• 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.

• Archives of Plastic Surgery
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• v.48 no.2
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• pp.219-223
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• 2021

Background A micro-arteriovenous fistula (AVF) is a minute, short shunt between an artery and a vein that does not pass through a capillary. We investigated the association between micro-AVFs and lymphedema using computed tomography angiography (CTA) and venous blood gas analysis. Methods In 95 patients with lower limb lymphedema, the presence or absence of early venous return (EVR) was compared between patients with primary and secondary lymphedema. Furthermore, we investigated the difference in the timing of edema onset in patients with secondary lymphedema with or without EVR using CTA. In 20 patients with lower limb lymphedema with confirmed early EVR in a unilateral lower limb, the partial pressure of oxygen (PO₂) was compared between the lower limb with EVR and the contralateral lower limb. Results Secondary lymphedema with or without EVR occurred at an average of 36.0±59.3 months and 93.5±136.1 months, respectively; however, no significant difference was noted. PO₂ was 57.6±11.7 mmHg and 44.1±16.4 mmHg in the EVR and non-EVR limbs, respectively, which was a significant difference (P=0.005). Conclusions EVR and venous blood gas analysis suggested the presence of micro-AVFs in patients with lower extremity edema. Further research is warranted to examine the cause of micro-AVFs, to advance technology to facilitate the confirmation of micro-AVFs by angiography, and to improve lymphedema by ligation of micro-AVFs.

• Journal of Korean Neurosurgical Society
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• v.65 no.5
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• pp.688-696
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• 2022

Objective : Transvenous embolization (TVE) via an occluded inferior petrosal sinus (IPS) in a cavernous sinus dural arteriovenous fistula (CSDAVF) is challenging, often requiring navigation of a microcatheter through resistive obstacles between the occluded IPS and shunted pouch (SP), although the reopening technique was successfully performed. We report five cases of successful access to the cavernous sinus (CS) or SP using the rigid-tipped microguidewire such as chronic total occlusion (CTO) wire aiming to share our initial experience with this wire. Methods : In this retrospective study, four patients with CSDAVF underwent five procedures using the CTO wire puncture during transfemoral transvenous coil embolization. Puncture success, shunt occlusion, and complications including any hemorrhage and cranial nerve palsy were evaluated. Results : Despite successful access through the occluded IPS, further entry into the target area using neurointerventional devices was impossible due to a short-segment stricture before the CS (three cases) and a membranous barrier within the CS (two cases). However, puncturing these structures using the rigid-tipped microguidewire was successful in all cases. We could advance the microcatheter over the rigid-tipped microguidewire for the navigation to the SP and achieved complete occlusion of the SP without complications. Conclusion : The use of the rigid-tipped microguidewire in the TVE via the occluded IPS of the CSDAVF would be feasible and safe.

• The Korea Journal of Herbology
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• v.25 no.1
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• pp.39-43
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• 2010

Objectives : This research was investigated the anticoagulant effect of the Gleditsiae spina extract. Methods : We researched prothrombin time (PT) assay, activated partial thromboplastin time (APTT) assay in vitro and in vivo using arteriovenous (A-V) shunt rat model and shortening Rat tail bleeding time (BT). A-V shunt and BT were treated with extract of Gleditsiae spina (GS) 400 mg/kg for a week. Results : Bleeding time of Gleditsiae spina extract in vivo had a significant increase as about 1.2 times and thrombus weight of Gleditsiae spina extract had a significant reduction of thrombus weight as 26%. Gleditsiae spina extract represented an effect of anticoagulation by operating on extrinsic pathway factor II, V, VII, X and intrinsic pathway factor VIII, IX, X, XI, XII in the coagulation system. Conclusions : Considering the above mentioned results, it is judged that a Gleditsiae Spina extract has a control effect of thrombus creation.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.420-425
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• 1999

We report a case of hepatopulmonary syndrome defined as a triad of chronic liver disease, increased alveolar oxygen gradient on room air, and intrapulmonary arteriovenous shunting. Chest rediographs showed bilateral, basilar, medium sized reticulonodular opacities. High resolution CT scand showed multiple centrilobular nodules and branching structures in the subpleural lung that suggested dilatation of lung vessels with abnormally large number of visible terminal branches. $^{99m}Tc$-macroaggregated albumin(MAA) perfusion lung scan showed right to left shunt. Contrast echocardiography demonstrated intrapulmonary vascular shunt without intracardiac shunt.

• Journal of Trauma and Injury
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• v.37 no.3
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• pp.182-191
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• 2024

Purpose: Vascular injuries require immediate surgical treatment with standard vascular techniques. We aimed to identify pitfalls in vascular surgery for trauma team optimization and to suggest recommendations for trauma and vascular surgeons. Methods: We reviewed 28 victims and analyzed the patterns of injuries, methods of repair, and outcomes. Results: Ten patients had torso injuries, among whom three thoracic aorta injuries were repaired with thoracic endovascular aortic repair, one left hepatic artery pseudoaneurysm with embolization, and two inferior vena cava with venorrhaphy, three iliac arteries with patch angioplasty or embolization, and three common femoral arteries with bypass surgery or arterioplasty. Four patients had upper extremity injuries, among whom one brachial artery and vein was repaired with bypass surgery after temporary intravascular shunt perfusion, two radial arteries were repaired with anastomoses, and one ulnar artery was repaired with ligation. One radial artery under tension was occluded. Fourteen patients had lower extremity injuries, among whom one superficial femoral artery and vein was repaired with bypass and concomitant ligation of the deep femoral artery and vein, three superficial femoral arteries were repaired with bypass (two concomitant femoral veins with bypass or anastomosis), one deep femoral artery with embolization, two popliteal arteries with bypass or anastomosis, four infrapopliteal transected arteries, one arteriovenous fistula with ligation, and one pseudoaneurysm with bypass. However, one superficial femoral artery and all femoral veins were occluded. One leg replantation failed. Conclusions: There are potential complications of vascular access during resuscitative endovascular balloon occlusion of the aorta procedures. Vascular repair should be performed without tension or spasm. Preservation of the harvested vein in papaverine solution and blood while using a temporary intravascular shunt is a method of eliminating spasms.

