• Journal of Chest Surgery
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• v.42 no.5
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• pp.597-603
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• 2009

Background: Atrioventricular valve regurgitation in pediatric patients with a functional single ventricles (FSV) - has been known as one of the important risk factors for death and unfavorable long-term results after a Fontan operation. We evaluated early and mid-term results of bivalvation valvuloplasty in FSV patients. Material and Method: We retrospectively evaluated 11 patients with a functional single ventricle who underwent bivalvationvalvuloplasty between 1999 and 2007. The degree of common atrioventricular valve regurgitation (CAVVR) was determined by color Doppler echocardiography (regurgitation grade scoring, trivial; 1, mild; 2, moderate; 3, severe; 4). Mean age at valve surgery was $6.9{\pm}7.0$ months (median 4 months, 24 days$\sim$21 months)and mean body weight was $6.2{\pm}2.8\;kg$ ($3.1{\sim}11.3\;kg$). Nine patients had isomerism heart and two of them had TAPVC. The concomitant procedures were performed in all but one patient. Additional commissural closure was performed in 3 patients and commissural annuloplasty in another 3 patients. Result: There was one hospital death after. surgery. A 32-day old patient who had been preoperatively dependent on a ventilator died of air way and lung problems 4.3 months after pulmonary artery banding and bivalvation valvuloplasty. Mean follow-up duration was 40 months ($4.3{\sim}114$ months). Mean preoperative CAVVR score was $3.3{\pm}0.6$, which decreased to $1.9{\pm}0.7$ postoperatively (p<0.0001). This residual regurgitation slightly increased to $2.2{\pm}0.4$ (no statistical significance) after a mean follow-up of 1.4.3 months. Six patients (60%) required re-operations for residual regurgitation at a subsequent bidirectionalcavopulmonary shunt or Fontan operation. One patient with Ebsteinoid malformation of the right sided atrioventricular valve required valve replacement due to stenoinsufficiency. Another patient required edge-to-edge repair at the right sided AV valve (between the right mural leaflet and the bridging leaflets). The remaining 4 patients required additional suture placements between bridging leaflets with or without commissural annuloplasty. All survivor had trivial or mild CAVVR at the latest follow-up. Conclusion: Bivalvation valvuloplasty for CAVVR in FSV patients is. an effective and safe procedure. However, significant numbers of the patients have small residual regurgitation and require additional valve procedures at subsequent operations. Long-term observations to monitor progression of the CAVVR is mandatory.

• Journal of Chest Surgery
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• v.43 no.5
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• pp.513-517
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• 2010

Background: Diaphragmatic plication through a thoracoscopic approach has been an effective modality to treat diaphragmatic enventration. However, the conventional technique for thoracoscopic plication has some disadvantages. We have developed an improved and simplified technique with utilizing the head up position, $CO_2$ insufflation and figure-of-eight sutures. Material and Method: Between October 2005 and September 2009, 9 patients with diaphragmatic paralysis underwent repair using our modified technique. The mean patient age was $38.5{\pm}53.0$ years (range: 2~76 years). Result: The mean operation time was $46.7{\pm}15.9$ min (range: 30~85 min). None of the patients died due to this procedure, but there was one case of prolonged air leakage, and a case of re-expansion pulmonary edema, which required 3 days of ventilator support after the procedure. The mean hospital stay was $6.22{\pm}2.04$ days (range: 4~11 days). The mean follow-up duration was $27.2{\pm}11.6$ months (range: 2~43 months). All the patients had their symptoms relieved and there was no recurrence of eventration except for one patient who developed more than 2 cm elevation of the diaphragm compared to the immediate post-operation status. Conclusion: With our technique, thoracoscopic diaphragmatic plication was feasible via using only three 5 mm ports and without a working window and the midterm results were favorable. Therefore, we advocate thoracoscopic diaphragmatic plication as a preferred technique to the conventional open plication technique.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.343-352
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• 2000

