• Journal of Chest Surgery
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• v.36 no.9
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• pp.638-645
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• 2003

The purposes of this study were to evaluate the effect of myocardial protection with our cold blood cardioplegic solution and to observe the relationship between ultrastructural study and other evaluation methods and its effectiveness. Material and Method: We evaluated the changes of myocardial ultrastructure using semi-quantitative scoring system, CK-MB fraction, SGOT and LDH1/LDH2, and EKG in 18 patients undergoing valvular heart surgery and coronary artery bypass grafting (CABG). Right atrial auricular biopsies were taken before the cardiopulmonary bypass (CPB) and shortly after the end of CPB. Myocardium-related serum enzymes ＆ EKG were checked for 3 days of postoperative period and their postoperative peak enzyme value and observed new Q wave ＆ ST segment elevation in EKG were choosen. Result: There were 8 males and 10 females, and their mean age was 55.6$\pm$13. Eight patients underwent valvular heart surgery and ten coronary artery bypass grafting, The mean CPB time was 119$\pm$29 minutes and the mean aortic cross-clamp (ACC) time was 75.4$\pm$24 minutes. Before the start of CPB, the mean mitochondrial score was 4.28$\pm$0.53 and after the end of CPB, it significantly increased to 2.35$\pm$0.79. There was no evidence of perioperative myocardial infarction in terms of myocardiumrelated serum enzyme value and Q wave and ST change in EKG. There was no significant relationship between pre-CPB and post-CPB mitochondrial score and the mean time of CPB and ACC, and the mean value of postoperative peak CK-MB, SGOT and LDH1/LDH2, but there was relatively positive correlation of CPB time with peak LDH1/LDH2. Conclusion: Despite the apparent satisfactory results in myocardium-related serum enzymes ＆ EKG, with this study using the cold blood cardioplegic solution, there were many changes in myocardial ultrastructures, and more studies are needed to obtain further information.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.440-448
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• 2006

Background: Surgery of descending thoracic or thoracoabdominal aorta has the potential risk of causing neurological injury including spinal cord damage. This study was designed to find out the risk factors leading to spinal cord and brain damage after surgery of descending thoracic and thoracoabdominal aorta. Material and Method: Between October 1995 and July 2005, thirty three patients with descending thoracic or thoracoabdominal aortic disease underwent resection and graft replacement of the involved aortic segments. We reviewed these patients retrospectively. There were 23 descending thoracic aortic diseases and 10 thoracoabdominal aortic diseases. As an etiology, there were 23 aortic dissections and 10 aortic aneurysms. Preoperative and perioperative variables were analyzed univariately and multivariately to identify risk factors of neurological injury. Result: Paraplegia occurred in 2 (6.1%) patients and permanent in one. There were 7 brain damages (21%), among them, 4 were permanent damages. As risk factors of spinal cord damage, Crawford type II III(p=0.011) and intercostal artery anastomosis (p=0.040) were statistically significant. Cardiopulmonary bypass time more than 200 minutes (p=0.023), left atrial vent catheter insertion (p=0.005) were statistically significant as risk factors of brain damage. Left heart partial bypass (LHPB) was statistically significant as a protecting factor of brain (p=0.032). Conclusion: The incidence of brain damage was higher than that of spinal cord damage after surgery of descending thoracic and thoracoabdominal aorta. There was no brain damage in LHPB group. LHPB was advantageous in protecting brain from postoperative brain injury. Adjunctive procedures to protect spinal cord is needed and vigilant attention should be paid in patients with Crawford type II III and patients who have patent intercostal arteries.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.177-184
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• 1996

