pg/ ml. Group A2 (n = 22): cases in which the preoperative ANP was more than 40. Group B1 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as mach as the normal level. Group B2 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as much as the normal level. Group B2 (n = 10): cases in which the preoperative BNP was more than that of 10 times as mach as normal level. We then carried out a comparative study of the perioperative cardiac and renal functions in group A1 and A2, and group B1 and B2, respectively. In the terms of preoperative cardiac and renal function, there were no significant differences between groups A1 and A2, and there were no significant differences in urinary volume during CPB or post operative CI. However, the urinary volume during CPB of group B1 was significantly more than that of B2. Furthermore, the incidence of postoperative CI in group B1. Furthermore, the incidence of postoperative CI in group B1 was significantly higher than in B2. The preoperative and post operative third day BNP level had significant negative correlations with postoperative CI and postoperative third day CI, respectively (r = -0.641, -0.514, p = 0.008, 0.012). The postoperative ANP and BNP levels tend to a mean level roughly similar to one another because of the easing of cardiac stress by surgery and postoperative management. According to these results and several instances in the literature, a preoperative high BNP is considered to suggest a potential perioperative risk for cardiac and renal function. We conclude that determination of the plasma BNP level can be helpful for decisions related to CPB flow and measures taken to enhance cardiac and renal protection during surgery, and therefore is a useful reference for perioperative management.

We evaluated the usefulness of noninvasive hemodynamic assessment of internal thoracic artery grafts (ITAGs) using duplex Doppler echocardiography from the supraclavicular fossa (transcutaneous pulsed Doppler method: PD method). Eighteen ITAGs were examined by PD method in comparison with Doppler catheter method using Doppler flowire (DC method). The hemodynamic indices used were the diastolic/systolic peak velocity ratio (DSVR) and the diastolic fraction of time-velocity integral (DF) in the ITAGs. A significant linear correlation was seen both in DSVR and DF between these two methods (p < 0.01). The subjects were assigned to two groups according to angiographic findings Group A (Gr-A: 5 grafts) with string sign including significant graft stenosis and group B (Gr-B 13 grafts) with good patency. In both PD and DC methods, DSVR and DF were significantly lower in Gr-A than in Gr-B (p < 0.01). The blood flow pattern was thus systolic dominant in the grafts with string sign, while it was diastolic dominant in the grafts with good patency. In some grafts in Gr-B, however, both DSVR ad DF were as low as that in Gr-A. Responding to pacing, Gr-B further increased both DSVR and DF, but Gr-A did not. As a result, the difference between both groups was further distinguished. In summary, ITAG function can be assessed by the noninvasive PD method. Interventions such as exercise, dobutamine infusion may make it more accurate, particularly in evaluating borderline data.

A 68-year-old man began complaining of dizziness and dyspnea on exertion 2 months ago. Chest X-ray and CT scan taken on admission revealed a giant tumor occupying almost all of the right thoracic cavity. The mediastinum, especially RA and IVC, was markedly oppressed and shifted by the tumor. MRI showed no invasive lesions of the tumor into adjacent organs. An operation was performed under the tentative diagnosis of solitary fibrous tumor (SFT) of the pleura by transcutaneous needle biopsy. The tumor was encapsulated and resected from the lower lobe of the right lung using a surgical stapler. Then the tumor was carefully dissected from the chest wall, pericardium and diaphragma, and removed completely. It weighed 3920 g and measured 22 x 20 x 20 cm. Various immunohistochemical properties of the specimen were morphologically compatible with SFT. The postoperative course was uneventful and the patient is now free of complaints. Because malignant cases of SFT have been reported a careful follow-up will be performed.

To evaluate the usefulness of the radial artery (RA) as a graft material for coronary artery bypass grafting (CABG), the histologic studies of the RA were performed. Specimens were obtained from both sides of 10 RAs during the operations. The degree of arteriosclerosis was evaluated by two methods. The one was microscopic examination by a pathologist, while the other was used by NIH Image 1.57 system. Using this system, the pathological index of arteriosclerotic change was expressed as a ratio (Rx: internal luminal area/tunica media area) of the cross section. From the pathological view the tunica media of RA was rich in smooth muscle cells and poor in elastic fiber. And there was little arteriosclerosis in this artery. The mean Rx of the proximal side of RA was 0.177 +/- 0.033 and that of the distal side was 0.258 +/- 0.132. There was no significant difference between the two, but the proximal side of the RA was slightly larger than the distal. These results showed that RA has a low grade of arteriosclerosis. This was confirmed on microscopic examination. According to these results, the RA can be expected to be a suitable bypass material for CABG.

