1.Research on injection flow velocity planning method for embolic agent injection system.
Jiasheng LI ; Dongcheng REN ; Bo ZHOU ; Shijie GUO ; Baolei GUO
Journal of Biomedical Engineering 2022;39(3):579-585
Interventional embolization therapy is widely used for procedures such as targeted tumour therapy, anti-organ hyperactivity and haemostasis. During embolic agent injection, doctors need to work under X-ray irradiation environment. Moreover, embolic agent injection is largely dependent on doctors' experience and feelings, and over-injection of embolic agent can lead to reflux, causing ectopic embolism and serious complications. As an effective way to reduce radiation exposure and improve the success rate of interventional embolization therapy, embolic agent injection robot is highly anticipated, but how to decide the injection flow velocity of embolic agent is a problem that remains to be solved. On the basis of fluid dynamics simulation and experiment, we established an arterial pressure-injection flow velocity boundary curve model that can avoid reflux, which provides a design basis for the control of embolic agent injection system. An in vitro experimental platform for injection system was built and validation experiments were conducted. The results showed that the embolic agent injection flow speed curve designed under the guidance of the critical flow speed curve model of reflux could effectively avoid the embolic agent reflux and shorten the embolic agent injection time. Exceeding the flow speed limit of the model would lead to the risk of embolization of normal blood vessels. This paper confirms the validity of designing the embolic agent injection flow speed based on the critical flow speed curve model of reflux, which can achieve rapid injection of embolic agent while avoiding reflux, and provide a basis for the design of the embolic agent injection robot.
Embolization, Therapeutic/methods*
2.Design and experiment of guide wire tele-manipulation system based on laser mouse sensor.
Jie SHEN ; Shenglin LI ; Daguo CHEN ; Yonghua YAN
Chinese Journal of Medical Instrumentation 2012;36(1):32-35
In order to realize the guide wire tele-manipulation in intervention operation, a method for guide wire motion detection with laser mouse sensor is proposed and experiments are carried out. On that basis, a guide wire tele-manipulation system which consists of guide wire detection appliance, guide wire manipulation appliance, and master slave type software is designed. Experiments are conducted on the system and acquired needed data, so that relationships between operating time and the distance from guide wire tip to destination and the angle are analyzed. The results validate the feasibility of the system and provide good foundation for future research.
Catheterization
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instrumentation
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methods
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Embolization, Therapeutic
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instrumentation
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Equipment Design
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Lasers
3.Hemodynamic effects of stenting on wide-necked intracranial aneurysms.
Yi-sen ZHANG ; Xin-jian YANG ; Sheng-zhang WANG ; Ai-ke QIAO ; Jia-liang CHEN ; Kun-ya ZHANG ; Zhi-cheng LIU ; Yu-jing ZHAO ; Ying ZHANG ; Bin LUO ; Chuan-hui LI
Chinese Medical Journal 2010;123(15):1999-2003
BACKGROUNDStent placement has been widely used to assist coiling in cerebral aneurysm treatments. The present study aimed to investigate the hemodynamic effects of stenting on wide-necked intracranial aneurysms.
METHODSThree idealized plexiglass aneurismal models with different geometries before and after stenting were created, and their three-dimensional computational models were constructed. Flow dynamics in stented and unstented aneurismal models were studied using in vitro flow visualization and computational fluid dynamics (CFD) simulations. In addition, effects of stenting on flow dynamics in a patient-specific aneurysm model were also analyzed by CFD.
RESULTSThe results of flow visualization were consistent with those obtained with CFD simulations. Stent deployment reduced vortex inside the aneurysm and its impact on the aneurysm sac, and decreased wall shear stress on the sac. Different aneurysm geometries dictated fundamentally different hemodynamic patterns and outcomes of stenting.
CONCLUSIONSStenting across the neck of aneurysms improves local blood flow profiles. This may facilitate thrombus formation in aneurysms and decrease the chance of recanalization.
Embolization, Therapeutic ; methods ; Humans ; Hydrodynamics ; Intracranial Aneurysm ; therapy ; Stents
7.Recent Update of Embolization of Upper Gastrointestinal Tract Bleeding.
