• Journal of Chest Surgery
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• v.54 no.1
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• pp.31-35
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• 2021

Background: Arteriovenous fistula (AVF) for hemodialysis is essential for patients with end-stage renal disease. However, it is difficult to maintain AVF reliably. It is vitally important to select proper blood vessels for AVF formation. In a previous study, a minimum diameter of 3 mm for the autologous vein was proposed. However, patients who did not meet the minimum vascular diameter before anesthesia, but fulfilled other criteria, showed satisfactory venous dilatation after brachial plexus block (BPB). This study investigated the extent of vein expansion by BPB and the surgical outcomes of dilated veins after BPB. Methods: Sixty-one patients who underwent AVF formation using an autologous vein between August 2018 and December 2019 were included in the study. The clinical characteristics of the patient groups, hemodynamic parameters including the diameter of blood vessels before and after BPB, and complications were investigated. Based on the venous diameter measured by sonography before anesthesia, patients were divided into group A (26 patients) and group B (35 patients), with venous diameters <3 mm and ≥3 mm, respectively. Results: The venous diameter expanded after anesthesia by 41% overall, by 62% in group A, and by 25% in group B. This difference between groups A and B was statistically significant (p=0.001). No other variables showed statistically significant differences. Conclusion: Sufficient venous dilatation was observed after BPB. Therefore, if the vein is sufficiently dilated after BPB, even in patients with a pre-anesthesia venous diameter <3 mm, surgery may still be performed with an expected desirable outcome.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.188-195
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• 2020

Purpose: This study aimed to review the recent scientific literature regarding nursing care of arteriovenous fistula (AVF) for the patients with Chronic Renal Failure (CRF) undergoing hemodialysis. Methods: An integrative review was conducted and articles were searched from Cochrane library, Medline, PubMed, Science direct and CINAHL databases by using the terms "nursing", 'Chronic Renal Failure', 'Haemodialysis', renal failure', 'or 'AV Fistula' nursing care', 'self-care'. The inclusion criteria were articles published in English in the year of 2015-2020 with availability of free full text. Reviewed data were carefully analyzed and charted regard to the nursing care of the patient with AVF. Results: 12 articles papers met the inclusion criteria. Three themes were derived from the data: (a) Intervention (b). Patient and nurse education (c) KPA Assessment of (Knowledge, Practice and Attitude) Conclusions: This review indicates the challenges that nursing care of AVF patients undergoing hemodialysis. The identified themes can be used in the development of more effective educational- programs. Future studies should focus on the development and evaluation of educational programs that include these selected themes.

• Journal of Korean Neurosurgical Society
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• v.63 no.4
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• pp.532-538
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• 2020

Traumatic arteriovenous fistulas (AVFs) involving the external carotid artery are exceedingly rare in young adults. Since an AVF is the most common life-threatening cause for pulsatile tinnitus (PT), meticulous evaluation and treatment of patients with PT is crucial. Here, we present two traumatic AVF cases treated with coil embolization leading to no residual fistulous connections followed by an immediate and complete resolution of PT. A 20-year-old man developed left ear tinnitus three months after a traumatic brain injury involving the right temporal bone fracture. Cerebral angiography demonstrated an enlarged left middle meningeal artery (MMA) and a fistular point at the posterior branch of the MMA draining to the middle meningeal vein (MMV) and the left pterygoid plexus, suggesting an AVF. Another 18-year-old girl developed left tinnitus, left exophthalmos, and conjunctival injection 6 months after a traffic accident involving no demonstrable abnormal findings in the radiologic exam. Magnetic resonance angiography demonstrated a markedly dilated left MMA draining to the MMV, left cavernous sinus, and left superior ophthalmic vein. In both cases, coil embolization was performed with total obliteration of the fistular point.

• Journal of Korean Critical Care Nursing
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• v.11 no.1
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• pp.28-34
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• 2018

Purpose : The purpose of this study was to compare the effect of recirculation rate according to cannulation direction and interval among hemodialysis patients with arteriovenous fistula (AVF). Method : The research used repeated measures design. This study was conducted among thirty patients who received hemodialysis three times a week for longer than a year through AVF at the I University hospital. Three different types of interventions were administered to the participants each week for three weeks. Needles were placed at a different distance and in a different direction each week: 7 cm apart from each other in antegrade direction during the first week, 5 cm apart in retrograde direction in the following week, and 7 cm apart in retrograde direction in the third week. Results : No significant differences in the recirculation rate were found due to any of the three tested methods (p = 1.00). Conclusion : This finding suggests that, if the patients have well-functioned AVF, we can choose an appropriate intervention from among the three methods in consideration of the patient's diverse needs.

