scholarly journals PS208. Increased Pressure Gradients Within an Aortic Arch Endograft Are Associated With Rapid Development of In-Stent Stenosis in a Porcine Model

2014 ◽  
Vol 59 (6) ◽  
pp. 83S
Author(s):  
Daniel Silverberg ◽  
Marcel Goodman ◽  
Edward Woo ◽  
Elisha Martinez ◽  
Udi Willenz ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Porcine Model ◽  
Rapid Development ◽  
Pressure Gradients ◽  
Stent Stenosis ◽  
Increased Pressure

scholarly journals Pituitary Apoplexy Causing Compression of Third Cranial Nerve—Management

2019 ◽  
Vol 08 (02) ◽  
pp. 119-122
Author(s):  
Václav Masopust
Keyword(s):  
Cavernous Sinus ◽  
Nerve Palsy ◽  
Clinical Symptoms ◽  
Rapid Development ◽  
Sella Turcica ◽  
Oculomotor Nerve ◽  
Oculomotor Nerve Palsy ◽  
Future Research ◽  
Third Nerve Palsy ◽  
Increased Pressure

AbstractLesions of the oculomotor nerve as the first sign of pituitary adenoma are rare. The cause of such lesions without other clinical symptoms is discussed in this study. A small cohort of 4 patients (3.1%) with oculomotor nerve palsy (third nerve palsy) as the only neurologic deficit, from 129 patients who got operated upon for pituitary adenomas, is presented. In this group (mean age: 55 years, range: 36–65 years), all patients (two women and two men) underwent surgery. In two cases, there was arrested pneumatization and thickened bone. In the remaining two cases, a macroscopically visible, very solid opaque diaphragm was present, after the removal of the tumor and thickened bone. Complete adjustment was observed in all patients within 1 week after the surgery. Two factors that seem to increase the high risk for the development of oculomotor nerve palsy are that the cavernous sinus may be the only weak structure surrounding the sella turcica when the diaphragm and bone are thickened; and the rapid development of increased pressure in this region. The increased pressure on the cavernous sinus during the anatomical variations is the primary cause for lesions on the oculomotor nerve. However, this conjecture cannot be statistically demonstrated because of the small number of cases. Future research should be conducted on larger samples to increase statistical inference and generalizability.

Transgastric gastro-jejunal anastomosis with flexible endoscope on a biosynthetic model

2007 ◽  
Vol 148 (4) ◽  
pp. 161-164 ◽  
Author(s):  
Péter Lukovich ◽  
Balázs Kádár ◽  
Attila Jónás ◽  
Mehdi Sadatakhavi ◽  
Gábor Váradi ◽  
...  
Keyword(s):  
Porcine Model ◽  
Single Channel ◽  
Rapid Development ◽  
Abdominal Cavity ◽  
Gastric Wall ◽  
Minimal Invasive ◽  
Invasive Procedures ◽  
Plastic Frame ◽  
Human Use ◽  
Needle Knife

Introduction: In the last few years the rapid development of flexible endoscopies has opened new possibilities in minimal invasive procedures. With the help of these techniques the exposure, the risk of complications and the healing period of the patient might be reduced. One of these procedures is the transgastric intervention. Through an incision on the wall of the stomach, the endoscope could be led into the abdominal cavity, where several interventions can be performed. The aim of the study was to examine the technical feasibility and the success of the formation of gastro-jejunal anastomosis. Meanwhile the difficulties of the method could be explored in order to introduce this method in human use. Method: A lifelike biosynthetic model was made from a slaughtered domestic pig’s gastrointestinal tract (stomach and the first few jejunum loops) which was fixed onto a plastic frame. Two single-channel gastroscopes were inserted into the stomach. On the wall of the stomach an approximately 2 centimetres wide incision was made by the electrocoagulator with a needle-knife. Through it the first jejunum loop was grasped by a foreign-body forceps and then was retracted into the stomach. Subsequently the jejunum loop was held safely with the first endoscope. Parallel to it an incision was made on the jejunum by the electrocoagulator. The authors managed to securely unite the open edges of the gastric wall and the jejunum with endoclips. Result: The model was good for practising. The anastomosis is technically feasible and was successfully made on biosynthetic porcine model using the transgastric route. Although the incisions both on the gastric wall and on the jejunum loop were made easily, the fixing of the anastomosis might be questionable. Conclusion: It was revealed that more experiments and the development of new, special instruments are needed in order to conduct the anastomosis safely.

