• Journal of Chest Surgery
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• v.48 no.3
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• pp.174-179
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• 2015

Background: The endoscopic vein harvesting (EVH) method has been used in coronary artery bypass surgery in many countries. We started using the EVH method recently, and investigated the results during the early learning period. Methods: Between March 2012 and June 2014, 75 patients (31 patients in the EVH method group, and 44 patients in the open method group) who underwent isolated first-time coronary artery bypass grafting using vein grafts were retrospectively analyzed with respect to the early outcomes including graft patency and risk factors for leg wound complications. For assessing the patency of vein graft, we performed coronary computed tomography angiography during the immediate postoperative period and 6 months later. Results: Mean harvesting time of endoscopic method was about 15 minutes. Patency rate during the immediate operative period and the 6-month patency rate were similar between the two groups (postoperative period: EVH 100% vs. open method 94.4%, p=0.493; at 6 months: EVH 93.3% vs. open method 90.9%, p=0.791). Leg wound complications occurred more frequently in the open method group (EVH 3.2% vs. open method 13.6%, p=0.127). According to the analysis, age was an independent risk factor for leg wound complications. Conclusion: EVH is a feasible method even for beginners and can be performed satisfactorily during their learning period.

• Journal of Chest Surgery
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• v.33 no.8
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• pp.630-637
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• 2000

Backgroud: There are well-known problems in the management of low weight neonates or infants with congenital heart defects. In the past, because of a perceived high risk of operations using cardiopulmonary bypass(CPB) in these patients, there was a tendency for staged palliation without the use of CPB. However, the recent trend has been toward early reparative surgery using CPB, with acceptable mortality and good long-term survival. Therefore we reviewed our results of the operations in infants weighing less than 3kg and considered the technical aspect of conducting the CPB including myocardial protection. Material and Method: Between Jan. 1995 and Jul. 1998, 28 infants weighing less than 3kg underwent open heart surgery for many cardiac anomalies with a mean body weight of 2.7kg(range; 1.9-3.0kg) and a mean age of 41days(range; 4-110days). Preoperative management in the intensive care unit was needed in 20 infants and preoperative ventilator support therapy in 11. Total correction was performed in 23 infants and the palliative procedure in 5. Total circulatory arrest was needed in 11 infants(39%). Result: There were seven hospital deaths(25%) caused by myocardial failure(n=3), surgical failure(n=2), multiorgan failure(n=1), and sudden death(n=1). The median duration of hospital stay and intensive care unit stay were 13days(range; 6-93days) and 6days(range; 2-77days) respectively. The follow-up was achieved in 21 patients and showed three cases of late mortality(15%) and a one-year survival rate of 62%. No neurologic complications such as clinical seizure and intracranial bleeding were noticed immediately after surgery and during follow-up. Conclusion: The early and late mortality rate of open heart surgery in our infants weighing less than 3 kg stood relatively high, but the improved outcomes are expected by means of the delicate conduct of cardiopulmonary bypass including myocardial protection as well as the adequate perioperative management. Also, the longer follow-up for the neurologic development and complications are needed in infants undergoing circulatory arrest and continuous low flow CPB.

• Journal of Chest Surgery
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• v.52 no.1
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• pp.16-24
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• 2019

Background: Optimal graft selection for coronary artery bypass grafting (CABG) in patients with severe left ventricular (LV) dysfunction remains debatable. We report an analysis of our experiences of isolated CABG in patients with severe LV dysfunction and the impact of graft strategy on long-term outcomes. Methods: We analyzed 209 patients with severe LV dysfunction (ejection fraction [EF] <30%) who underwent primary isolated CABG. Of these, 169 were revascularized with a bilateral internal thoracic arterial (ITA) graft (BITA group) and 40 were revascularized with a single ITA graft (SITA group). The mean follow-up duration was $22{\pm}32$ months. Results: There were 18 early deaths (8.6%). Overall survival at 5 years was 66.7%. The rate of freedom from cardiac-related death at 5 years was 74.1%, and was significantly higher in patients who underwent off-pump CABG (p=0.005) and in the BITA group (p=0.023). Multivariate analysis demonstrated that old age (hazard ratio [HR], 2.548; 95% confidence interval [CI], 1.134-5.762; p=0.024), off-pump CABG (HR, 0.245; 95% CI, 0.090-0.661; p=0.006), and BITA grafts (HR, 0.333; 95% CI, 0.146-0.757; p=0.009) were correlated with cardiac mortality. Conclusion: CABG in patients with severe LV dysfunction (EF <30%) showed reasonable long-term outcomes. The rate of freedom from cardiac-related death was significantly higher in patients who underwent off-pump CABG and in the BITA group. Off-pump BITA grafting strategies can be accepted as a viable primary option in patients with severe LV dysfunction if performed by an experienced surgeon.

