• Journal of Chest Surgery
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• v.51 no.6
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• pp.406-409
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• 2018

Aortocaval fistula (ACF) occurs in <1% of all abdominal aortic aneurysms (AAAs), and in 3% to 7% of all ruptured AAAs. The triad of clinical findings of AAA with ACF are abdominal pain, abdominal machinery bruit, and a pulsating abdominal mass. Other findings include pelvic venous hypertension (hematuria, oliguria, scrotal edema), lower-limb edema with or without arterial insufficiency or venous thrombus, shock, congestive heart failure, and cardiac arrest. Surgery is the main treatment modality. We report successful surgical treatment in a patient with a ruptured AAA with ACF who presented with cardiogenic shock.

• 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.53 no.5
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• pp.297-300
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• 2020

Background: This study aimed to assess the effect of vessel size and flow characteristics on the maturation of autogenous radiocephalic arteriovenous fistulae (RCAVFs). Methods: We retrospectively reviewed records of patients undergoing RCAVF creation at a single medical center from January 2013 to December 2019. Operative variables were compared between patients whose fistulae matured and those whose fistulae failed to mature. Results: Overall, 152 patients (33 of whom were women) with a mean age of 62.6±13.6 years underwent RCAVF creation; functional maturation was achieved in 123. No statistically significant differences were observed between patients in whom maturation was or was not achieved in terms of the following variables: female sex (20.3% vs. 25.0%), radial artery size (2.5 vs. 2.4 mm), and pulsatility index (0.69 vs. 0.62). Low intraoperative transit time flowmetry (TTF; 150.4 vs. 98.1 mL/min) and small vein size (2.4 vs. 2.0 mm) were associated with failure of maturation. The best cutoff diameter for RCAVF TTF and cephalic vein size were 105 mL/min and 2.45 mm, respectively. Conclusion: In patients who undergo RCAVF creation, vein diameter on preoperative ultrasonography and intraoperative TTF are predictors of functional maturation. We identified an intraoperative TTF cutoff value that can be used for intraoperative decision-making.

• Journal of Korean Clinical Nursing Research
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• v.21 no.2
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• pp.215-222
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• 2015

Purpose: For hemodialysis, a vascular access which can maintain a certain speed for a long time is required. The prevention of the vascular access dysfunction is very important to decrease morbidity and to improvethe quality of life of patients receiving hemodialysis It is reported that far infrared heat increases the blood flow by expanding capillaries and micro-arteriovenouses. This study aimed to evaluate the effect of far infrared heat therapy as a new nursing intervention for maintaining vascular access function and improving the blood flow of patients receiving hemodialysis. Methods: The quasi-experimental research of nonequivalent control group pre-post test design was carried out for 59 patients receiving hemodialysis 3 times per week at K medical center. A far infrared heat was applied to the experimental group for 3 months. Results: The arteriovenous fistula blood flow of the experimental group (far infrared heat therapy group) increased significantly when compared to the control group (p=.047). However, static intra-access pressure ratio(SIAPR)was not different statistically (p=.101). Conclusion: The far infrared therapy could be considered as nursing intervention of choice as it demonstrated increase in the arteriovenous fistula blood flow in the patients receiving hemodialysis.

• 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.

• 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.45 no.5
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• pp.326-329
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• 2012

Pulmonary arteriovenous malformation (PAVM) is a rare anomalous direct communication between the pulmonary artery and vein with a considerable risk of serious complications such as cerebral thromboembolism or abscess and pulmonary hemorrhage. Although the past, surgical resection such as lobectomy was mostly used to treat PAVM, the recent development of endovascular treatment has made it a primary consideration to perform transcatheter embolization using coils or detachable balloons. We report a case of successful transcatheter embolization of giant PAVM with the second generation Amplatzer vascular plug II as a new self-expanding device.

