• Journal of Chest Surgery
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• v.30 no.2
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• pp.131-136
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• 1997

The hemodynamic effects of thyroid hormones which is well established, affect myocardial contractility, heart rate, and myocardial oxygen consumption. The alterations in thyroid function test are frequently seen in patients with nonthyroidal illness and often correlate with the severity of the illness and the prosnosis. In this study, thyroid hormone changes were investigated in 20 patients who received cardiopulmonary bypass(CPB). All patients showed a state of biochemical euthyroidism preoperatively: The results were as follows : 1. Serum triiodothyronine(73) reached to its nadir(30.05 $\pm$ 17.5ng/dl, p(0.001) at 10 minutes after the start of CPB and remained low(p(0.05) throughout the study period. 2. Serum thyroxine(74) concentr tion slightly decreased after CPB, but maintained within normal range. 3. Serum free thyroxine(W4) concentration slightly increased after CPB, but maintained within normal range. 4. Serum thyroid stimulating hormone(TSH) concentration increased 10 minute after CPB, reached to its nadir(3.37 $\pm$ 0.81u1U/m1, p(0.001) at 2 hours after CPB. After then, serum TSH concentration decreased and reached its normal levels at 24 hours after CPB. 5. The patients whose postoperative recovery was uneventful(Group 1) had higher serum 73 levels than those who had postoperative complications(Group 2)(p<0.05). Group 1 showed elevating patterns of serum 73 in the fourth day after operation, whereas group 2 did not show such an elevating pattern. These findings are similar to the euthyroid sick syndrome seen in severely ill patients and indicate that patients undergoing open heart surgery have suppression of the pituitary-thyroid axis.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.579-587
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• 2006

Background: Preoperative risk analysis for Fontan candidates is still less than optimal in that patients with apparently low risks may have poor surgical outcome; prolonged pleural drainage, protein losing enteropathy, pulmonary thromboembolism and death. We hypothesized that low pulmonary vascular compliance (PVC) is a risk factor for prolonged pleural effusion drainage after the Fontan operation. Material and Method: A retrospective review of 96 consecutive patients who underwent the Extracardiac Fontan procedures (median age: 3.9 years) was performed. Fontan risk score (FRS) was calculated from 12 categorized preoperative anatomic and physiologic variables. PVC $(mm^2/m^2{\cdot}mmHg)$ was defined as pulmonary artery index $(mm^2/m^2)$ divided by total pulmonary resistance $(W.U{\cdot}/m^2)$ and pulmonary blood flow $(L/min/m^2)$ based on the electrical circuit analogue of the pulmonary circulation. Chest tube indwelling time was log-transformed (log indwelling time, LIT) to fit normal distribution, and the relationship between preoperative predictors and LIT was analyzed by multiple linear regression. Result: Preoperative PVC, chest tube indwelling time and LIT ranged from 6 to 94.8 $mm^2/mmHg/m^2$ (median: 24.8), 3 to 268 days (median: 20 days), and 1.1 to 5.6 (mean: 2.9, standard deviation: 0.8), respectively. FRS, PVC, cardiopulmonary bypass time (CPB) and central venous pressure at postoperative 12 hours were correlated with LIT by univariable analyses. By multiple linear regression, PVC (p=0.0018) and CPB (p=0.0024) independently predicted LIT, explaining 21.7% of the variation. The regression equation was LIT=2.74-0.0158 PVC+0.00658 CPB. Conclusion: Low pulmonary vascular compliance is an important risk factor for prolonged pleural effusion drainage after the extracardiac Fontan procedure.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.749-755
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• 1998

Background: Twelve patients with acyanotic tetralogy of Fallot(TOF), characterized by the combination of a malaligned ventricular septal defect(VSD) and infundibular pulmonic stenosis with the clinical finding of acyanosis at rest, underwent surgical correction between January 1988 and July 1997. Materials and methods: 9.92% of patients with the diagnosis of TOF were acyanotic TOF in the same period. Ages ranged from 12 to 42 months(mean 25.2 months). 2D-echocardiographic studies, cardiac catheterization, and angiocardiograms were performed in all patients before operation. The preoperative mean systemic arterial oxygen saturation was 93.5%. According to the 2D-echocardiographic analysis, there was Lt-to-Rt shunt through VSD in 4 patients, bidirectional shunt in 2 patients, and no shunt in 6 patients. Results: The preoperative mean right ventricle to pulmonary artery(RV-PA) pressure gradients were 52.3 mmHg on 2D- echocardiogram and 48.4 mmHg on cardiac catheterization. The repair of ventricular septal defect was performed through a right atrial approach and the hypertrophic infundibular muscle bundles were resected by the transatrial and transpulmonary approach. Six patients(50%) received a transannular patch. The mean cardiopulmonary bypass time was 135.0 minutes, and the aortic crossclamp time was 87.8 minutes. Postoperative complications included bleeding necessitating reentry in one and chylothorax in one. No patient died after operation and there were no late deaths. Postoperative 2D-echocardiograms revealed tiny patch dehiscence in 5 cases and a moderate RV-PA pressure gradients(mean 15.3 mmHg). All patients were in New York Heart Association functional class 1 after operation. Conclusions: acyanotic TOF is the uncommon form of TOF, and acyanotic TOF can be repaired with a good outcome.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.517-523
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• 2004

