• 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 Korean Neurosurgical Society
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• v.44 no.6
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• pp.364-369
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• 2008

Objective : The aim of this study was to evaluate the efficacy of endovascular therapy as a primary treatment for spinal dural arteriovenous fistula (DAVF). Methods : The authors reviewed 18 patients with spinal DAVFs for whom endovascular therapy was considered as an initial treatment at a single institute between 1993 and 2006. NBCA embolization was considered the primary treatment of choice, with surgery reserved for patients in whom endovascular treatment failed. Results : Surgery was performed as the primary treatment in one patient because the anterior spinal artery originated from the same arterial pedicle as the artery feeding the fistula. Embolization was used as the primary treatment modality in 17 patients. with an initial success rate of 82.4%. Two patients with incomplete embolization had to undergo surgery. One patient underwent multiple embolizations, which failed to completely occlude the fistula but relieved the patient's symptoms. Spinal DAVF recurred in two patients (one collateral development and one recanalization) during the follow-up period. The collateral development was obliterated by repeated embolization, but the patient with recanalization refused further treatment. The overall clinical status improved in 15 patients (83.3%) during the follow-up period. Conclusion : Endovascular therapy can be successfully used as a primary treatment for the majority of patients with spinal DAVFs. Although it is difficult to perform in some patients, endovascular embolization should be the primary treatment of choice for spinal DAVF.

• 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.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1628-1633
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• 2021

Spinal epidural arteriovenous fistulas (SEDAVFs) are rare spinal vascular malformations that are difficult to diagnose and treat. SEDAVFs can be asymptomatic; however, symptoms can arise from the compression of adjacent nerve roots by dilated vein and perimedullary venous reflux, caused by shunting into the epidural venous plexus. A 31-year-old male presented to our institution with a 2-year history of progressively worsening low-back pain, radiating thigh pain, and sensory changes in his lower extremities. MRI and CT angiography demonstrated dilated epidural vascular lesion compressing the nerve root. The SEDAVF was embolized with multiple coils, which alleviated the nerve root compression from the engorged venous varix and improved the patient's radiculopathy. Our experience from this case shows that endovascular coil embolization using the transarterial approach can be an effective treatment for SEDAVF and an alternative to surgical ligations.

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.116-119
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• 2010

Purpose: Arteriovenous fistulas that involve the cavernous sinus often produce ophthalmologic symptoms and signs. Transvenous endovascular access is the method of choice for a carotid-cavernous sinus fistula. The superior ophthalmic vein is a safe and reasonable alternative route for the transvenous embolization of carotid-cavernous sinus fistula. We report a case of the embolization of a carotid-cavernous sinus fistula using the superior ophthalmic vein approach. Methods: A 58 year old female had conjunctival congestion, periocular pain and diplopia with a 2 month duration. Diagnostic orbital CT, brain MRI and cerebral angiography revealed a carotid-cavernous sinus fistula. The fistula occlusion was treated by coil embolization using the superior ophthalmic vein approach. Results: The initial presenting symptoms, conjunctival congestion, periocular pain and diplopia, decreased after surgery. Coil embolization via the superior ophthalmic vein approach was difficult because of the venous tortuosity and friability. During the follow up period, the patient was in a good condition without complications. Conclusion: Surgical exposure of the superior ophthalmic vein provides direct venous access to the cavernous sinus as well as an effective and safe treatment approach. The cooperation of the plastic surgeon and interventionist is a factor in successful treatment.

• 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 Korean Neurosurgical Society
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• v.66 no.6
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• pp.672-680
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• 2023

Objective : We evaluated the diagnosis, treatment, and long-term results of patients with dural arteriovenous fistula (dAVF), which is a very rare cause of posterior fossa hemorrhage. Methods : This study included 15 patients who underwent endovascular, surgical, combined, or Gamma Knife treatments between 2012 and 2020. Demographics and clinical features, angiographic features, treatment modalities, and outcomes were analyzed. Results : The mean age of the patients was 40±17 years (range, 17-68), and 68% were men (11/15). Seven of the patients (46.6%) were in the age group of 50 years and older. While the mean Glasgow coma scale was 11.5±3.9 (range, 4-15), 46.3% presented with headache and 53.7% had stupor/coma. Four patients (26.6%) had only cerebellar hematoma and headache. All dAVFs had cortical venous drainage. In 11 patients (73.3%), the fistula was located in the tentorium and was the most common localization. Three patients (20%) had transverse and sigmoid sinus localizations, while one patient (6.7%) had dAVF located in the foramen magnum. Eighteen sessions were performed on the patients during endovascular treatment. Sixteen sessions (88.8%) were performed with the transarterial (TA) route, one session (5.5%) with the transvenous (TV) route, and one session (5.5%) with the TA+TV route. Surgery was performed in two patients (14.2%). One patient (7.1%) passed away. While there were nine patients (64.2%) with a Rankin score between 0 and 2, the total closure rate was 69.2% in the first year of control angiograms. Conclusion : In the differential diagnosis of posterior fossa hemorrhages, the differential diagnosis of dAVFs, which is a very rare entity, should be considered, even in the middle and elderly age groups, in patients presenting with good clinical status and pure hematoma. The treatment of such patients can be done safely and effectively in a multidisciplinary manner with a good understanding of pathological vascular anatomy and appropriate endovascular treatment approaches.

• 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.

• 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.