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Shinichi Takamoto

Publications and source records attributed to Shinichi Takamoto.

At least 37 records · Page 2Linked to original sources
PubMed2005

Superior vena cava graft for right liver and right lateral sector transplantation.

BACKGROUND: The usefulness of cryopreserved superior vena cava (SVC) grafts for venous reconstruction remains to be evaluated in right liver and right lateral sector transplantation. METHODS: Reconstruction of the hepatic vein was performed when the congested area in the liver graft was significant. A vein graft with a suitable shape and length meeting the demands for the venoplasty was selected, and SVC grafts were used in 20 recipients. Surgical techniques were classified into five types according to the necessity of middle or short hepatic vein reconstruction in the liver graft. Surgical outcomes and vein graft patency were evaluated. RESULTS: All 20 recipients survived the operation without any complications caused by congestion. Liver functions were well recovered in the early postoperative period. The 1-year primary patency rates of cryopreserved vein grafts used for reconstructed right hepatic veins, inferior right hepatic veins, and middle hepatic vein tributaries were 100%, 94%, and 42%, respectively. CONCLUSIONS: SVC grafts were feasible for outflow tract reconstruction in right liver and right lateral sector transplantation, although the long-term patency of the grafts for middle hepatic vein reconstruction remains to be evaluated.

Aspartate Aminotransferases↗
PubMed2005

Comparison of neurocognitive results after coronary artery bypass grafting and thoracic aortic surgery using retrograde cerebral perfusion.

OBJECTIVE: Retrograde cerebral perfusion (RCP) is used as an adjunctive method to hypothermic circulatory arrest to enhance cerebral protection in patients undergoing thoracic aortic surgery. It remains unclear whether RCP provides improved neurological and neuropsychological outcome. METHODS: Forty-six patients undergoing thoracic aortic surgery using RCP, and 28 undergoing coronary artery bypass grafting (CABG; n = 28) with CPB, were enrolled in the study. Patients receiving RCP were subdivided into two groups, those with less than 60 min of RCP (S-RCP; n = 27) and with 60 min or more (L-RCP; n = 19). The patients' neurocognitive state was assessed by the revised Wechsler Adult Intelligence Scale a few days before operation, at 2-3 weeks and 4-6 months after operation. RESULTS: There were no stroke, seizure, and hospital mortality in either group. Significant decline between baseline and early scores were seen in three subtests (digit span, arithmetic, and picture completion) for S-RCP and four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP. Significant decline between baseline and late scores were seen in one subtest (arithmetic) for S-RCP, four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP, and one (object assembly) for CABG. The mean change of scores for one late test (digit symbol) was significantly lower in S-RCP than in CABG. The mean change of scores for three early tests (digit span, vocabulary, and picture arrangement) and four late tests (information, digit span, picture completion, and picture arrangement) were significantly lower in L-RCP than in CABG. Stepwise logistic regression analysis disclosed that, after considering the other variables, significant difference in test score changes were observed between CABG and L-RCP for two early tests (picture completion and digit symbol) as well as for three late tests (digit span, similarities, and picture completion). None of test score changes showed significant difference between CABG and S-RCP. CONCLUSIONS: The neurocognitive outcome in patients undergoing RCP less than 60 min were comparable with patients undergoing CABG without circulatory arrest. Prolonged RCP of 60 min or more in patients undergoing surgery of the thoracic aorta was associated with postoperative neurocognitive impairment.

Adult↗
PubMed2005

Human umbilical cord blood cells improve cardiac function after myocardial infarction.

Human umbilical cord blood (UCB) contains an abundance of immature stem/progenitor cells and has been clinically used as an alternative to bone marrow transplantation. In addition, cord blood can be obtained non-invasively, in contrast to invasive bone marrow aspiration. We investigated the potential of human UCB CD34(+) cells to improve cardiac function following myocardial infarction. Myocardial infarction was induced in Wistar rats by ligation of the left coronary artery. Either 2x10(5) human UCB CD34(+) cells or equivalent cell-free medium was injected into the injured myocardium of the rats following induction of myocardial infarction. CD34(+) cell transplantation significantly improved ventricular function as compared to the control group. Immunofluorescence staining for human CD34, CD45, and PECAM-1 revealed surviving cells in the myocardium. Our findings suggest that transplanted human cells survived and improved cardiac function following myocardial infarction. These results may show the usefulness of UCB CD34(+) cells for myocardial infarction.