• Archives of Plastic Surgery
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• v.50 no.6
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• pp.568-572
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• 2023

Cutaneous squamous cell carcinoma (CSCC) overlying an arteriovenous fistula (AVF) is rare and presents unique challenges. This case report describes a method of fistula preservation after CSCC excision using a flow-through venous free flap. The saphenous vein of the venous flap was used as flow-through segment for AVF preservation. The flap was inserted along the dorsal aspect of the forearm wound and microvascular anastomosis of the arterial inflow was completed using a vein just proximal to the radiocephalic fistula anastomosis. Venous outflow was established by creating an end-to-end vascular anastomosis between the cephalic vein and the greater saphenous vein. A separate subcutaneous vein was used to provide a low-pressure outflow for the flap to avoid congestion. This case demonstrates an option for AVF preservation that has not been previously described. It also highlights the importance of a multidisciplinary approach for the safe treatment of CSCCs overlying AVFs.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.440-446
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• 2023

Craniotomy is known as a cause of iatrogenic dural cerebral arteriovenous fistula (AVF). However, mixed pial and dural AVFs after craniotomy are extremely rare and require accurate diagnosis and prompt treatment due to their aggressiveness. We present a case of an iatrogenic mixed pial and dural AVF diagnosed 2 years after pterional craniotomy for surgical clipping of a ruptured anterior choroidal aneurysm. The lesion was successfully treated using single endovascular procedure of transvenous coil embolization through the engorged vein of Labbe and the superficial middle cerebral vein. The possibility of the AVF formation after the pterional approach should always be kept in mind because it usually occurs at the middle cranial fossa, which frequently has an aggressive nature owing to direct cortical venous or leptomeningeal drainage patterns. This complication is believed to be caused by angiogenetic conditions due to coagulation, retraction, and microinjuries of the perisylvian vessels, and can be prevented by performing careful sylvian dissection according to patient-specific perisylvian venous anatomy.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.642-647
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• 2010

Background: It is very important to obtain vascular access that resists repeated punctures and maintains an adequate blood flow for performing hemodialysis in patients with ESRD. This study was designed to identify the risk factors that may influence the patency rate of arteriovenous fistula (AVF) using perforating vein on antecubital fossa. Material and Method: We analyzed 205 cases of AVF in 195 patients who underwent hemodialysis access surgery on antecubital fossa in our hospital from May 2006 to December 2009. Result: The patency rate of AVF from 6 months after surgery using perforating vein was 75.91%. The risk factors that influence the patency rate was age. There was no statistic difference between used vessels. Conclusion: The patency of the AVF using perforating vein on antecubital fossa was comparable. The condition of sex and location and presence or absence of diabetes and hypertension and other cardio-neurovascular disease did not make statistically significant effect on the AVF patency rate. The age was an independent risk factor for patency rate.

• Journal of Korean Neurosurgical Society
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• v.59 no.3
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• pp.296-301
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• 2016

Dural arteriovenous fistula (DAVF) of the transverse sinus with ophthalmic manifestations in young children are rare. We reviewed two cases of direct AVF of the transverse sinus with ocular manifestations managed at our institution. The first, a 2.5 years old male child presented with left exophthalmos. Angiography revealed AVF between the occipital artery and the transverse sinus. The second, a 2 years old female child, complained of left exophthalmos. Imaging studies showed bilateral direct AVFs of the transverse sinus with bilateral dysmaturation of the sigmoid sinus. Transarterial embolization was done in both cases. Clinical and radiological follow up revealed complete cure. This report suggests that DAVF of the transverse sinus supplied by the external carotid branches can present with ophthalmic manifestations especially if there is distal venous stenosis or obliteration involving sigmoid sinus. Transarterial embolization using coils and liquid embolic agents could be safe and feasible to obliterate the fistula.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.788-789
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• 2015

본 논문에서는 사이클로트론 전자석의 설계과정을 체계화하고, 자기장 최적화 과정을 순차적 근사화 기법을 이용하여 설계를 진행하였다. 설계하는 전자석은 방사성동위원소생산을 목적으로하는 PET(Positron Emission Tomography) 사이클로트론 이며, 크기를 줄이고 동위원소의 효율적인 생산을 위해 에너지대역은 10MeV로 선정하였다. 설계과정은 실험계획법 중 하나인 LHS(Latin Hypercube Sampling) 기법을 통해 샘플 데이터를 구성하고, 이를 바탕으로 크리깅을 이용해 근사모델을 구성한다. 근사 모델과 진화 알고리즘을 이용해 목적에 맞는 최적의 형상을 찾을 수 있다. 이러한 과정을 반복함으로써 점진적으로 목적에 부합하는 형상을 찾을 수 있다. 각각의 형상의 성능을 판단하는 목적함수를 단계별로 규칙을 정함으로써 결과의 신뢰도를 높인다. 이로써 시간적 효율을 증대시키고 전문지식이 부족한 설계자도 고성능의 형상을 얻을 수 있다. 최적화과정은 STEP1과 STEP2로 나누어 진행되며, STEP1에서는 초기사이클로트론 전자석을 설계하고, 자기장 최적화를 진행한다. STEP2에서는 빔 시뮬레이션 및 분석을 통하여 최적화를 진행하고, 최종적으로 전자석모델을 완성한다.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.2
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• pp.119-129
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• 2024

Knowledge of the venous anatomy is essential for appropriately treating dural arteriovenous fistulas (AVFs). It is challenging to determine the overall venous structure despite performing selective angiography for dural AVFs with feeder from multiple selected arteries. This is because only a part of the veins can be observed through the shunt in the selected artery. Therefore, after performing selective angiography of all vessels to understand the approximate venous anatomy, the venous anatomy can be easily understood by closely examining the source image of computed tomographic angiography or magnetic resonance angiography. Through this, it is possible to specify the vein that is to be blocked (target embolization), thereby avoiding extensive blocking of the vein and avoiding various complications. In the case of dural AVF with feeder from single selected artery, if the multiplanar reconstruction image of the three-dimensional rotational computed tomography obtained by performing angiography is analyzed thoroughly, a shunted pouch can be identified. If embolization is performed by targeting this area, unnecessary sinus total packing can be avoided.