Backgrounds : Respiratory care for patients in intensive care units (ICUs) has been performed mainly by nurses in Korea. However, the current status of respiratory care in the Korea ICUs is not well known. Respiratory care and the methods of delivery in ICUs were surveyed. Method : A confidential questionnaire was distributed to the head nurses working the ICUs at 117 hospitals in Korea. One hundred hospitals returned the questionnaires, for a response rate of 85%. The hospitals were divided into three groups : Main university hospitals (MUH), university associated hospitals (UAH), and general hospitals (GH) Result : Eighteen units of 66 units in MUH and 35 units of 58 units in GH were organized as a general ICUs. The percentage of ICUs with full-time doctors was 47.1%. The nurses usually delivered respiratory care spending from 1 to 4 h during their 8 h of working time. Although the respondents felt that respiratory care should be delivered by trained respiratory therapists, these therapists were not found at the hospitals. Most of the units performed percussion, tracheal suctioning, and positional changes. However, vibration and IPPB were less frequently performed in GH. Among oxygen supply apparatus, venturi mask and T-piece were not frequently used in GH. GH applied a noninvasive ventilator mode less frequently than MUH and UAH. The percentage of Swan-Ganz catheter monitoring was only 21.4% in GH. Conclusion : Respiratory care for patients in the Korean ICUs was provided by nurses on the whole. In addition, there were many differences in the level of respiratory care according to the type of hospital. To overcome the current problems revealed, an effective in-hospital training program for the development of full-time respiratory care therapists should be established urgently in Korea.

• Clinical and Experimental Pediatrics
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• v.51 no.8
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• pp.874-878
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• 2008

Purpose : This study was undertaken to develop an animal model of periventricular leukomalacia (PVL) induced by in utero clamping of pregnant rat aorta in fetal rats. Methods : A timed pregnanct Sprague-Dawley rat on embryonic day 21 just prior to delivery was sedated and anesthetized, and a Harvard ventilator for small animals was applied. Following laparotomy, the maternal aorta was clamped reversibly for 40 minutes using a surgical clip. The fetal rats were then delivered by Cesarean section, resuscitated if necessary, and reared by a surrogate mother rat until postnatal day 21 to obtain the brain specimen. After systemic perfusion and fixation, $10{\mu}m$ thick serial brain sections were obtained and stained for pathologic examination and assessment of ventriculomegaly. Ventriculomegaly was assessed by the measured ventricle to total brain volume ratio. Results : Eight out of eleven fetal rats (73%) survived in the ischemia group after induction of in utero ischemia by clamping maternal rat aorta, and all ten survived in the control group. Body and brain weights measured at postnatal day 21 were significantly lower in the ischemia group compared to the control group. In pathologic findings, significant ventriculomagaly ($3.67{\pm}1.21%$ vs. $0.23{\pm}0.06%$) was observed in the ischemia group compared to the control group; although cystic lesion was not observed, mild (n=6) and moderate (n=2) rerefaction of the brain tissue was observed. Conclusion : A fetal rat model of PVL induced by in utero clamping of pregnant rat aorta was developed.

• Clinical and Experimental Pediatrics
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• v.53 no.4
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• pp.532-537
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• 2010

Purpose : Early postoperative arrhythmias are a major cause of mortality and morbidity after open heart surgery in the pediatric population. We evaluated the incidence and risk factors of early postoperative arrhythmias after surgery of congenital heart disease. Methods : From January 2002 to December 2008, we retrospectively reviewed the medical records of the 561 patients who underwent cardiac surgery in Kyungpook National University Hospital. We analyzed patients' age and weight, occurrence and type of arrhythmia, cardiopulmonary bypass (CPB) time, aortic cross clamp (ACC) time, and postoperative electrolyte levels. Results : Arrhythmias occurred in 42 of 578 (7.3%) cases of the pediatric cardiac surgery. The most common types of arrhythmia were junctional ectopic tachycardia (JET) and accelerated idioventricular rhythm (AIVR), which occurred in 17 and 13 cases, respectively. The arterial switch operation (ASO) of transposition of the great arteries (TGA) had the highest incidence of arrhythmia (36.4%). Most cases of cardiac arrhythmia showed good response to management. Patients with early postoperative arrhythmias had significantly lower body weight, younger age, and prolonged CPB and ACC times ($P$<0.05) than patients without arrhythmia. Although the mean duration of ventilator care and intensive care unit stay were significantly longer ($P$<0.05), the mortality rate was not significantly different among the 2 groups. Conclusion : Early postoperative arrhythmias are a major complication after pediatric cardiac surgery; however, aggressive and immediate management can reduce mortality and morbidity.