Animals↗
PubMed2005

Alternatives to the double vena cava method in partial liver transplantation.

Minimizing graft congestion in partial liver transplantation is important, especially when the graft weight is marginal for the recipient metabolic demand. We prefer the double vena cava technique for reconstructing middle hepatic vein tributaries with thick, short hepatic veins because the technique can reduce the warm ischemic time of the graft and make a wide anastomosis. This technique requires a cryopreserved superior or inferior vena cava. We devised an alternative double vena cava method using iliac or femoral vein grafts and applied it to two right liver transplantation patients. There was no postoperative hepatic venous outflow block in either patient. In conclusion, application of this technique, even in the absence of a suitable vena cava, can help to minimize graft congestion.

Adult↗
PubMed2005

Appraisal of surgical treatment for pulmonary metastasis from hepatocellular carcinoma.

The outcome of pulmonary metastasectomy of hepatocellular carcinoma (HCC) was appraised in this study. Twenty patients with pulmonary metastasis from HCCs undergoing pulmonary resection between 1990 and 2003 were included in this study. They had undergone curative treatment for the primary lesion and were candidates for a pulmonary metastasectomy for complete resection. Among the 20 patients, 13 died: 5 from hepatic failure, 5 from respiratory failure, and 2 from brain metastasis due to recurrence of the HCC. One patient died from cardiac failure without HCC recurrence. At the latest observation, three of the seven survivors were doing well without HCC recurrence, and others survived with recurrence. The overall survival rates after the initial lung surgery were 45.3% at 1 year and 23.8% at 3 years, respectively. The survival rates without recurrence were 32.4% at 1 year and 21.6% at 3 years, respectively. A Kaplan-Meier analysis showed that multiple lung surgeries and a negative histologic finding of the liver cut surface were favorable characteristics for survival without recurrence. In conclusion, the selected patients were Candidates for pulmonary metastasectomy after a curative hepatectomy for HCC and could benefit from the complete resection. Also, repeated pulmonary resections through thoracoscopy could result in the long-term survival of patients with pulmonary recurrence of HCC.

Adult↗
PubMed2005

Management of infected grafts and aneurysms of the aorta.

Seventeen patients treated for infected grafts (11/17) or aneurysms (6/17) of the aorta between 1998 and 2003 were reviewed to evaluate our experience with aortic infection. The causative organisms were identified in 12 patients (71%), with 5 (29%) having methicillin-resistant Staphylococcus aureus. A periaortic abscess occurred in eight patients, and all of them were associated with infected grafts. Surgical treatment included cryopreserved allograft replacement in eight patients, prosthetic graft replacement in four patients, and drainage with or without omental wrapping in five patients. One patient was still hospitalized at the end of the study period. Five patients with infected grafts died after the operation during the initial hospitalization. No early mortality occurred in the aneurysm group. The early mortality rate was 31% for all patients, 50% for the graft group, and 63% for patients with a periaortie abscess. Another patient with an infected aneurysm died of arrhythmia after discharge from the initial hospitalization, Ten patients are still alive without evidence of reinfection. The early mortality rate for patients with infected aortic grafts is higher than that for those with infected aneurysms, especially when a periaortic abscess accompanies them. However, the late outcome is favorable, with no reinfection or late treatment-related deaths.

Abscess↗
PubMed2005

Japanese multicenter clinical evaluation of the HeartMate vented electric left ventricular assist system.

Implantable left ventricular assist device systems (LVAS) are increasingly being used to bridge patients to heart transplantation because of the limited number of available donor hearts. This prospective, multicenter trial was designed to evaluate the usefulness of the HeartMate vented electric (VE) LVAS as a bridge to transplantation in Japan. Between November 2001 and June 2003, six patients with end-stage heart failure [New York Heart Association (NYHA) class IV] were supported with the LVAS and five of the six were able to implement the evaluation (one dropped out). The five were men with an average age of 38.6 years and were supported for 2390 cumulative days (6.6 years). Average preimplant cardiac index improved from 1.93 l/min/m(2) to a 3.79 l/min/m(2) VAD flow index at the end of the clinical trial. All five patients improved to NYHA class I or II, survived more than 1 year, and one patient was discharged from the hospital. Mean LVAS support duration was 478 days (range 390-575 days) and four patients remain supported. One patient died from cardiac failure and sepsis. Device-related complications included: infections (four patients), thromboembolism (one patient), hemolysis (two patients), and repeat operation for bleeding (two patients). There was one case of inflow valve incompetence and two pump motor malfunctions. We conclude that the LVAS can effectively support patients as they await cardiac transplantation and offers improvement to the patient's quality of life.

