• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.583-592
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• 2018

In this study, plans to apply 3D conformal radiotherapy, intensity modulated radiotherapy, and volumetric intensity modulated arc radiotherapy to esophageal cancer radiotherapy were compared. In particular, arc therapy was applied to reduce irradiated volume and spread of low-dose during intensity modulated radiation therapy and volumetric intensity modulated arc radiotherapy by limiting part of irradiated angle, in order to compare target doses and dose for surrounding normal tissues of the two methods and those of 3D conformal radiotherapy. No significant difference in target dose was found among the three methods. The 5 Gy volume(V5) of the lung showed 56.53% of conformal radiotherapy, 52.03% of intensity modulated radiotherapy, and 47.84% of volumetric modulated arc therapy(CRT-IMRT p=0.035, CRT-VMAT p<0.001, IMRT-VMAT p<0.001). The 10 Gy volume(V10) showed a significant difference in conformal radiotherapy 35.12%, intensity modulated radiotherapy 34.04%, and volumetric modulated arc radiotherapy 33.28%, showing significant difference in intensity modulated radiotherapy(p=0.018), volumetric modulated arc therapy(p=0.035), no significant difference in dose was found at 20 Gy volume. The mean dose and 20 Gy volume of the heart were not significantly different according to the treatment plan, but the 30 and 40 Gy volumes were 37.16% and 22.46% in the volumetric modulated arc radiotherapy, showing significant differences(p=0.028) in comparison with conformal radiotherapy. It is believed that, by limiting part of the irradiated angle during intensity modulated radiotherapy and volumetric intensity modulated arc radiotherapy, the irradiated volume and, thereby, the 5-10 Gy area and toxicity of the lung can be reduced while maintaining dose distribution of the target dose.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.277-283
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• 2005

Arterial oxygen saturation $(SaO_2)$ instability frequently takes place after systemic-pulmonary shunt without shunt occlusion. We analyzed actual incidence and risk factors for $SaO_2$ instability after shunt operations, and possible mechanisms were speculated on. Material and Method: Ninety three patients, who underwent modified Blalock-Taussig shunt from January 1996 to December 2000, were enrolled in this study. Adequacy of shunt was verified in all patients, either by ensuing one ventricle or biventricular repair later on or by appropriate pulmonary artery growth on postoperative angiogram. Age, body weight, hemoglobin level at operation were 3 day to 36 years (median: 1.8 months), 2.5kg to 51kg (median: 4.1kg) and $10.7\~24.3$ gm/dL (median: 15.2 gm/dL) respectively. Preoperative diagnoses were functional single ventricle with pulmonary stenosis or atresia in 39, tetralogy of Fallot in 38 and pulmonary atresia with intact ventricular septum in 16. Pulmonary blood flow (PBF) was maintained pre-operatively by patent ductus or previous shunt in 64 and by forward flow through stenotic right ventricular outflow tract (RVOT) in 29. $SaO_2$ instability was defined as $SaO_2$ less than $50\%$ for more than 1 hour with neither anatomic obstruction of shunt nor respiratory problem. Result: 10 patients $(10.7\%)$ showed $SaO_2$ instability after shunt operation. After shunt occlusion was ruled out by echocardiogram, they received measures to lower pulmonary vascular resistance (PVR), which worked within a few hours in all patients. Risk factors for $SaO_2$ instability included older age at operation (p=0.039), lower preoperative $SaO_2$ (p=0.0001) and emergency operation (p=0.001). PBF through stenotic RVOT showed marginal statistical significance (p=0.065). Conclusion: $SaO_2$ instability occurs frequently after shunt operation, especially in patients with severe hypoxia pre-operatively or unstable clinical condition necessitating emergency operation. Temporary elevation of pulmonary vascular resistance is a possible mechanism in this specific clinical setting.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.142-149
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• 2003

To know the feasibility of the coronary artery bypass graft (CABG) for multivessel coronary artery disease with purely bilateral internal thoracic arteries (ITAs), we analyzed the short-term clinical results and the coronary angiography of the patients. Material and Method: From March 2001 to June 2002, four hundred and five patients underwent CABG. Purely bilateral ITAs were used in 159 patients (39.3%). We analyzed these patients retrospectively The mean age of these patients was $61.2{\pm}8.5$ (range: 30 ~80) years and there were 123 male patients. The preoperative risk factors were as follows: diabetes in 54 patients (34.0%), history of acute myocardiac infarction within 4 weeks in 29 (18.2%), and emergency operation in 6 (3.8%). Off-pump CABG was carried out in 128 patients (80.5%). Associated procedures were mitral valvuloplasty (5), aortic valve replacement (3), Dor procedure (1), and so on. Result: The mean number of distal anastomoses was $3.1{\pm}0.9$ (range: 2~6), the mean duration of hospital stay was $8.4{\pm}4.5$ days. There was one (0.6%) operative death. Except for one early death, no other patients suffered from low cardiac output. The other postoperative complications were occurred as follows: reoperation due to bleeding in 3 patients, perioperative myocardiac infarction in 1, transient cardiac arrest in 2, transient cognitive dysfunction in 7, and transient ischemic attack in 1, and deep sternal wound infection in 1 patient. Recently, early postoperative angiography was performed in 19 patients who had triple vessel disease. The total number of distal anastomosis was 78 (mean $4.1{\pm}0.8$/patient). All distal anastomosis sites were patent, but competition flow was observed at the bypass sites where the native coronary artery stenosis was not significant. Conclusion: The CABG with purely bilateral ITAs for triple vessel disease was performed safely. The early patency rate was relatively good in small number of patients. However the long-term patency rate and the functional study to evaluate the sites where competition flow was observed should be followed.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.646-650
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• 2003