• Journal of Chest Surgery
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• v.39 no.9 s.266
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• pp.692-698
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• 2006

Background: Owing to the fact that the average life span has increased and the progress in medical science has been made, the number of patients with chronic renal failure (CRF) who have to take hemodialysis (HD) has been going up gradually. Accordingly, it is considered to be as a significant issue to obtain blood vessels which can be used repetitively and supply enough blood flows. Therefore, there have been various kinds of study on an inosculation rate andfactors influencing it following an arteriovenous fistula (AV fistula) and lots of studies are ongoing for the purpose of escalating the inosculation rate. The authors analyzed the effects of short-term result, age, sex, diabetes and hypertension on arteriovenous inosculations in 134 anatomical snuffbox operated subjects among the patients who have taken an AV fistula at this center. Material and Method: Based on 134 patients who underwent an AV fistula at the department of thoracic surgery of this center from July, 2000 to May, 2004, the difference in arteriovenous inosculation rate was compared and analyzed depending or age (discriminated by 65-year-old), sex and the condition of the presence or absence of diabetes and hypertension. Correlation analyses were conducted for each parameter and statistical tests were performed by using SPSS for windows Release 11.0.1, which were determined to be statistically significant if p value was below 0.05. Result: The total number of operations was 169 including 35 of re-operations. The male/female rate was 70 : 64 (52% : 48%). The average age was $56.3{\pm}12.26$ years and there were 33 (24%) old aged patients above 65-year-old; there were 103 (71%) patients with hypertension and 90 (67%) patients with diabetes. Overall arteriovenous inosculation rate was $93{\pm}2.4%,\;91{\pm}2.7%,\;89{\pm}3.0%$ at 6, 12, 24 months, respectively. The arteriovenous inosculation rate of above 65-year-old patient group was $85{\pm}4.8%,\;80{\pm}5.8%,\;80{\pm}5.8%$ and below 64-year-old patient group's was $85{\pm}4.8%,\;80{\pm}5.8%,\;80{\pm}5.8%$ at given time points, respectively, which showed higher inosculation rate in below 64-year-old patient group with a statistical significance (p=0.0034). However, no statistical significance was found between the patients with hypertension and diabetes and the patients with no complication. In addition, there was no statistical significance in inosculation rate between male and female. Conclusion: The arteriovenous inosculation ratewas higher in the treated patient below 64-year-old than in the treated patient above 65-year-old. Thus it is advantageous for increase in long-term inosculation rate to obtain hemodialysis routes at an early age. The conditions of sex and the presence or absence of diabetes and hyper- tension do not make statistically significant effect on the arteriovenous inosculation rate.

• Journal of Chest Surgery
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• v.19 no.4
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• pp.683-687
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• 1986

A direct communication between the left ventricle and right atrium is a relatively uncommon defect. Familiarity with this anomaly has become increasingly important, however, since the preoperative findings may be identical with those of an atrial septal defect. The left ventricle is directly related to the right atrium over. an area of the membranous ventricular septum which extends superior to the septal attachment of the right atrioventricular valve in the LV-RA communication. The clinical triad of a ventricular septal defect murmur, cardiac enlargement, and an arteriovenous shunt at atrial level is characteristic of the malformation. A 2-year-old boy with left ventriculo-right atrial communication has operated at the Maryknoll Hospital. Under the cardiopulmonary bypass, the atrium was opened, there was a jet-blood stream just above the atria-ventricular portion adjacent to the septal leaflet of the tricuspid valve.

• 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 Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.85-96
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• 2024

Objective: Congenital intracranial pial arteriovenous fistula (PAVF) is a rare cerebral vascular pathology characterized by a direct shunt between one or more pial feeding arteries and a cortical draining vein. Transarterial endovascular embolization (TAE) is widely considered first line therapy. Curative TAE may not be achievable in the multi-hole variant due to the potential to harbor innumerable small feeding arteries. Transvenous embolization (TVE) may be considered to target the final common outlet of the lesion. Here, we present a series of four patients with complex multi-hole congenital PAVF treated with staged TAE followed by TVE. Methods: A retrospective review was conducted on patients who underwent treatment for congenital, multi-hole PAVFs treated by a combined TAE/TVE approach at our institution since 2013. Results: We identified four patients with multi-hole PAVF treated by a combined TAE/TVE. Median age was 5.2 (0-14.7) years. Median follow-up of 8 (1-15) months by catheter angiography and 38 (23-53) months by MRI/MRA was obtained. TVE achieved complete occlusion in three patients that proved durable on radiographic follow-up and demonstrated excellent clinical outcomes with a modified Rankin Score (mRS) of 0 or 1. Complete occlusion of the draining vein was not achieved by TVE in one case. This patient is graded as pediatric mRS=5 three years post-procedure. Conclusions: With thorough technical considerations, our series indicates that TVE of multi-hole PAVF that are refractory to TAE is feasible and effective in arresting the consequences of chronic, high-flow AV shunting produced by this pathology.