Search results for "shunt"
showing 10 items of 114 documents
Radiation exposure in biliary procedures performed to manage anastomotic strictures in pediatric liver transplant recipients: comparison between radi…
2013
The aim of this study was to estimate radiation exposure in pediatric liver transplants recipients who underwent biliary interventional procedures and to compare radiation exposure levels between biliary interventional procedures performed using an image intensifier-based angiographic system (IIDS) and a flat panel detector-based interventional system (FPDS). We enrolled 34 consecutive pediatric liver transplant recipients with biliary strictures between January 2008 and March 2013 with a total of 170 image-guided procedures. The dose-area product (DAP) and fluoroscopy time was recorded for each procedure. The mean age was 61 months (range 4–192), and mean weight was 17 kg (range 4–41). The…
Fistulous-type vein of Galen malformation phantom model for endovascular training and research.
2016
IntroductionVein of Galen malformation (VGM), a high-flow intracranial arteriovenous shunt, is among the most severe neurovascular diseases in childhood. In many cases untreated children die or survive only severely disabled. Endovascular embolization is the preferred treatment.ObjectiveTo develop a simple fistulous-type VGM phantom model for teaching and training of different endovascular treatment methods and to investigate new treatment options and devices.MethodsAn experimental in vitro pulsatile phantom model was developed imitating a high-flow fistulous-type VGM, which is typical, especially in the neonatal phase. Pressure measurements at different arterial sites were performed before…
Delayed and incomplete treatment may result in dural fistula development in children with Vein of Galen malformation
2017
The association of dural arteriovenous fistulas (DAVF) in children with Vein of Galen malformation (VGM) has recently been reported for the first time. In a larger series of cases treated with transarterial NBCA embolization, 30% had DAVF. We wanted to analyze the development of DAVF in our cohort of children with VGM and to evaluate whether their occurrence depends on different treatment timing and embolic materials. We analyzed 43 VGM cases treated with a combined transarterial and transvenous approach between 2003 and 2016. In our early series until 2011, we used coils solely in 21 children. Since 2012, 22 children were treated with the combination of coils and Onyx. In the early series…
Long-Term Efficacy of Shunt Therapy in Idiopathic Normal Pressure Hydrocephalus.
2019
Background: Idiopathic normal pressure hydrocephalus (iNPH) is one of the very few treatable types of dementia. Shunt therapy has been shown to be effective in improving symptoms. However, the long-term results of cerebrospinal fluid diversion are variable. The aim of this retrospective study was to investigate long-term outcomes of patients with idiopathic normal pressure hydrocephalus treated with ventriculoperitoneal shunt by using programmable valves. Methods: Symptoms before treatment were recorded. Clinical symptoms and outcome after ventriculoperitoneal shunt were assessed based on changes in gait, urinary incontinence, and cognitive dysfunction at yearly follow-up spanning at least …
Sildenafil reduces neuroinflammation and restores spatial learning in rats with hepatic encephalopathy: underlying mechanisms
2015
Background: There are no specific treatments for the neurological alterations of cirrhotic patients with minimal hepatic encephalopathy (MHE). Rats with MHE due to portacaval shunt (PCS) show impaired spatial learning. The underlying mechanisms remain unknown. The aims of this work were to assess: (a) whether PCS rats show neuroinflammation in hippocampus, (b) whether treatment with sildenafil reduces neuroinflammation and restores spatial learning in PCS rats, and (c) analyze the underlying mechanisms. Methods: Neuroinflammation was assessed by determining inflammatory markers by Western blot. Phosphorylation of MAP-kinase p38 was assessed by immunohistochemistry. Membrane expression of GA…
Coronary artery fistulas as a cause of angina: How to manage these patients?
2015
Abstract Coronary artery fistulas represent the most common hemodynamically significant congenital defect of the coronary arteries and the clinical presentation is mainly dependent on the severity of the left-to-right shunt. We describe a case of a 55-year-old man with history of chest pain and without history of previous significant chest wall trauma or any invasive cardiac procedures. A coronary multislice computed tomography showed two large coronary fistulas arising from the left anterior descending coronary artery and ending in an angiomatous plexus draining into the common pulmonary trunk. Coronary angiography confirmed the CT finding and showed a third fistulous communication arising…
Comparison between local and regional anesthesia in arteriovenous fistula creation.
2011
Purpose Assessment of the effectiveness of Brachial Plexus Block (BPB) via axillary approach compared to regional anesthesia for arteriovenous fistula surgery in patients affected by end-stage renal disease. Methods We compared forty patients randomly divided into two groups. Group A underwent BPB procedure with 15 mL ropivacaine 1% and 10 mL of saline (0.9% NaCl) via axillary approach. Group B received local anesthesia with lidocaine 2%. The forearm blood vessels were assessed by Doppler ultrasonography before and after the intervention. Results BPB performed on Group A was associated with a considerable venous dilation and a significant decrease (48.7%, P<.05) in pulsatility index (PI)…
Mesenterico-caval shunt in rats
1980
A microsurgical technique for mesenterico-caval shunting in the rat is described. The method results in a partial blood drainage from the upper abdominal content whereas the blood of the mesenteric vein is shunted to the inferior caval vein. Controls were undertaken after 1 and 3 weeks, either visually or radiologically. Twenty-two of 26 surviving animals showed patency of the shunt. All animals had undisturbed blood supply to the portal stump.
Is It Possible to Create a “Mechanical” Arteriovenous Fistula in Hemodialysis Patients?
2010
Manual suturing still remains the best technique for the creation of vascular anastomoses on uremic patients with excellent results, despite being time consuming, difficult to perform with small vessels, and associated with a significant learning curve. We created a full mechanical arteriovenous fistula on a 65-year-old uremic patient with a new device already used in cardiac bypass surgery. The fistula was created automatically and rapidly, without the need for temporary occlusion of the artery, reducing the risk of blood clotting. We believe that mechanical devices may be useful to produce precise and fast anastomoses requiring minimal training for the surgeon.
Modeling and parameter identification of crystalline silicon photovoltaic devices
2011
This paper tests the standard single-exponential model of the electrical characteristics of crystalline-Si photovoltaic devices, focusing on the (apparent) shunt current. Measured characteristics of illuminated polycrystalline-Si photovoltaic modules are modeled, and the apparent shunt current is analyzed. It is shown that an Ohmic-like behavior only takes place at voltages well below the maximum-power point. At higher voltages, the apparent shunt current quickly drops to negligible values. Modeling a crystalline-Si PV device with a fixed shunt resistance may therefore lead to underestimation of the maximum power exceeding 10% at certain irradiance levels.