Between 1987 and 1994, 21 patients were treated surgically for aortic aneurysm involving the thoracoabdominal aorta. There were 11 males and 10 females, and their age ranged from 20 to 67 years old and mean age was 41.5 years. Many complained of back pain, chest pain or discomfort, and flank pain, but three patients were asymptomatic. 15 patients had chronic dissection (71.4%) and 6 had nondissecting fusiform or saccular aneurysm(28.5%), and of those 15 patients with chronic dissection, 6(28.5%) had atherosclerosis assniated with hypertension, 5 (23.8%) were Martian syndrome, and 2 (9.5%) were associated with pregnancy. The diameter of an aneurysm ranged from 6cm to 12cm, and their extent was classified as type I in 7(33.3%), type II in 8(38.1%), type III in 3(14.3%), and type IV in 3(14.3%) patients based on Crawford classification for TAA . Diseased aorta was replaced with artificial vascular graft in all but one patient. In whom the aortic tear site due to pseudoaneurysm was closed by primary suture. For the spinal cord protection during the operation, we used partial cardiopulmonary bypass (FV-FA or PA-FA bypass) in 12 patients (57.1%), Biopump (LA-FA bypass) in 4(19.0%), total circulartory arrest and CPB in 2 (9.5%), Gott's heparinized shunt in 1(4.7%), and simple aortic cross clamping in 2 (9.5%). The most common complication after the operation was hoarseness due to unilateral vocal cord palsy which onured in 5 patients (23.8%), and the next common complication was wound infection in 4 patients(19.0%), paraplegia in 2 patients (9.5%), chylothorax in 1 patient(4.7%). The hospital mortality rate was 9.5% (2deaths), and there was no late death. Our experience shows that the graft replacement of TAAA had reasonable rate of mortality, low rate of serious complication, and provided good post operative state of the pati nts, and since the thoracoabdominal aortic operation is not a high risky procedure anymore, we recommend a radical operation for the indicated patients.

• Journal of Chest Surgery
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• v.36 no.11
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• pp.828-833
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• 2003

Background: It has been reported that the recently developed intermittent antegrade warm blood cardioplegia (IAWBC) has better myocardial protective effects during coronary artery bypass surgery than cold blood cardioplegia or continuos retrograde cold blood cardioplegia. The aim of this study is to evaluate the safety and usefulness of IAWBC by comparing it retrospectively with intermittent retrograde cold blood cardioplegia (lRCBC). Material and Method: From April 2001 to Feb. 2003, fifty seven patients who underwent isolated coronary surgery were divided into two groups (IAWBC vs. IRCBC). The two group had similar demographic and angiographic characteristics. There were no statistical differences in age, sex, Canadian Cardiovascular Society Functional Classification for angina, ejection fraction, and number of grafts. Result: Aortic cross clamping time and total pump time in IAWBC (99$\pm$23 and vs. 126$\pm$32 min) were shorter than those of IRCBC (118$\pm$32 min. and 185$\pm$48 min.)(p<0.05). The reperfusion time (13$\pm$7 min) in IAWBC was shorter than that of IRCBC (62$\pm$109 min.)(p<0.05). CKMB at 12 hours and 24 hours (16$\pm$15 and 9$\pm$13) in IAWBC was lower than that of IRCBC (33$\pm$47 and 17$\pm$26)(p<0.05). The awakening time in IAWBC (2$\pm$1 hour) was shorter than that of IRCBC (4$\pm$3)(p<0.05). The number of spontaneous heart beat recovery in IAWBC (85%) was more than that of IRCBC (35%)(p<0.05). The cardiac index after discontinuing cardio-pulmonary bypass was significantly elevated in the IAWBC group. The prevalence of perioperative myocardial infarction in IAWBC (4%) was lower than that of IRCBC group (20%)(p<0.05). Conclusion: Intermittent antegrade warm blood cardioplegia is a safe, reliable, and effective technique for myocardial protection. It can also provide simpler and economic way than the retrograde cold cardioplegia by shortening of cardiopulmonary bypass time and avoiding retrograde cannulation for coronary sinus.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.309-315
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• 2003

