• Title/Summary/Keyword: Cardiovascular flow

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Conduits for Coronary Bypass: Internal Thoracic Artery

  • Barner, Hendrick B.
    • Journal of Chest Surgery
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    • v.45 no.6
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    • pp.351-367
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    • 2012
  • This second report in the series on coronary artery bypass presents the authors experience and personal views on the internal thoracic artery (ITA) which date to 1966. There has been a very gradual evolution in the acceptance of this conduit which was initially compared with the saphenous vein and viewed as an improbable alternative to it. As is common with concepts and techniques which are 'outside the box' there was skepticism and criticism of this new conduit which was more difficult and time consuming to harvest for the surgeon who had to do it all. It was viewed as small, fragile, spastic and its flow capacity was questioned. Only a few surgeons employed it because of these issues and some of them would frequently graft it to the diagonal artery as it was thought not to supply adequate flow for the left anterior descending unless it was small. After a decade, angiographic data revealed superior patency to vein grafts. Even this evidence and survival benefit reported a few years later did not convince many surgeons that their concerns about limitations justified its use. Thus widespread adaption of the ITA as the conduit of choice for the anterior descending required another decade and bilateral use is only now expanding to more than 5% of patients in the US and somewhat faster in other countries.

Effects of aprotinin on isolated rat heart in myocardial preservation in prolonged hypothermic cardioplegic followed by reperfusion (아프로티닌이 흰쥐 적출심장의 심근보호에 미치는 영향)

  • 이헌재
    • Journal of Chest Surgery
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    • v.28 no.6
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    • pp.549-556
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    • 1995
  • We investigated the effects of aprotinin, a protease inhibitor, on isolated rat heart subjected to cardioplegia and global ischemia for 4 hours and then reperfused for 40 minutes. Before ischemia, hearts were perfused with either aprotinin 1x105KIU/L[Aprotinin group,n=8 or no aprotinin[control group,n=8 added to Krebs-Henseleite solution for 30 minutes. Hemodynamic and biochemical parameters such as heart rate, LVP, dP/dt, coronary flow and creatine kinase were measured before cardioplegia and after reperfusion 10,20,30,40 minutes. After completion of experiment, wet and dry heart weight were measured for tissue water and water content evaluation. On reperfusion, recovery of LVP of aprotinin group at each time point was significantly better than that of control group[p<0.05 , and of dP/dt at reperfusion 40 minutes[p=0.034 . No statistically significant differences in heart rate, coronary flow and CK were observed between the two groups, but aprotinin group seemed to have better recovery. No significant differences in tissue water and water content were observed between the two group.These results suggest that pretreatment of aprotinin is effective in myocardial preservation in prolonged hypothermic ischemia and reperfusion.

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Experiment for Animal Heart Transplantation (동물에서의 심장동종이식에 관한 실험)

  • 서경필
    • Journal of Chest Surgery
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    • v.22 no.1
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    • pp.1-9
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    • 1989
  • We have performed one case of autotransplantation and 11 cases of orthotopic homotransplantation using Korean mongrel dogs, and have scrutinized the hematologic and hemodynamic results. The mean weight of recipients was 15.42*1.2kg and varied from 14kg to 20kg. During the operation, anesthesia and other technical procedures including cardiopulmonary bypass were similar to the usual methods in human cardiac transplantation. It was found that the hematologic values were similar to those of human beings although there was wide variance. Hemodynamically the mean systolic and diastolic arterial pressures were 165.0* 12.9 mmHg and 100.0 *11.8 mmHg respectively, and the mean heart rate was 155.5*23.5/min. All cases died within 24hrs, and the mean survival in all but 6 cases where operative death occurred was 6.83*8.01 hrs[range 2-21 hrs]. The major causes of deaths were bleedings in 7 cases, failure to protect myocardium during the procedure in 2 cases, pulmonary edema in 1 case and multiorgan failure in 2 cases. From the above results we concluded that the most frequent complication was bleeding, and the cardiopulmonary bypass flow of 50-500ml/kg min was not suitable to the dog in CPB. In further experiment after this study, the technical and the bypass flow was increased. Bleeding was not significant. And the immunosuppresion during operation and postoperative period was tried.

