• Journal of Chest Surgery
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• v.42 no.4
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• pp.487-491
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• 2009

Background: Salvaging prosthetic arteriovenous grafts can be performed using surgical or endovascular techniques. We conducted a retrospective analysis to compare the efficacy of these two methods for restoring dialysis graft function. Material and Method: We studied 41 patients who had received surgical thrombectomy with revision (Group A) or percutaneous thrombectomy with angioplasty (Group B) from January 2006 to December 2007. We compared them according to the patient characteristics and the location of stenotic lesions, and we analyzed the post-intervention primary patency rates. Result: 21 patients underwent surgery and 20 patients underwent percutaneous balloon angioplasty. There were no significant differences of the patients' characteristics between the two groups. Venous anastomotic stenosis was the most common cause of graft thrombosis in both groups. In Group A, 90.5% of the grafts remained functional at 6 months and 38.1% remained functional at 12 months. In Group B, 55.0% of the grafts were functional at 6 months and 20.0% of the grafts were functional at 12 months. The post-intervention primary patency rate was significantly better in Group A (p=0.034). Conclusion: Surgical treatment resulted in significantly longer post-intervention primary patency in this study, and this supports its use as the primary method of management for most patients in whom dialysis graft obstruction develops.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.883-888
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• 1996

Expanded polytertrafluoroethylene (expanded PTFE) graft fistulas are widely used as secondary vascu- lar access for patients receiving long-term hemodialysis treatment. We implanted 48 grafts in )5 patients during the period from August 1990 to August 1995. Forty-three grafts in 32 patients were followed for 1 to 46 months. We performed forearm straight grafts in 36 grafts and upperarm straight grafts in 7 grafts. We experienced 3 operative failures, 22 early and late complications(15 graft thrombosis). Cumulative patency for all grafts at 12 months was 63%, at 24 months 32%, at 36 months 32% Forearm graft survival at 12 months was 55%, at 24 months 30%, at )6 months 30%. Upperarm graft survival at 12 months was 8)oyo and 24 months 41%. After reviewing our experience, we think that expanded-PTFE grart as secondary vascular access still have many complications and low survival than autogenous a teriovenous fistula. And so utilization of the expanded PTFE fistula requires better techniques, close observation and maintenance to keep it functional.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.369-374
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• 2002

Background: Proper construction of vascular access and adequate maintenance are essential for the prognosis of the hemodialysis patients. Though arteriovenous fistula using autogenous vessel is the first of choice, the incidence of arteriovenous fistula using artificial graft is gradually increasing. The aim of this study was to analyse the patency rates between autogenous and artificial fistula, among artificial graft types, according to the accompanied disease. Material and Method: A retrospective study was conducted on 186 patients who underwent 292 arteriovenous fistula operations for hemodialysis at Korea University Guro Hospital between 1996 and 2000. Mean age of the patients was 54.37 $\pm$ 12.79years, and the male: female ratio 99:87. Result: Among 292 operations, there were 156 autogenous fistula and 116 graft fistula. The other 20 operations were thrombectomy, takedown of graft, revision, and balloon dilatation. Patency rates of autogenous fistula were 92.78 $\pm$ 2.35% at 1 year and 39.03$\pm$9.08% at 5 years, and those of graft fistula were 96.09 $\pm$ 2.22% at 1 year and 16.45 $\pm$ 10.15% at 5 scars. However, there was no statistical significance between the two operations. The patients who had hypertension, diabetes or both had no statistical significance in the patency rate compared to that of patients without underlying disease. In addition, the type of graft used did not affect the patency rate. Second operation was needed in 62 patients and third operation in 31 patients, but their patency rate again had no statistical significance compared to that of the first operation. Conclusion: The patency of the artificial graft fistula was comparable to the autogenous fistula, but the patency according to types of graft need to be studied further. Furthermore, the underlying diseases did not affect the fistula patency.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.41-45
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• 2009