Korean Journal of Radiology 2012;13(Suppl 1):S31-S39
Nonvariceal upper gastrointestinal (UGI) bleeding is a frequent complication with significant morbidity and mortality. Although endoscopic hemostasis remains the initial treatment modality, severe bleeding despite endoscopic management occurs in 5-10% of patients, necessitating surgery or interventional embolotherapy. Endovascular embolotherapy is now considered the first-line therapy for massive UGI bleeding that is refractory to endoscopic management. Interventional radiologists need to be familiar with the choice of embolic materials, technical aspects of embolotherapy, and the factors affecting the favorable or unfavorable outcomes after embolotherapy for UGI bleeding.
Angiography
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Embolization, Therapeutic/*methods
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Endoscopy, Gastrointestinal
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Gastrointestinal Hemorrhage/etiology/*therapy
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Hemostasis, Endoscopic
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Humans
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*Upper Gastrointestinal Tract
8.Transvenous Coil Embolization for Dural Arteriovenous Fistulas of the Ophthalmic Sheath: Report of Two Cases and Review of the Literature.
Juyoung HWANG ; Kyung Il JO ; Je Young YEON ; Seung Chyul HONG ; Jong Soo KIM
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(2):135-140
We present two patients with a dural arteriovenous fistula (dAVF) of the ophthalmic sheath who developed progressive exophthalmos, conjunctival chemosis, and visual loss. These symptoms mimic those of cavernous sinus dAVFs. Dural AVFs of the ophthalmic sheath are extremely rare and their clinical management is controversial. We successfully treated these two patients by transvenous coil embolization. Transvenous embolization appears to be a safe and effective method to treat dAVFs of the ophthalmic sheath.
Cavernous Sinus
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Central Nervous System Vascular Malformations*
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Embolization, Therapeutic*
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Exophthalmos
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Humans
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Methods
9.Clinical Outcomes of Angiography and Transcatheter Arterial Embolization for Acute Gastrointestinal Bleeding: Analyses according to Bleeding Sites and Embolization Types.
Soo Min NOH ; Ji Hoon SHIN ; Ha Il KIM ; Sun Ho LEE ; Kiju CHANG ; Eun Mi SONG ; Sung Wook HWANG ; Dong Hoon YANG ; Byong Duk YE ; Seung Jae MYUNG ; Suk Kyun YANG ; Jeong Sik BYEON
The Korean Journal of Gastroenterology 2018;71(4):219-228
BACKGROUND/AIMS: The clinical outcomes of angiography and transcatheter arterial embolization (TAE) for acute gastrointestinal bleeding (GIB) have not been completely assessed, especially according to bleeding sites. This study aimed to assess the efficacy of angiography and safety of TAE in acute GIB. METHODS: This was a retrospective study evaluating the records of 321 patients with acute GIB who underwent angiography with or without TAE. Targeted TAE was conducted in 134 patients, in whom angiography showed bleeding sources. Prophylactic TAE was performed in 29 patients when the bleeding source was not detected but a specific vessel was strongly suspected by other examinations. The rate of technical success, clinical success, and complications were analyzed. RESULTS: The detection rate of bleeding source via angiography was 50.8% (163/321), which was not different according to the bleeding sites. The detection rate was higher if the probable bleeding source had already been found by another investigation (59.7% vs. 35.8%, p<0.001). TAE sites were upper GIB in 67, mid GIB in 74, and lower GIB in 22. The technical success rate was 99.3% (133/134), and the clinical success rate was 63.0% (104/163). The prophylactic embolization group showed lower clinical success rate than the targeted embolization group (44.8% vs. 67.9%, p=0.06). The TAE-related complication rate was 12.9% (21/163). Ischemia and/or infarction was more common after TAE for mid and lower GIB than for upper GIB (15.6% vs. 3.0%, p=0.007). CONCLUSIONS: Angiography with or without TAE was an effective method for acute GIB. Targeted embolization should be performed if possible given that it has a higher clinical success rate.
Angiography*
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Embolization, Therapeutic
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Gastrointestinal Hemorrhage
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Hemorrhage*
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Humans
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Infarction
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Ischemia
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Methods
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Retrospective Studies