An Experimental Study of a New Pull-through Technique for Aortic Arch Aneurysm in a Porcine Model

2005 ◽  
Vol 39 (3) ◽  
pp. 253-256
Author(s):  
Hiroshi Ohtake ◽  
Junichiro Sanada ◽  
Hiroki Kato ◽  
Keiichi Kimura ◽  
Hiroshi Nagamine ◽  
...  
Keyword(s):  
Experimental Study ◽  
Aortic Arch ◽  
Porcine Model ◽  
Aortic Arch Aneurysm ◽  
Pull Through ◽  
Arch Aneurysm

Development of a Selective Aortic Arch Perfusion System in a Porcine Model of Exsanguination Cardiac Arrest

10.3791/61573 ◽  
2020 ◽  
Author(s):  
Marta J. Madurska ◽  
Hossam Abdou ◽  
Michael J. Richmond ◽  
Noha N. Elansary ◽  
Peng F. Wong ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Aortic Arch ◽  
Porcine Model ◽  
Perfusion System

A Study of Pressure Homogeneity in the Hexahedral Anvil High-Pressure Apparatus

1964 ◽  
Vol 86 (4) ◽  
pp. 729-735 ◽  
Author(s):  
G. A. Samara ◽  
A. Henius ◽  
A. A. Giardini
Keyword(s):  
High Pressure ◽  
Stress Distribution ◽  
Material Flow ◽  
Applied Load ◽  
Pressure Gradients ◽  
Operational Characteristics ◽  
Large Pressure ◽  
Heater Tube ◽  
High Pressure Apparatus ◽  
Increased Pressure

A study of operational characteristics and stress distribution in a large volume hexahedral apparatus has been made. Pyrophyllite containers with integral preformed gaskets were found to be superior to plain blocks. Pregasketing reduced material flow and sample deformation, increased by over 100 percent the central region of the container over which little or no deformation occurs, and greatly increased anvil life. Even so, large pressure gradients still existed within the container. These gradients become more severe the higher the pressure. Pressure efficiency and distribution were appreciably changed by varying the length and thickness of preformed gaskets. Built-in metal intensifiers increased pressure efficiency by up to 30 percent. The inclusion of a metal heater tube had no measurable influence on pressure gradients. Cycling decreased the applied load required to reach a given pressure only if the load was not allowed to fall below a certain minimum. This is attributed to the ability of pyrophyllite to remain static while supporting large stress gradients.

scholarly journals Transparent Inflatable Column Film Dome for Nuclear Stations, Stadiums, and Cities

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Alexander Bolonkin ◽  
Shmuel Neumann ◽  
Joseph Friedlander
Keyword(s):  
Thin Film ◽  
Negative Pressure ◽  
Nuclear Reactor ◽  
Dust Particles ◽  
Positive Pressure ◽  
Pressure Gradients ◽  
Atmospheric Conditions ◽  
Pumping Station ◽  
Air Overpressure ◽  
Increased Pressure

In a series of previous articles, one of the authors published designs of the AB Dome which can cover a city, important large installations or subregions by a transparent thin film supported by a small additional air overpressure. The AB Dome keeps the outside atmospheric conditions from the interior protecting a city from chemical, bacterial, and radioactive weapons (wastes). The design in this article differs from previous one as this design employs an inflatable columns which does not need an additional pressure (overpressure) inside the dome and is cheaper in construction (no powered air pumping station) and in operation (no special entrance airlock and permanent pumping expense). When dome is supported by columns, no overpressure is required inside the dome which is important when the dome covers a damaged nuclear reactor. The nuclear reactor may produce radioactive gases and dust, and, as inflatable domes are not typically hermetically sealed, the increased pressure inside the dome can leak out gas and dust into the atmosphere. The suggested design does not have this drawback. Positive pressure gradients expel dust particles—neutral pressure gradients will not. (Negative pressure gradients may even be possible in certain configurations.)

