Biomedical subjects

Mikio Masuda

Publications and source records attributed to Mikio Masuda.

9 recordsLinked to original sources

PubMed2004

Technical considerations using a composite graft for aortic root replacement.

We performed modified aortic root replacement using a composite graft in seven patients over a 7-year-period. Six patients underwent emergency surgery for acute aortic dissection and one patient underwent elective surgery for an aortic aneurysm. To make the composite graft, we chose an artificial valve that was 1 mm larger than the graft, and when performing the proximal anastomosis, we sutured only the graft edge using the horizontal mattress suture technique, applying an additional running suture for reinforcement. The button technique was routinely used for coronary reattachment. To assess hemostasis of the aortic proximal and coronary suture line, cardioplegia was injected via the left atrial vent, which enabled us to confirm hemostasis before performing the distal anastomosis. Blood loss and the need for blood transfusion were minimized by this modified technique. None of the six survivors has required reoperation during 7-year period. Our technique of aortic root replacement based on a composite graft with some operative modifications seems to be safe and reliable, resulting in a satisfactory outcome.

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PubMed2004

Diagnostic and therapeutic thoracoscopy for mediastinal disease.

OBJECTIVE AND METHODS: In order to clarify the utility of video-assisted thoracoscopic surgery (VATS) for mediastinal disease, we analyzed retrospectively 34 thoracoscopic surgical cases (seven lymph node, nine thymic, eight cystic and 10 cases with solid lesions that excluded thymic diseases) between February 1993 and July 2002. RESULTS: In lymph node disease, adequate specimens were obtained in all cases; pathologic diagnoses were three sarcoidosis, two tuberculosis, and two other tumors. In thymic disease, all cases underwent thoracoscopic partial resection of the thymus. Conversion to thoracotomy or mediansternotomy was necessary in two cases of epithelial thymic tumors. In cases of cystic diseases, complete resections of the cysts were performed in five cases. Final diagnoses of these cysts were four bronchogenic, three pericardial, and one parathyroid cyst. In solid diseases, nine tumors were completely resected. Final diagnoses of these tumors were six neurogenic, and four other tumors. CONCLUSION: VATS is an effective and reliable approach for managing mediastinal diseases. Cases of small lesions surrounded by thymic tissue, cystic lesions excluding lymphatic duct origin, and neurogenic tumors without evidence of intraspinal invasion are good indications for VATS.

Adult↗

PubMed2004

Coronary artery bypass in patients 80 years and older: comparison with a younger age group.

Octogenarians are at increased risk for perioperative morbidity and mortality following coronary artery bypass grafting (CABG). We compared the perioperative outcome after CABG from March 1997 to June 2003, between patients 80 years and older (n=15), and those aged 70 to 79 years (n=64). In comparison with younger patients, more octogenarians had congestive heart failure (40% vs. 9% in patients aged 70 to 79 years, p=0.003) and underwent off-pump CABG more frequently (80% vs. 42%, p=0.008). There were no significant differences in the incidence of emergent surgery (27% vs. 28%) and number of bypass grafts (2.3+/-0.7 vs. 2.5+/-0.9) between the two groups. Octogenarians had less complete revascularization compared to the younger group (67% vs. 81%, not significant). There was no mediastinitis, and no stroke in either groups. Octogenarians had more minor wound complications (20% vs. 3%, p=0.01). There were no operative deaths in octogenarians, while the mortality rate of the younger group was high (6%). Surgical myocardial revascularization in octogenarians can be performed with acceptable mortality and morbidity using off-pump CABG.

Age Factors↗

PubMed2003

Clinical study of biocompatibility between open and closed heparin-coated cardiopulmonary bypass circuits.

The objective of this study was to investigate the difference between the closed circuit system and the open circuit system in clinical heparin-coated cardiopulmonary bypass (CPB) circuits with a centrifugal pump. We evaluated the coagulation, fibrinolysis, and inflammatory response in valvular heart surgery. Nineteen patients were assigned at random to a group for the closed circuit system or the open circuit system. This is the first report on the effect of a closed circuit in valvular surgery. We measured the platelet count, white blood cell count, plasma fibrinogen concentration, thrombin-antithrombin III complex, plasmin-Alpha2 plasmin inhibitor complex, D-dimer, interleukin-6, polymorphic neutrophil-elastase, and the plasma free hemoglobin. Blood samples were collected before the start of perfusion, 15 and 60 min after the start of perfusion, 60 min after the administration of protamine, and 1 day after the operation. During the perfusion, coagulation, fibrinolysis, and inflammatory responses were activated; however, no significant differences between the two groups were noted. In this clinical investigation with suction and the cell saving system, the closed circuit was not found to be superior to the open circuit with regard to biocompatibility.

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PubMed2003

A technique using a rectus abdominis muscle flap in the treatment of adult congenital tracheoesophageal fistulas.