Many surgical techniques for ischemic mitral regurgitation (IMR) have been used with their excellent results and advantages. Here, we report our simple posterior annuloplasty techniques using vascular graft strip with their early results. Material and Method: Twenty two patients (13 male) underwent the operations for IMR (excluding the papillary muscle rupture) from December 2001 to January 2003. Preoperative risk factors were low ejection fraction (<35％, n=9), hypertension (n=13), diabetes (n=9), and renal failure (Cr>2.5, n=4). The wide dissection beneath the both vena cavae and interatrial groove after bicaval cannulation enabled the easy exposure of mitral valve even in the small left atrium. After eight or nine interrupted sutures in posterior annulus for anchoring the 6 mm width vascular graft strip, symmetric (n=8) or asymmetric (n=14) annuloplasty were done. Combined surgeries were CABG (n=21), Dor procedures (n=3), tricuspid valve annuloplasty (n=1), Maze operation (n=1), and aorto-right subclavian artery bypass (n=1). Result: Except for one surgical mortality, all the patients were doing well and the mean grade of regurgitation was decreased from 2.95 to 0.88, however the ejection fraction had not changed significantly just before discharge. Post-operative valve function evaluated before discharge revealed no residual regurgitation in 8 (including 1 patient with mild stenosis due to over reduction), minimal in 11, mild in 2, and mild to moderate regurgitation in 1. One patient who had ischemic cardiomyopathy and renal failure died of the arrhythmia during the hemodialysis. Conclusion: These observations suggest that the annuloplasty with vascular graft strip could be a safe and cost effective techniques for ischemic mitral regurgitation. However, the long term evaluation for the mitral valve function should be defined for the final conclusion.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.659-665
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• 2003

The aim of this study was to evaluate the early and midterm results of off-pump total arterial revascularization using the skeletonized right gastroepiploic artery (RGEA) as a third arterial conduit. Material and Method: We prospectively analyzed 103 patients who underwent off-pump total arterial revascularization using bilateral internal thoracic arteries (ITAS) and RGEA. The RGEA was used as in situ graft in 88 patients, composite graft in 10 patients, and free graft in 5 patients. Postoperative coronary angiographies were performed before discharge in 100 patients, and at postoperative one year in 88 patients. Result: The RGEA showed a significantly higher free flow (130$\pm$95 ml/min) than that of right ITA(113$\pm$57 ml/min) or left ITA (107$\pm$55 ml/min), which was measured before anastomosis (p < 0.05). The total number of distal anastomoses was 3.8$\pm$0.7. The number of distal anastomoses per bilateral ITAs was 2.8$\pm$0.7 and the number of distal anastomosis per RGEA was 1.0. There were two morialities including one operative mortality. The late mortality was not related to cardiac events. Early postoperative morbidities were atrial fibrillation in 15 patients, bleeding reoperation in 4 patients, mediastinitis in 1 patients, perioperative myocardial infarction in 2 patient, and transient ARF in 3 patients. Postoperative coronary angiographies showed the early patency rate of 98.6％ (272/276) for ITAs and 97.0％ (97/100) for RGEA, respectively (p=ns), and the one-year patency rate of 95.9％ (234/244) for ITAs and 88.6％ (78/88) for RGEA, respectively (p=0.07). Flow competition between the RGEA and NCA (native coronary artery) was seen in 5 of the 100 patients (5.0％) immediate postoperatively and 7 of the 88 patients (8.0％) 1 year after surgery. Since July, 2000, we measured transit time flow intraoperatively and could reduce flow competition significantly Conclusion: The skeletonized RGEA demonstrated excellent early and midterm patency rates and could be used as a third arterial graft following the bilateral ITAs.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.787-792
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• 2004