Rapid formation of collateral arteries in a neonate with interruption of the aortic arch

2001 ◽  
Vol 11 (4) ◽  
pp. 464-467 ◽  
Author(s):  
J. Sander Starreveld ◽  
Albert C. van Rossum ◽  
Jaroslav Hruda
Keyword(s):  
Aortic Arch ◽  
Septal Defect ◽  
Left Subclavian Artery ◽  
Rapid Development ◽  
Atrioventricular Septal Defect ◽  
Resonance Imaging ◽  
Descending Aorta ◽  
Collateral Arteries ◽  
Rapid Formation ◽  
Distal Perfusion

In a neonate born prior to term with a weight of 1825 grams, and diagnosed prenatally as having atrioventricular septal defect and Down's syndrome, we found the aortic arch to be interrupted between the left carotid artery and the left subclavian artery, with the arterial duct being the only route of distal perfusion. Three days later, however, echocardiographic interrogation revealed marked collateral connections between the aortic arch and the descending aorta, the picture then mimicking coarctation rather than interruption of the aortic arch. The rapid development of the collateral arteries was confirmed by magnetic resonance imaging and during cardiac surgery.

Outcomes of transcatheter balloon angioplasty of obstruction in the neo-aortic arch after the Norwood operation

2001 ◽  
Vol 11 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Jarupim Soongswang ◽  
Brian W. McCrindle ◽  
Thomas K. Jones ◽  
Robert N. Vincent ◽  
Daphne T. Hsu ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Balloon Angioplasty ◽  
Ventricular Dysfunction ◽  
Balloon Dilation ◽  
Systolic Pressure ◽  
Pressure Gradients ◽  
Norwood Operation ◽  
Kaplan Meier ◽  
Left Heart Syndrome

AbstractObstruction of the reconstructed aortic arch, or the neoaortic arch, is now known to be an important factor increasing mortality after the Norwood operation for hypoplastic left heart syndrome. Transcatheter balloon angioplasty has been shown to provide effective relief of both native aortic coarctation and obstructions of the aortic arch occurring subsequent to therapeutic intervention. We sought to determine the outcomes of balloon angioplasty used as an initial treatment for obstruction of the neoaortic arch occurring after the Norwood operation. We gathered the characteristics of 58 patients with such obstruction from 8 institutions, noting procedural factors and outcomes of initial balloon dilation. Obstruction occurred at a median interval of 4 months, with a range from 1.5 months to 6.3 years, after a Norwood operation. Ventricular dysfunction was present before dilation in 13 patients. Mean peak to peak systolic pressure gradients were acutely reduced from 31±20 mm Hg to 6±9 mmHg (p<0.001), with outcome subjectively judged to be successful in 89%- Three patients with pre-existing ventricular dysfunction died within 48 hours of dilation. There were 10 additional deaths during the period of followup, with Kaplan Meier estimates of survival after intervention of 87% at 1 month, 77% at 12 months, and 72% after 15 months. In addition, 9 patients required re-intervention during the period of follow-up, with Kaplan Meier estimates of freedom from re-intervention after dilation of 87% at 6 months, 78% at 12 months and 74% after 18 months. Although transcatheter dilation of neoaortic arch obstructions after Norwood operation is successful, there is a high risk of re-intervention and ongoing mortality in this subgroup of patients. Close follow-up is recommended.

Direct Videoscopic Approach to the Descending Thoracic Aorta for Aortic Arch Endograft Delivery: Evaluation in a Porcine Model

2007 ◽  
Vol 14 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Matteus A. M. Linsen ◽  
Vincent Jongkind ◽  
Laurens Huisman ◽  
Kak K. Yeung ◽  
Jeroen Diks ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Thoracic Aorta ◽  
Porcine Model ◽  
Descending Thoracic Aorta
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