Purpose of the present study was to evaluate functional and biochemical effects of hypoxia and hypothermia on cardiac myocytes, in order to identify the optimal temperature of cardiac myocyte preservation. Cardiac myocytes isolated from the neonatal rat ventricles (1.5 x 10(6) myocytes/culture flask) were incubated under the severely hypoxic conditions (partial pressure of oxygen was 20 mmHg) for 24 hours at 4 degrees C, 10 degrees C, 15 degrees C, 20 degrees C, 25 degrees C, and 37 degrees C. After each hypoxic incubation, CPK and LDH were measured in the incubation media. The myocytes were then cultured for additional 24 hours at 37 degrees C to evaluate the recovery of the myocyte beating rate. In 4 degrees C and 37 degrees C groups, the myocyte beating rate recovery was markedly low as 0.0% and 34.5% of the control, compared to the beating rate pr or to hypoxia, respectively (p < 0.001). Release of CPK and LDH (mIU/flask) was significantly higher in 4 degrees C (CPK: 197.1, LDH: 1395) and 37 degrees C (CPK: 138.6, LDH: 1201) groups, respectively (p < 0.001). CPK and LDH levels did not significantly increase among four (10 degrees C, 15 degrees C, 20 degrees C, and 25 degrees C) groups. In order to further confirm the optimal temperature, hypoxic incubation time was prolonged to 48 hours in 10 degrees C, 15 degrees C, 20 degrees C, and 25 degrees C groups. In 20 degrees C group, the myocyte beating rate recovery was highest to be 83.7% among the groups (p < 0.001 vs 10 degrees C, 25 degrees C, p < 0.05 vs 15 degrees C). Release of CPK, 33.1 mIU/flask, was lowest in 20 degrees C group (p < 0.001 vs 10 degrees C, p < 0.05 vs 15 degrees C). Release of LDH, 550.3 mIU/flask, was lowest in 20 degrees C group (p < 0.001 vs 10 degrees C, 25 degrees C, p < 0.05 vs 15 degrees C). Thus, cellular damage was lesser in 20 degrees C group both functionally and biochemically than the other temperature groups. These results suggested that 20 degrees C appears to be an optimal temperature for severely hypoxic preservation of the cardiac myocyte. This cell culture system may provide a useful and simple method for evaluation of the direct effects of hypoxia and hypothermia on cardiac myocytes in vitro.

A 70-year-old woman underwent radical mastectomy for carcinoma of the left breast in 1982. Postoperative radiation therapy was given in a total dose of 50 Gy for parasternal and left subclavian nodes. Symptoms of heart failure such as exertional dyspnea, facial edema, and hepatomegaly manifested in 1992. Cardiac catheterization revealed marked elevation of mean right atrial pressure and right ventricular end-diastolic pressure. The pressure wave form of the right ventricle showed the so called "dip and plateau" feature. Pericardiectomy without using extracorporeal circulation was performed in 1994. Operative findings and pathological study results were compatible with radiation-induced constrictive pericarditis. She rapidly recovered from heart failure after this operation, and has done very well to date.

A 60-year-old man with bloody sputum was admitted to our institute. Prior to the present admission, he had undergone coronary artery bypass graft surgery (GABG) at our institute 20 month earlier. The fiber optic bronchoscopy findings showed the cause of bleeding to be due to the migration of a post surgical temporary myocardial pacing lead which had been cut off at skin level after a CABG. Under general anesthesia we thus removed this migrated lead using both a fiber optic bronchoscope and forceps. The wire lead was easily removed and the patient has since suffered no more instances of bloody sputum.

Two successful cases underwent simultaneous repair for funnel chest using sternal turnover with rectus abdominal flap and intracardiac lesions were reported. A 7-year-old female (case 1) was diagnosed with funnel chest and annulo-aortic ectasia due to Marfan's syndrome. Second patient was a 12-year-old male (case 2) with funnel chest and ventricular septal defect (VSD). Both patients underwent sternal turnover and intracardiac repair (case 1: Bentall's operation, case 2: patch closure of VSD), simultaneously. Removing the cost-sterno complex before cardiac operation allowed an excellent surgical exposure. Bleeding was minimum, especially no homologous blood transfusion was needed in case 2. Simultaneous surgery consisted of intracardiac repair and sternal turnover is recommended even for pediatric patients.

Life-threatening complications can occur unexpectedly during general anesthesia in operations for superior vena caval (SVC) syndrome due to intrathoracic tumors. To prevent such sequelae, we have placed a temporary extracorporeal axillofemoral venous bypass graft with satisfactory results. In six patients (malignant mediastinal tumor, four; lung cancer, two), under local anesthesia before induction of general one, the cannulas, each appropriately sized in accordance with the diameter of the axillary and femoral veins, were directly introduced into the corresponding veins after systemic heparinization. The two cannulas were connected with a tube to which a side arm, which was usually clamped, was connected. The venous pressure of the internal jugular vein decreased immediately after establishment of the temporary bypass in all patients. The symptoms that accompanied SVC syndrome did not worsen and the life-threatening complications at the time of induction of general anesthesia were avoided with this procedure. In each case cardiopulmonary bypass on stand-by was unnecessary at this time. Venous bypass grafting with vascular prostheses were mainly performed under cardiopulmonary bypass, which was required for such operative procedures. In three patients the side arms were used for part of the venous drainage during cardiopulmonary bypass. The SVC syndrome instantly disappeared after operations in all patients including one in hospital death. No serious complications related to the temporary bypass procedure have been observed. This temporary bypass procedure has several advantages. It can be safely performed under local anesthesia with no special technique for the cannulation. Venous blood naturally drains from the upper part to the lower part of the body by pressure gradient, that warrants the safe induction of general anesthesia and ensuing operative procedures. The side arm is available for venous drainage during cardiopulmonary bypass. There are no serious complications related to the bypass procedure. Thus this temporary bypass is recommended as a life-saving and auxiliary device in urgent operations for acute progressive SVC syndrome with symptoms of cerebral edema and upper airway obstruction due to intrathoracic malignancies.

Aortic arch coarctation proximal to the left subclavian artery is a rare anomaly. It is about 1% of all coarctation of the aorta. This 16 days neonate with coarctation of aortic arch with severe subaortic stenosis and ventricular septal defect was underwent two staged repair. In the first-stage operation, coarctation of the aortic arch was reconstructed by extended end to end direct anastomosis through posterolateral thoracotomy. In the second stage, we performed intracardiac repair with use of a technique which included resection of superior margin of conus septum through VSD and patch closure of VSD. The postoperative pressure study showed no gradient between left ventricle and left radial artery. The postoperative course was satisfactory. This patient is doing well.