• Journal of Chest Surgery
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• v.36 no.1
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• pp.15-20
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• 2003

Myasthenia gravis is a rare autoimmune disease involving acetylcholine receptor and its autoantibody on neuromuscular junction. The methods of treatment are medical treatment and surgical thymectomy. In this paper we analyzed the result of thymectomy and the factors affecting the postoperative symptom improvement. Material and method : This study obtained medical records of 37 patients who received the thymectomy for myasthenia gravis from March 1986 to December 1998. Result Out of 37 cases, 21 cases(57%) showed improvement, of which 8 cases (50%) in the group of thymoma(n=16), and 13 cases (62%) in the group of thymic hyperplasia(n=21) showed the improvement of symptoms. Postoperative complications were respiratory insufficiency due to aggravation of symptoms after operation, including tracheal intubation for ventilator support in 9 cases, pneumonia in 3 cases, pneumothorax in 2 cases and left vocal cord palsy in 1 case. There was one postoperative mortality. The relation between postoperative improvement and sex(P=0.3222), age(P=0.7642), thymic pathologic variants,(P=0.4335) and classification of thymoma(P=0.20) showed no statistically significant correlation. However, the lower grade of preoperative symptoms can predict the lower grade of postoperative symptoms significantly(P=0.0032). Follow up study to 36 postoperative survivors was performed in October 2002 based on the out-patient records and call with patients. Out of 36 cases, 33 cases(91.7%) could be investigated and 3 cases could not. Mean follow up period was 83.2 months. Out of 33 cases, 25 cases(75.8%) showed symptomatic improvement, of which 8 cases(53.3%) in the group of thymoma(n=15) and 17 cases(94.4%) in the group of thymic hyperplasia(n=18) showed the improvement of$\boxUl$ symptoms. Conclusion : In myasthenia gravis, thymectomy showed the good improvement, and more important factor affecting the improvement of symptoms was the grdae of preoperative symptoms. Also midterm and long term follow up results showed good symptomatic improvement.

• Journal of Chest Surgery
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• v.36 no.8
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• pp.576-582
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• 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
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• v.36 no.2
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• pp.63-72
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• 2003

Although a variety of synthetic vascular grafts are available in modern vascular surgery, no ideal prosthesis ha,4 yet been developed. Small-caliber vascular grafts with low flow, as used in the lower extremity, continue to become thrombosed at unacceptable rates. We have developed and evaluated the new antithrombogenic blood contacting surfaces in canine model. Material and Method: Two now antithrombogenic blood contacting surfaces(Polyvinylalcohol -Polyurethane(PVA-PU) blend and natural Graphite-polyurethane(G-PU) blend) have been developed and evaluated in canine model, using vascular grafts and patches. The luminal surfaces of the test vascular grafts(5 mm ID) were fabricated by dipping a glass rod in PVA-PU blend solution(50 % PVA) using phase separation method. Mongrel dogs of either sex weighing 18-22 kg were anesthetized by endotracheal intubation using halothane and their lungs were ventilated with a volume-cycled ventilator, Maintenance anesthesia with 0.5-1.0% halothane and supplemental oxygen was used. Two pairs were used for comparison in the bilateral femoral arteries for both vascular grafts(PVA-PU vs. PU) and vascular patches(G-PU vs. PU). Bilateral groin incisions were made and the arteries were exposed and clamped. After an excision of 1 cm of the artery between clamps, a grail of 2.5 cm in length was implanted end-to-end using 6-0 polypropylene suture. The vascular patch was implanted as a form of on-lay patch. Animals were sacrificed at 1, 2, 4, 6, 8 and 16 weeks for vascular grafts and 1, 2. 4 and 6 weeks for vascular patches. Result The vascular grafts of PVA-PU blends showed patent lumina in the 2 and 16 weeks animals, while those of PU showed a patent lumen in 2 weeks animal. PVA-PU graft of 16 weeks showed a fairly clean luminal surface. A light microscopic finding of this graft demonstrated good tissue infiltration through porosity, The animals with vascular patches showed patent arteries in both groups except 2 weeks animal. Scanning electron microscopy of the luminal surfaces of G-PU patches in 4 and 6 weeks animals showed endothelial cell covering with microvilli. PU patches showed qualitatively less endothelial cell covering. Conclusion: In conclusion, PVA-PU and G-PU blends can be a promising blood contacting surfaces for application in a synthetic vascualr graft. However, further animal study is needed to determine the real long-term effects of these methods of surface modifications.

