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Biomedical subjects

R Omoto

Publications and source records attributed to R Omoto.

At least 37 records · Page 2Linked to original sources

Does intensive perioperative dialysis improve the results of coronary artery bypass grafting in haemodialysed patients?

BACKGROUND: Between January 1996 and April 1998, 17 chronic haemodialysed patients underwent coronary artery bypass grafting (CABG). Two of them simultaneously had valve replacement. METHODS: Except for two cases in which CABG was performed in an emergency, 15 patients (CRF group) received 3 consecutive days of haemodialysis in the preoperative period, intraoperative haemodialysis connected to cardiac pulmonary bypass (CPB) and continuous hemodiafiltration in the early postoperative period. The perioperative clinical parameters of the CRF group were compared with those of 17 age-matched patients with normal renal function undergoing CABG as the control (NRF group). RESULTS: When the perioperative variables were compared, no significant differences were seen in total operation time and CPB time, but we noted significant increases in the mean volume of transfused blood in the 6 perioperative days, postoperative intubation time, postoperative fasting time, and time spent in the intensive care unit. Levels of central venous pressure, systolic blood pressure, respiratory index (PaO2/FiO2) and daily fluid balance of the CRF group were the same as the control group in the early postoperative period. In addition, the levels of serum creatinine, urea nitrogen, potassium and hematocrit of CRF group remained almost constant in the early postoperative period. After all, the hospital morbidity of the CRF group was not more serious than that of the NRF group, and hospital mortality of the CRF and NRF groups was 0%. CONCLUSIONS: Our intensive perioperative dialysis programme could successfully manage the perioperative clinical course of haemodialysed patients undergoing CABG.

Coronary Artery Bypass↗

[Single-dose and high-volume Bretschneider cardioplegic solution for congenital heart surgery].

Bretschneider cardioplegic solution is used widely in Europe. The aim of this study is to investigate the efficacy of Bretschneider cardioplegic solution for open heart surgery of congenital heart disease in comparison with blood cardioplegia. From June 1995 to July 1997, we treated 32 congenital heart disease patients using Bretschneider cardioplegic solution and 20 patients using blood cardioplegia. Hospital mortality, water balance during operation, percentage of arrhythmia, and intubation time were not significant in both group. Also CPK and CPK-MB were not significant in both group. Bretschneider cardioplegic solution had preserved the heart as same as blood cardioplegia. This is a very convenient method so that we can use only one time infusion.

Cardiac Surgical Procedures↗

[Report of three cases of emergency operation for acute pulmonary embolism].

Three successful surgical cases of acute pulmonary embolism with severe cardiopulmonary impairment were reported. Currently, thrombolysis is widely accepted as the front-line treatment for most patients with pulmonary embolism. However, treatment failure is high and can lead to death in the most severe cases. If these patients have severe cardiopulmonary impairment, pulmonary embolectomy should be done immediately.

Acute Disease↗

[The effect of milrinone for the shock patients after cardiac surgery].

The effect of milrinone in the 16 postoperative shock patients of cardiovascular surgery was studied. The preoperative hemodynamic status were 12 of cardiogenic shock, 2 cases of chronic heart failure and 2 cases of unstable angina pectoris. The operative procedure were 8 cases of coronary artery bypass grafting, 4 cases of valvular surgery, 2 cases of closure of ventricular septal perforation, 2 cases of Bentall operation and 1 case of ascending aortic replacement. The postoperative hemodynamic status were 15 cases of cardiogenic shock, 10 cases of hemorrhagic shock and 1 case of septic shock. Continuous intravenous infusion of 0.5 microgram/kg/min without initial bolus loading was administered immediately after the entrance of the intensive care unit. Significant increase in the maximum blood pressure 3 hours after the infusion were observed (84 +/- 17 mmHg vs 94 +/- 12, p = 0.033). The maximum blood pressure was increased gradually until 24 hours after the infusion. Significant increase in the peripheral body temperature 3 hours after the infusion were observed (32.5 +/- 2.0 degrees C vs 35.9 +/- 1.1 degrees C, p = 0.001). The difference between the peripheral temperature and the central body temperature diminished until 24 hours after the infusion. No significant change in the central venous pressure, pulmonary arterial pressure, pulmonary and cardiac index wedge pressure were observed. No significant change in the platelet number was observed until 3 days after the infusion. Twenty patients (75%) were discharged. Four hospital deaths included 1 cardiac and 3 septic cause were seen. These data suggest that the administration of milrinone for the shock patients after cardiac surgery showed safe and that the continuous intravenous infusion of 0.5 microgram/kg/min without bolus loading showed effective for the recovery of the peripheral circulation.

Aged↗

[Computed tomography-guided hookwire localization of small pulmonary nodules for thoracoscopic biopsy].

