• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.11
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• pp.985-990
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• 2013

An arteriovenous fistula is artificially produced using a graft for hemodialysis in patients. In an arteriovenous graft (AVG), the angle of its arterial or venous anastomosis play an important role in producing flows inside blood vessels, through which a stenosis may occur. Most studies thus far have focused on CFD results. In this study, a PIV technique is used to analyze the hemodynamic characteristics at the arterial or venous anastomosis of an AVG having an angle of $30^{\circ}C$. For flow dynamic similarity, the Reynolds number is set to be the same for real and simulated flows. A PIV experiment is performed with a control valve in the arterial part. In conclusion, the recirculation flow appeared in the bifurcation area and the total blood velocity changed according to the extent of valve opening.

• 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.

• Journal of Chest Surgery
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• v.50 no.2
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• pp.133-136
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• 2017

A 27-year-old female patient was referred due to an edematous left lower extremity. Both saphenous veins had been ablated with an endovenous laser procedure used to treat varicose veins. Venography revealed that the left common femoral vein had been divided and that thrombosis was present at the site of division. No veins were available around the thighs. The patient was treated using a staged procedure. During the first stage, a ringed polytetrafluoroethylene graft was used to repair the common femoral vein, and an arteriovenous fistula was constructed from the femoral artery to the graft using a short segment of cephalic vein to increase graft patency. The edema was relieved postoperatively and the graft was patent. During the second stage, which was performed 6 months later, the fistula was occluded by coil embolization. The staged procedure described herein provides an alternative for venous reconstruction when autologous vein is unavailable.

• Journal of Chest Surgery
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• v.28 no.1
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• pp.73-77
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• 1995

We are reporting one case of right subclavian vein thrombotic occlusion as a result of previous hemodialysis catheter placement in a patient with a functioning right brachio-cephalic arteriovenous fistula. Its complication was painful right arm swelling, limitation of motion and cellulitis. Diagnosis was confirmed by right subclavian venography and the complication was successfully managed by right subclavian vein-superior vena cava bypass with a GoreTex vascular graft. The arteriovenous fistula had remained to protect patency of the bypass at first, but two months later after the operation, the arteriovenous fistula had to be occluded because of the heart failure resulting from shunt over flow. After ligation of arteriovenous fistula, heart failure improved, and uncomfortable arm swelling did not develop again.

• Journal of Chest Surgery
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• v.43 no.5
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• pp.534-537
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• 2010

A twenty six year old man was admitted to our clinic for bleeding from a venous ulcer of the left leg. His left femoral vein had been ligated for bleeding control after a traffic accident that happened when he was 5 years old. He had a varicose vein, stasis dermatitis, and a venous ulcer on his left leg. To shunt left femoral venous return to the right femoral vein, we did a crossover bypass with arteriovenous fistula using the right greater saphenous vein. To get good patency of the arteriovenous fistula, the bypass graft was closed 6 weeks after the initial operation. He maintained his left leg circumference relatively well for 6 months after the operation. We report the case of a patient who had a vein crossover bypass for a chronic femoral vein ligation.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.36-42
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• 1997

Though myocardial perfusion was usually expected to improve after coronary artery bypass graft(CABG) surgery, some myocardial segments were aggravated after operation, as we compared perfusion changes on postoperative SPECT with preoperative ones. In this study, we evaluated perfusion changes after operation in rest and stress myocardial SPECT in 44 patients (M:F=25:19, age 57.1 $year{\pm}8.2$) who had CABG before and 3 months after operation. We tried to find out possible causes for perfusion aggravation with multivariate logistic regression analysis regarding whether bypass graft was artery or vein and which coronary artery territory was operated. Among 616 myocardial segments which were operated, 89(14.4%) aggravated after operation. In the univariate analysis, myocardial segments in the left circumflex arteries(LCx) aggravated more often(p<0.01) than others and segments having operative angioplasty did less often(p<0.01). Multivariate logistic regression revealed that LCx was risk factor for perfusion aggravation [odds ratio=2.54 (95% confidence interval : 1.53-4.22, p<0.01)]. However, this was not the case when we analysed in terms of arterial territories. Among 106 coronary arterial territories which were operated, 27(25.5%) aggravated. The territories having aggravated had similar characteristics regarding whether they received arterial or venous grafts, angioplasty and whether the operated territories were left anterior descending, right coronary or left circumflex arteries. In conclusion, myocardial segments in the left circumflex artery tended to aggravate more often after bypass surgery than the others. In short-term comparison of perfusion after surgery, we could not find any tendency that arterial or venous graft was associated with more frequency of the aggravation of perfusion after operation.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.481-487
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• 1998

The surgical management of acute type B dissection is controversial. The complexity of the repair usually requires a period of aortic cross-clamping exceeding 30 minutes, which can cause ischemic injury of the spinal cord. Several forms of distal perfusion have been considered for use to prevent this injury. To determine the safety and efficacy of a graft replacement with cardiopulmonary bypass in reparing acute dissection of descending thoracic aorta, we retrospectively reviewed our surgical experience treating 8 patients who had aortic dissection secondary to atherosclerosis, trauma, and carcinoma invasion. Cardiopulmonary bypass was performed with two aortic cannulas for simultaneous perfusion of the upper and lower body and one venous cannula for draining venous blood from the right atrium or inferior vena cava. Although aortic cross-clamp time was relatively long (average, 117.8 minutes; range, 47 to 180 minutes) in all cases, there was no neurologic deficit immediately after graft replacement for the aortic lesion. Two patients(25%) of relatively old age died on the postoperative 31st and 41st days, respectively, because of delayed postoperative complications, such as pulmonary abscess and adult respiratory distress syndrome. Although any of several maneuvers may be appropriate in managing dissection of the descending aorta, graft replacement with cardiopulmonary bypass during aortic cross-clamping may be a safe and effective method for the treatment of acute dissection of the descending thoracic aorta.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.1-14
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• 2006

