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*

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 ; instrumentation ; methods ; Embolization, Therapeutic ; instrumentation ; Equipment Design ; Lasers

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.

Catheter Ablation ; methods ; Combined Modality Therapy ; methods ; Embolization, Therapeutic ; methods ; Humans ; Liver Neoplasms ; surgery

Bariatric Surgery ; methods ; Embolization, Therapeutic ; methods ; Ghrelin ; blood ; Humans ; Obesity ; blood ; surgery ; therapy

Bleomycin ; analogs & derivatives ; therapeutic use ; Embolization, Therapeutic ; methods ; Female ; Hemangioma ; therapy ; Humans ; Infant ; Iodized Oil ; therapeutic use ; Syndrome ; Thrombocytopenia ; therapy

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 ; Embolization, Therapeutic/*methods ; Endoscopy, Gastrointestinal ; Gastrointestinal Hemorrhage/etiology/*therapy ; Hemostasis, Endoscopic ; Humans ; *Upper Gastrointestinal Tract

Renovascular hypertension is caused by narrowing of the arteries supplying the kidneys. There are several methods to treat renal artery stenosis, such as medications, percutaneous transluminal renal angioplasty, and atherosclerosis. A boy presented to our hospital with severe hypertension. Computed tomography angiogram revealed severe narrowing of the left renal artery and hypoplastic left kidney. Total renal artery embolizaton was performed to make a complete occlusion of the left renal artery. Follow-up renin and aldosterone levels were gradually decreased. The main advantage of renal artery embolization is that it is minimally invasive compared with extensive surgical procedures. Therefore, renal artery embolization should be considered as an alternative to surgical nephrectomy in pediatric patients with renovascular hypertension.
Child ; Embolization, Therapeutic/*methods ; Humans ; Hypertension, Renovascular/*therapy ; Male ; Renal Artery

OBJECTIVETo evaluate the safety and efficacy of stent placement for the treatment of complex intracranial aneurysms.

DATA SOURCESWe searched six databases, including Pubmed, Embase, SCI-expanded, the Cochrane Library, ISI Proceedings and ProQuest Dissertations & Theses for the relevant studies using multiple key words from December, 1997 to February, 2009.

STUDY SELECTIONThirty-three studies about stent placement for intracranial aneurysms were identified, which reported data from a total of 1069 patients with 1121 intracranial aneurysms.

DATA EXTRACTIONWe prepared a standardized data extraction form (DEF), which was used by two independent researchers to extract data from the included 33 studies.

RESULTSThe overall initial complete occlusion rate was 52.5% (456/869, 95%CI: 49.2% - 55.8%). The overall complication rate was 14.3% (162/1130, 95%CI: 12.3% - 16.4%), of which 3.6% (38/1044, 95%CI: 2.5% - 4.8%) were permanent. Clinical follow-up showed a dependence rate of 8.4% (39/465, 95%CI: 5.9% - 10.9%). Angiographic follow-up showed an improvement rate of 24.3% (117/481, 95%CI: 20.5% - 28.2%) and a recurrence rate of 12.9% (62/481, 95%CI: 9.9% - 15.9%). Chi-squared tests were performed to compare the following subgroups: self-expandable vs. balloon-expandable stents, unruptured vs. acutely ruptured aneurysms, and with vs. without pre-medication. Statistical significance was reached in eight tests.

CONCLUSIONSIntracranial stent is a safe and effective tool for embolizing complex intracranial aneurysms. Self-expandable stents are significantly easier and safer than balloon-expandable stents with respect to navigation and deployment through the tortuous cerebral vasculature. Patients with acutely ruptured aneurysms are more likely to be dependent, but not more likely to suffer more procedure-related complications.

Renal angiomyolipoma is a type of benign tumor that occurs sporadically in addition to being associated with tuberous sclerosis. Preoperative embolization of large tumors is important to avoid excessive blood loss during surgery. We reported a patient with a 5505-g giant renal angiomyolipoma in a solitary kidney. The patient was treated with preoperative embolization and radical nephrectomy without complications. This type of treatment for an enormous angiomyolipoma can reduce the risk of uncontrolled hemorrhage caused by rupture of the tumor during the operation and should be considered for the treatment of similar tumors.
Adult ; Angiomyolipoma ; surgery ; Arteries ; surgery ; Embolization, Therapeutic ; methods ; Humans ; Kidney Neoplasms ; surgery ; Male