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Surgical Technique thor the Removal of Deep Vein Thrombi of the Lower Extremities (하지 심부정맥 혈전의 외과적 제거)

  • 이상호;최준영;김성호;김병균;장인석;이정은;옥창대;김종우;나재범
    • Journal of Chest Surgery
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    • v.35 no.5
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    • pp.402-406
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    • 2002
  • The conventional surgery method of thrombectomy of venous thrombi from the deep veins of the lower extremity was the use of Forgarty balloon catheter. The catheter is inconvenient due to the presence of the balloon and prohibiting venous valves within the venous trees. With the use of a stone-forceps(Fig. 1), thrombi within iliofemoral vein could be easily removed without the obstacle of the valves because the instrument keeps valves open. This instrument is also useful in monitoring the back-flow from the iliac vein. Thrombi within the veins below the level of inguinal incision are removed successfully only by effective manual compression of the calf and thigh muscles. 1 recommend operating on the iliac vein first rather than the lower venous tree.

Effects of Head-Down Tilt$(-6^{\circ})$ on Hemodynamics and Plasma Catecholamine Levels (도립$(-6^{\circ})$이 혈장 Catecholamine 및 심장혈관계에 미치는 영향)

  • Song, Dae-Kyu;Bae, Jae-Hoon;Park, Won-Kyun;Chae, E-Up
    • The Korean Journal of Physiology
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    • v.21 no.2
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    • pp.211-223
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    • 1987
  • Head-down tilt (HDT) at $-6^{\circ}$ has been commonly used as the experimental model in both man and animals to induce the blood shift toward the head or central protion of the body, demonstrating similar physiological effect encountered in the weightlessness in the orbital flight. There are few reports about the physiological response upon the cardiovascular regulatory system or the tolerance to the $(-6^{\circ})$ HDT within a relatively short period less than 1 hour. Therefore, the purpose of this study way to observe the effects of $-6^{\circ}$ HDT on cardiovascular system within 30 minutes and to evaluate early regulatory mechanism for simulated hypogravity. Ten mongrel dogs weighing 8-12 kg were anesthetized with the infusion of 1% ${\alpha}-chloralose$ (100 mg/kg) intravenously, and the postural changes were performed from the supine to the $-6^{\circ}$ head-down Position, then from the head-down to the supine (SUP), and each posture was maintained for 30 minutes. Blood flow $({\dot{Q}})$ through common carotid and femoral arteries were determined by the electromagnetic flowmeter. Mean arterial pressure (MAP), heart rate (HR), respiratory rate , and pH, $P_{O_2}$, $P_{CO_2}$ and hematocrit (Hct) of arterial and venous blood were also measured. The peripheral vascular resistance was calculated by dividing respective MAP values by ${\dot{Q}}$ through both sides of common carotid or femoral arteries. The concentration of plasma epinephrine and norepinephrine was determined by Peuler & Johnson's radioenzymatic method. The results are summarized as follows: In the initial 5 minutes in $-6^{\circ}$ HDT, HR was significantly (p<0.05) increased and MAP slightly decreased. Although ${\dot{Q}}$ and carotid peripheral artery resistance were not significantly changed, ${\dot{Q}}$ through femoral artery was diminished and femoral peripheral artery resistance was elevated. In the SUP, the initial changes of MAP and HR were increased (p<0.05), but those of ${\dot{Q}}$ and peripheral vascular resistance through both common carotid and femoral arteries were not significant. After 10 minutes of each postural change in both HDT and SUP, MAP was maintained almost equal to that of the level of pretilting control. During 60 minutes of both postural changes of HDT and SUP, $P_{O_2}$ and Hct were not changed significantly. However pH tended to increase slowly and $P_{CO_2}$ was gradually decreased. The pH and $P_{CO_2}$ seemed to be related to the increased respiratory rate. Plasma epinephrine concentration was not changed significantly and plasma norepinephrine concentration was slightly decreased in the course of HDT and also at 10 minutes of SUP. However these concentration changes were statistically insignificant. From these results, it may be concluded that the effect of $-6^{\circ}$ HDT for 30 minutes on the cardiovascular system and plasma catecholamine levels of the dog is minimum and it is suggestive that the cardiovascular regulatory mechanism, possibly mediated by so called gravity receptors including baroreceptor and volume receptor, has been properly and adequately operated.

