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N Sakakibara

Publications and source records attributed to N Sakakibara.

At least 37 records · Page 2Linked to original sources
PubMed1998

Myocardial oxygenation during terminal warm blood cardioplegia.

BACKGROUND: Terminal warm blood cardioplegia accelerates myocardial metabolic recovery. The process of myocardial oxygenation during terminal warm blood cardioplegia and its optimal administration are not clear. METHODS: We measured the myocardial tissue oxygen saturation (SO2) during reperfusion using near-infrared spectroscopy. Twenty-four dogs underwent 1 hour of ischemic arrest with cold crystalloid cardioplegia. They were then divided into four equal groups. Group 1 dogs received normal blood reperfusion. The other dogs received 15 mL/kg of terminal warm blood cardioplegia at 80 mm Hg in group 2 or at 60 mm Hg in group 3, and 30 mL/kg of cardioplegia at 60 mm Hg in group 4, followed by blood reperfusion. RESULTS: In group 1, the SO2 increased gradually during the early reperfusion and decreased transiently during the late reperfusion. In group 2, the SO2 increased rapidly but it decreased transiently during blood reperfusion. In groups 3 and 4, the SO2 increased rapidly and remained at high levels during the blood reperfusion. Reperfusion ventricular fibrillation occurred along with a SO2 decrease only in groups 1 and 2. The postischemic troponin-T levels of groups 3 and 4 were lower than that of group 1. The functional recovery in group 4 was better than those in the other three groups. CONCLUSIONS: Terminal warm blood cardioplegia accelerates the early SO2 increase and abolishes the SO2 decrease during subsequent reperfusion and reduces the incidence of reperfusion arrhythmia, suggesting that it ameliorates reperfusion injury and consequently improves postischemic functional recovery.

Animals↗
PubMed1998

Coronary bypass flow during use of intraaortic balloon pumping and left ventricular assist device.

BACKGROUND: Intraaortic balloon pumping (IABP) and left ventricular assist device (LVAD) are used for left ventricular support when low cardiac output occurs after a coronary bypass operation for serious coronary artery disease. There are hemodynamic differences in blood flow in various kinds of coronary artery bypass grafts, caused by their inherent physiologic characteristics. The hemodynamic effects of left ventricular assistance with IABP and LVAD on blood flow through various coronary artery bypass grafts were investigated. METHODS: An ascending aorta-coronary bypass graft (ACB), an internal thoracic artery, and a descending aorta-coronary bypass graft were anastomosed to the left anterior descending coronary artery in a canine model. In this experimental model, the blood flow to the same coronary bed in the three types of grafts could be evaluated. Blood flow in the left anterior descending coronary artery through the three types of coronary bypass grafts was studied in this model during or in the absence of ventricular assistance. RESULTS: In the control study, the systolic blood flow did not differ among the three types of grafts, but the diastolic flow decreased in the following order: with the ACB, the internal thoracic artery, and the descending aorta-coronary bypass graft. The systolic flow during IABP and LVAD was similar to the control flows. Use of IABP increased the diastolic flow by 75.3%+/-12.4% of the control value in the ACB, 37.9%+/-25.0% in the internal thoracic artery, and 21.2%+/-11.4% in the descending aorta-coronary bypass graft. The LVAD increased the diastolic flow by 97.7%+/-18.7% of the control value in the ACB, 64.5%+/-25.7% in the internal thoracic artery, and 63.0%+/-27.9% in the descending aorta-coronary bypass graft. The diastolic blood flows in the left anterior descending coronary artery and the three types of grafts were significantly greater with IABP than the control values, and significantly greater with LVAD than with IABP and the control values. The degrees of increase of diastolic flows in the left anterior descending coronary artery and the ACB with IABP and LVAD were significantly greater than in the arterial grafts (p < 0.01). CONCLUSIONS: The diastolic flows in the internal thoracic artery and descending aorta-coronary bypass graft increased less than in the native left anterior descending coronary artery and ACB during left ventricular assistance, particularly with IABP. It is important for the selection of tactics for the management of catastrophic status after coronary bypass grafting to consider the hemodynamic characteristics of the graft.