Background: To avoid the adverse effects of cardiopulmonary bypass and to overcome late vein graft failure we routinely peformed off-pump total arterial coronary revascularization. Material and Method: From July 2000 to August 2001, 104 consecutive patients underwent first elective off-pump total arterial coronary revascularization. Both internal mammary, radial and gastroepiploic arteries were used. Sequential and composite grafts were used to achieve complete revascularization. Perioperative adverse events and postoperative angiograms were analyzed. Result: A total of 252 arterial conduits were used with an average of 2.47 grafts per patient. A total of 326 distal anastomosis were performed with a mean of 3.13 distal anastomosis per patient. Cross over to on-pump occurred in seven patients (6.7%). Of these 4 were due to unstable hemodynamics during lateral or posterior wall stabilization as a result of cardiomegaly and 3 were due to uncontrolled bleeding during dissection of diffusely dimunitive deeply placed intramyocardial coronary arteries. There were no opeartive deaths. Two cases of perioperative myocardial infarction and transient neurologic complications occurred, respectively. Of the 312 distal anastomoses, 308 (98.7%) were compatible with Fitz-Gibboll A or B patency grading. Conclusion: Off-pump total arterial coronary revascularization was technically feasible in most elective cases with satisfactory early results. However, on-pump coronary bypass surgery should be considered in difficult circumstances, such as cardiomegaly or unfavorable anatomy of the target coronary artery.

• Journal of Chest Surgery
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• v.35 no.6
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• pp.420-429
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• 2002

Moderate hypothermic cardiopulmonary bypass (CPB) has commonly been used in cardiac surgery. Several cardiac centers recently practice normothermic CPB in cardiac surgery, However, the clinical effect and safety of normothermic CPB on cerebral metabolism are not established and not fully understood. This study was prospectively designed to evaluate the clinical influence of normothermic CPB on brain metabolism and to compare it with that of moderate hypothermic CPB. Material and Method: Thirty-six adult patients scheduled for elective cardiac surgery were randomized to receive normothermic (nasopharyngeal temperature ＞34.5 $^{\circ}C$, n=18) or hypothermic (nasopharyngeal temperature 29~3$0^{\circ}C$, n=18) CPB with nonpulsatile pump. Middle cerebral artery blood flow velocity (VMCA), cerebral arteriovenous oxygen content difference (CAVO$_{2}$), cerebral oxygen extraction (COE), modified cerebral metabolic rate for oxygen (MCMRO$_{2}$), cerebral oxygen transport (TEO$_{2}$), cerebral venous desaturation (oxygen saturation in internal jugular bulb blood$\leq$50 %), and arterial and internal jugular bulb blood gas analysis were measured during six phases of the operation： Pre-CPB (control), CPB-10 min, Rewarm-1 (nasopharyngeal temperature 34 $^{\circ}C$ in the hypothermic group), Rewarm-2 (nasopharyngeal temperature 37 $^{\circ}C$ in the both groups), CPB-off and Post-CPB (skin closure after CPB-off). Postoperaitve neuropsychologic complications were observed in all patients. All variables were compared between the two groups. Result： VMCA at Rewarm-2 was higher in the hypothermic group (153.11$\pm$8.98%) than in the normothermic group (131.18$\pm$6.94%) (p＜0.05). CAVO$_{2}$ (3.47$\pm$0.21 vs 4.28$\pm$0.29 mL/dL, p＜0.05), COE (0.30$\pm$0.02 vs 0.39$\pm$0.02, p＜0.05) and MCMRO$_{2}$ (4.71 $\pm$0.42 vs 5.36$\pm$0.45, p<0.05) at CPB-10 min were lower in the hypothermic group than in the normothermic group. The hypothermic group had higher TEO$_{2}$ than the normothermic group at CPB-10 (1,527.60$\pm$25.84 vs 1,368.74$\pm$20.03, p＜0.05), Rewarm-2 (1,757.50$\pm$32.30 vs 1,478.60$\pm$27.41, p＜0.05) and Post-CPB (1,734.37$\pm$41.45 vs 1,597.68$\pm$27.50, p＜0.05). Internal jugular bulb oxygen tension (40.96$\pm$1.16 vs 34.79$\pm$2.18 mmHg, p＜0.05), saturation (72.63$\pm$2.68 vs 64.76$\pm$2.49 %, p＜0.05) and content (8.08$\pm$0.34 vs 6.78$\pm$0.43 mL/dL, p<0.05) at CPB-10 were higher in the hypothermic group than in the normothermic group. The hypothermic group had less incidence of postoperative neurologic complication (delirium) than the normothermic group (2 vs 4 patients, p＜0.05). Lasting periods of postoperative delirium were shorter in the hypothermic group than in the normothermic group (60 vs 160 hrs, p<0.01). Conclusion: These results indicate that normothermic CPB should not be routinely applied in all cardiac surgery, especially advanced age or the clinical situations that require prolonged operative time. Moderate hypothermic CPB may have beneficial influences relatively on brain metabolism and postoperative neuropsychologic outcomes when compared with normothermic CPB.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.523-529
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• 2002