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Hybrid Off-pump Coronary Artery Bypass Combined with Percutaneous Coronary Intervention: Indications and Early Results (심폐바이패스 없이 시행하는 관상동맥우회술과 경피적 관상동맥중재술의 병합요법 : 적응증 및 조기성적)

  • Hwang Ho Young;Kim Jin Hyun;Cho Kwang Ree;Kim Ki-Bong
    • Journal of Chest Surgery
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    • v.38 no.11 s.256
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    • pp.733-738
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    • 2005
  • Background: The possibility of incomplete revascularization and development of flow competition after revascularization of the borderline lesion made the hybrid strategy as an option for complete revascularization. Material and Method: From January f998 to July 2004, 25 $(3.2\%)$ patients underwent hybrid revascularization among 782 total OPCAB procedures. Clinical results and angiographic patencies were evalulated. Percutaneous coronary intervention (PCI) was peformed before CABG in 8 patients and after CABG in 47 patients. Result: The causes of PCIs before CABG were to achieve complete revascularization with minimally invasive surgery (n=7) and emergent PCI for culprit lesion (n=1). The indications of PCIs after CABG were high possibility of flow competition in the borderline lesion of right coronary artery territory (n=8), diffuse atheromatous lesion preventing anastomosis of graft (n=5), severe calcified ascending aorta with no more arterial grafi available (n=3), and intramyocardial coronary lesion (n=1). Mean number of distal anastomoses was $2.3\pm1.0$. Mean number of lesions treated by PCI was $1.2\pm0.4$. There was no operative or procedure-related mortality. PCI-related complication was periprocedural myocardial infarction in one patient, and complications related to CABG were transient atrial fibrillation (n=5), perioperative myocardial infarction (n=1), and transient renal dysfunction (n=1). Early postoperative coronary angiography $(1.8{pm}1.6days)$ revealed $100\%$ patency rate of grafts (57/57). The stenosis occurred in one patient performed PCI before CABG, which was successfully treated with re-ballooning. During midterm follow-up (mean; $25{\pm}26$ months), 1 patient died of congestive heart failure. All survivors (n=24) accomplished follow-up coronary angiographics, which showed .all grafts (56/57) were patent except one string sign. In-stent restenosis was developed in 2 patients who received bare metal stents. Conclusion: In selected patients, complete revascularization was achieved with low risk by taking the hybrid strategy.

Myocardial Perfusion after Transmyocardial Mechanical Revascularization in Rat Heart Transplant Model, Acute Model (백서 동종이식 심장모델에서 기계적 경심근 혈관재형성의 심근 혈류 개선 효과 : 급성기 모델)