• Journal of Chest Surgery
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• v.52 no.2
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• pp.70-77
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• 2019

Background: Extracorporeal life support (ECLS) is used as a bridge to revascularization in high-risk patients with ischemic heart disease. We reviewed our experiences of coronary artery bypass grafting (CABG) after ECLS in patients with cardiac arrest or refractory cardiogenic shock. Methods: We retrospectively reviewed 4,616 patients who underwent CABG at our institution between May 2006 and February 2017. We identified patients who underwent CABG following ECLS for cardiogenic shock or cardiac arrest. Twenty-three patients (0.5% of all CABG cases) were enrolled in the analysis. Their median age was 65 years (Q1-Q3, 58-77 years). Nine patients (39.1%) were diagnosed with ST-elevation myocardial infarction. Mechanical complications after acute myocardial infarction, including acute mitral regurgitation, left ventricular rupture, and ventricular septal defect, occurred in 9 patients (39.1%). Results: The median time from cardiopulmonary resuscitation to ECLS initiation was 25 minutes (Q1-Q3, 18.5-28.5 minutes). Conventional CABG was performed in 10 patients (43.5%) who underwent concomitant intracardiac procedures. Postoperative ECLS was required in 16 patients (69.5%). The rate of successful ECLS weaning was 91.3% (n=21). There were 6 early mortalities (26.1%). Conclusion: CABG after ECLS was very rare in real-world circumstances. Although the early mortality rate was high, the risk of mortality may be acceptable under such devastating circumstances.

• Journal of Chest Surgery
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• v.54 no.2
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• pp.117-126
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• 2021

Background: Several factors, such as the degree of target vessel stenosis, are known to be associated with radial artery (RA) graft patency in coronary artery bypass grafting (CABG). There is a lack of data regarding the effect of the RA proximal configuration (aortic anastomosis versus T-anastomosis). This study evaluated the effects of the RA proximal configuration on the patency rate and clinical outcomes after CABG. Methods: We conducted a retrospective study, analyzing 328 patients who had undergone CABG with an RA graft. We divided the patients into 2 groups. The primary endpoint was RA patency and the secondary endpoints were overall mortality and major adverse cardiac and cerebrovascular events (MACCE). We performed a propensity score-matched comparison. Results: Aorta-RA anastomosis was performed in 275 patients, whereas the rest of the 53 patients received T-RA anastomosis. The mean age was 67.3±8.7 years in the T-RA anastomosis group and 63.8±9.5 years in the aorta-RA anastomosis group (p=0.02). The mean follow-up duration was 5.13±3.07 years. Target vessel stenosis ≥70% (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.20-0.91; p=0.03) and T-RA anastomosis configuration (HR, 2.34; 95% CI, 1.01-5.19; p=0.04) were significantly associated with RA occlusion in the multivariable analysis. However, T-RA anastomosis was not associated with higher risks of overall mortality and MACCE following CABG (p=0.30 and p=0.07 in the matched group, respectively). Conclusion: Aorta-RA anastomosis showed a superior patency rate compared to T-RA anastomosis. However, the RA proximal anastomosis configuration was not associated with mortality or MACCE.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1129-1136
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• 2009

The paper presents the performance characteristics for a cooling system using EEV. The water cooler was used to reduce thermal deformation and contraction due to high speed of machine tools and the EEV was used for capacity control for water cooler. The apparatus was designed for hot-gas bypass system which a hot-gas can flows from outlet of compressor to the inlet of evaporator. This experiment is the intermediary study for precise temperature control through PID control. The results show that the evaporator pressure increased and refrigeration capacity decreased as the EEV opening step of hot-gas bypass increased. These results can be used as basic data for the design of effective water cooler.

• International Journal of Vascular Biomedical Engineering
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• v.1 no.1
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• pp.32-40
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• 2003

Axillo-bifemoral (Ax-Fem) bypass are now well accepted for bilateral iliac artery occlusion as the second best option. This extra-anatomical (unnatural) bypasses, however, have various hemodynamic liabilities affecting the patency. Hemodynamic conditions of each different type of Ax-Fem bypass were assessed with computer simulation model to determine the hemodynamically more sound type. Simulation models of five different types of Ax-Fem bypass were constructed. Our investigation based on the computer simulation models have shown distinct differences between two most popular Lazy-S type and Inverted-C type on the distribution of flow volume, shear stress and recirculation zone, etc., though both types have shown similar clinical results. Lazy-S type has shown better hemodyanmic status than inverted-C type. The theoretical advantage of "Lazy-S" type has never been adequately proved for its superiority clinically over the inverted-C type. Inverted-C type is now in more favor with clinically better results in spite of many hemodynamic liabilities including retrograde flow to the branching graft. The improvement of over-all long-term patency rate of various extra-anatomical bypasses is still warranted through proper correction of the hemodynamic liability. Even though clinical outcome of the extra-anatomical bypass has been equal regardless of the type of crossover femoral graft configuration, there are distinct differences on the hemodynamic characteristics among various types of configuration. Further hemodynamic study in the pulsatile flow status is warranted to correct hemodynamic defects with proper modification of various hemodynamic factors of each model.

