• Journal of Chest Surgery
• /
• v.38 no.7 s.252
• /
• pp.468-475
• /
• 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.

• Journal of Chest Surgery
• /
• v.30 no.1
• /
• pp.27-33
• /
• 1997

Retrograde myocardial protection is widely accepted in CABG operation because of the limitations of the antegrade method in the coronary arterial stenosis lesions. We analyzed 76 c ses of retrograde myocardial protection among 96 cases of CABG operation performed between April 1994 and August 1995, There were 48 males and 25 females, and the mean age was 58.2 $\pm$ 8.3 years. 53 patients (70%) were operated for unstable angina, 14 (18%) for stable angina, 6 (8%) for post-infarct angina, 1 (1%) for acute myocardial infarction, and 2()%) for failed PTCA. Preoperative coronary angiography revealed 3-vessel disease in 42 cases, 2-vessel disease in 11, 1-vessel disease in 10, and left main disease in 13 cases. We used SVG(63 cases), LIMA(69 cases), RIMA(11 cases), radial artery(6 cases), and gastroepiploic artery(1 case) for the grafts. Mean anastomosis was 3.2 $\pm$ 1.1. We protected the myocardium with antegrade induction and retrograde maintenance in all the cases except a case of retrograde induction and maintenance. During the aortic cross-clamping, blood cardioplegia was administered intermittently in 19 cases, and continuously in 57 In 39 cases, we used retrograde ardioplegia and antegrade perfusion of RCA graft simultaneously. We had no operative motality. Perioperative complications were arrhythmia in 15 cases, perioperatve myocardial infarction in 10, low cardiac output syndrome In 8, transient neurologic problem in 7, transient psychiatric problem in 6, ARF in 3, bleeding in 2, pneumonia in 2, wound infection in 1, and duodenal ulcer perforation in 1 . In this report, we experienced 76 cases of CABG operation with retrograde myocardial protection under the acceptable operative risk without operative mortality.

• Journal of Chest Surgery
• /
• v.30 no.12
• /
• pp.1159-1166
• /
• 1997

For Improvement of lung preservation, many tripes of preservation solution were developed and tested. The aim of this study was to compare the effect of the most frequently used extracellular type pieservation solution (Low Potassium Dextran, LPD) with a newly developed trehalose containing extracellular type preservation solution(ET-Kyoto, ETK) on postischemic lung function. Twelve New-Zealand white rabbit lungs were harvested and studied on an isolated, blood-perfused model of lung function after 4 hours of cold ischemia at $10^{\circ}C$ In group I (n=6), lungs were preserved with 100 mL/kg of LPD solution; in group II(n=6), lungs were preserved with 100 mL/kg of ETK solution. A few minutes before flushing with preservation solutions, 20$\mu\textrm{g}$ of PGEI were injected into main pulmonary artery. Functions of the preserved lung were compared with PO2, PA pressure, t acheal air pressure, and drylwet ratio. The pulmonary efferent blood oxygen tension at the end of the 60-minute reperfusion period was higher in group II compacted with group I(486.5 $\pm$ 80.3 mmHg versus $432.5\pm82.9$ mmHg at FiO2 1.0, p-value = NS). The mean pulmonary arterial pressure was similar in both $groups.(33.7\pm2.2$ mmHg versus $35.5\pm2.0$ mmHg, p-value : NS). The peak inspiratory airway pressure was significantly lower in group 11(8.010.6 mmHg versus 11.8 $\pm$ 1.4 mmHg, p-value=0.02) The water content of the lung was lower in group II $(70.2\pm6.9%$ versus 78.5 $\pm6.1%),$ but not significant. These data demonstrate that a newly-developed trehalose-containing ET-Kyoto solution yield equal or slightly superior lung function after reperfusion compared with LPD solution.