• Neonatal Medicine
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• v.17 no.1
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• pp.21-33
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• 2010

Purpose : The increased survival of preterm infants in the neonatal intensive care unit recently has resulted in an increased frequency of bronchopulmonary dysplasia (BPD), especially with atypical forms. However, there have been few studies compairing classic and atypical BPD. The aim of this study was to investigate the differences between these two types of BPD. Methods : Infants with a gestational age less than 32 weeks born at the Seoul National University Hospital and Bundang Seoul National University Hospital from May 2004 to April 2007 were included. The data were categorized in 2 groups, classic and atypical BPD. We determined the incidence of BPD, and compared perinatal factors and postnatal managements between two groups. Results : Among 260 study subjects, 141 (54.2%) infants had BPD. Classic BPD infants were 64 and atypical BPD infants were 77. Comparison of differences between 2 groups, classic BPD infants were associated with respiratory distress syndrome, patent ductus arteriosus, intrauterine growth restriction, more high-frequency ventilator (HFV) use, low 1 and 5 minute Apgar scores. Atypical BPD infants were associated with antenatal steroid use, maternal premature rupture of membrane and chorioamnionitis (CAM). In multivariate analysis, more HFV use was associated with classic BPD. Antenatal steroid use, clinical CAM and histological CAM were associated with atypical BPD. Conclusion : The results of this study showed that antenatal factors (antenatal steroid use, clinical CAM, histological CAM) were associated with atypical BPD and postnatal factors (HFV used more) were associated with classic BPD. Further studies are needed for prevention and treatment of BPD.

• Neonatal Medicine
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• v.17 no.1
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• pp.34-43
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• 2010

Purpose : The aim of this study was to examine whether hypercapnia during the first seven days of life was associated with severe intraventricular hemorrhage (IVH) in preterm infants requiring mechanical ventilation. Methods : A matched pair analysis was performed for 19 preterm infants with severe IVH(grade$\geq$3) and 38 infants with no severe IVH (normal or grade 1), who required mechanical ventilation for more than seven days. The univariate and multivariate analysis of severe IVH with maximal and minimal $PaCO_2$, averag $PaCO_2$, SD of $PaCO_2$, and difference in the $PaCO_2$ were assessed. The major perinatal factors and maximal ventilator index (VI) were also compared. Results : Infants with severe IVH had a higher maximal $PaCO_2$ (86.1$\pm$18.4 mmHg vs. 60.1$\pm$ 11.6 mmHg, P <0.001) and mean $PaCO_2$ (47.5$\pm$5.6 mmHg vs. 41.2$\pm$6.3 mmHg, P=0.004) and a larger SD or difference in $PaCO_2$ (14.0$\pm$4.4 mmHg vs. 9.0$\pm$2.4 mmHg; 60.3$\pm$20.9 mmHg vs. 35.5$\pm$11.8 mmHg, P <0.001). However the minimal $PaCO_2$ values did not differ between the groups. Disseminated intravascular coagulation, pulmonary hemorrhage, and the air leak syndrome were more frequent in the IVH group than in the controls. The maximal VI on each day was higher in the IVH group. The multivariate logistic regression analysis after controlling for bleeding tendency showed that the air leak syndrome, maximal VI, and maximal $PaCO_2$ were independently associated with severe IVH [OR, 1.324 (95% CI, 1.011-1.733; P=0.041)]. Conclusion : Extreme hypercapnia was significantly associated with severe IVH in preterm infants, after adjustment for major perinatal risk factors. Frequent monitoring of the $PaCO_2$ may be important for early detection of inadvertent hypercapnia and prompt correction of high PaCOS levels.