Background: The location of intimal tear can vary in type A acute aortic dissection. The aim of this study was to assess the operative result according to the intimal tear site. Material and Method: From January, 1995 to May, 2003, 18 patients underwent surgery for acute type A aortic dissection. The patients were classified according to the intimal tear site. In Group I (n=11), the intimal tear site was located within the ascending aorta, in Group II (n=7), the intimal tear site was located in the aortic arch, descending aorta, or intramural hematoma only. All clinical data were analyzed retrospectively. Result: In Group I, the operative time, cardiopulmonary bypass time, aorta cross clamp time and circulatory arrest time were 381.5$\pm$81.0 min, 223.5$\pm$42.5 min, 146.4$\pm$34.8 min and 36.5$\pm$17.4 min, respectively; and in group II, 461.7$\pm$54.0 min, 252.5$\pm$45.3 min, 162.5$\pm$45.3 min and 47.0$\pm$14.4 min respectively. All of those were greater in group II. The overall hospital mortality rate was 27.8% (5/18) and was significantly higher in Group II (57.1%)(p=0.003) compared to that in Group I (9.1%). The causes of death were hemorrhage (n=1) in group I and hemorrhage (n=2), multiple organ failure (n=1), and rupture of abdominal aorta (n=1) in group II. Conclusion: Surgical treatment of acute type A aortic dissection with intimal tear in the ascending aorta results in an acceptable mortality rate, but in patients with intimal tear in the aortic arch or descending aorta, the operative mortality still remains high when only ascending aorta replacement was performed. In these circumstances, in order to improve surgical results, efforts to include the intimal tear site in the operative procedure will be needed.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.482-491
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• 2004

Background: The xenogenic or allogenic valves after in Vitro repopulation with autologous cells or in vivo repo-pulation after acellularization treatment to remove the antigenicity could used as an alternative to synthetic polymer scaffold. In the present study, we evaluated the process of repopulation by recipient cell to the acellu-larized xenograft treated with NaCl-SDS solution and grafted in the right ventricular outflow tract. Material and Method: Porcine pulmonary valved conduit were treated with. NaCl-SDS solution to make the grafts acellularized and implanted in the right ventricular outflow tract of the goats under cardiopulmonary bypass. After evaluating the functions of pulmonary valves by echocardiography, goats were sacrificed at 1 week, 1 month, 3 months, 6 months, and 12 months after implantation, respectively. After retrieving the implanted valved conduits, histopathologic examination with Hematoxylin-Eosin, Masson' trichrome staining and immunohistochemical staining was performed. Result: Among the six goats, which had been implanted with acellularized pulmonary valved conduits, five survived the expected time period. Echocardiographic examinations for pulmonary valves revealed good function except mild regurgitation and stenosis. Microscopic analysis of the leaflets showed progressive cellular in-growth, composed of fibroblasts, myofibroblasts, and endothelial cells, into the acellularized leaflets over time. Severe inflammatory respon-se was detected in early phase, though it gradually decreased afterwards. The extracellular matrices were regenerated by repopulated cells on the recellularized portion of the acellularized leaflet. Conclusion: The acellularized xenogenic pulmonary valved conuits were repopulated with fibroblasts, myofibroblasts, and endothelial cells of the recipient and extracellullar matrices were regenerated by repopulted cells 12 months after the implantation. The functional integrity of pulmonary valves was well preserved. This study showed that the acellularized porcine xenogenic valved conduits could be used as an ideal valve prosthesis with long term durability.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.184-192
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• 2009