The purpose of the present study was to evaluate the histologic results of bone cavities that were surgically created in the calvaria of rabbit and filled with $HA/{\beta}-TCP$ composite powders, which had been developed in Korea (Dentium, Korea). Ten young adult rabbits were used. Four defects were surgically produced in calvaria of each rabbit. Each rabbit was anesthetized with Ketamine-HCI (5 mg/kg, Yuhan Cor. Korea) and Xylazine-HCI (1.5 ml/kg, Yuhan Cor. Korea)). An incision was made to the bony cranium and the periosteum was reflected. Using a trephine bur (external diameter: 8 mm, 3i, USA), 4 'through-and-through' bone defects were created with copious irrigation, and classified into 4 groups: control group: no graft materials, experimental group I: normal saline + graft materials: experimental group II: venous blood + graft materials: experimental group III: graft materials only. The defects were randomly filled with graft materials. The defects were closed with resorbable suture material. At the end of the surgical procedure, all animals received a single intramuscular injection of antibiotics Gentamicin (0.1 mg/kg, Dae Sung Microb. Korea). Rabbits were sacrificed with phentobarbital (100 mg/kg) intravenously at 1-, 2-, 4-, 6- and 8-week after. Specimens were treated with hydrochloric acid decalcifying solution (Fisher Scientific, Tustin, CA) and sectioned by bisecting the 8 mm diameter defects. The histologic specimens were prepared in the general method with H & E staining at 6 ${\mu}m$ in thickness. The results were as follows; 1. New bone formation showed from after 2-week of surgery in defect area. As time lapsed, lots of new bone formation and mature bones showed. 2. Histologically, degree of new bone formation could not be discerned among the experimental groups. But, for experimental group II, lots of cells gathered around graft materials after 1-week of surgery, new bone formed slightly faster and than the others at 1-week after. For experimental group I, a few inflammatory finding showed around graft material at after 1-week and after 2-week of surgery. 3. No bone formation did show for control group. Based on histologic results, the new $HA/{\beta}-TCP$ composite powders appeared to act as a scaffolding material for regeneration of osseous defects.

• Journal of Chest Surgery
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• v.27 no.9
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• pp.764-769
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• 1994

From november, 1985 to May, 1993, 222 arteriovenous fistulae were made in 201 patients with chronic renal failure. Among them, a total of 183 arteriovenous fistulae in 173 patients were reviewed to evaluate the factors influencing patency rate of the vascular access. The results were revealed as follows: There were 102 men and 71 women,aged 10 to 76 years [mean = 45.7 years]. Sixteen patients of them had previous shunts. The procedures included establishment of 214 radiocephalic or brachioocephalic fistulae, 203 side to end, 9 side to side, 2 end to end, 2 autologous saphenous vein grafts, 6 Gore-Tex grafts. There were 28 early shunt failures[12%] due to use of 23 inadequate veins and 5 thrombosis.There were 32 late complications[14%]; 19 thrombosis, 4 aneurysm, 4 venous hypertension, 3 steal syndrome, 2 infections. There were 32 diabetic patients [17 %]. No significant differences in graft patency were noted between diabetic and nondiabetic individuals. There were no significant difference in graft patency between male and female. Overall shunt patency in 183 cases with chronic renal failure was 96% at I month, 95% at 3 months, 93% at I year, 91% at 2 years, 84% at 3 years, 56% at 5years.This Study showed that early postoperative thrombosis and diabetic vasculopathy were most causes of the vascular access failure and suggested that prevention of thrombi and well control of diabetes mellitus were most important to enhance patency rates of the vascular access.

• Archives of Reconstructive Microsurgery
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• v.18 no.1
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• pp.23-26
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• 2009

Purpose: Artificial dura maters are commonly used in cranioplasty, but sometimes they can result in serious postoperative infection. Once complications such as epidural abscess or chronic draining ulcer arise, they are very difficult to treat. In this case, reclosure of dura defect using artificial dura mater may give rise to recurrence of infection. We experienced a case of intractable epidural abscess caused by use of artificial dura. To avoid repeated infection, we decided to use autologous tissue for the coverage of dura and soft tissue defect. Therefore, autologous tensor fascia lata graft and anterolateral thigh free flap were harvested at the same donor site incision to cover composite defect on the scalp and dura mater. Methods: A 13 year old male patient, who underwent the decompression cranioplasty and duroplasty, suffered from the intractable infection lesion. Twice, the epidural abscess was removed, both times the infection recurred. And eventually dura mater was exposed through the infected open wound. Nine months after dura exposed, infected aritificial dura mater was removed and extensive debridement was performed. Through a surgical incision on donor thigh, first, tensor fascia lata graft was harvested in process of the anterolateral thigh flap elevation. After the fascia lata graft was fixed over the dural defect, the anterolateral thigh flap was used to fill the dead space as well as the scalp defect. Results: Postoperatively, no recurrent infection and cerebrospinal fluid leakage are observed for a year. After the surgery, on the first and second day, venous congestion of the flap was observed, this problem was solved by thrombectomy and vein reanastomosis. And partial necrosis of flap occurred, but completely healed as conservative treatment for two weeks. Conclusion: Using the autologous tensor fascia lata graft and anterolateral thigh flap, we could obtain satisfactory results as treatment for the intractable infection lesion after duroplasty. Autologous tensor fascia lata in conjunction with anterolateral thigh flap is useful method for covering composite defect of scalp and dura mater.