• Journal of Chest Surgery
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• v.48 no.1
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• pp.13-24
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• 2015

Background: Controversy persists regarding the use of coronary endarterectomy (CE) in patients with severe coronary artery disease. We compared the comorbidities and perioperative characteristics of patients undergoing coronary artery bypass grafting (CABG) with and without CE. Methods: This study was performed in two private hospitals in Shiraz, Iran from May 2010 to December 2011 on 967 patients who underwent CABG without CE and 84 patients who underwent CABG with CE (the CE+ group). After follow-up at $9.66{\pm}3.65$ months post-surgery, 28 patients from the CE+ group underwent angiography to evaluate the patency of grafts and native coronary vessels. Results: Patients in the CE+ group had a more prevalent history of diabetes (48% vs. 36%) and number of diseased vessels ($2.88{\pm}0.39$ vs. $2.70{\pm}0.85$). The overall hospital mortality was 1.8%, and no significant difference was observed between the two groups. In the 28 patients who underwent reangiography, 113 vessels were bypassed and 29 endarterectomies were performed, mostly on the left anterior descending artery (12 endarterectomies) and the right coronary artery (8 endarterectomies). In the endarterectomized vessels, a 66% patency rate was found in both the grafts and the native vessels. The native coronary vessels were more likely to be patent when the left internal mammary artery was used as a conduit than when a saphenous vein bypass graft was used. Conclusion: The lack of a significant difference in postoperative complications in patients who underwent CABG with or without CE may indicate that CE does not expose patients to a higher risk of complications. Since most of the endarterectomized vessels were shown to be patent during the follow-up period, we propose that endarterectomy is a viable option for patients with severely diseased vessels.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.985-1000
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• 2005

In vitro anaerobic incubations of timothy (Phleum pretense L.) forage with bovine rumen fluid were conducted at 39℃ for 0, 3, 6, 9, 24, and 36 h in three trials to examine the biohy- drogenation of linolenic (C18:3) and linoleic acids (C18:2) and their bypass from the rumen. The objectives of the first trial was to study the effect of growth stage (stem elongation, early heading, late heading, and early flowering) and N-fertilization (0 and 120 kg N ha－1) on in vitro biohydrogenation of C18:2 and C18:3. The hydrogenable fraction, the effective disappearance and the bypass of C18:2 and C18:3 were high in timothy harvested at stem elongation, and decr- ease linearly with maturity. The N-fertilization increased the hydrogenable fraction of C18:3, the effective disappearance and the bypass of C18:2 and C18:3. However, the rate of disappearance of C18:2 and C18:3 were not affected by maturity and N-fertilization (P>0.1). In trial 2, the effect of timothy conservation method on in vitro C18:2 and C18:3 biohydrogenation was determined. Silage had the highest effective disappearance of C18:2 and C18:3, and grass hay had lowest one. The amounts of C18:2 and C18:3 biohydrogenated were higher in haylage and silage than in grass hay. Comparative to haylage timothy, the bypass of C18:3 was higher in fresh grass, wilted grass and grass hay. The bypass of C18:2 was higher in fresh grass and silage in comparison to grass hay and haylage. In trial 3, the effects of formic acid and Lactobacillus plantarum inoculum addition to timothy haylage and silage on C18:2 and C18:3 disappearance and bypass were studied. Haylage and silage additives had no effect (P>0.1) on effective disappearance and bypass of C18:2 and C18:3. The addition of formic acid increased the rate of biohydrogenation of C18:3 in haylage and silage, but it decreased the hydrogenable fraction of C18:2 in silage. The results of these three incubation trials show that the hydrogenable fraction and the bypass of C18:2 and C18:3 in timothy decreased with maturity and increased with N-fertilization. Higher amount of C18:2 and C18:3 were biohydrogenated in haylage and silage than in grass hay, and C18:3 ruminal disappearance was higher in fresh grass, wilted grass and grass hay than in haylage.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.979-982
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• 2003

Two rapeseed meal samples (Sample A, hybrid 5900 and sample B, double low rapeseed No.4) obtained from China and one Canola meal sample obtained from a local crushing plant in Canada were used to investigate the amino acid degradability of rapeseed/Canola meal in rumen and amino acid digestibility of ruminal incubation residues by precision-fed rooster bioassay. Results show that in ruminal incubation the degradation rate of non amino acid nitrogen in crude protein is higher than that for amino acid nitrogen in crude protein, the results also suggest that the degradation rate of amino acid nitrogen in Chinese rapeseed meal sample B was lower than that for Canadian Canola, but that in Chinese rapeseed meal sample A is much close to that for Canadian canola meal. For all amino acids the digestibility of the bypass or residual protein as measured by the precision-fed rooster bioassay tended to be lower for Chinese rapeseed meal sample A than for sample B or Canadian canola meal which had similar digestibility values. However following a calculation of total amino acid availability, involving the digestibility of amino acids in the rumen and rooster bioassay the results are less contradictory. Results indicated that in traditional roasting-expelling process, heat treatment, especially dry heat treatmeat could decrease amino acids degradability in rumen of rapeseed/canola meal, but also may decrease total availability of amino acids of rapeseed/canola meal.