Animals↗
PubMed1998

Ultrastructural assessment of the myocardium receiving intermittent antegrade warm blood cardioplegia.

Ultrastructural changes in the myocardium during intermittent warm blood cardioplegia were studied in 12 dogs. During cardiopulmonary bypass, dogs received three 5-minute periods of warm blood cardioplegia, interrupted by three 10-minute episodes of ischemia in group A or three 20-minute episodes of ischemia in group B. Biopsy specimens were taken from the right ventricle before each cardioplegic infusion and at the end of the aortic cross-clamp period to analyze ultrastructural changes. Functional recovery was measured after cardiopulmonary bypass. Mild and principally reversible ultrastructural changes were observed in group A. In group B, moderate ultrastructural changes were observed, and these changes suggested cumulative ischemic injury. Functional recovery was good in group A, but significantly deteriorated in group B. We concluded that three 10-minute interruptions of warm blood cardioplegia cause mild ultrastructural changes and seem to be safe, but three 20-minute interruptions cause cumulative ischemic injury in normal dog hearts.

Animals↗
PubMed1998

Epitope mapping of bovine leukemia virus transactivator protein Tax.

The immunogenicity of the bovine leukemia virus (BLV) transactivator protein (tax) was studied by mapping its B-cell and T-cell epitopes. Peptides (18 to 20-mer) overlapping by 10 amino acids, spanning whole amino acid sequence of BLVtax were synthesized. Recombinant BLVtax protein was used to immunize two different strains of mice, C57BL/6 and BALB/c. B-cell and T-cell epitopes of recombinant BLVtax protein was determined by screening all the 30 synthetic peptides, against immune serum in ELISA for antibody reactivity, and against immune spleen cells in lymphocyte proliferation assay for T-cell stimulation. Peptides with amino acids at position 111-130 and 131-150 were T-cell epitopes for C57BL/6 and BALB/c mice immune cells, respectively. B-cell epitope was mapped to amino acid sequence at 261-280 in both strains of mice. These results imply that BLVtax protein contains some of BLV- immunodominant epitopes and this information may be applied for designing an effective peptide vaccine capable of inducing neutralizing antibodies as well as cellular immunity.

Amino Acid Sequence↗
PubMed1998

Low incidence of minor myocardial damage associated with coronary stenting detected by serum troponin T comparable to that with balloon coronary angioplasty.

The use of the serum troponin T (TnT) level as a means of assessing minor myocardial injury, which affects the long-term prognosis, has not been fully clarified in patients with coronary artery disease in whom a coronary stent has been implanted. We measured the TnT level to determine the incidence of myocardial damage associated with stent implantation. A total of 29 patients who underwent successful stent implantation (stenting group) were studied and compared with 45 patients who underwent successful coronary balloon angioplasty during the same period (balloon angioplasty group). The serum TnT level was measured by enzyme immunoassay 36 hours after the stenting or balloon angioplasty. The activities of serum creatine kinase (CK) and its isoenzyme MB (CK-MB) were measured by a modified Rosalski method and an immunoinhibition method, respectively, before, immediately after, and 6, 12, and 24 hours after the procedure. Elevation of the TnT level was found in 3.4% (1/29; 0.35 ng/ml) of the patients in the stenting group and in 8.9% (4/45; 0.75 +/- 0.21 ng/ml) of those in the balloon angioplasty group. Elevation of the CK and CK-MB activities was found in 3.4% (1/29; 163 IU/l) and 0%, respectively in the stenting group, and 15.5% (7/45; 375 +/- 143 IU/l) and 4.4% (2/45; 24 and 49 IU/l), respectively, in the balloon angioplasty group. TnT elevation was not invariably accompanied by CK or CK-MB elevation, or by angiographically visible side branch occlusion. For TnT, CK-MB activity and CK activity, there was no significant difference between in the incidence of elevation in the balloon angioplasty group and that in the stenting group. In summary, the incidence of myocardial damage associated with stent implantation seems to be low and comparable to that associated with balloon angioplasty. Despite the low incidence, measurement of the serum TnT level in addition to CK-MB measurement is essential in assessing minor myocardial damage.