• Journal of Chest Surgery
• /
• v.30 no.4
• /
• pp.378-382
• /
• 1997

To evaulate the effectiveness and risk factors for shunt failure of the Blalock-Taussig shunt in neonates, we analyzed the 21 neonates who were undergone Blalok-Taussig shunt operation at Dong-A University Hospital from December 1991 to Feburary 1996. We evaluated operative mortality, patency of the shunt. and distortion of pulmonary artery. We also determined the risk factors for the shunt failure. Age at operation was from 1 day to 30 days(mean 11.7 days). We ghts were 2.4 to 4.5kg(mean 3.1 kg). The underlying lesions included severe tetralogy of Fallot with pulmonary stenosls or atresia(N=11) and single ventricle varieties with. pulmonary stenosis or atresia(N=10). Prostaglandin El was given in 13 neonates prior to operation. The mean preoperative(prior to prostaglandin El therapy) and postoperative arterial oxygen tension were 30.1 mmHg and 46.3 mmHg respectively(P(0.01). The shunt was performed through a left thoracotomy in 11 patients and through a right thoracotomy In 10. A 5 mm graft was used in 15 patients and a 4 mm graft in 6 patients. The incidence of early shunt occlusion was 9.5%(2 patients). The hospital mortality was 9.5%(2 patients with early shunt occlusion). Univariate analysis revealed that body weight of 2.6 kg or less(p=0.021), pulmonary artery size of 3mm or less(p=0.008), and 4 mm graft (p=0.021) were risk factors predictive of early shunt failure. The patency rate of the shunt in hospital survivors was 100% at mean ollow-up of ll.3 months(There was not death or reoperation related to shunt failure). 10 patients were catheterized during postoperative follow-up. There was no significant distorsion of pulmonary artery. So we concluded that the modified Blalock-Taussig shunt in neonates was excellent in the hospital survivors.

• Journal of Chest Surgery
• /
• v.36 no.8
• /
• pp.576-582
• /
• 2003

During the Off-Pump Coronary Arterial Bypass surgery (OPCAB), the manipulation of the heart can depress cardiac contractility and cause hemodynamic instability. In this study, hemodynamic parameters were measured during operation and the laboratory and clinical data were investigated to evaluate their effects on postoperative outcome. Material and Method: From March 2001 to August 2002, 50 consecutive patients who underwent OPCAB were included in this study. During the same period, total number of CABG was 71 The blood pressure, pulmonary artery pressure, mixed venous oxygen saturation, and cardiac index were measured before manipulation, after application of stabilizer, and at the end of anastomosis. Postoperatively, we measured the cardiac enzymes such as CK-MB, troponin 1 and checked the amount of inotropes required, chest tube drainage, the amount of transfusion, duration of ventilator support, and duration of ICU stay. Result: The number of mean distal anastomoses was 2.8$\pm$0.9 per patient. On elevation and stabilization of the heart, systolic blood pressure was depressed and pulmonary artery pressure was elevated significantly, but during each anastomosis no significant changes were detected. The peak level of cardiac markers was 29.2$\pm$46.7 for CK-MB, 0.69$\pm$0.86 for troponin 1 on postoperative day f. Among the intraoperative hemodynamic parameters, the ischemic change of EKG and bolus injection of inotropes significantly affected the posteroperative cardiac enzymes. But, no difference other than the level of cardiac enzymes between the two groups with or without the ischemic change of EKG and bolus injection of inotropes was noticed. Conclusion: The significant hemodynamic changes occurred when the heart was elevated and stabilized, however during anastomoses there were no significant changes. Serum cardiac enzymes rose significantly in the group that showed the ischemic charge of EKG or needed the bolus injection of inotropes for maintaining hemodynamic stability intraoperatively, but it did not affect the postoperative outcome. In conclusion, the ischemic change of EKG and the need for bolus injection of intropes during operation may be very indicative for probable ischemia.

