Search results for "shunt"
showing 10 items of 114 documents
Chronic Adult Hydrocephalus
1974
Knowledge of Wallerian degeneration began in 1852 and, following experimental research on degeneration and regeneration of interrupted nerves, surgeons realized that reinnervation of end organs depended on growth of axons through the interrupted area of nerve. Therefore surgeons tried to reanastomose the stumps. Failures of reinnervation could not be blamed on lack of axoplasma metabolism and flow from cell body to suture line because the clinical observation of amputation neuromas and their constant recurrence demonstrated the unfailing delivery of axoplasma by the nerve cell body; at times to the deep concern of the surgeon, and the constant pain of the patient. The electron microscope sh…
Ventilation/perfusion ratios measured by multiple inert gas elimination during experimental cardiopulmonary resuscitation
2014
Background During cardiopulmonary resuscitation (CPR) the ventilation/perfusion distribution (VA/Q) within the lung is difficult to assess. This experimental study examines the capability of multiple inert gas elimination (MIGET) to determine VA/Q under CPR conditions in a pig model. Methods Twenty-one anaesthetised pigs were randomised to three fractions of inspired oxygen (1.0, 0.7 or 0.21). VA/Q by micropore membrane inlet mass spectrometry-derived MIGET was determined at baseline and during CPR following induction of ventricular fibrillation. Haemodynamics, blood gases, ventilation distribution by electrical impedance tomography and return of spontaneous circulation were assessed. Inter…
Perimeter leakage current in polymer light emitting diodes
2009
Observation of leakage current paths through the device perimeter in standard poly(phenylene vinylene)-based light-emitting devices is reported. Perimeter leakage currents govern the diode performance in reverse and low positive bias and exhibit an ohmic character. Current density correlates with the perimeter-to-area ratio thus indicating that leakage currents are mainly confined on polymer regions in the vicinity of metallic contact limits (device perimeter). © 2008 Elsevier B.V. All rights reserved.
Neuroendoscopic Navigated One-Step Removal of Crossed Ventricular Catheter Fragments: Technical Note
2021
Abstract Introduction Neuroendoscopy plays an important role in minimally invasive neurosurgery. The authors reported an interesting case of a pediatric patient with multiple ventriculoperitoneal shunt (VPS) revision surgeries, presenting with VPS infection and with two crossed intraventricular floating catheter fragments, successfully removed through a neuroendoscopic navigated one-step procedure. A literature review regarding this exceedingly rare condition has also been discussed. Case Description An 11-year-old female patient with a history of congenital hydrocephalus was admitted to the emergency department with symptoms of intracranial hypertension, psychomotor agitation, and tetrapar…
Physiopathological, clinical and therapeutic aspects of hepatopulmonary syndrome
2010
Flußquantifizierung von intrakardialen Shuntvolumina unter Verwendung der MR-Phasenkontrast-Technik in Atemanhaltephase
1998
PURPOSE Comparison of a breath-hold, velocity-encoded, phase-difference magnetic resonance (MR) sequence for intracardiac shunt flow measurement with the invasive shunt size determination by oximetry. PATIENTS AND METHODS 10 patients with different cardiac shunts (6 ASD/3 VSD/1 PDA) and four healthy individuals were investigated using a 1.5 Tesla Siemens Vision system. For flow measurements a breath-hold, velocity-encoded, phase-difference magnetic resonance (MR) sequence was used ('through plane', FLASH 2D-sequence, TR/TE 110/5 ms, 'velocity encoding' 250 cm/s). Mean flow (ml/R-R interval) in the ascending aorta, the pulmonary trunk, and the right and left pulmonary arteries was determined…
The subway tunneling technique for distal shunt catheter insertion.
2019
Dear Editor,We read with interest the article by Osman et al. titled ‘Trocar assisted distal shunt tube insertion with intra-operative X-Ray confirmation’. The authors purpose their technique to pl...
Erfassung hämodynamischer Parameter bei Patienten mit chronischer thromboembolischer pulmonaler Hypertonie mittels MRT vor und nach Thrombendarteriek…
2003
Purpose: To evaluate the potential of MRI to grade cardiac impairment and pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension (CTEPH) in comparison with invasive pressure measurements before and after surgery. Materials and Methods: We examined 35 patients with CTEPH before and after pulmonary thromboendarterectomy (PTE). For assessment of hemodynamics, velocity-encoded segmented GE-sequences (pulmonary arteries and ascending aorta) and segmented cine GE-sequences along the short axis of the heart were performed. The analysis comprised calculation of ejection fractions, peak velocities, mean pulmonary arterial flow and vessel diameter. 10 volunteers served …
Abnormalities of the umbilico-portal venous system in Down syndrome: A report of two new patients
2003
Congenital anomalies of the umbilical and portal venous system are rare vascular malformations which are often associated with anomalies of the heart and gastrointestinal tract. Association with chromosomal disorders has been sporadically reported. We now report on two patients with trisomy 21 and congenital anomalies of the umbilico-portal system. A male fetus showed absence of the intrahepatic portal vein (PV) and ductus venosus with a direct communication between portal sinus and inferior vena cava exhibiting an umbilicosystemic total shunt during the fetal life and a portosystemic total shunt after birth. A female infant showed absence of the intrahepatic PV and a total portocaval shunt…
A coronary right fistula canalized in a small accessory right atrial chamber.
2007
The coronary artery fistulas are rare congenital anomalies with a very low incidence. These can be symptomatic or asymptomatic because the hemodynamic consequences of the fistula vary and depend on the shunt dimensions. Discordant opinions instead are present in the literature for the defect closing in asymptomatic patients. Here, we describe a patient affected by a coronary right fistula canalized in a small accessory right atrial chamber. During follow-up, we observed a progressive dilatation of the right coronary artery (maximum diameter 10.3 mm) with hemodynamic overload of the right sections.