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Shunei Kyo

Publications and source records attributed to Shunei Kyo.

49 records · Page 3Linked to original sources
PubMed2003

[Impact of cimetidine on growth and metastasis of surgically transplanted Lewis lung cancer].

PURPOSE: Histamine has multiple biological functions and its immunomodulatory actions are not fully understood. In the current study, we investigated the effect of cimetidine, which is a histamine-2 receptor antagonist, on the progress of transplanted Lewis lung cancers using a mouse model. METHODS: A piece of Lewis lung cancer weighing 15 mg was transplanted into the subcutaneous space on the back of each C 57 BL/6 mouse. Mice were randomized into a no-treatment control group (CO) or one of two treatment groups. In the treatment groups, 16 mg/kg/day (LD) or 160 mg/kg/day (HD) of cimetidine was orally administered from one week before the day of transplantation to the time of sacrifice. Subcutaneous tumors and lungs were excised on the 28th or 42nd postoperative day. RESULTS: The mean vascular densities of the subcutaneous tumors on day 28 were 55.7 +/- 23.9/mm2 in CO, 88.0 +/- 16.3/mm2 in LD and 122.6 +/- 16.9/mm2 in HD (p < 0.05; CO vs. LD or HD, LD vs. HD). On day 42, mean weights of the subcutaneous tumors and the numbers of metastatic lung tumors were 6.0 +/- 2.1 g in CO, 7.9 +/- 1.2 g in LD and 10.0 +/- 1.9 g in HD (p < 0.05; CO vs. HD), and 7.5 +/- 6.0 in CO, 17.0 +/- 3.0 in LD and 19.8 +/- 7.4 in HD (p < 0.05; CO vs. HD), respectively. CONCLUSIONS: These results suggest that cimetidine dose-dependently enhances the angiogenesis, growth and metastasis of surgically transplanted Lewis lung cancer in a mouse model of this type.

Animals↗
PubMed2003

Simultaneous abdominal aortic aneurysm repair during the on-pump coronary artery bypass grafting.

A case of simultaneous coronary artery bypass grafting (CABG) and abdominal aortic aneurysm (AAA) repair on cardiopulmonary bypass (CPB) is reported. A 74-year-old man was diagnosed with left main coronary disease and infrarenal AAA. Triple CABG and infrarenal AAA repair were performed simultaneously, by different surgeons, on CPB. The duration of CPB, aortic clamp time, and total operation time was 81 min, 33 min, and 245 min, respectively. The patient was extubated three hours after ICU admission and the postoperative course was uneventful. This method is useful for reduction of operation time, for blood salvage, and for adjustment of preload and afterload of the vulnerable heart during AAA repair.

Aged↗
PubMed2002

Ventricular afterload and ventricular work in fontan circulation: comparison with normal two-ventricle circulation and single-ventricle circulation with blalock-taussig shunts.

BACKGROUND: Recent studies have indicated that there are inherent limitations associated with Fontan physiology. However, there have been no quantitative analyses of the effects of right heart bypass on ventricular afterload, hydraulic power, and resultant overall hemodynamics. Methods and Results- During routine cardiac catheterization, aortic impedance and ventricular hydraulic power were determined, both at rest and under increased ventricular work induced by dobutamine, in 17 patients with Fontan circulation, 15 patients with a single ventricle whose pulmonary circulation was maintained only by Blalock-Taussig shunts, and 13 patients who had normal 2-ventricle circulation. Both vascular resistance (nonpulsatile load on the ventricle) and pulsatile components of ventricular afterload (represented by low-frequency impedance) were significantly higher in the Fontan group than in the other groups (P<0.01), and this was associated with decreased cardiac output in the Fontan patients. In addition, hydraulic power cost per unit forward flow was 40% lower in the 2-ventricle circulation than in the single-ventricle circulation, suggesting lower ventricular efficiency in single-ventricle circulation attributable to the lack of a pulmonary ventricle. Furthermore, in the Fontan group, beta-adrenergic reserve was markedly decreased because of a limited preload reserve. CONCLUSIONS: Fontan physiology is associated with disadvantageous ventricular power and afterload profiles and has limited ventricular reserve capacity. Thus, to improve the long-term prognosis of patients after Fontan surgery, future research should be conducted into medical interventions that can overcome these limitations inherent in Fontan circulation.

Adrenergic beta-Agonists↗
PubMed2002

Allograft pulmonary artery root replacement for refractory isolated pulmonic valve endocarditis.

A 45-year-old diabetic woman was subjected to percutaneous cardiopulmonary support for a life-threatening pulmonary embolism. One month later, she developed isolated pulmonic valve endocarditis. The causative organism was methicillin-resistant Staphylococcus aureus. Because of the uncontrollable infection and residual pulmonary hypertension, she underwent pulmonary artery root replacement with a cryopreserved pulmonary allograft. The postoperative course was very good. In this case, allograft implantation with a full root played a very important role because this method permitted thorough resection of the infected tissues and reconstruction which is highly resistant to infection.

