Biomedical subjects

Hideki Nakahara

Publications and source records attributed to Hideki Nakahara.

7 recordsLinked to original sources

PubMed2004

Double-patch technique for postinfarction ventricular septal perforation.

A modified infarct-exclusion technique for postinfarction ventricular septal perforation is presented. The perforation is closed directly by a small patch next to the conventional patch, and biological glue is applied between the patches to induce stable polymerization. The patch stuck to the infarcted septum, and no residual shunt was observed in any patient because the wide adhesion prevents excessive pressure on the suture line. Seven of 9 patients in whom this method was used had good results. This technique appears suited for repair of ventricular septal perforations, especially those with extensive fresh infarction.

Cardiac Surgical Procedures↗

PubMed2003

Intraoperative near-infrared spectroscopy for evaluating hepatic venous outflow in living-donor right lobe liver.

BACKGROUND: This study was performed to determine the usefulness of intraoperative near-infrared spectroscopy (NIRS) for evaluating the extent of congestion in the anterior segment of the graft after living-donor liver transplantation using right lobe grafts that do not have the middle hepatic vein. METHODS: Fifteen patients undergoing living-donor liver transplantation using a right lobe graft without the middle hepatic vein were enrolled in this study. During the course of harvesting and implantation, in vivo NIRS was performed on the liver grafts to determine hemoglobin (Hb) and cytochrome oxidase content in the hepatic tissues. RESULTS: The 15 cases were divided into three groups according to the caliber of the middle hepatic vein tributaries in the right lobe grafts: the small group (<4 mm), the intermediate group (4-7 mm), and the large group (>7 mm). After implantation, congestion (increase in tissue Hb) in the anterior segment was more severe than that in the posterior segment in the intermediate and large groups. However, well-preserved mitochondrial cytochrome oxidase redox state was observed in both segments except for two cases in the large group with severe congestion in the anterior segment. The extent of postoperative congestion in the anterior segment was significantly correlated with the tissue content of remaining Hb in that segment after ex vivo flushing. CONCLUSIONS: Intraoperative NIRS enables quantification of the extent of congestion in the anterior segment after implantation of a right lobe liver graft and even enables prediction of such congestion at the phase of ex vivo perfusion.

Adult↗

PubMed2003

Decreased plasma brain natriuretic peptide levels after a successful maze procedure.

BACKGROUND AND AIM OF THE STUDY: Previous reports indicate that plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) increase in atrial fibrillation (AF), but decrease after successful direct current (DC) cardioversion. Although the maze procedure is the only curative therapy for AF, the effects on atrial and left ventricular function remain unclear. The study aim was to determine whether plasma ANP and BNP levels decrease after the maze procedure in patients with mitral valve disease. METHODS: Twenty-seven patients either with (n = 23) or without (n = 4) AF underwent mitral valve surgery; of these patients, 13 underwent a maze procedure for chronic AF. Blood samples and echocardiographic data were obtained before and at one year after surgery. RESULTS: Ten patients with AF achieved sinus rhythm (SR) or junctional rhythm after the maze procedure. In patients subjected to mitral valve surgery, mean plasma levels of ANP and BNP were 59.8 +/- 11.9 and 139.2 +/- 53.7 pg/ml, respectively. ANP and BNP plasma levels fell significantly after surgery (to 32.1 +/- 4.1 and 46.7 +/- 10.2 pg/ml, respectively; p = 0.04 and p = 0.004). In patients with successful maze procedure, plasma levels of BNP and left ventricular end-diastolic dimension (LVDd) were significantly decreased by 35.7% and 82.7% compared with preoperative values (BNP, 35.7 +/- 4.9% for SR versus 83.4 +/- 9.6% for AF, p = 0.008; LVDd, 82.7 +/- 3.7% for SR versus 97.0 +/- 3.2% for AF, p = 0.0159). CONCLUSION: A successful maze procedure significantly decreased LVDd and plasma levels of BNP after surgery. These results show that the maze procedure is effective in improving left ventricular diastolic dysfunction for a mid-term period in patients with mitral valve disease.

Adult↗

PubMed2002

Hepatic arterial infusion of 5-fluorouracil and cisplatin for unresectable or recurrent hepatocellular carcinoma with tumor thrombus of the portal vein.

BACKGROUND AND OBJECTIVES: This study was designed to evaluate the efficacy of hepatic arterial infusion of 5-fluorouracil (5-FU) and cisplatin (CDDP) for unresectable or recurrent hepatocellular carcinoma (HCC) with tumor thrombus of the trunk or first branches of the portal vein (PVTT). METHODS: Seven unresectable or recurrent HCC patients with PVTT were enrolled in this study. A one-week course of chemotherapy consisted of intraarterial administration of CDDP (10 mg on days 1-5) for 1 h and 5-FU (250 mg on days 1-5) for 24 h, followed by cessation of administration for the subsequent 2 days (days 6 and 7). Three or more sequential courses of chemotherapy were given through an implanted reservoir. RESULTS: Serum alpha-fetoprotein (AFP) levels before the chemotherapy were >20 ng/ml in six of the seven patients. Serum AFP levels were decreased in four of the six patients after chemotherapy, including two patients (cases 1 and 7) whose AFP levels later returned to normal. Six of the seven patients had measurable lesions in the liver, with a response rate of 33%. In three of the seven patients (43%), PVTTs decreased in size or disappeared after chemotherapy. The mean and median survival periods of all patients were 8.0 and. 7.5 months, respectively. CONCLUSIONS: The chemotherapy described in this report is beneficial in terms of survival for HCC patients with PVTT for whom transcatheter arterial embolization or surgical treatment is contraindicated.