The authors successfully treated an adult with congenital tracheoesophageal fistula (TEF) Gross-C type by the addition of an effective pedicled muscle flap. This patient had undergone 2 thoracotomies when he was an infant at another hospital; however, the fistula recurred. After transection and closure of the fistula, a right rectus abdominis muscle flap between the 2 stumps was interposed. The current case followed a favorable postoperative course; neither fistula nor abdominal hernia occurred.

Adult↗

PubMed2003

Does myocardial revascularization with multiple arterial grafts improve the prognosis of dialysis patients?

In the present study it was examined whether myocardial revascularization with multiple arterial grafts improves the prognosis of dialysis patients. The 20 subjects underwent coronary artery bypass grafting over 2 vessels (extra-corporeal circulation in 11 patients, off-pump bypass in 9 patients) and were divided into 2 groups according the number of arterial grafts. Group A consisted of 9 patients in whom more than 2 arterial grafts were used and Group B, 11 patients requiring 1 internal thoracic artery and additional saphenous vein grafts. The surgical procedure was examined, as well as the short-term and long-term results of both groups. There were no differences in the profiles of the 2 groups. The mean arterial graft number in group A was 2.2+/-0.6 and 1.0+/-0.0 in group B. There was neither mediastinitis nor brain complication in either group. There were no operative deaths in group A and 1 in group B. The 55-month actuarial survival rate including all deaths, and estimated by cardiac deaths, was, respectively, 0.53+/-0.21 and 0.80+/-0.18 in group A and 0.42+/-0.21 and 0.53+/-0.23 in group B. The survival rate estimated by cardiac death in group A was better, but there was not a significant difference. Myocardial revascularization with multiple arterial grafts for dialysis patients had good short-term results without increased operative risk and may improve the long-term results related to cardiac death. However, there was no significant difference in survival including all deaths because of the numerous non-cardiac deaths.

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PubMed2003

Atrial blood cyst with ischemic heart disease.

A 52-year-old male with coronary artery disease had the extremely rare occurrence of a blood cyst in the right atrium. Surgical removal with coronary artery bypass grafting was performed successfully.

Coronary Artery Bypass↗

PubMed2002

Pulmonary vein isolation for chronic atrial fibrillation associated with mitral valve disease: the midterm results.

OBJECTIVE: The Cox Maze procedure is widely performed for the surgical treatment of atrial fibrillation. However it requires numerous incision lines and therefore is a time-consuming operation. We report a simplified operation for chronic atrial fibrillation associated with mitral valve disease. METHODS: Pulmonary vein isolation procedure was performed on atrial fibrillation associated with mitral valve disease in thirteen patients. This simple procedure consisted of isolation of the four pulmonary veins only. Combined mitral valve surgery involved mitral valve plasty, mitral valve replacement with or without aortic valve replacement and tricuspid annuloplasty. RESULTS: Eleven patients returned to sinus rhythm (84.6%). Mean follow-up time is 32.7 +/- 11.7 months. Three patients required a DDD pacemaker implant for sick sinus syndrome but two out of these three resumed sinus rhythm most of the time recently. Left atrial contraction was detected in eight cases by trans-esophageal echo. One patient died of liver failure two months postoperatively. Eight patients had no blood transfusion. Twelve patients are classified as New York Heart Association class I. CONCLUSION: Compared with the Maze procedure, this operation was less invasive and preserved the atrial appendage and was thought to have a normal level of secretion of atrial natriuretic peptide. This study suggests that the pulmonary vein isolation procedure may be an effective and simple maneuver for atrial fibrillation associated with mitral valvular disease.

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PubMed2002

The left internal thoracic artery and radial artery composite graft in off-pump coronary artery bypass grafting.

Arterial multivessel bypass grafting without extra corporeal circulation and manipulation of the ascending aorta should be a good surgical option for the treatment of coronary artery disease. An internal thoracic artery (ITA)-radial artery (RA) composite graft was used for this purpose. Between July 2000 and October 2001, we employed the LITA-RA composite graft for off-pump coronary artery bypass in 15 cases. Mean patient age was 71.3 +/- 5.8 years old. Left main trunk disease was present in six patients and triple-vessel disease in four patients. Preoperative concomitant disease was renal dysfunction in three cases, cerebrovascular disease in four and diabetes mellitus in five cases. Two patients had a so-called bad aorta. Twelve elective operations and three urgent operations were carried out for unstable angina. Two to four (mean 2.6 +/- 0.7) anastomoses were performed per patient. Complete revascularization was achieved in 12 out of 15 patients. Mean operating time was 335 +/- 53 min. Mean intraoperative blood loss was 595 +/- 375 ml and nine patients underwent the operation without blood transfusion. There was no PMI, no brain disorder, and no death. Postoperative coronary angiography in all patients documented a good patency rate (LITA 15/15, RA 21/21, right gastroepiploic artery (RGEA) 2/2, and saphenous vein graft (SVG) 0/2). LITA-RA composite grafting in off-pump coronary artery bypass enables arterial multivessel revascularization using an aortic no touch technique. This can be done with minimum postoperative complications and without risk of cerebral infarction even in patients at high risk for extracorporeal circulation (ECC).

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