Background: Previous reports present that the early results of coronary artery bypass grafting (CABG) has been improving with the accumulation of surgical experience. We conducted a retrospective analysis of the patients who received CABG to evaluate the recent results of CABG. Material and Method: Between January 1996 and August 2001, 154 patients underwent CABG at Hanyang University Hospital. There were 47 patients(group I) who were operated between 1996 and 1998, and 107 patients(group II) who were operated thereafter. The preoperative diagnosis, operative procedure, mortality, and complications were analyzed retrospectively. Result: There were 35 males and 12 females in group I, and 78 males and 29 females in group II, which shows similar ratio of sexes between the two groups. The average age of patients for group I and group II was $55.9{\pm}6.2$ years and $61.0{\pm}8.0$ years, respectively, showing a significant increase in group II(p<0.05). The average left ventricular ejection fraction(LVEF) for group I and group II was $54.6{\pm}11.8$% and $56.9{\pm}13.0$%, respectively. The number of patients who had previous MI in group I and group II were 13 patients(27.7%) and 14 patients(13.1%), respectively, which shows a significant difference (p<0.05). All procedures were performed using the cardiopulmonary bypass(CPB) and moderate systemic hypothermia. Myocardial protection was achieved using intermittent hypothermic ischemia under ventricular fibrillation state or cold crystalloid cardioplegic solution for most of group I patients, whereas cold blood cardioplegic solution was used for group II patients. The mean CPB times for group I and group II were $149.2{\pm}48.7$ minutes and $113.1{\pm}30.6$ minutes, respectively. The mean aortic cross clamp times for group I and group II were $81.3{\pm}26.5$ minutes $72.2{\pm}23.9$ minutes, respectively. These figures show that CPB and aortic cross clamp times were significantly reduced in group II(p<0.05). The use of the left internal thoracic artery(LITA) was increased from 42%(20/47) for group I to 81% (87/107) for group II. The mean number of grafts also significantly increased from $2.5{\pm}0.6$ for group I to $3.0{\pm}1.1$ for group II(p<0.05). Intra-aortic balloon pump(IABP) was applied in 7 cases in group I and 17 cases in group II. Of these, 28.6%(2/7) and 52.9%(9/17) were broadly applied preoperatively in patients with LVEF<40% or congestive heart failure. The operative mortalities for group I and II were 10.6%(5/47) and 0.9%(1/107), respectively, which shows significant decrease for group II(p.0.05). Conclusion: This report suggest that CABG using CPB can recently be performed more safely in virtue of the accumulation of surgical experience with reduction in CPB and aortic cross clamp times and improved surgical techniques and myocardial protection. And we think that the optimal treatment of patients with left ventricular dysfunction associated with congestive heart failure and the extended application of IABP, especially have contributed to the reduction of operative mortality and morbidity.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.583-590
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• 2001