Background: Although complications from transfusion are known to happen, transfusion is performed during most open heart surgeries. The aim of this study was to investigate the possibility of performing cardiac surgery without allogenic blood transfusion. Material and Method: Between January to August 2007, 44 consecutive patients who underwent open heart surgery with using various blood conservation methods were retrospectively enrolled. They were divided into group I (the onpump group, n=17) and group II (the offpump group, n=27). The blood conservation methods were intraoperative autologous donation, cell saver, retrograde autologous priming, conventional ultrafiltration and modified ultrafiltration. Antianemic agents were administered to all the patients postoperatively. We analyzed the possibility of bloodless operations, the causes of homologous transfusion, the serial change of the hematocrit and the postoperative chest tube drainage, and we compared the results between the two groups. If comparison between the two groups was not reasonable, then we compared two groups with the individual control groups I and II (49 patients) in 2006. Result: 40 (90.9%) of 44 patients were successfully operated on without transfusion and the success rate was 88.2% (15/17) for group I and 92.6% (25/27) for group II. There was no statistical difference between the two groups (p=NS). The causes of transfusion were 2 cases of postoperative bleedings, 1 case of intraoperative bleeding and 1 mistake of the indication for transfusion. There was no statistical difference of the total chest tube drainage (Group I: $417{\pm}359mL$, Group II: $451{\pm}237mL$) (p=NS), but the total chest tube drainages of the two groups were less than each of the control groups 1 and II (p<0.05). The lowest hematocrit level of Group I was $16.4{\pm}2%$, and this occurred just after infusion of cardioplegics and the hematocrits of both groups were recovered to the preoperative level at 2 months postoperatively. Conclusion: In this study, bloodless open heart surgery could be performed in 90.9% of the patients with intraoperative autologous donation, cell saver, retrograde autologous priming, conventional ultrafiltration and modified ultrafiltration. A combination of various blood conservation methods is the most important and bloodless cardiac surgery could be performed with meticulous bleeding control and strictly following the transfusion indications.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.591-597
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• 2008

Background: Pulmonary endarterectomy is widely accepted as a treatment for chronic thromboembolic pulmonary hypertension. Based on our experiences, we sought to find ways to reduce perioperative complications and to improve surgical outcomes in patients undergoing pulmonary endarterectomy. Material and Method: This study was designed as a retrospective analysis of 20 patients with pulmonary hypertension who underwent pulmonary endarterectomy between January 1998 and March 2008. All patients presented with chronic dyspnea. Deep vein thrombosis (DVT) was the major cause of chronic pulmonary thromboembolism (55%). Seventeen patients (85%) underwent inferior vena cava (IVC) filter placement. Thirteen patients underwent surgery under total circulatory arrest, while the others underwent surgery while on low flow cardiopulmonary bypass. Concomitant tricuspid annuloplasty was done in 6 patients (66%) whose tricuspid regurgitation was as severe as grade IV/IV. The mean follow-up duration was $45{\pm}32$ months. Result: Using of University of California, San Diego (UCSD), thromboembolism classification, 4 patients (20%) were type 1, 8 patients (40%) were type II, and 8 patients (40%) were type III. Right ventricular systolic pressure was reduced significantly from $77{\pm}29$ mmHg to $37{\pm}19$ mmHg after pulmonary endarterectomy (p<0.001). The degree of tricuspid regurgitation and the NYHA functional class were all improved postoperatively. Reperfusion edema occurred in 7 cases (35%). The incidence of reperfusion edema was higher in the UCSD type III group than in the other group (25% vs 50%, p=0.25) and the length of postoperative intensive care unit stay was longer in type III group ($5{\pm}2$ days vs $9{\pm}7$ days, p=0.07). The early mortality rate was 10%, and the late mortality rate was 15% (n=3); one death was due to progression of underlying non-Hodgkin's lymphoma, and the other deaths were related to recurrent thromboembolism and persistent pulmonary hypertension, respectively. Conclusion: Pulmonary endarterectomy, as a curative surgical method for treating chronic thromboernbolic pulmonary hypertension, should be performed aggressively in patients diagnosed with chronic thromboembolic pulmonary hypertension, and an effort should be made to reduce the frequency of perioperative complications and to improve surgical outcomes.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.573-579
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• 2008