Aged↗

PubMed2002

Non-depolarizing cardioplegia activates Ca2+-ATPase in sarcoplasmic reticulum after reperfusion.

OBJECTIVES: Depolarizing cardioplegia is the most common method for myocardial preservation in cardiac operations. However, depolarizing cardioplegia causes depolarization of the membrane potential by extracellular hyperkalemia, resulting in depletion of energy stores and calcium overload. This study examined the hypothesis that non-depolarizing cardioplegia would provide superior protection compared with depolarizing cardioplegia. METHODS: In an isolated rat heart Langendorff model, hearts were perfused for 10 min with St. Thomas' Hospital cardioplegic solution (Group I: n=20), St. Thomas' Hospital cardioplegic solution+Lidocaine 1 mM (Group II: n=20) or non-depolarizing cardioplegia (Group III: n=20). The hearts then were subjected to 60 min of normothermic global ischemia, after which they were perfused with Krebs-Henseleit buffer at 37 degrees C for 30 min. The percent recovery of functional data, myocardial cyclic AMP contents, and myocardial cyclic GMP contents were recorded at each time point (base, after the administration of cardioplegia, after global ischemia, and after 30 min of reperfusion). Ca(2+)-ATPase in sarcoplasmic reticulum was measured at pre-ischemia and 30 min of reperfusion. RESULTS: The percent recovery of developed pressure and +/-dp/dt were significantly higher in Group III than in other groups. Myocardial cyclic AMP and GMP contents were elevated after reperfusion in all groups. However, in Group III, myocardial cyclic AMP contents after 30 min of reperfusion were significantly higher than in other groups (Group III: 14.7+/-1.6 vs. Group I: 8.7+/-1.0, Group II: 8.3+/-0.2 pmol/mg dry weight, P=0.05) but not cGMP. The sarcoplasmic reticulum Ca(2+)-ATPase activities at 30 min of reperfusion significantly increased in Group III compared with Groups II and I (Group III: 70.3+/-3.6 vs. Group I: 46.8+/-3.4, Group II: 53.9+/-6.1 micromol Pi/mg per h, P=0.025 and P=0.030). CONCLUSIONS: Non-depolarizing cardioplegia induced the activity of Ca(2+)-ATPase in sarcoplasmic reticulum after reperfusion. The activity would be increased by the cyclic AMP pathway. These findings suggested that non-depolarizing cardioplegia prevented calcium overload after reperfusion, especially decreased cytosolic calcium during the diastolic phase.

Animals↗

PubMed2002

Gasless laparoscopic hepatic resection for cirrhotic patients with solid liver tumors.

Gasless laparoscopic hepatic resection with a 5-cm minilaparotomy was performed in 10 cirrhotic patients with small liver tumors. To maintain good visualization and working space during hepatic resections, we developed a simple retraction system. Mean operative time and blood loss were 291 minutes and 249 mL, respectively. No blood transfusion was required during the operations. No serious complications occurred such as gas embolism. Our laparoscopic procedures had various advantages. Blood, smoke, and water vapor could be aspirated by suction without disturbance of the visual field. There was no risk of gas embolism. It was possible to use conventional instruments through the ports or the wound made by a minilaparotomy. Hemostasis therefore could be performed easily. The procedure could be applicable to cirrhotic patients with some complications. This laparoscopic procedure is recommended for patients with small HCCs associated with liver cirrhosis who are not candidates for major hepatectomy.

Adult↗

PubMedDate not supplied

Significance of the molar ratio of branched-chain amino acids to tyrosine before hepatectomy.

BACKGROUND/AIMS: To predict the degree of liver fibrosis and select a safe operative procedure, the correlation between liver fibrotic ratio and preoperative liver function variables were analyzed, and the significance of the molar ratio of branched-chain amino acids to tyrosine determined preoperatively was investigated. METHODOLOGY: Forty-four patients with hepatectomy were enrolled in this study. Liver tissue specimens excised from the patients were stained by Azan-Mallory's method. The liver fibrotic ratio was measured using an Image Cytometer. The correlation between liver fibrotic ratio and preoperative liver function values, including the serum level of branched-chain amino acids to tyrosine, were determined. RESULTS: The degrees of liver fibrosis (normal group, 1.4 +/- 0.7%; chronic hepatitis group, 4.5 +/- 2.8%; cirrhosis group, 8.4 +/- 2.4%) correlated significantly with preoperative liver function values such as branched-chain amino acids to tyrosine, hepaplastin test, type IV collagen 7s domain, total bilirubin, indocyanine green clearance retention rate at fifteen minutes, and platelet count. The serum level of branched-chain amino acids to tyrosine showed the most-significant correlation with the degree of liver fibrosis. CONCLUSIONS: The serum level of branched-chain amino acids to tyrosine correlates well with the degree of liver fibrosis, and this value is a useful preoperative parameter for predicting the degree of liver fibrosis and for selecting a safe operative procedure.

Adolescent↗