• Proceedings of the KSME Conference
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• 2001.06e
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• pp.560-565
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• 2001

The objective of the present study is to investigate the characteristics for flow and wall shear stress in the aneurysm which is a local dilatation of the blood vessel. The numerical simulation using the commercial software for the laminar and steady flow were carried out over the diameter ratios(ratio of maximum diameter of aneurysm to the diameter of blood vessel) ranging from 1.5 to 2.5 and Reynolds number ranging from 900 to 1800. It was shown that a recirculating vortex occupied the entire bulge with its core located closer to the distal end of the bulge and the strength of vortex increased with increase of the Reynolds number and diameter ratio. Especially, for the Reynolds number of 1800 and diameter ratio of 2.5, the very weak secondary recirculating flow was produced at the left upper of the aneurysm. The position of a maximum wall shear stress was the distal end of the aneurysm(z=18mm) regardless of the Reynolds number and diameter ratios. But the maximum values of the wall shear stress increased in proportion to the increase of Reynolds number and diameter ratio.

• Journal of Chest Surgery
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• v.33 no.10
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• pp.839-842
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• 2000

Aortoesophageal fistula is an uncommon and fatal complication after surgery of aortic aneurysm. A case of aortoesophageal fistula as a complication of synthetis patch aortoplasty for mycotic aneurysm of descending thoracic aorta is described. After 3 months since patch aortoplasty for mycotic aneurysm of descending thoracic aorta this patient visited the emergency room due to melena and hematemesis. After gastrofiberoscopy and computed tomography the patient was taken ot the operating room. The surgical intervention was performed in two steps. Median sternotomy and midline laparotomy were made. Hemashield's Dacron(16mm) bypass between ascending thoracic aorta and infra-renal abdominal aorta was established first. Through the posterolateral thoracotomy false aneurysm and previous Hemashield's Dacron patch of descending aorta were resected. The two ends of the aorta were sutured and esophageal fistula was repaired. The esophageal suture line and the stumps were covered with omental graft. Thirty months later the patient has had no difficulty referable to the aortic surgery.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.7
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• pp.920-928
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• 2003

The objective of the present study was to investigate the characteristics of flow and wall shear stress under steady and pulsatile flow in the aneurysm. The numerical simulation using the software were carried out for the diameter ratios ranging from 1.5 to 3.0, Reynolds number ranging from 900 to 1800 and Womersley number, 15.47. For steady flow, it was shown that a recirculating vortex occupied the entire bulge with its core located closer to the distal end of the bulge and the strength of vortex increased with increase of the Reynolds number and diameter ratio. The position of a maximum wall shear stress was the distal end of the aneurysm regardless of the Reynolds number and diameter ratios. For the pulsatile flow, a recirculating flow at the bulge was developed and disappeared for one period and the strength of vortex increased with the diameter ratio. The maximum values of the wall shear stress increased in proportion to the diameter ratio. However, the position of a maximum wall shear stress was the distal end of the aneurysm regardless of the diameter ratios.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.300-307
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• 1997

We have experienced 25 cases of aortic aneurysm from October 1987 to January 1996. Patients ranged in age from 26yrs to 73yrs(mean age 52. Syrs). There were 13 males and 12 females. Eighteen cases were thoracic aneurysm and seven were abdom nal aneurysm. The cause of aneurysm were dissecting in 16cases aneurysms and non-dissecting in 9 cases. Risk factors of aortic aneurysm were hypertension, hypercholesterolemia, Marfan's syndrome. In thoracic aneurysm patients, 1'S cases of dissecting aneurysm underwent aneurysmectomy and replacement of vessel interposition graft with or without coronary artery implantation on the graft. 6 cases of non-dissecting aneurysm underwent operation with same policy as dissecting aneurysm. In 7 case of abdominal aneurysm,all patients underwent aneurysmectomy and graft interposition with straight i)r Y graft. Thcre were 5 postoperative death(mortality 20%). Several cases of complications were improved with proper managements. All survivors showed improvement in clinical symptom and sign and discharged without specific complications.

• International Journal of Vascular Biomedical Engineering
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• v.2 no.2
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• pp.10-15
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• 2004

Purpose: In the treatment of aortic aneurysm, endovascular stent-graft application has become an established method of treatment. To observe the outcomes of the procedure as the size change of aneurysm in relation with endoleak, a retrospective analysis was done for the consecutive cases who undertook the procedure. Materials & Method: Stent-graft was applied to the aortic aneurysm in 33 patients. The location of the aneurysm was thoracic in 11 patients and abdominal in 22 patients. CT angiographic was done for the follow-up evaluation to analyze the aneurysm size and the presence of endoleak. Results: Technical success rate was 97% (32/33). The primary success rate without endoleak was 84% (28/33). The secondary success was 90% (30/33). During the follow-up period of 3 months to 7years and 6months in 26 patients, a secondary endoleak developed in 5 cases. Post-implantation syndrome developed in 17 cases (51%). Among the 14 cases with follow-up imaging data for size, endoleak was negative in 10 cases. The aneurysm decreased in 5 cases, stable in size in 4 cases and enlarged in one case (10%).Among the 4 cases with endoleak positive, the aneurysm enlarged in two cases (50%). Conclusion: In the stent-graft application for aortic aneurysm, there is high chance of decrease of aneurysm size in those cases with endoleak negative. However, the aneurysm may increase and eventually rupture in the cases with en do leak positive. Close observation with CT angiography is necessary for the evaluation for the presence of endoleak and size change.