The aim of this study was to compare one-year graft patency after coronary artery bypass grafting without cardiopulmonary bypass(OPCAB) with that of conventional CABG and that of on-pump beating CABG, and to demonstrate any differences in patency of various conduits among the three groups. Material and Method: We analyzed the results of OPCAB cases(group I; n=122) compared with those of conventional CABG cases(group II; n=65) and those of on-pump beating CABG cases(group III; n=19). In group I, coronary angiography(CAG) was performed immediately postoperatively and 1 year after surgery. In group II and III, CAG was performed 1 year after surgery. Graft patency was graded as grade A(excellent), grade B(fair), or grade O(occluded). Result: The average number of distal anastomoses in groups I, II, and II were 3.1$\pm$1.1, 3.7$\pm$0.9, and 3.6$\pm$0.9, respectively. In group I, postoperative CAG was performed in 92%(112/122) of patients before discharge. The patency rate(grade A+B) was 96.4$(162/168) for arterial grafts, and 85.6%(160/187) for saphenous vein grafts(SVG). One-year follow-up CAG was performed in 74%(90/122) of patients. The patency rate was 97.8%(132/135) for arterial grafts, and 67.9%(106/156) for SVG. In group II, one-year follow-up CAG was performed in 65%(42/65) of patients. The patency rate(grade A+B) was 93.5%(43/46) for arterial grafts, and 86.8%(33/38) for SVG. Conclusion: Our results demonstrated that the patency rate of SVG after OPCAB was significantly lower than that of arterial grafts in the early postoperative CAG(p<0.001), and was also significantly lower than those of SVG of group II(p<0.001) and group III(p<0.01) in the postoperative one-year CAG, although there was no significant difference is one-year patency of arterial grafts among the three groups. Our data suggest that a specific perioperative anticoagulant therapy may be advisable in patients undergoing OPCAB with SVG.

• Journal of Chest Surgery
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• v.36 no.7
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• pp.472-482
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• 2003

Recent studies have demonstrated that cerebral desaturation during rewarming period of CPB was associated with postoperative neurologic dysfunction. The prevention of cerebral desaturation during CPB may reduce the incidences of neurologic and neuropsychological complications. The present study was prospectively undertaken to compare the clinical effects between two strategies (hypercapnic CPB and high flow CPB) to prevent cerebral desaturation for establishing a proper CPB technique. Material and Method: Thirty-six adult patients scheduled for elective cardiac surgery were randomized into either hypercapnic (Pa$CO_2$ 45~50mmHg, n＝18) or high flow group (flow rate 2.75 L/ $m^2$/min and Pa$CO_2$ 35~40mmHg, n＝18) during rewarming period of CPB. In each patient, middle cerebral artery blood flow velocity ( $V_{MCA}$), cerebral arteriovenous oxygen content difference (C(a-v) $O_2$), modified cerebral metabolic rate for oxygen (MCMR $O_2$), cerebral oxygen transport rate ( $T_{E}$ $O_2$), incidence of cerebral desaturation (internal jugular bulb blood oxygen saturation $\leq$ 50%), increased rate of S-100 $\beta$ concentration, and arterial and internal jugular bulb blood gas were measured during the five phases of the operation; Pre-CPB, CPB-10 min (steady-state CPB, nasopharyngeal temperature 29~3$0^{\circ}C$), Rewarm-1 (rewarming phase, nasopharyngeal temperature 33$^{\circ}C$), Rewarm-2 (nasopharyngeal temperature 37$^{\circ}C$), and CPB-off. Incidence of postoperative delirium and duration were assessed in all patients. All variables were compared between the two groups. Result: $V_{MCA}$ (157.88$\pm$10.87 vs 120.00$\pm$6.18%, p＝0.006), internal jugular bulb $O_2$ saturation (68.01$\pm$2.75 vs 61.28$\pm$2.87%, p＝0.03) and $O_2$ tension (41.01$\pm$2.25 vs 32.02$\pm$ 1,67 mmHg, p＝0.03), and $T_{E}$ $O_2$(110.84$\pm$7.41 vs 81.15$\pm$8.11%, p＝0.003) at rewarming periods were higher in the hypercapnic group than in the high flow group. C(a-v) $O_2$ (4.0$\pm$0.30 vs 4.84$\pm$0.38 mg/dL, p＝0.04), COE (0.36$\pm$0.03 vs 0.42$\pm$0.03, p＝0.04), increased rate of S- 100$\beta$ (391.67$\pm$23.40 vs 940.0$\pm$17.02%, p＝0.003), and incidence of cerebral desaturation (2 vs 4 patients, p＝0.04) at rewarming periods, and duration of postoperative delirium (18 vs 34 hr, p＝0.02) were low in the hypercapnic group compared to the high flow group. Conclusion: These results indicate that hypercapnic CPB may provide relatively diminished cerebral injury and beneficial effects for cerebral metabolism relatively compared to high flow CPB.low CPB.