We performed thoracoscopic biopsies of small pulmonary nodules in 13 patients by placing hookwires adjacent to the target nodules under computed tomographic (CT) guidance. Biopsies were successfully performed in 10 of the 13 patients. Placement of individual hookwires for this purpose took from 20 to 50 minutes (30 minutes on average). Excisional biopsies of individual nodules required 20 to 60 minutes (37 minutes on average). Although pneumothorax developed in one patient, treatment was not considered necessary. This biopsy technique was unsuccessful in 3 cases, in 2 of which the hookwire became dislodged, and in 1 of which the target nodule was not contained in the resected specimen. These experiences seemed to underscore the importance of placing CT-guided hookwires more deeply into lung tissue near the target nodules. The technique appears to be useful for thoracoscopic biopsies of peripheral pulmonary nodules that otherwise would be difficult to identify by endoscopic probing forceps.

Biopsy↗

[Aortic regurgitation caused by the proximal dissecting flap invagination to the left ventricle].

A 68-year-old male with sudden back pain and cardiogenic shock status transferred to our ward. Transthoracic echocardiography revealed that the abnormal round shape string was in the left ventricular outflow tract. The continuity from the staring to the aortic valve was unclear. Intimal flap could not be detected at the level of the ascending aorta. Color Doppler flow imaging showed that the severe AR jet extended into the round string. TEE showed that the intimal tear and flap was seen just above the left subclavian artery. Preoperative diagnosis was acute Stanford type A dissection and acute severe AR due to the inversion of the proximal intimal flap to the left ventricular outflow tract through the aortic valve. At operation, the proximal intimal flap was dissected circumferentially and was cut all the way around 8 cm above the aortic valve ring and was inverted to the left ventricular outflow tract. The aortic valve was preserved because of its normal character after exclusion of the proximal intimal flap. Ascending and arch replacement was carried out. Postoperative TEE and TTE slowed no findings of AR. The patient's postoperative course was uneventful. To our knowledge, this is the first reported case that severe AR caused by the proximal intimal invagination to the left ventricle.

Acute Disease↗

Expression of metastasis-related genes in surgical specimens of human gastric cancer can predict disease recurrence.

It was determined whether the expression level of several genes that regulate different steps of metastasis in formalin-fixed paraffin-embedded archival specimens of human gastric cancers correlated with disease recurrence and metastasis. The steady-state mRNA expression level for epidermal growth factor receptor (EGF-R), basic fibroblast growth factor (bFGF), E-cadherin, type IV collagenase and multidrug resistance (MDR-1) were examined by a colorimetric in situ hybridisation (ISH) technique, concentrating on reactivity at the periphery of the lesions. All patients were operated on for cure. 15 cases were disease-free and 10 had disease recurrence by 4.5 years after resection of the primary tumours. The expression of EGF-R and bFGF type IV collagenase was higher and expression of E-cadherin was lower in the disease-recurrence cases than in the disease-free cases. The ratio between the expression level of collagenase type IV and E-cadherin at the periphery of the surgical specimens differed significantly between the disease-free cases and the recurrent-metastatic cases. These data show that multiparametric ISH analysis for several metastasis-related genes may allow prediction of disease recurrence of gastric cancer.

Cadherins↗

Endoscopic harvest of saphenous vein graft for coronary artery bypass grafting: Saitama-Olympus technique.

OBJECTIVE: This study was undertaken to examine the clinical feasibility of a newly developed video-assisted endoscopic technique (Saitama-Olympus technique) to harvest saphenous vein graft (SVG) in 40 CABG patients. METHODS: There were 37 males and three females with an average age of 59+/-11 years. The special instruments developed were optical sheath, solid dilators, tunnel retractor, vessel dissector, GCC forceps which were utilized in conjunction with the thoracoscopic surgery system (Olympus, Tokyo, Japan). The course of the saphenous vein (SV) was marked on the skin prior to operation. SV was identified in the femoral region with a 4-cm skin incision and dissected with an open technique. The anterior surface of SV was dissected for 30 cm by the optical sheath mounted on the endoscope. Then another 4-cm skin incision above SV was placed in the popliteal region, resulting in a subcutaneous space over the SV. The subcutaneous space was then dilated and maintained with the tunnel retractor which has an endoscope channel at the top. With this system SV was visualized stably by endoscope without any assistance. All side branches were dissected and divided with the vessel dissector. When longer SVG is required, the same procedure was extended to the ankle with additional one or two skin incisions. RESULTS: SV was easily harvested in all patients with spending 15-84 min. The average number of skin incisions was 2.4+/-0.5 and the average length of the harvested SVG was 41+/-12 cm. The average number of bypassed grafts was 3.4+/-1.0 with use of left internal mammary artery (IMA) in 31 patients. The average operation time was 272+/-52 min, there were no significant prolongation relating to endoscopic SVG harvesting. The remainder of SVG in each patients was pathologically examined and there were no evidence of intimal injury. There were no major wound complications during the average follow-up of 10+/-4 months and this technique seemed to be advantageous for patients with less wound pain and better cosmetic appearance. CONCLUSIONS: The Saitama-Olympus technique to endoscopically harvest the SV is a clinically feasible surgical technique with the unique potential of a significant reduction in morbidity and decreased wound scarring in CABG patients.