Even though there well developments in various treatment techniques for acute limb ischemia, this disease is both life threatening and limb threatening. We investigated early and mid-term results of operation for acute limb ischemia with symptoms, the combined diseases, location of occlusion, complication in our patients. Material and Method: A retrospective review was conducted in 54 patients (43 men, 11 women, mean age 67.2 years) presenting with acute limb ischemia due to arterial thrombosis or embolism between Jan. 1996 and Dec. 2003, initially underwent thromboembolectomy. Result: In 33 patients (61.1%) the timeinterval from the onset of symptom to admission was within 24 hours. Causes of acute limb ischemia were embolic occlusion (27.8%), native arterial thrombosis (66.7%), and bypass graft thrombosis (5.6%). The distribution of arterial occlusion location was at 8 aortoiliac (14.8%) and 43 distal to femoral (79.6%) and brachial (5.6%). Clinical categories were grade I in 64.8%, IIa in 24.1%, IIb in 7.4%, and III in 3.7%, All the patients were received embolectomy. Underlying diseases were heart disease (72.2%), hypertension (33.3%), cerebrovascular accident (16.7%) and diabetes (18.5%). History of smoking was noted in 96,3% of the cases. Mortality rate was 5.6％ and overall amputation rate was 9.3% (5/54). The 1-year limb salvage rate was 93.62%. Postoperative complications were 1 wound infection, 1 G1 bleeding, 3 acute renal failure, and 1 compartment syndromes. The functional outcomes of the salvaged limb according to the recommended scale for gauging changes in clinical status, revised version in 1997 were +3 in 68.5%, +2 in 9.3%, +1 in 7.4%, -1 in 5.6%, -2 in 3.7%, and -3 in 5.6%. Conclusion: This study revealed 5.6% mortality and the amputation rate was 9.3%. We have retrospectively shown good results from early diagnosis & early operation. To improve outcome, early diagnosis and understand the underlying diseases, prompt treatment and operation would be appreciated.

• Journal of Chest Surgery
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• v.35 no.4
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• pp.290-295
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• 2002

Backgroud: Pneumonectomy carries the possibility of numerous dangerous complications as well as the vast effect the operation itself has on the cardiopulmonary function. Most of operations are done with the insertion of the chest tubes upon completion, but because of the high incidence of pyothorax as its complications, we have tried to analyze and compare the cases without inserting the chest tubes. Material and Method: During a 5 year period from January, 1996 to December 2000, 100 cases, which were operated at the Hanyang University Hospital, were selected using the patient's charts. The age, gender, indication of operation, associated diseases, and operation site(left or right) were classified accordingly and the postoperative complications and mortality were statistically analyzed using the $\chi$ 2-test. After resecting the lung, the intrathoracic pressure was set at -15 ~ -20cm $H_2O$ using the nelaton catheter, and the thoracotomy site was then closed. The gradual collection of the fluid and blood in the thorax of the operated side, as well as the mediastinum location, were observed carefully for 4~5 days postoperatively with the aid of the simple chest x-rays. Result: Of the 100 cases, 16 cases of pulmonary tuberculosis(16%), 81 cases of lung tumor(81%), 2 cases of bronchiectasis(2%), and 1 case of aspergilloma associated bronchiectasis were noted. There were 8 mortality cases(8%), and of the 34 cases(34%), 44 complications were noted. The age, sex, and operation site(left or right) were not statistically significant with the complications. 7 of the 16 cases of pulmonary tuberculosis(44%) and 27 of the 81 cases of lung tumor(33%) had complications, but they were found not to be statistically significant. The increase of the complication rate in the pulmonary tuberculosis patients was 3.86. The evidence of postoperative bleeding was observed in 6 cases with the 3 cases being the pulmonary tuberculosis patients and the 3 cases were others. This shows that the increase in postoperative bleeding in the pulmonary tuberculosis is statistically significant(p=0.019). Of the 100 cases, there were 8 mortality cases(8%), with 5 cases from the 81 cases of the lung tumor group(6.1%), 3 cases from the 16 cases of pulmonary tuberculoses group(18.7%).

• Journal of Chest Surgery
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• v.35 no.4
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• pp.274-282
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• 2002