• Journal of Chest Surgery
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• v.48 no.2
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• pp.120-125
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• 2015

Background: The purpose of this study was to evaluate the use of a Fogarty arterial embolectomy catheter (Fogarty catheter) in intraoperative balloon angioplasty of the cephalic vein, in order to determine its effect on the patency of arteriovenous fistulas (AVFs) created for hemodialysis access. Methods: A total of 156 patients who underwent creation of an AVF were divided into two groups, based whether a Fogarty catheter was used during AVF creation. Group A (89 patients) comprised the patients who underwent balloon angioplasty with a Fogarty catheter during the operation. Group B (67 patients) included the patients in whom a Fogarty catheter was not used during the operation. Patient records were reviewed retrospectively and documented. The patency rate was determined by the Kaplan-Meier method. Results: The records of 156 patients who underwent the creation of an AVF from January 2007 to October 2011 were included. The mean follow-up duration was $40.2{\pm}19.4$ months (range, 1 to 97 months). The patency rates in group A at 12, 36, and 72 months were $83.9%{\pm}3.9%$, $78.3%{\pm}4.6%$, and $76.3%{\pm}4.9%$, respectively, while the corresponding patency rates in group B were $92.5%{\pm}3.2%$, $82.8%{\pm}0.5%$, and $79.9%{\pm}5.7%$, respectively. The patency rates in group B were found to be slightly higher than those in group A, but the difference was not statistically significant (p=0.356). Conclusion: Intraoperative balloon angioplasty of the cephalic vein using the Fogarty catheter is a simple and easily reproducible procedure, and it can be helpful in increasing AVF patency in cases of insufficient runoff or a suboptimal cephalic vein.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.658-668
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• 2022

Purpose To evaluate the effectiveness of the transradial artery approach (TRA) for treating malfunctioning arteriovenous fistulas (AVFs) in patients on hemodialysis. Materials and Methods A retrospective analysis was conducted in this single-center study of TRA endovascular procedures in 73 patients (43 male and 30 female; mean age of 67.4 years (range, 42-92 years) with malfunctioning AVFs, between January 2008 and April 2019. Patients' baseline and lesion characteristics, technical and clinical success, and complications were evaluated, and functional patency was analyzed using the Kaplan-Meier method. Results Radial artery approaches were successful in all patients. Angioplasty performed using the TRA achieved technical and clinical success rates of 98.6%(72/73) and 91.7%(67/73), respectively. The median primary patency time was 18.8 ± 15.9 months. The primary functional patency rates at 3, 6, and 12 months were 82.1%, 68.6%, and 63.9%, respectively. There were no major complications or adverse events, such as hand ischemia, related to the radial artery approach. Conclusion In selected cases, the TRA can be used complementary to the transvenous approach to treat malfunctioning AVFs.

• Korean Journal of Radiology
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• v.23 no.10
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• pp.949-958
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• 2022

Objective: To investigate the feasibility of using a deep learning-based analysis of auscultation data to predict significant stenosis of arteriovenous fistulas (AVF) in patients undergoing hemodialysis requiring percutaneous transluminal angioplasty (PTA). Materials and Methods: Forty patients (24 male and 16 female; median age, 62.5 years) with dysfunctional native AVF were prospectively recruited. Digital sounds from the AVF shunt were recorded using a wireless electronic stethoscope before (pre-PTA) and after PTA (post-PTA), and the audio files were subsequently converted to mel spectrograms, which were used to construct various deep convolutional neural network (DCNN) models (DenseNet201, EfficientNetB5, and ResNet50). The performance of these models for diagnosing ≥ 50% AVF stenosis was assessed and compared. The ground truth for the presence of ≥ 50% AVF stenosis was obtained using digital subtraction angiography. Gradient-weighted class activation mapping (Grad-CAM) was used to produce visual explanations for DCNN model decisions. Results: Eighty audio files were obtained from the 40 recruited patients and pooled for the study. Mel spectrograms of "pre-PTA" shunt sounds showed patterns corresponding to abnormal high-pitched bruits with systolic accentuation observed in patients with stenotic AVF. The ResNet50 and EfficientNetB5 models yielded an area under the receiver operating characteristic curve of 0.99 and 0.98, respectively, at optimized epochs for predicting ≥ 50% AVF stenosis. However, Grad-CAM heatmaps revealed that only ResNet50 highlighted areas relevant to AVF stenosis in the mel spectrogram. Conclusion: Mel spectrogram-based DCNN models, particularly ResNet50, successfully predicted the presence of significant AVF stenosis requiring PTA in this feasibility study and may potentially be used in AVF surveillance.