Adult↗
PubMed2005

Coccidioidomycosis of the lung contracted abroad.

Coccidioides immitis is endemic in the southwestern United States. Coccidioidomycosis is rare in Japan, but the number of coccidioidomycosis cases from overseas is expected to increase markedly in the near future. A 33-year-old Japanese man with coccidioidomycosis who had lived in Arizona presented to our hospital. We performed wedge resection of the lung by video-assisted thoracoscopic surgery (VATS), and were able to completely remove the lesion. VATS wedge resection of the lung is effective in treating localized coccidioidomycosis. Before the operation, we could not confirm the existence of satellite lesions, but microscopically the main lesion was accompanied by several daughter lesions. It is very important that the surgical margin be sufficient to achieve complete resection.

Adult↗
PubMed2005

Beneficial effect of acute normovolemic hemodilution in cardiovascular surgery.

OBJECTIVE: The efficacy of acute normovolemic hemodilution (ANH) in avoiding homologous blood transfusion (HBT) during cardiovascular surgery remains controversial. Our objective was to evaluate the impact of ANH on blood transfusion requirements during open cardiovascular surgery using cardiopulmonary bypass (CPB). METHODS: We retrospectively reviewed 243 patients who had undergone open cardiac or thoracic aortic surgery using CPB between September 2001 and July 2003 in our department. ANH was performed when the hematocrit was over 35% and the patient was hemodynamically stable. Risk factors were selected in accordance with the Japanese Adult Cardiovascular Surgery Database and analyzed to determine their effect on perioperative HBT requirement. RESULTS: Of the 243 patients, 64 (26%) underwent preoperative autologous blood donation and 62 (26%) ANH. HBT was required in 62% of patients (150/243) overall, in 32% (20/62) of ANH patients, and in 76% (130/171) of non-ANH patients. Multivariate stepwise logistic regression analysis revealed that preoperative or pre-donation hemoglobin value (p < 0.001), duration of surgery (p = 0.001), intraoperative minimum rectal temperature (p = 0.001), age (p = 0.002), need for emergency surgery (p = 0.003), amount of ANH (p = 0.018), blood loss (p = 0.033) and amount of preoperative autologous blood donation (p = 0.042) were independent predictors of the need for perioperative HBT. CONCLUSIONS: Our data showed that open cardiovascular surgery using CPB continues to pose a high risk of HBT, but that ANH is an effective means of reducing this risk in those patients undergoing these operations.

Adult↗
PubMed2005

Epicardial maze procedure on the beating heart with an infrared coagulator.

PURPOSE: Maze surgery is widely used to treat atrial fibrillation (AF) but requires cardiopulmonary bypass and longer aortic cross-clamping time. Percutaneous transcatheter pulmonary vein (PV) isolation is time consuming and relies on fluoroscopy and contrast media, and PV obstruction and cardiac tamponade are still major problems. To overcome these drawbacks, we developed an epicardial maze procedure with an infrared coagulator on the beating heart, and the aim of this study was to confirm electrophysiologically the efficacy of this method. DESCRIPTION: Light from a lamp in the infrared coagulator is focused into a quartz rod, and the distal exit-plane of the rod is connected to a sapphire tip that allows 10 mm of linear photocoagulation. In an experiment in 5 dogs with AF, instead of making all of the incisions usually required for maze surgery, the infrared coagulator was applied epicardially to create a continuously overlapping linear lesion that was the same as the incision line in the maze III procedure except for the intraatrial incision. After the procedure, 11 electrodes were attached to both atria, and an electrophysiologic study was performed. EVALUATION: The electrophysiologic study confirmed electrophysiologic isolation of both atrial appendages and within the PV encircling lesion. Sustained atrial fibrillation could no longer be induced. CONCLUSIONS: The epicardial maze procedure was successfully performed on a beating heart with the infrared coagulator.

Animals↗
PubMed2005

A novel protocol of retrograde cerebral perfusion with intermittent pressure augmentation for brain protection.