• Journal of Chest Surgery
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• v.39 no.10 s.267
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• pp.782-785
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• 2006

Chronic pulmonary obstructive disease is known to be a significant risk factor for mortality in patients who under-went operation for abdominal aortic aneurysm. To decrease perioperative respiratory complication in these patients, maintenance of self respiration as possible is one of the better method. A seventy-seven year old male patient complained of abdominal pain and he was diagnosed for 9 cm sized abdominal aortic aneurysm. But he had severe chronic obstructive pulmonary disease which was expected to increase surgical mortality. So we introduced epidural anesthesia with maintenance of self respiration and performed surgical resection and graft replacement of abdominal aorta, and he recovered without any complication.

• Journal of Chest Surgery
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• v.50 no.6
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• pp.430-435
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• 2017

Background: Mycotic aortic aneurysms are rare and life-threatening. Unfortunately, no established guidelines exist for the treatment of patients with mycotic aortic aneurysms. The purpose of this study was to evaluate the midterm outcomes of the open repair of mycotic thoracic and thoracoabdominal aneurysms and suggest a therapeutic strategy. Methods: From 2006 to 2016, 19 patients underwent open repair for an aortic aneurysm. All infected tissue was extensively debrided and covered with soft tissue. We recorded the clinical findings, anatomic location of the aneurysm, bacteriology results, antibiotic therapy, morbidity, and mortality for these cases. Results: The median age was $62{\pm}7.2years$ (range, 16 to 78 years), 13 patients (68%) were men, and the mean aneurysm size was $44.5{\pm}4.9mm$. The mean time from onset of illness to surgery was $14.5{\pm}2.4days$. Aortic continuity was restored in situ with a Dacron prosthesis (79%), homograft (16%), or Gore-Tex graft (5%). Soft-tissue coverage of the prosthesis was performed in 8 patients. The mean follow-up time was $43.2{\pm}11.7months$. The early mortality rate was 10.5%, and the 5-year survival rate was $74.9%{\pm}11.5%$. Conclusion: This study showed acceptable early and midterm outcomes of open repair of mycotic aneurysms. We emphasize that aggressive intraoperative debridement with soft-tissue coverage results in a high rate of success in these high-risk patients.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.134-139
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• 1986

Seventeen patients underwent operations for aneurysm of ascending aorta with aortic regurgitation from August 1979 to October 1985. 10 patients underwent complete replacement of the ascending aorta and the aortic valve with a composite graft and implantation of coronary ostia on the graft. Seven patients underwent supracoronary noncomposite graft replacement and aortic valve replacement. The patients ranged in age from 25 to 55 years [mean 37.6 years]. There were 11 male and 6 female patients. All patients had aortic incompetence and aneurysmal dilatation of the ascending aorta. Seven of the patients has concomitant aortic dissection in ascending aorta and one had dissection in abdominal aorta. Eight patients had signs of Marfan syndrome and the other 3 patients had cystic degeneration in the medial layer of the aorta. There was one hospital death[5.8%]. He died of sepsis on the 23rd postoperative day. All survivors showed improvement in NYHA functional classification in the 34.9 patient-year follow-up period.

• Journal of Chest Surgery
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• v.53 no.6
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• pp.339-345
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• 2020

Background: Iliac artery aneurysm is frequently found in patients undergoing surgical repair of an abdominal aortic aneurysm. The use of commercial bifurcated grafts is insufficient for aorto-biiliac replacement with complete iliac artery aneurysm resection. We evaluated the effectiveness of handmade composite grafts for this purpose. Methods: A total of 233 patients underwent open surgery for abdominal aortic aneurysm between 2003 and 2019, including 155 patients (67%) treated with commercial grafts and 78 patients (33%) treated with handmade composite grafts. Their operative characteristics, postoperative outcomes, and late outcomes were retrospectively reviewed. Results: The early mortality rate did not differ significantly between the groups. On average, the handmade composite graft technique took approximately 15 minutes longer than the commercial graft technique (p=0.037). Among patients who underwent elective surgery, no significant differences between the conventional and composite groups were observed in the major outcomes, including red blood cell transfusion volume (2.8±4.7 units vs. 3.1±4.7 units, respectively; p=0.680), reoperation for bleeding (2.7% vs. 3.1%, respectively; p>0.999), bowel ischemia (0% vs. 1.6%, respectively; p=0.364), and intensive care unit stay duration (1.9±6.6 days vs. 1.6±2.4 days, respectively; p=0.680). The incidence of target vessel occlusion also did not differ significantly between groups. Conclusion: The increased technical demand involved with handmade composite grafting did not negatively impact the outcomes. This technique may be a viable option because it overcomes problems associated with commercial grafts.

• Journal of Chest Surgery
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• v.35 no.6
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• pp.483-486
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• 2002

71 years old man was operated on due to abdominal aortic aneurysm associated with complete occlusion of left common iliac artery. The coexisting chronic deep vein thrombosis of the left femoral and iliac vein was not diagnosed preoperatively. Resection of aneurysm and Y-graft interposition was performed. Recurrent edema and pain occured to the left lower extremity immediately postoperatively, which aggrevated with the lapse of time, resulting in fatal extensive venous thrombosis. This report regards the surgical treatment and complication of the aortoiliac occlusive disease associated with chronic deep vein thrombosis.