Angiography↗
PubMed2002

Possible close relationship between non-occlusive mesenteric ischemia and cholesterol crystal embolism after cardiovascular surgery.

A senile patient developed fatal intestinal necrosis right after uneventful cardiovascular operation using usual cardiopulmonary bypass. Cholesterol crystal embolism (CCE) was demonstrated histologically, but angiograms were typical of non-occlusive mesenteric ischemia (NOMI). Very severe vasoconstriction occurred not only in the superior mesenteric artery but also in other splanchnic arteries. The clinical course strongly suggested that NOMI resulted from CCE and that some humoral factors were released and played very important roles in this case.

Aged↗
PubMed2002

The results of total arch graft implantation with open stent-graft placement for type A aortic dissection.

BACKGROUND: One problem that conventional ascending treatment for type A aortic dissection has not satisfactorily resolved is chronic enlargement of residual dissection in the aortic arch and descending aorta. To address this problem, we have developed a new method for type A aortic dissection: total arch graft implantation with open-style stent-graft placement. METHODS: From October 1994 through October 1999, 19 patients with type A aortic dissection (13 acute and 6 chronic dissections) underwent total arch graft implantation with open-style stent-graft placement. After achievement of general anesthesia and hypothermic extracorporeal circulation, we replaced the dissected ascending aorta and neck vessels with a 4-branched graft and repaired the descending aorta with a stent graft to close the entry site completely and to obtain better peripheral perfusion. We then examined the acute-phase and chronic-phase results and the outcomes of the false lumen and dissected aorta. RESULTS: There were 1 (5.3%) hospital death and 2 late deaths. The survivals at 1 and 3 years were 89.5% and 82.6%, respectively. The following complications occurred in the perioperative period: 1 stroke, 2 cases of temporary paraparesis, 2 cases of temporary hemodialysis, and 3 cases of mediastinitis. No pulmonary complications were observed. Six months postoperatively, the targeted entry sites were completely closed in all cases, 80% (8/10) of preoperatively patent false lumina were clotted at the level of the end of the stent graft, and 60% (9/15) of the false lumina and 40% (6/15) of the dissected aorta had shrunk significantly. Two (13.3%) of 15 cases of postoperative dilatation in the dissected aorta were observed, and reoperation related to residual dissected aorta was performed in only 1 (1/17 [5.9%]) patient during the mean follow-up period of 2.4 +/- 1.6 years. CONCLUSION: Our preliminary review of the total arch graft implantation with a stent graft suggests that this new procedure for type A aortic dissection might provide better results in both the acute and the chronic phase, especially with regard to the outcome for the false lumen and dissected aorta.

Adult↗
PubMed2002

Mitral valve surgery under perfused ventricular fibrillation with moderate hypothermia.

The safety and myocardial protective effect of perfused ventricular fibrillation (VF) under moderate hypothermia were investigated. Through a midline sternotomy and opening the left atrium from the right side, isolated mitral valve surgery was performed under aortic cross-clamping (ACC) and cardioplegic arrest using Bretschneider HTK solution in 96 patients, and under perfused VF in 20 patients (VF Group). Patient characteristics, clinical outcomes, and perioperative variables were compared. A satisfactory surgical view was obtained in all VF Group patients. Patient characteristics in the 2 groups were similar, and both groups had comparable results for mortality and morbidity, operation time, cardiopulmonary bypass time, peak levels of creatine kinase (CK) and its myocardial fraction, hours of mechanical ventilation, intensive care unit stay, and postoperative left ventricular ejection fraction. Even in VF Group patients with preoperative critical hemodynamic compromise, inotropes could be discontinued within 3 days. Thus, no detrimental effect of perfused VF was observed. On the other hand, in patients who underwent ACC and cardioplegic arrest of 120min or longer, peak levels of CK and its myocardial fraction were significantly higher than those of the rest of C group patients and VF Group patients. Perfused VF under moderate hypothermia can be a good alternative myocardial protection strategy during mitral valve surgery, particularly in patients in whom ACC is unsuitable or the duration of ACC is expected to be long.

Adult↗
PubMed2002

The efficacy and safety of additional bypass graft during isolated coronary artery bypass grafting.

In 19 patients with an undesirable hemodynamic condition (n=15) or with regional asynergy and coexistent ST-T change (n=4) during isolated coronary artery bypass grafting (CABG) surgery, one (n=17) or two (n=3) additional saphenous vein grafts were placed onto left anterior descending (LAD) (n=16), right (n=4), and left circumflex (LCx) (n=2) coronary arteries. Diagnosis of the cause of the suboptimal condition was insufficient graft flow in 16 patients, and spasm of the ungrafted coronary artery in 3. Additional myocardial ischemic time was 17 9 minutes, and the graft flow was 59 25 ml/min. Additional bypass was effective in 94.5%. Eighteen patients could be weaned from cardiopulmonary bypass, and 17 (89.5%) survived and were discharged from hospital. Median duration of mechanical ventilatory support and intensive care unit stay was 15 hours and 4 days, respectively. During 63 44 months follow-up, the additional graft was occluded and the treadmill test was positive for ischemia in 2 patients, and one child patient is now considered for redo CABG. Placement of additional bypass grafts thus appeared to be an effective and relatively safe strategy, although the decision has to be made cautiously.