OBJECTIVES: We examined a novel protocol of retrograde cerebral perfusion with intermittent pressure augmentation to improve the clinical usefulness of this procedure, in a canine model, because a high retrograde cerebral perfusion pressure may be required to open cerebral vessels. METHODS: Eighteen dogs (25.2 +/- 4.1 kg) were randomly divided into the following 3 groups: circulatory arrest group (circulatory arrest alone), conventional-retrograde cerebral perfusion group (conventional retrograde cerebral perfusion at 25 mm Hg), and intermittent-retrograde cerebral perfusion group (retrograde cerebral perfusion at 15 mm Hg with intermittent pressure augmentation to 45 mm Hg). The animals were cooled down to 26 degrees C under cardiopulmonary bypass and underwent 60 minutes of circulatory arrest with or without retrograde cerebral perfusion in accordance with the protocol described. They were weaned from cardiopulmonary bypass after rewarming and observed for 12 hours after the procedures. The retinal vessels were observed as a means of noninvasive direct visualization of the cerebral vascular system. The level of Tau proteins in the cerebrospinal fluid was measured as a marker of neuronal damage. RESULTS: While the retinal vessels were fully distended with blood (100%) at a retrograde cerebral perfusion pressure of 45 mm Hg in the intermittent-retrograde cerebral perfusion group, full distension of the retinal vessels was not observed in the conventional-retrograde cerebral perfusion group (67%). The level of Tau proteins, measured 12 hours after the operation, was lower in the intermittent-retrograde cerebral perfusion group (247 +/- 70 pg/mL) than in the circulatory arrest group (1313 +/- 463 pg/mL; P < .05) or the conventional-retrograde cerebral perfusion group (1449 +/- 693 pg/mL; P < .05). Histopathologic examination revealed that the most effective brain protection was obtained in the intermittent-retrograde cerebral perfusion group (P < .05). CONCLUSIONS: Intermittent-retrograde cerebral perfusion effectively opens up cerebral vessels to allow adequate blood supply to the brain, thereby minimizing brain damage. This novel method may protect the cerebral system effectively from ischemia during circulatory arrest.

Animals↗
PubMed2005

Does a bidirectional Glenn shunt improve the oxygenation of right ventricle-dependent coronary circulation in pulmonary atresia with intact ventricular septum?

OBJECTIVE: There is a risk of myocardial ischemia in patients with pulmonary atresia and intact ventricular septum associated with the right ventricle-dependent coronary circulation. In this patient group, the oxygen delivery to the myocardium depends on the oxygen saturation of the right ventricular cavity. We hypothesized that bidirectional Glenn shunt would improve the oxygenation of right ventricle-dependent coronary circulation relative to a systemic-pulmonary artery shunt. The reduction of systemic venous return to the right atrium due to a bidirectional Glenn shunt could increase the oxygen saturation of the right ventricle in the clinical setting, when the mixture of systemic and pulmonary venous blood is unchanged at the atrial level. METHODS: Patients with right ventricle-dependent coronary circulation were defined as those with right ventricle-coronary artery fistulas plus stenoses of the right or left coronary arteries. For 7 patients with right ventricle-dependent coronary circulation before and after bidirectional Glenn shunt, cardiac catheterization was performed and the oxygen saturation of the right ventricular cavity was measured. RESULTS: For all 7 patients, the bidirectional Glenn shunt was performed at a mean age of 18 months. Ischemic changes in the electrocardiogram before the bidirectional Glenn shunt improved after the procedure in 2 patients. The oxygen saturation of the right ventricular cavity before the bidirectional Glenn shunt was 54.6 +/- 8.8%, and that after the BGS significantly increased to 75.6% +/- 5.8% (P < .01). All 7 patients have subsequently undergone the Fontan procedure with excellent results. CONCLUSION: Early bidirectional Glenn shunt could prevent progression of myocardial ischemia in pulmonary atresia with intact ventricular septum with right ventricle-dependent coronary circulation.

Anastomosis, Surgical↗
PubMed2005

Surgical treatment of atypical aortic coarctation complicating Takayasu's arteritis--experience with 33 cases over 44 years.