  • Shinn Sung Ho;Chung Won Sand;Kang Jung Ho;Jeon Yang-Bin
    • Journal of Chest Surgery
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    • v.38 no.7 s.252
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    • pp.468-475
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    • 2005
  • Transmyocardial revascularization (TMR) in end stage ischemic heart disease results in variable clinical responses. We investigated the acute effect of early reperfusion and the angiogenesis after formation of the transmyocardial channel in a transplanted rat heart model with acute myocardial infarction. Material and Method: In the 30 transplanted hearts we induced acute myocardial infarction by ligating the proximal left coronary artery and inserted a porous 22G intravenous cannula into the left ventricle. After ten minutes of reperfusion, we removed the cannula. At every stage, we recorded the heart rate, QRS size, and left coronary arterial blood flow using the electrocardiogram and Doppler. One week later the rats were sacrificed and evaluated for the patency of intramyocardial channels and the angiogenesis. Result: The heart rates after ligation and after cannula insertion were $239.1\pm61.7,\;235.8\pm58.0bpm$ respectively, and they were statistically significantly slower than that of before ligation, $277.6\pm40.3bpm\;(p=0.017,\;p=0.007\;respectively)$. QRS sizes before ligation, after ligation, and after cannula insertion were $3.6\pm3.3mm,\;2.8\pm3.3 mm,\;and\;2.4\pm2.2mm,$respectively, and there was no significant difference in the three groups. Doppler findings after ligation showed that average peak and mean values of coronary perfusion were significantly decreased from $2.11\pm0.17kHz,\;1.25\pm0.22kHz\;to\;0.83\pm0.15kHz,\;0.38\pm0.11kHz$(p<0.05 respectively). After insertion of the porous cannula, the average peak and mean values of coronary perfusion were $0.61\pm0.05kHz\;and\;0.33\pm0.05 kHz$ respectively, but there was no statistically significant change compared to values after ligation. In all cases except one, pathologic findings showed no patent channels in the acute stage, however, one case showed the angiogenesis. Conclusion: We confirmed that TMR in a rat heart transplant model did not show blood flow through the channel in the acute stage. However, reperfusion effect in some cases had a potential for angiogenesis.

Comparison of Patency and Viability in Fresh and Cryopreserved Arterial and Venous Allograft Conduits in Dogs (개에서 동맥과 정맥 동종 이식편의 냉장, 보존 방법에 따른 개존율 및 생육성에 관한 연구)

  • Song, Hyun;Kang, Shin-Kwang;Ryu, Yang-Gi;Kim, Yong-Jin
    • Journal of Chest Surgery
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    • v.41 no.2
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    • pp.149-159
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    • 2008
  • Background: With increasing coronary bypass and peripheral vascular surgeries, the demand for homologous vascular or synthetic conduits has continued to grow, but wide-spread application has been limited by dismal patency rates. Although cryopreserved allograft valves may provide a suitable alternative, current viability or patency of implanted allograft vascular conduits has been unsatisfactory. Material and Method: We serially analyzed the outcomes of canine femoral artery and saphenous vein allograft implants after storage in either $4^{\circ}C\;or\;-170^{\circ}C$. Result: There were no differences in graft flow rate (patency) (p=0.264), rate of thrombosis (p=0.264), presence of endothelium (p=0.587), or immunohistochemical staining for thrombomodulin (p=0.657) were detected between grafts stored in $4^{\circ}C\;and\;-170^{\circ}C$. Greater flow occurred in the arterial grafts versus the venous grafts (p=0.030), irrespective of the preservation method, with a significantly lower incidence of thrombosis (p=0.030) in arterial allografts. There was a correlation coefficient of -0.654 between thrombosis and positive immunohistochemical staining for thrombomodulin (p=0.006) and a correlation coefficient of 0.520 (p=0.0049) between the endothelial presence and positive immunohistochemical staining for thrombomodulin. The relationship between the presence of endothelium and thrombomodulin expression failed to show any correlation within the first 2 weeks (p=0.306). However, a strong correlation was seen after 1 month (p=0.0008). Conclusion: Tissue storage in either $4^{\circ}C\;or\;-170^{\circ}C$ in 10% DMSO/RPMI-1640 preservation solution preserved grafts equally well. In terms of thrombosis and graft patency, arterial grafts were superior to venous grafts. Considering the poor correlation between thrombomodulin expression and the presence of an endothelium in the implanted graft within the first two weeks, grafts in this period would not be thromboresistant.