• Journal of Chest Surgery
• /
• v.40 no.3 s.272
• /
• pp.180-192
• /
• 2007

Background: As determined from the recent investigations of discordant cardiac xenotransplantation, hyperacute rejection occurs mainly at the endothelial cells in donor microvascular systems, but this does not occur at cardiac valve leaflets or at medium-to-large caliber vessels. On the basis of this background, this study was performed to look into the biocompatibility for transplantation of a middle or large diameter xenogenic blood vessel by conducting xenogenic arterial transplantation with the carotid artery in a pig-to-goat model. Material and Method: The experimental group was composed of 10 pairs of pig-to-goat combinations. They were divided into each period of 1 week, and 1, 3, 6 and 12 months. Four carotid artery grafts obtained through collection of the bilateral carotid arteries from two pigs were preserved at $-70^{\circ}C$ without other treatment, and then they were transplanted into the bilateral carotid arteries of two goats. Doppler ultrasonography was done on a periodic basis after transplantation to evaluate the patency of the grafted blood vessel. At the ends of a predetermined period, the grafts were explanted from the goats and they underwent gross examination. Hematoxylin-eosin and Masson's trichrome staining were conducted. In addition, in order to examine the immunological rejection of the grafted xenogenic blood vessel, immunohistochemical staining was conducted with T-lymphocyte indicator and von Willebrand factor. Result: Two goats at the each one-week period and the one-year period died during the experimental period because of a reason unrelated to the experimental procedure, and the remaining 8 goats survived until the end of each experiment period. On Doppler ultrasonography, unilateral carotid artery occlusion was found in a goat, whose period was specified as 3 months, among the 8 survived goats. However, the vascular patency was maintained well and there was no graft that formed aneurysms in the other goats. On gross examination, the region of vascular anastomosis was preserved well, and calcification of the grafted blood vessel was not shown. Histologically, the endothelial cells of the graft disappeared one week after transplantation, and then there was progressive spread of the recipients' endothelial cells from the anastomotic site. The reendothelialization occurred over the whole graft at one month after transplantation. The neointimal thickening and adventitial inflammation became severe by 3 months after transplantation, but this lessened at 6 months and 12 months, respectively. The rate of CD3 positive cells was very low among the infiltrated inflammatory cells. Conclusion: The fresh-frozen xenogenic artery kept its patency without being greatly influenced by xenogenic immune reaction.

• Journal of Chest Surgery
• /
• v.40 no.8
• /
• pp.546-551
• /
• 2007

Background: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other gratis with retrospective manner. Material and Method: From January 2001 to Jure 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month ($2{\sim}110$ month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. Result: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p < 0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. Conclusion: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

• Journal of Biomedical Engineering Research
• /
• v.19 no.3
• /
• pp.279-284
• /
• 1998

Deep hypothermic circulatory arrest(DHCA), in which systemic temperatures of 2$0^{\circ}C$ or less are used to allow temporary cessation of the circulation, is an useful adjunct in cardiac surgery. Because man in natural circumstances is never exposed to the extreme hypothermic condition, however, one of the controversial aspects is appropriate blood gas management($\alpha$STAT versus PH-STAT) during DHCA. This study aims to compare $\alpha$STAT with PH-STAT management for control of blood gases in experimental cardiopulmonary bypass(CPB) circuits with a membrane oxygenator. Fourteen young pigs were assigned to one of two strategies of gas manipulation. After a median sternotomy, CPB was established. Core cooling was initiated and continued until nasopharyngeal temperature fell below 2$0^{\circ}C$. The flow rate was set at 2,500 ml/min. Once their temperatures were below 2$0^{\circ}C$, the animals were subjected to circulatory arrest for 40mins. During cooling, blood gas was maintained according to either $\alpha$$\alpha$STAT or pH-STAT strategies. After DHCA, the body was rewarmed to normal body temperature. Arterial blood gases were measured before the onset of CPB, before cooling, before DHCA, at the point of 27$^{\circ}C$ during re-warming, on completion of re-warming. Cooling time was significantly shorter in $\alpha$-STAT than PH-STAT strategy, while there was no significant differences in rewarming time between two groups. Carbon dioxide was added between 5.5 and 3.0% in PH-STAT, while no carbon dioxide was added in $\alpha$STAT management. Amounts of oxygen administration were gradually lowered as temperature decreased. In this way, criteria of PH, PaCO, and PaO adjustments were satisfied in both $\alpha$STAT and PH-STAT management groups.