PURPOSE: This study was conducted to evaluate the long-term outcomes of surgical treatment for atypical aortic coarctation due to Takayasu's arteritis and to elucidate the factors that affected outcome. METHODS: The outcomes of surgical treatment for atypical aortic coarctation complicating Takayasu's arteritis in 33 consecutive patients over the previous 44 years at our institution were reviewed retrospectively. Preoperatively, 29 patients had coarctation proximal to the renal arteries and hypertension in the upper half of the body. Four hospital deaths occurred, and the remaining 29 patients were followed from 0.5 to 42.0 years (median, 17.9 years). The impacts of several risk factors on survival as well as cardiac and vascular events were analyzed. RESULTS: Among 27 initial survivors who had hypertension preoperatively, 15 did not show normalization of blood pressure. The overall cumulative survival and event-free survival rate at 20 years were 62.3% and 58.4%, respectively. Serious long-term complications were anastomotic aneurysms, congestive heart failure, cerebrovascular accident, graft deterioration, abdominal aortic aneurysms, and renal failure. Among several risk factors analyzed, only the presence of postoperative hypertension had an effect on event-free survival. CONCLUSIONS: The long-term survival after surgery for atypical aortic coarctation was satisfactory. However, our study showed that complications associated with cardiovascular system or the operation could occur at any time after surgery; thus, life-long follow-up is mandatory. Further, the absence of normalization of blood pressure after surgery was a poor prognostic factor. Our results demonstrate the need for an intimate preoperative evaluation of renal and carotid artery lesions, which often coexist and may also cause secondary hypertension, to fully manage hypertension by surgery.

Adolescent↗
PubMed2005

Is the guideline the cause of structural failure in current polyester vascular prostheses? An experimental study.

To evaluate the impact of the guideline on the structural failure of current polyester vascular prostheses, we studied seven unsealed polyester vascular prostheses. An accelerated time test was used for assessing degradation of polymeric medical materials at pH 7.4 in phosphate buffer at a temperature of 95 degrees C. Probe burst strength was determined on the guideline and on standard parts of the prostheses during the accelerated time test. Weight-average molecular weights of the guideline and of the standard parts in all knitted grafts during the accelerated time test were measured. The guideline was significantly weaker than the standard parts in most prostheses. The guideline had significantly lower values of weight-average molecular weights than the standard parts in most knitted grafts. This study showed that guideline degeneration was one factor responsible for the structural failure of some current polyester vascular prostheses.

Blood Vessel Prosthesis↗
PubMed2005

Rearrangement of T-cell receptor beta and gamma genes in thymoma.

To investigate the differentiation stage of tumor-infiltrating lymphocytes in thymoma tissue, we performed Southern blot analysis of T-cell receptor beta and gamma genes in thymomas resected from 19 patients. At the same time, we conducted flow cytometric analysis of T-cell surface markers and examined the clinicopathological features of the thymomas. We found that the incidence of T-cell receptor gamma gene rearrangement was significantly higher in Masaoka stage I thymomas (11 of 12 cases) than in stage II or III invasive thymomas (3 of 7 cases). Moreover, gamma gene rearrangement was observed in all 10 type AB and B1 thymoma specimens and in 4 of 6 type B2 thymoma specimens. The 2 specimens of type B3 thymomas, which were classified as stage III, showed neither gamma nor beta gene arrangement and were single-positive for CD4 or CD8. Six thymoma specimens that showed beta gene rearrangement expressed both CD4 and CD8. In conclusion, thymomas have the capability of T-lineage cell differentiation, except for a subset of invasive thymomas with malignant characteristics.

Aged↗
PubMed2005

Genetic analysis in a patient with recurrent cardiac myxoma and endocrinopathy.

A 60 year-old male was referred for treatment of a cardiac myxoma in the right atrium. He had a past history of left atrial cardiac myxoma at age 49 and pituitary microadenoma related to acromegaly at age 55. He did not have a family history of cardiac neoplasm or endocrinopathy. The intracardiac tumor was resected and its pathology was compatible with myxoma. A diagnosis of Carney complex (CNC) was made because the diagnostic criteria of this neoplastic syndrome were satisfied by the presence of recurrent cardiac myxoma, endocrine tumor and spotty skin pigmentation. In genetic analysis novel frame shift mutation was detected in exon 2 in a heterozygous fashion in the causative gene of CNC, protein kinase A regulatory subunit 1 alpha (PRKAR1A). This genetic mutation is thought to cause haplo-insufficiency of PRKAR1A resulting in tumorigenesis. Although it is the most common, usually benign, cardiac tumor, myxoma can cause a critical clinical situation and thus detecting the PRKAR1A mutation can assist with prognosis.

Acromegaly↗