Aged↗
PubMed1998

[Pitfall of minimally invasive direct coronary artery bypass].

Six thoroughly selected patients underwent minimally invasive direct coronary artery bypass grafting (MIDCAB). While monitoring left ventricular function with transesophageal echocardiography, MIDCAB was done by performing small left thoracotomy through the fourth intercostal space, dissection of the left internal thoracic artery without thoracoscopy, ischemic preconditioning, and grafting of the internal thoracic artery to the left anterior descending coronary artery with 8-0 polypropylene continuous suture. A home-made cardiac stabilizer and Visuflow enabled us to perform precise suturing of the internal thoracic artery. The patency of all grafts was confirmed by early transthoracic Doppler echocardiography and selective angiography. A new stenosis of the coronary artery distal to the anastomosis was detected probably due to coronary snaring in one patient. The anastomosis sites were confined to the distal segments of the left anterior descending coronary artery in MIDCAB patients. The optimal anastomosis site may be missed in the patients with proximal left anterior descending artery disease. An experimental study of myocardial tissue oxygen saturation using near infrared spectroscopy showed that two times of coronary occlusion and reperfusion provided satisfactory effects of ischemic preconditioning. Measurement of the myocardial tissue oxygen saturation may be helpful for confirming effective ischemic preconditioning and a safe coronary occlusion during MIDCAB. Although MIDCAB is an attractive procedure, we should consider the accuracy of anastomosis, the risk of possible incomplete revascularization, the indications, and long-term results.

Aged↗
PubMed1998

[A case report of cavernous hemangioma of the left atrial epicardium].

Cardiac hemangioma is a rare benign vascular tumor. A 44-year-old woman with hemangioma arising from the left atrium and transient atrial fibrillation is reported. Echocardiography, computed tomography and magnetic resonance imaging suggested a hypervascular tumor with clear borders in the pericardial cavity. Selective coronary angiography demonstrated feeding arteries arising from the right and left circumflex coronary arteries. Under cardiopulmonary bypass the tumor was successfully resected. Pathological examination showed a cavernous hemangioma. There is no evidence of recurrence and the patient is doing well three years after the operation.

Adult↗
PubMed1998

[Evaluation of the effect of ischemic preconditioning using near-infrared spectroscopy].

Ischemic preconditioning (IP) protects the myocardium from subsequent sustained ischemic insults. Temporary occlusion of the coronary artery is indispensable for anastomosing the graft vessel during coronary artery bypass operation without cardiopulmonary bypass. In the canine model of ischemia and reperfusion, we measured myocardial tissue oxygen saturation (SO2) continuously using near-infrared spectroscopy to determine the effect of IP on myocardial oxygen metabolism. Nine dogs underwent occlusion of the left descending coronary artery for three 5-minute periods, followed by three 5-minute periods of reperfusion. The dogs were then subjected to a 20-minutes periods of sustained coronary artery occlusion, followed by prolonged reperfusion. The myocardial SO2 was 82 +/- 2% at the baseline before coronary occlusion and was decreased to 74 +/- 2%, 76 +/- 2%, 77 +/- 3%, 77 +/- 3% at the first, second, third and sustained coronary occlusion, respectively. The increase in the minimum myocardial SO2 value at the second and third coronary occlusion suggested the effect of IP. Near-infrared spectroscopy is a useful method of continuously monitoring myocardial oxygenation and of evaluating the effect of IP during off-pump heart surgery.

Animals↗
PubMed1997

Complications after cyst excision with hepaticoenterostomy for choledochal cysts and their surgical management in children versus adults.