Background: Arteriovenous fistula formation is not always easy to perform in hemodialysis patients because of poor preservation of veins due to repeated venipuncture and cannulation. We analyzed the patency rate and complications of prosthetic arteriovenous fistulas using the vena comitantes as a venous outflow in the antecubital fossa, which are protected from venipuncture. Material and Method: Between January 2006 and June 2008, 12 patients underwent prosthetic arteriovenous fistula formation using the vena comitantes as a venous outflow. Arterial inflow was via the brachial artery and the graft was placed in a loop fashion. The male-to-female ratio was 7 : 5 and the mean age was $59{\pm}14$ years. Six patients had diabetes mellitus and 10 patients had hypertension. Result: There were no complications, such as a graft infection or bleeding. Five patients showed postoperative stenosis at an average of 3 months. The primary patency rate was 75.0, 65.6, and 52.2% at 3, 6, and 12 months, respectively. All the patients with stenosis were able to continue hemodialysis after intervention therapy. The secondary patency rate was 100% at 12 months. Conclusion: Creation of a prosthetic arteriovenous fistula using uninjured vena comitantes resulted in a good patency rate and this vein may become a substitute for inappropriate superficial veins.

• Journal of computational fluids engineering
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• v.16 no.4
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• pp.84-91
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics through arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.342-348
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• 2004

It is very important for hemodialysis in patients with end stage renal disease to obtain vascular access that resists repeated punctures and maintains adequate blood flow. This study was designed to indentify factors that may influence early patency rate of autogenous arteriovenous fistula. Material and Method: 49 cases in 47 patients who underwent radiocephalic fistula formation in our hospital from June 2002 through May 2003 were reviewed and analyzed. Result: The early patency rate was 79.6%. Age, sex, hypertension, and diabetes mellitus were not significant factors for patency. Body mass index and duration of hypertension and diabetes did not influence the early results either. Cephalic vein diameter measured preoperatively and blood flow at radio-cephalic fistula were significantly positive correlative factors. Groups with the vein diameter less than 2.7mm, or with the blood flow less than 100 mL/min had significantly lower early patency rate than the other groups. Conclusion: To improve early patency rate of radiocephalic fistula, large sized cephalic vein should be selected and if the intraoperative flow at radiocephalic fistula is less than 100 mL/min, another arteriovenous fistula formation should be considered.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.197-211
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• 2023

Purpose To evaluate the circuit patency after nitinol bare-metal stent (BMS) placement according to the type of access and location of the stent in dysfunctional hemodialysis access. Materials and Methods Between January 2017 and December 2019, 159 patients (mean age, 64.1 ± 13.2 years) underwent nitinol BMS placement for dysfunctional access. The location of stents was as follows: 18 brachiocephalic vein, 51 cephalic arch, 40 upper arm vein, 10 juxta-anastomotic vein, 7 arteriovenous (AV) anastomosis, and 33 graft-vein (GV) anastomosis. Circuit patency was evaluated by the Kaplan-Meier method, and cox regression model. Results A total of 159 stents were successfully deployed in 103 AV fistula (AVF) and 56 AV graft (AVG). AVG showed lower primary and secondary patency at 12-months compared with AVF (primary patency; 25.0% vs. 44.7%; p = 0.005, secondary patency; 76.8% vs. 92.2%; p = 0.014). Cox regression model demonstrated poorer primary patency at 12 months after stenting in the cephalic arch and GV anastomosis compared with the other sites. Conclusion AVF showed better primary and secondary circuit patency at 12 months following the placement of BMS compared with AVG. Stents in the cephalic arch and GV anastomosis were associated with poorer primary patency at 12 months compared to those in other locations.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.14-19
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• 2013

Renal failure patients have to operate arteriovenous graft for hemodialysis. Blood flow characteristics influence the patency rate of arteriovenous graft. Numerical investigation is performed with the arteriovenous graft according to injection of blood. As a result, when the injection is not applied to venous graft, the low wall shear stress region appears at venous anastomosis. It may cause intimal hyperplasia at venous anastomosis.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.469-476
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics though arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.