Coronary Artery Bypass↗

[A surgical case of quadricuspid aortic valve associated aortic regurgitation and severe mitral regurgitation due to infective endocarditis].

We report a case of rare anomaly of quadricuspid aortic valve associated aortic regurgitation and severe mitral regurgitation due to infective endocarditis. A 50-year-old man was admitted to our hospital for fever and dyspnea. The transesophageal echocardiography showed severe aortic regurgitation due to four equal aortic cusps and severe mitral regurgitation due to infective endocarditis. At the operation, aortic valve and mitral valve were replaced with 23 mm and 29 mm SJM valves. His postoperative course was uneventful.

Aortic Valve↗

An assay method for nitric oxide-related compounds in whole blood.

Recent evidence suggests that nitric oxide (NO) generated in vivo will be converted into the forms of nitrite/nitrate, nitrosyl hemoproteins, nitrosyl metal complexes, and S-nitroso-compounds in the circulation. Nitrosothiols have also been reported to be relatively stable metabolites with micromolar levels in plasma. We hypothesized, therefore, that the determinations of all the NO-related compounds in blood would be of diagnostic significance. The assay method described here consists of the thermolysis of all the NO-related compounds in whole blood and the detection of resulting nitrate by fluorometry or chemiluminescence after an enzymatic reduction. S-Nitroso-albumin and nitrosyl hemoglobin can be easily thermolysed to nitrate, and relatively stable S-nitroso-glutathione is also degraded to nitrate in the presence of blood constituents with high molecular mass (above 30 kDa). Concentrations of NO-related compounds in blood from healthy human as well as control or lipopolysaccharide-stimulated rats were determined. We found that membrane-bound NO which showed the augmented levels under the pathophysiological states could also be detected. Together with electron spin resonance spectra, our data indicate that the fraction of NO diffused and metabolized within red cells and the other NO-metabolites in plasma such as nitrite/nitrate and S-nitroso-compounds, both of which can reflect NO-production in vivo, would be recovered and detected quantitatively by this method.

Animals↗

Usefulness of transesophageal echocardiography in detecting changes in flow dynamics responsible for malperfusion phenomena observed during surgery of aortic dissection.

Intraoperative transesophageal echocardiography (TEE) was performed in order to study the flow dynamics in the descending aorta during surgery of aortic dissection Stanford A. TEE was seen to be a sensitive and accurate method to promptly detect severe decrease in retrograde pump flow and to clarify some of the mechanisms that can result in malperfusion during cardiopulmonary bypass.

Adult↗

Intravascular ultrasound assessment of regional aortic wall stiffness, distensibility, and compliance in patients with coarctation of the aorta.

BACKGROUND: Impaired aortic pulsatility has been demonstrated by angiography in children and in studies of experimental animals with coarctation of the aorta. OBJECTIVES: The purpose of this study was to assess regional aortic stiffness, distensibility, and compliance before and after balloon dilation in patients with coarctation of the aorta. METHODS AND RESULTS: Intravascular ultrasound examination was performed in 13 pediatric patients with the diagnosis of coarctation of the aorta to yield aortic diameter. Area transverse sections at both systolic and diastolic period were measured at three aortic levels: the proximal, distal, and coarctation segments. Balloon dilation was also performed in eight of 13 patients. By using pressures measured in the same areas, an aortic stiffness index (beta) was calculated as In(Ps/Pd)/(Ds-Dd), where In is natural logarithm, Ps is systolic pressure, Pd is diastolic pressure, Ds is systolic diameter, and Dd is diastolic diameter. Aortic distensibility and an estimation of aortic compliance were also calculated. The beta stiffness index of the coarctation and the proximal segments of the aorta were significantly greater than that of the distal segment of the aorta (p < 0.01). The aortic wall stiffness beta index did not acutely change after successful balloon dilation, but the distensibility and compliance of distal aorta were nonetheless significantly decreased after balloon dilation (p < 0.01, p < 0.05) as a function of changes of pulsatility of flow. CONCLUSIONS: Abnormal proximal aortic stiffness may be a strong contributing factor that promotes the genesis of hypertension in patients with coarctation even after successful repair or balloon angioplasty.

Adolescent↗