The aim of this study was to review the cases 200 children and 40 adults who had cyst excision combined with hepaticoenterostomy (CEHE) for choledochal cyst, with particular emphasis on post-CEHE complications and their surgical management. Patients who had CEHE at the age of 15 years or less were defined as children, and those aged 16 years or older were defined as adults. The mean age when patients became initially symptomatic was 3 years in children and 26 years in adults. Eleven adults became symptomatic as children (< or = 15 years of age). The mean age of CEHE in children and adults was 4.2 years and 35 years, respectively. The time interval between the onset of initial symptoms and CEHE was significantly less in children than in adults (P < .0001). Of the 200 children, 176 had primary CEHE, and 24 had secondary CEHE converted from cystoenterostomy or other biliary surgery. Seventy children had intraoperative cyst endoscopy, which enabled us to examine the proximal intrahepatic bile ducts for stenosis and debris, and to wash out debris, protein plugs, and stones from the intrapancreatic ducts. Of the 40 adults, 22 had primary CEHE, 18 had secondary CEHE. The mean follow-up period was 10.9 years in children and 10.7 years in adults. The number of patients with post-CEHE complications in children and adults was 18 (9.0%) and 17 (42.5%), respectively. The post-CEHE complication rate in children was significantly lower than in adults (P < .0001). The 18 children had 25 post-CEHE complications such as cholangitis, intrahepatic bile duct stones, pancreatitis, stone formation in the intrapancreatic terminal choledochus or pancreatic duct, and bowel obstruction. Twenty-seven post-CEHE complications developed in the 17 adults including 2 cases of cholangiocarcinoma. There were no post-CEHE complications in the 70 children who had intraoperative cyst endoscopy. No stone formation was seen in the 145 children who had CEHE at the age of 5 years or less. Eight stone formations were seen in seven (12.7%) of the remaining 55 children aged over 5 years. Stones developed in seven (17.5%) adults. The incidence of post-CEHE stone formation in children aged 5 years or less was significantly lower than in other children and adults (P < .0001). Reoperation was required in 15 children: revision of hepaticoenterostomy in 4, percutaneous transhepatic cholangioscopic lithotomy (PTCSL) in 1, excision of intrapancreatic terminal choledochus in 2, endoscopic sphincterotomy of the papilla of Vater in 1, pancreaticojejunostomy in 1, and laparotomy for bowel obstruction in 6. Ten adults required reoperations: revision of hepaticoenterostomy in 2, PTCSL in 2, left hepatic lobectomy in 1, endoscopic sphincterotomy in 2, exploratory laparotomy in 2, and adhesiolysis in 1. The authors conclude that early diagnosis followed by CEHE is the treatment of choice for choledochal cyst, and intraoperative cyst endoscopy is recommended as a valuable adjunct to CEHE.

Adolescent↗
PubMed1997

Failure of gastroepiploic artery graft due to gastroduodenal artery stenosis.

We report a patient with recurrent angina after gastroepiploic artery grafting to the right coronary artery because of a stenotic lesion of the gastroduodenal artery, which limited blood flow through the right gastroepiploic artery graft and caused myocardial ischemia. The patient was successfully treated by saphenous vein grafting to the right coronary artery without cardiopulmonary bypass.

Aged↗
PubMed1997

Near-infrared monitoring of myocardial oxygenation during intermittent warm blood cardioplegia.

OBJECTIVE: This study was performed to examine the ability of near-infrared spectroscopy to monitor tissue oxygenation in the cardioplegically arrested heart and to assess myocardial oxygen metabolism during intermittent warm blood cardioplegia. METHODS: Using a three-wavelength near-infrared spectroscopy, we continuously measured myocardial tissue oxygen saturation and the tissue hemoglobin concentration during intermittent warm blood cardioplegia. Under normothermic cardiopulmonary bypass, 20 dogs received three 5-min periods of antegrade warm blood cardioplegia, interrupted by three 10-min episodes of ischemia in group 1 (n = 7), three 15-min episodes of ischemia in group 2 (n = 6), or three 20-min episodes of ischemia in group 3 (n = 7). RESULTS: Myocardial oxygen saturation during beating and ventricular fibrillation was 80 +/- 1 and 59 +/- 1%, respectively. Myocardial oxygen saturation rapidly increased to 82 +/- 1% at blood cardioplegic infusion and decreased to 58 +/- 1% 3 min after cardioplegic interruption. The time required to reach the peak oxygen saturation level decreased significantly at the second and third infusions compared to the first infusion in group 1, whereas the time increased significantly at the third infusion in groups 2 and 3. The slower rate of increase in oxygen saturation suggested reduced coronary vasodilator reserve due to microvascular abnormalities. Reperfusion ventricular fibrillation occurred in none of group 1, one of group 2 and three of group 3. CONCLUSIONS: Near-infrared spectroscopy is a useful method of continuously monitoring myocardial oxygenation and ischemia during warm heart surgery. Episodes of ischemia longer than 10 min during warm blood cardioplegia resulted in less-than-optimal myocardial preservation and should be avoided.