Background: Composite valve graft replacement is currently the treatment of choice for a wide variety of the lesions of aortic root disease. The purpose of this study was to explore the results of aortic root replacement after using the Cabrol technique over a 13-year period at our institution, and we analyzed the results to help surgeons make better decisions when repairing aortic root disease. Material and Method: Between January 1994 and December 2006, twenty-five patients underwent a Cabrol technique operation at our institution. The mean patient age was $43.7{\pm}14.1$ years old (range: $6{\sim}65$ years) and the male and female ratio was 21:4 (84% : 16%). The patients' follow-up was 100% complete, and the mean follow-up period was $60.7{\pm}50.4$ (range:$1{\sim}162$) months. Annuloaortic ectasia (n=18) was the most frequent cause of aortic disease in this series, followed by aortic dissection (n=7). The mean cardiopulmonary bypass time was $177.2{\pm}44.9$ minutes and the mean aortic cross clamping time was $123.4{\pm}34.1$ minutes. Nine patients were checked with MDCT (Multidetector computed tomography) for evaluating a well functioning secondary graft and the coronary anastomosis site. Result: The early mortality rate was 4% (1 of 25 patients). A significant stenosis, kinking or occlusion of the secondary graft was detected by MDCT in 4 patients. The overall survival rate was 88%. Conclusion: The Cabrol technique demonstrated a significant incidence of long-term complications such as secondary graft stenosis or obstruction. It could be used when the modified Bentall technique is not feasible.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.297-306
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• 2004

Current artificial heart valves have several disadvantages, such as thromboembolism, limited durability, infection, and inability to grow. The solution to these problems would be to develop a tissue-engineered heart valves containing autologous cells. The aim of this study was to optimize the protocol to obtain a porcine acellular matrix and seed goat autologous endothelial cells on it, and to evaluate the biological responses of xenograft and xeno-autograft heart valves in goats. Material and Method: Fresh porcine pulmonic valves were treated with one method among 3 representative decellularization protocols (Triton-X, freeze-thawing, and NaCl-SDS). Goat venous endothelial cells were isolated and seeded onto the acellularized xenograft leaflets. Microscopic examinations were done to select the most effective method of decellularizing xenogeneic cells and seeding autologous endothelial cells. Two pulmonic valve leaflets of. 6 goats were replaced by acellularized porcine leaflets with or without seeding autologous endothelial cells while on cardiopulmonary bypass. Goats were sacrificed electively at 6 hours, 1 day, 1 week, 1 month, 3 months, and 6. months after operation. Morphologic examinations were done to see the biological responses of replaced valve leaflets. Result: The microscopic examinations showed that porcine cells were almost completely removed in the leaflets treated with NaCl-SDS. The seeded endothelial cells were more evenly preserved in NaCl-SDS treatment. All 6 goats survived the operation without complications. The xeno- autografts and xenografts showed the appearance, the remodeling process, and the cellular functions of myofibroblasts, 1 day, 1 month, and 3 months after operation, respectively. They were compatible with the native pulmonary leaflet (control group) except for the increased cellularity at 6 months. The xenografts revealed the new endothelial cell lining at that time. Conclusion: Treatment with NaCl-SDS was most effective in obtaining decellularized xenografts and facilitate seeding autologous endothelial cells. The xenografts and xeno-autografts were repopulated with myofibroblasts and endothelial cells in situ serially. Both of grafts served as a matrix for a tissue engineered heart valve and developed into autologous tissue for 6 months.

• Journal of Chest Surgery
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• v.38 no.5 s.250
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• pp.335-348
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• 2005

Background: This retrospective review examines the preoperative condition, postoperative course, mortality and cause of death for the patients who underwent modified Blalock-Taussig shunt for complex congenital heart defects in early infancy. Material and Method: Fifty eight patients underwent modified Blalock-Taussig shunts from January 2000 to November 2003. The mean age at operation was $23.1\pm16.2$ days ($5\~81\;days$), and the mean body weight was $3.4\pm0.7\;kg\;(2.1\~4.3\;kg)$. Indications for surgery were pulmonary atresia with ventricular septal defect in 12 cases, pulmonary atresia with intact ventricular septum in 17, single ventricle (SV) in 18, and hypoplastic left heart syndrome (HLHS) in 11. Total anomalous pulmonary venous return (TAPVR) was associated with SV in 4 cases. Result: There were 11 ($19.0\%$) early, and 5 ($10.6\%$) late deaths. Causes of early death included low cardiac output in 9, arrhythmia in 1, and multiorgan failure in 1. Late deaths resulted from pneumonia in 2, hypoxia in 1, and sepsis in 1. Risk factors influencing mortality were preoperative pulmonary hypertension, metabolic acidosis, use of cardiopulmonary bypass, HLHS and TAPVR. Twenty four patients ($41.4\%$) had hemodynamic instability during the 48 postoperative-hours. Six patients underwent shunt revision for occlusion, and 1 shunt division for pulmonary overflow. Conclusion: Modified Blalock-Taussig shunt for complex congenital heart defects in early infancy had satisfactory results except in high risk groups. Many patients had early postoperative hemodynamic instability, which means that continuous close observation and management are mandatory in this period. Aggressive management may appear warranted based on understanding of hemodynamic changes for high risk groups.