• Biomedical Science Letters
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• v.2 no.2
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• pp.133-151
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• 1996

After cardiac surgery, it has been recognized that various complications were associated with injured humoral and cellular immunity by cardiopulmonary bypass(CPB). Especially, in postoperative pulmonary dysfunction, transpulmonary leukostasis followed complement activation and inflammatory responses are major pathogen. Some studies have showed that pretreated-corticosteroids before CPB protected postoperative pulmonary dysfunction. Corticosteroids may inhibit complement and leukocyte activation. On based previous studies, present investigator determined changes of leukocyte counts and transpulmonary leukostasis during cardiac surgery and postoperative periods. For the evaluation of postoperative pulmonary function and edema, $PaO_2$ and chest X-ray were compared between pre-CPB and post-CPB. Fever and other parameters were also observed postoperatively. The aim of this study was to define for the prophylactic effects of corticosteroid(Solu-Medrol: 30mg/kg) on all the researched parameters. This study was prospectively designed with randomized-blind fashion for 50 patients undergoing cardiac surgery. According to the purpose of study, all patients were divided into placebo and steroid group. : Placebo group was 25 patients received normal saline(not corticosteroid), and steroid group was 25patients received corticosteroid(Solu-Medrol: 30mg/kg) before initiation of CPB. The results of study were summarized as follows. 1. Total peripheral leukocyte counts decreased significantly at 5 minutes of CPB in all patients(P<0.01), and began to increase progressively at later periods of CPB with neutrophilia. The significant rise remained at postoperative 7th day(P<0.05). 2. During partial CPB, transpulmonary leukostasis occurred in placebo group(P<0.001), whereas it was prevented in steroid group. 3. In both groups, peripheral lymphocyte counts were stable during CPB, but began to reduce at time of intensive care unit(ICU) and the lymphocytopenia remained until postoperative 3rd day. The lymphocyte counts recovered on postoperative 7th day. 4. In both groups, peripheral counts of monocyte were relatively stable in the early peroid of CPB, and increased gradually in the later periods of CPB. This significant monocytosis remained throughout postoperlative periods(P<0.05). 5. The mean value of postoperative $paO)_2$ was lower than that of pre-CPB in placebo group(P=0.01) but didn't significant in steroid group(P=0.90). In the incidence of pulmonary edema signs and fever, placebo group was higher than steroid group(P=0.001, p=0.01, respectively). However mechanical respiratory supporting and care periods at intensive care unit were not significant difference between two groups(P>.0.05).With the above results, the investigator concluded that leukocyte activation and pulmonary sequestration were caused by cardiac surgery with CPB and demonstrated that high dose corticosteroid will provide prophylactic effect for pulmonary leukostasis and higher neutrophilia. These effects may ameliorate postoperative pulmonary dysfunction and contribute to postoperative less morbidity. However, further study should be performed because postoperative lymphocytopenia continued for 3 days in both groups, which may suspected damage or suppression of cell-mediated immunity with used corticosteroid.