Analysis of Variance↗
PubMed1997

[Clinical study of gasless laparoscopic adrenalectomy in 17 cases--comparison between laparoscopic adrenalectomy with and without pneumoperitoneum].

PURPOSE: To determine the efficiency of gasless laparoscopic adrenalectomy, this procedure was compared to that with pneumoperitoneum. PATIENTS AND METHODS: Between February 1994 and December 1996, 17 gasless laparoscopic adrenalectomy were performed in 5 men and 12 women, 36 to 79 years old. Clinical diagnosis was primary aldosteronism in 8, pheocromocytoma in 2, incidentaloma in 4 and adrenal cyst in 3. When gasless laparoscopic adrenalectomy was performed, the laparoscope was inserted through the upper margin of the umbilicus by open laparotomy. To create a workable space, a 1.2 mm Kirschner wire was advanced subcutaneously below the costal arch and attached to a retractor. Operating time, estimated blood loss, changes of the end tidal CO2 concentration during operation, operative complications and postoperative course were compared to those with pneumoperitoneum in 12 cases. RESULTS: In both procedures, satisfying workable spaces were created in all cases. The mean operating time and estimated blood loss were 245 min and 201 ml without pneumoperitoneum, 317 min and 274 ml with pneumoperitoneum, respectively. The mean changes of end tidal CO2 concentration during operation were 3.2 mmHg without pneumoperitoneum and 5.1 mmHg with pneumoperitoneum. As operative complications, open operations were required in 2 cases (1 without pneumoperitoneum and another with pneumoperitoneum) to control intraoperative bleeding. They had the histories of transabdominal operations. Postoperative bleeding was observed in 2 cases (1 without pneumoperitoneum and another with pneumoperitoneum). One of them (with pneumoperitoneum) needed surgical management for hemostasis. Fever over 38 degrees C that occurred in 1 case with pneumoperitoneum appeared to be absorption fever. No differences were observed in the number of the days to the start of oral intake and for postoperative hospitalization between the two groups. CONCLUSIONS: Gasless laparoscopic adrenalectomy is available for most adrenal tumors. Suction could be used unrestrictedly and there were no hemodynamic or ventilatory effects due to pneumoperitoneum. This procedure appears to be safe and advantageous for the treatment of most adrenal tumors.

Adrenal Gland Diseases↗
PubMed1997

[Urgent medical situation and therapeutic strategy in patients undergoing digestive cancer surgery (inflammation, stenosis, hemorrhage)].

Inflammation, stenosis, and hemorrhage are thought to create an urgent medical situation in patients with digestive cancer. Peritonitis originating in perforation or penetration and intra-abdominal abscess are inflammations due to cancer. An urgent operation is necessary for patients with panperitonitis. In a patient with localized peritinitis and intra-abdominal abscess, primarily conservative therapy using antibiotics and immunoglobulin is tried, but surgical or stabbing drainage is necessary when symptoms take a turn for the worse. Bougienage, insertion of prosthesis, and detention of expandable metallic stent are considered conservative therapy for stenosis due to cancer. Surgical resection of tumor or bypass operation is applied as surgical therapy for stenosis due to cancer. Blood transfusion, endoscopic hemostasis, and transcatheter arterial embolization are considered conservative therapy for hemorrhage due to cancer, while surgical hemostasis and resection of tumor are used as surgical therapy for hemorrhage due to cancer. In any case, surgical therapy is timely and necessary when symptoms take a turn for the worse in spite of conservative therapy for urgent medical treatment of patients with digestive cancer.

