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.

Embolization, Therapeutic ; methods ; Humans ; Hydrodynamics ; Intracranial Aneurysm ; therapy ; Stents

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

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.

Cerebral Angiography ; Embolization, Therapeutic ; methods ; Humans ; Intracranial Aneurysm ; diagnostic imaging ; therapy ; Stents ; adverse effects

OBJECTIVETo determine the effect, safety, and feasibility of embolization of high flow arteriovenous malformations (AVMs) with HepaSphere microspheres.

METHODSHepaSphere particles swell by absorbing fluids and become soft and deformable with a precisely calibrated diameter. 13 patients with AVMs were treated by transarterial embolization with HepaSphere particles. 3 cases underwent a following AVMs resection surgery. The follow-up period was 3 months to 3 years. Symptoms improvement and image examination were studied.

RESULTS28 transarterial embolizations were performed in 13 cases. The resection operation was performed in 3 cases after transarterial embolizations. The symptoms in diffused AVMs improved after several transarterial embolizations. Histologically, HepaSphere particles penetrated into the intralesional vessels and conformed to the vessel lumen, resulting in vessel occlusion. Minimal perivascular reaction was observed.

CONCLUSIONSEmbolization of high flow AVMs with HepaSphere microspheres is safe and effective. Combined treatment is necessary for diffuse AVMs.

Adolescent ; Adult ; Arteriovenous Malformations ; therapy ; Embolization, Therapeutic ; methods ; Female ; Humans ; Male ; Microspheres ; Middle Aged ; Young Adult

OBJECTIVETo evaluate the safety and value of preoperative transarterial embolization of hypervascular vertebral tumors.

METHODSSixteen patients with hypervascular vertebral tumors underwent transarterial embolization before surgery. The lesions were located between the middle cervical and lower lumbar spine. Forty-one arteries were embolized with permanent particles injected through a microcatheter, including polyvinyl alcohol (PVA) particles (150 - 500 micro m) in 25 arteries and Dextran particles (150 - 350 micro m) in 16. Of these, 31 had pieces of gelatin sponge added for proximal pedicled embolization. The criteria for judging the effectiveness of embolization were completeness of tumor removal and estimated blood loss during surgery.

RESULTSThe particles were injected into the tumor feeders through superselection in 17 arteries or flow control in 24. Tumor embolization was defined as "total" in five patients, "nearly total" in eight, "subtotal" in two, and "partial" in another. There were no symptomatic complications associated with embolization. Tumors were entirely removed in all patients. The average estimated blood loss during surgery was 1510 ml (range of 200 - 6000 ml) for all 16 patients.

CONCLUSIONPreoperative embolization of hypervascular vertebral tumors is safe and effective. It can make complete resection of a tumor possible and can make a previously unresectable tumor resectable. Superselection or flow control is necessary to achieve effective devascularization and to avoid complications.

Adolescent ; Adult ; Arteries ; Embolization, Therapeutic ; methods ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Spinal Neoplasms ; surgery

One case of traumatic carotid-cavernous fistula (TCCF) with small fistula treated by transarterial detachable coil embolization was reported. The intermittent ipsilateral carotid compression was used to identify the final blocking of the residual fistula. The follow-up digital subtraction angiography showed that the TCCF was cured finally. From this case, we conclude that this method may be an effective way to treat TCCF with small fistula.
Adult ; Carotid-Cavernous Sinus Fistula ; therapy ; Embolization, Therapeutic ; methods ; Endovascular Procedures ; Female ; Fistula ; therapy ; Humans