Initial clinical experience with a novel absorbable graft underlines the potential of this new material to improve cardiac and vascular surgical procedures. In addition, better biocompatibility may reduce permanent implant-related complications. A longer follow-up is needed to assess the long-term effectiveness of biodegradable vascular grafts, including their ability to grow.
Palliative surgical treatment of CHDs associated with UAPA can be performed with a relatively low risk. Systemic-to-pulmonary artery shunt and transluminal balloon pulmonary valvuloplasty are methods of choice in patients with non-severe hypoplasia of the single pulmonary artery. The intravascular intervention is indicated more in patients with a prevailing valvular component of the pulmonary stenosis. Palliative reconstruction of the right ventricular outflow tract is a more favourable procedure for patients with a severe hypoplasia of the single pulmonary artery.
A new method of determination of chemical stability of automobile gasolines based on the proportion of absorbed oxygen (PAO) is proposed. Storage test results are used to formulate the chemical stability requirements for prolonged gasoline storage and to determine the standard PAO values.For organizations that store automobile gasolines for a prolonged period, a pressing task is prevention of deterioration in gasoline quality below what is specified by the normative documents until the storage expiry time. Determination of the level of potential tendency for oxidation of each batch of stored gasolines will help achieve this task.It is customary to assess the potential tendency of automobile gasolines for oxidation from the induction period [GOST (Federal State Standard) R 52068-2003] or from the total content of oxidation products (G0ST 22054-76) [1]. But these methods do not allow reliable prediction of the gasoline storage period and have several other deficiencies that impede their use in laboratories of petroleum products supplying organizations [1-3].In order to eliminate their intrinsic deficiencies and to determine the possible automobile gasoline storage period, a new chemical stability determination method was developed.As is well known, oxidation of hydrocarbons under storage conditions occurs in the liquid phase with absorption of oxygen [1, 2], so the amount of oxygen absorbed by the gasoline under test conditions is the most objective information parameter of its chemical stability.In order to determine the chemical stability from the proportion of absorbed oxygen, an installation based on GOST 52068-2003 was used as the experimental one after its modification: · a leak-proof metallic bomb fitted with a valving system, a device for oxygen supply, and a pressure gage; · a glass vessel for the test specimen with a lid that allows free access of oxygen to the specimen;· a liquid thermostat for maintaining the temperature at the 120 ± 1°C level; and · steel cylinders containing 98-99% oxygen under pressure.
Background: To present a 2-year follow-up regarding safety and hemodynamic performance of a new restorative vascular graft used as extracardiac cavo-pulmonary connection in patients with univentricular congenital heart malformations. Methods: The graft was implanted in five patients (aged 4-12 years) as extracardiac connection between the inferior vena cava and the pulmonary artery. The conduit consists of a bioabsorbable polymer-based implant able to generate endogenous tissue restoration leading to a fully functional neo-vessel while the polymer progressively absorbs. All patients have reached more than 24 months following surgery and underwent echocardiography and magnetic resonance imaging. Results: All patients are doing well at 24 months follow-up, with no graft-related serious adverse events.Transthoracic echocardiography demonstrated adequate function of the conduit in all patients while magnetic resonance imaging showed anatomical and functional stability of the restorative grafts. Conclusions: The new restorative conduit has been successfully used for the second step of the Fontan procedure as extracardiac total cavopulmonary connection. The results are promising because they suggest that complete transformation of a bioabsorbable polymer and replacement through endogenous tissue may represent a major advantage in the treatment of congenital heart disease patients. Further monitoring will allow to evaluate the long-term behavior of this new graft, in terms of clinical and hemodynamic performance, thrombogenicity and ability to grow.
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