Abdominal Abscess↗
PubMed1997

[A case of advanced gastric cancer with carcinomatosa peritonitis effectively treated by 5-FU and low-dose CDDP therapy].

A 66-year-old woman was admitted to our clinic for appetite loss and abdominal distension in August 1995. Endoscopic study revealed an advanced gastric cancer in the upper body of her stomach. Abdominal CT study revealed massive ascites and para-aortic lymph nodal involvement. Cytological study of the ascites revealed class V. She was diagnosed to be in the terminal stage of gastric cancer with carcinomatosa peritonitis. Combination chemotherapy with 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) was given by continuous intravenous injection of 5-FU 500 mg/day, and intermittent intravenous injection of CDDP 30 mg/week was performed for reduction of the ascites and her complaint. Endoscopic study 6 weeks after starting chemotherapy could not find crater of the gastric cancer but only a shallow ulcerative lesion. The biopsy specimen of that lesion was group III. No ascites and over 50% reduction of the para-aortic lymph node were found by the abdominal CT study. This state persisted over 4 weeks. No myelo-suppression, renal dysfunction or any severe side effect were observed during chemotherapy. Her performance status improved from 3 to 1.

Aged↗
PubMed1997

Coronary to bronchial artery anastomosis in patients with noncyanotic cardiopulmonary disease: report of seven cases.

An angiographically visible coronary to bronchial artery anastomosis was found in seven (0.12%) of 6045 patients with noncyanotic cardiopulmonary disease who underwent coronary angiography between 1989 and 1995. Aortitis syndrome was associated with four patients, whereas pulmonary embolism, aortic regurgitation and vasospastic angina were the diagnoses in the others. Coronary stenotic lesions were not observed in any patients. In five of six patients who underwent pulmonary perfusion scintigraphy, perfusion defect was observed in the area supplied by the bronchial artery, which had the anastomosis to the coronary artery. In each patient this anastomosis seemed to function as collateral circulation, compensating for decreased perfusion in either the lung or the heart. When coronary to bronchial artery anastomosis is found, ischemic conditions in either the lung or the heart are likely.

Angina Pectoris↗
PubMed1996

Two cases of recurrent pulmonary metastasis resected after operation for gastric cancer.

It is said that the prognosis is poor in cases with recurrent pulmonary metastasis after operation for gastric cancer. In this article, 2 cases with nodular type of pulmonary metastasis resected after operation for gastric cancer and surviving well are reported by the authors. Case 1: 57-year-old female. The patient underwent a total gastrectomy for the 3'type of cardiac cancer. As the serum levels of tumor markers increased and the chest X-ray examination revealed a mass lesion in the right lung (S10), the operation for the lesion under the diagnosis of metastatic lung cancer was performed 1 year and 2 months after gastrectomy. The patient died of pulmonal and pleural metastasis 4 years and 7 months after the first operation. Case 2: 65-year-old male. The patient underwent a subtotal gastrectomy for the 5' type of gastric cancer. Chest X-ray examination for follow-up study revealed a mass lesion in the left lung (S5). The patient underwent a left pulmonary superior lobe resection 2 years and 9 months after gastrectomy. The patient is still alive 6 years after the first operation. Surgical treatment must be actively considered for nodular type of metastatic lung cancer after operation for gastric cancer.

Adenocarcinoma↗
PubMed1996

Coronary artery bypass grafting in a patient with antiphospholipid syndrome.

We report a 32-year-old female patient with antiphospholipid syndrome including severe coronary artery disease and multiple arterial and venous thrombosis. The patient had occlusion of the right internal thoracic artery, diffuse stenosis of the left internal thoracic artery, and occlusion of the left saphenous vein. The patient underwent successful coronary artery bypass grafting using the right gastroepiploic artery and a segment of the right saphenous vein. Antiphospholipid syndrome should be considered in young patients with myocardial infarction.

Adult↗