Background: Paravalvular leakage or false aneurysm developed after isolated aortic valve replacement(AVR) for aortic regurgitation(AR) associated with Behcet's disease is one of the most serious complications, and requires subsequent reoperations. We describe the surgical result of homograft aortic root replacement(ARR) for AR associated with Behcet's disease. Material and Method: From January 1992 to December 2001, 6 patients with AR associated with Behcet's disease underwent 7 ARR with homograft and 1 Ross operation. Five patients were male and one was female. The grafts used for ARR were 5 aortic and 2 pulmonic homografts. Ages at operation ranged from 27 to 51 years(mean, 37$\pm$9 years). Two patients underwent ARR with aortic homograft at the first operation. In the remaining 4 patients, ARR using a homograft was performed for paravalvular leakage that developed after AVR, and the mean interval from AVR to ARR was 21 $\pm$29 months(range, 5 to 73.3 moths, median, 7.6 months). Result: There was no early death. All patients were followed up for an average of 18.9$\pm$24.0 months(range, 1.9 to 68.9 months, median, 8.4 months). Two of 4patients who had undergone ARR after AVR required subsequent reoperations for false aneurysm of the ascending aorta and failure of pulmonary homograft. One patient underwent re-replacement of the aortic root, ascending aorta and partial aortic arch with an aortic homograft, the other underwent Ross operation. Conclusion: This study suggests that aortic root replacement using a homograft in aortic regurgitation with Behcet's disease may provide good clinical results and decrease the incidence of paravalvular leakage or false aneurysm after aortic valve replacement. However, the adequate perioperative management and complete removal of the inflarrunatory tissue at operation were also important for the good long-term results.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.889-896
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• 1996

Aggressive revascularization of the ischemic lower extremities in atherosclerotic occlusive diseases or acute embolic arterial occusion due to cardiac valvular disease by thromboembolectomy or an arterial by- pass operation has been advocated by some authors. To evaluate clinical pattern and operative outcome of the ischemic lower extremity, surgical experience in 101 patients who were admitted to Dong-A Univer- sity Hospital between March 1990 and August 1995 was analyzed. The patients were 92 males and 9 females ranging fro 25 to 87 years of age. The underlying causes of arterial occlusive disease were atherosclerotic obliterances in 54 case, Buerger's disease in 20 cases, thromboembolism in 24 cases, vascular trauma in 3 cases and pseudoaneurysm in 3 cases. - The major arterial occlusive sites of atherosclerotic obliterance were femoral artery in 30 cases, iliac artery in 23 cases, popliteal artery in 10 cases, distal aorta in 6 cases and the major arterial occlusive sites of Buerger's disease were posterior tibial artery in 14 cases, anterior tibial artery in 8 cases, popliteal artery in 5 cases. The operative procedures of arterial occlusive disease were bypass graft operation in 61 cases, thromboembolectomy in 21 cases, sympathectomy in 20 cases. Arterial bypass operations with autogenous or artificial vascular prosthesis were done in 61 cases which Included femoro-popliteal bypass in 21 cases, femoro-femoral bypass in 15 cases, axillo-bifemoral bypass in 7 cases, aorto-bifemoral with inverted Y-gr ft In 3 cases, femoro-profundafemoral bypass in 3 cases, popliteo-tibial bypass in 2 cases, aorto-iliad bypass in 1 case Over all postoperative patency rates were 83.6 oyo at 1 year, 75.5% at 3 years and limb salvage rate was 86.8 oyo . Six patients died in the hospital following vascular surgery for ischemic lower extremities, although the causes of death were not directly related to the vascular reconstructive operative proccedures. The leading causes of death were in the order of multiple organ failure, acute renal failure, and sepsis.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.137-145
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• 1997

From July 1983 to December 1993, total 112 consecutive mitral valve replacements in 107 patients were performed in patient with mitral valvular abnormalities. To estimate the risk factor related to operative death, all patient's perioperative data were reviewed retrospectively. Except 20 patients received concomitant aortic valve replacement and 2 patients had incomplete data, 85 patients were included in this study. Mean age were $37.3\pm$ 13.1 years ranging from 13 to 72 years. Thirty-seven patients were male and fourty-eight patients were female. Mean follow-up durations were $51.1\pm33.8$ months ranging from 6 months t 11 years. Patients in this study showed improvement in mean NYHA functional clssification, from $3.02\pm0.73$ to 1 $78\pm0.55,$ and also in cardiothoracic ratio, from 0.61 $\pm0.09$ to $0.58\pm0.08$ at 6 months follow-up after operation. Operative complications were detected in 23 patients(27.1 %) and common postoperative complications were rhythm disturbance in 7 cases, pulmonary complications in 6 cases and low cardiac output syndrome in 6 cases. Early mortality was 10.6%(n=9) and the most common cause of death was a congestive heart failure due to low cardiac output syndrome. Main cause of our higher operative mortality than other study was that operative mortality in the initial period of our mitral surgery was high(5 operative deaths among 19 mitral valve replacement from July 1983 to December 1985). Actuarial survival was 80.8% at 5 years, 71.8% at 11 years including operative deaths. Actuarial freedom from anticoagulant-related bleeding was 85.3% at 5 years, 78.3% at 11 years. 95.1% at 5 years and 88.8% at 11 years among the patient in this study were free from thromboembolism, and 97.5% at 5 years and 75.1% at 11 years were free from reoperation. Preoperative cardiothoracic ratio and patient's age were statistically significant operative risk factors.