• Tuberculosis and Respiratory Diseases
• /
• v.48 no.4
• /
• pp.487-499
• /
• 2000

Background : Acute lung injury is an hypoxic respiratory failure resulting from damage to the alveolar-capillary membrane, which can be developed by a variety of systemic inflammatory diseases. In this study the therapeutic effects of intra-tracheal pulmonary surfactant instillation was evaluated in the intratracheal endotoxin induced acute lung injury model of a rat. Methods : Twenty Sprague-Dawley rats were divided into 4 groups, and normal saline (2 ml/kg, for group 1) or LPS (5 mg/kg, for group 2, 3, and 4) was instilled into the trachea respectively. Either normal saline (2 ml/kg, for group 1 & 2, 30 min later) or bovine surfactant (15 mg/kg, 30 min later for group 3, 5 hr later for group 5) was instilled into the trachea. The therapeutic effect of intratracheal surfactant therapy was evaluated with one chamber body plethysmography (respiratory frequency, tidal volume and enhanced pause), ABGA, BAL fluid analysis (cell count with differential, protein concentration) and pathologic examination of the lung. Results : Intratracheal endotoxin instillation increased the respiration rate decreased the tidal volume and int creased the Penh in all group of rats. Intratracheal instillation of surfactant decreased Penh, increased arterial oxygen tension, decreased protein concentration of BAL fluid and decreased lung inflammation at both times of administration (30 minute and 5 hour after endotoxin instillation). Conclusion : Intratracheal instillation of surfactant can be a beneficial therapeutic modality as discovered in the acute lung injury model of rats induced by intratracheal LPS intillation. It deserves to be evaluated for treatment of human acute lung injury.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.4
• /
• pp.500-511
• /
• 1999

Background: Noninvasive positive pressure ventilation (NPPV) using facial or nasal mask have been widely used for several years in stable patients with chronic neuromuscular disease or central alveolar hypoventilation, and recently have been tried in patients with acute respiratory failure. In a few studies, NPPV was also used to rescue the patients with post-extubation respiratory failure. However, yet it has not been adopted as a weaning method in patients on long-term mechanical ventilation. So we performed this prospective clinical study to evaluate the usefulness of NPPV as a weaning method after removing endotracheal tube intentionally in patients on long-term mechanical ventilation. Method: Twelve patients who had been on invasive mechanical ventilation over 10 days were enrolled and 14 trials of NPPV were done. All had failed at least one weaning trial and showed ventilator dependence(pressure support requirement between 8-15cm $H_2O$, and PEEP requirement between 5-10cm $H_2O$), so tracheostomy was being considered. After removing the endotracheal tube, NPPV was applied using facial mask. Respiratory rate, arterial blood gas, pressure support level, and PEEP level were monitored just before intended extubation, at 30 minutes, 1 to 6, 6 to 12, 12 to 24 hours, 2nd day, and 3rd day following initiation of NPPV, and just before weaning from NPPV. The successful weaning was defined as spontaneous breathing off the ventilator for 48 hours or longer without respiratory distress. Results: The weaning through NPPV after intended extubation was successful in 7(50%) of 14 trials, and tracheostomy could be avoided in them. There were no differences in age, sex, APACHE III score, duration of invasive mechanical ventilation, baseline respiratory rate, $PaCO_2$ $PaO_2/FiO_2$, and ventilatory requirement(PS and PEEP) between the success and failure groups. In the success group, respiratory rate, pH, $PaCO_2$, and $PaO_2/FiO_2$ were not different between invasive MV and NPPV period. But in the failure group, pH decreased after 30 minutes of NPPV initiation compared with that of invasive MV($7.40\pm0.08$ vs. $7.34\pm0.06$, p<0.05). The causes of failure were worsening of ABG(n=3), retained tracheal secretion(n=2), mask intolerance(n=1), and flail chest(n=1). Conclusion: NPPV may be worth trying as a bridge method in weaning patients on long-term invasive mechanical ventilation.