Unilateral Pulmonary Vein Stenosis with Life-threatening Hemoptysis - A case report - (위급한 객혈을 동반한 일측성 폐정맥 협착증)

  • Lee, Jae-Hang;Kang, Chang-Hyun;Noh, Chung-Il;Seo, Jeong-Wook;Lee, Jeong-Ryul
    • Journal of Chest Surgery
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    • v.38 no.10 s.255
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    • pp.725-728
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    • 2005
  • A case is described in a girl who presented with recurrent life-threatening hemoptysis at the age of 18 months, and had been diagnosed as atrial septal defect with severe cardiomegaly which was presumed to result in pulmonary vein stenosis at the age of 6 months. Closure of atrial septal defect was associated with decreased heart size and improved pulmonary venous flow. However, recurrent life-threatening hemoptysis occurred during follow-up, Computed tomography scan demonstrated left pulmonary vein stenosis and extrinsic compression of the left bronchus by multiple soft tissue density-masses. Exploratory thoracotomy revealed single stenotic left pulmonary vein, and flat left main bronchus compressed by multiple hypertrophied lymph nodes, Unexpected endotrachial tube bleeding during left hilar dissection mandated to proceed to left pneumonectomy, The patient's postoperative course was uneventful. Follow-up chest roentgenography revealed acceptable left hydrothorax without mediastinal shifting, Nevertheless, a long-term follow-up is necessary.

Changes of the Structural and Biomechanical Properties of the Bovine Pericardium after the Removal of ${\alpha}$-Gal Epitopes by Decellularization and ${\alpha}$-Galactosidase Treatment

  • Nam, Jinhae;Choi, Sun-Young;Sung, Si-Chan;Lim, Hong-Gook;Park, Seong-Sik;Kim, Soo-Hwan;Kim, Yong Jin
    • Journal of Chest Surgery
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    • v.45 no.6
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    • pp.380-389
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    • 2012
  • Background: Bovine pericardium is one of the most widely used materials in bioprosthetic heart valves. Immunologic responses have been implicated as potential causes of limited durability of xenogenic valves. This study aimed to determine the effectiveness of decellularization and ${\alpha}$-galactosidase (${\alpha}$-gal) to remove major xenoreactive antigens from xenogenic tissues. Materials and Methods: Recombinant Bacteroides thetaiotaomicron (B. thetaiotaomicron) ${\alpha}$-gal or decellularization, or both were used to remove ${\alpha}$-gal from bovine pericardium. It was confirmed by ${\alpha}$-gal-bovine serum albumin-based enzyme-linked immunosorbent assay (ELISA), high-performance anion exchange chromatography, flow cytometry, 3,3'-diaminobenzidine-staining, and lectin-based ELISA. The mechanical properties of bovine pericardium after decellularization or ${\alpha}$-gal treatment were investigated by tests of tensile-strength, permeability, and compliance. Collagen fiber rearrangement was also evaluated by a 20,000${\times}$ transmission electron microscope (TEM). Results: Recombinant B. thetaiotaomicron ${\alpha}$-gal could effectively remove ${\alpha}$-gal from bovine pericardium B. thetaiotaomicron (0.1 U/mL, pH 7.2) while recombinant human ${\alpha}$-gal removed it recombinant human ${\alpha}$-gal (10 U/mL, pH 5.0). There was no difference in the mechanical properties of fresh and recombinant ${\alpha}$-gal-treated bovine pericardium. Furthermore, the TEM findings demonstrated that recombinant ${\alpha}$-gal made no difference in the arrangement of collagen fiber bundles with decellularization. Conclusion: Recombinant B. thetaiotaomicron ${\alpha}$-gal effectively removed ${\alpha}$-gal from bovine pericardium with a small amount under physiological conditions compared to human recombinant ${\alpha}$-gal, which may alleviate the harmful xenoreactive immunologic responses of ${\alpha}$-gal. Recombinant ${\alpha}$-gal treatment had no adverse effects on the mechanical properties of bovine pericardium.