Adolescent↗
PubMed2002

[Left ventricular assist system].

Two types of artificial heart, the total artificial heart (TAH) and ventricular assist system (VAS), have been utilized in patients with end-stage heart failure waiting for heart transplantation (bridge to transplantation). The TAH is a system to replace the native heart, whereas the VAS is a system to support the left ventricle (LVAS), right ventricle (RVAS), or both ventricles (BVAS) while maintaining native cardiac function. There are two types of VAS, paracorporeal VAS and implantable VAS. Implantable VAS devices such as Novacor LVAS and HeartMate LVAS are only available for LVAS, although paracorporeal VAS, such as Toyobo VAS, Zeon VAS, and Thoratec VAS, are available for RVAS, LVAS, or BVAS. Due to recent advances in the VAS, the "patient discharge program" from hospital has been promoted for improvement of the quality of life (QOL) and reduction of medical costs. VAS also have been utilized as "bridges to recovery" for native hearts or for "semipermanent use" in patients without indications for heart transplantation, and superior clinical results of VAS therapy compared with conservative therapy have been reported in terms of one-year survival rate and improvement of QOL. Recently, several inexpensive VAS systems with an axial or centrifugal pump have been developed and the initial clinical trials of these systems have recently started in Western countries. Another remarkable technological advance in VAS is the Lion Heart (Arrow) which is a totally implantable VAS system the includes an energy transmission system. We expect that recent technological progress in VAS will improve the survival and QOL in patients with end-stage heart failure.

Heart Failure↗
PubMed2002

[Regenerative potential of mesodermal stem cells for the heart].

There has been increasing interest in recent years in the phenomenon of "regeneration," especially in the function of the bone marrow stromal cell system in the support of hematopoiesis. The stromal cell system has been proposed to consist of mesodermal stem cells that are capable of self-renewal and differentiation into a variety of mesodermal tissues, including bone, cartilage, tendon, fat, endothelium, skeletal muscle, and cardiomyocytes. These findings raise the possibility that bone marrow-derived cells may provide an alternative source of cardiomyocytes in patients with severe cardiac failure due to loss of muscle cells. Some studies have indicated that locally or systemically delivered mesodermal stem cells can generate de novo cardiomyocytes. Despite their potential clinical utility for cellular and gene therapy, the mechanism of differentiation in mesodermal stem cells and characterization of stem cells in terms of surface antigen expression remain to be resolved. Although some clinical trials have been initiated using crude bone marrow-derived stromal cells, we need more knowledge of stem cells to establish a standard protocol for cellular therapy.

Heart↗
PubMed2002

[Advantages and limitations in minimally invasive cardiac surgery].

The introduction of endoscopic technology to cardiovascular surgery was significantly delayed compared to abdominal and lung surgery, although it has been gradually introduced in this field during the past decade in closure of patent ductus arteriosus, repair of the vascular ring, implantation of pacemaker leads or AICD, and pericardectomy. Endoscopic technology also started to be used in harvesting saphenous vein grafts (SVG) and the left internal thoracic artery for coronary artery bypass grafting(CABG) from the mid-1990s. Although complete endoscopic surgery has not yet been established in the major field of standard cardiovascular surgery, many cardiac surgeons attempt to minimize the size of chest wounds with 6- to 8-cm skin incisions, which is called minimally invasive cardiac surgery (MICS) or minimally invasive direct coronary artery bypass (MIDCAB). Complete endoscopic cardiac surgeries were performed utilizing the Zeus system and Da Vinci system at the end of the 20th century. Another method to minimize the invasiveness of CABG is to perform it without cardiopulmonary bypass, so-called off-pump coronary artery bypass (OPCAB). Currently, less-invasive procedures are mainly applied for relatively simple cardiac surgeries, although these procedures are also potentially effective to avoid postoperative cerebral or respiratory complications in high-risk patients. MICS is effective in reducing the size of surgical wounds and in decreasing intraoperative blood loss. On the other hand, the duration of anesthesia and surgery can be prolonged due to technical difficulty, and the risk of unsatisfactory anastomosis or incomplete revascularization can also be increased. The cardiopulmonary bypass circuit utilized for MICS requires a more complicated system including negative pressure venous drainage. The detection of accidental trouble during surgery, which is related to the extracorporeal circulation or the MICS procedure itself, can be delayed due to the limited surgical view. MICS procedures carry additional risks related to the more complicated cardiopulmonary bypass system and small surgical wound. We must be deliberate in determining the indications for MICS and obtain complete informed consent from patients when we perform MICS, including informing them of the additional risks related to the MICS procedure itself and the possibility of conversion to standard open-heart surgery.

Cardiac Surgical Procedures↗