Perspective Chapter: Transcatheter Interventions in the Management of Aortic Valve Stenosis

Transcatheter interventions that are useful in the management of valvar aortic stenosis will be reviewed. This chapter focuses on congenital aortic valve stenosis. The procedure of balloon aortic valvuloplasty (BAV) and the results were reviewed; BAV offers good relief of aortic valve obstruction and serves as substitute to surgery and is considered a favored option in the management of aortic stenosis in all age groups. However, BAV in elderly patients with calcific aortic stenosis offers only a temporary relief of aortic valve obstruction and BAV is not recommended for this subgroup of patients. Except for neonates, most patients are discharged home within 24-hours after BAV. While there is conclusive data for provision of pressure gradient relief both acutely and at follow-up as well as deferral of any surgery after BAV, the development of aortic insufficiency (AI) at long-term follow-up is a most important drawback. In neonates, severe AI may develop necessitating surgical intervention. Notwithstanding these drawbacks, BAV is presently believed to be a therapeutic procedure of option in the treatment of valvar aortic stenosis in pediatric and young adult patients. Methodical follow-up to identify reappearance of aortic obstruction and development of substantial AI is suggested

Fontan Operation: A Comprehensive Review

Since the first description of the Fontan operation in the early 1970s, a number of modifications have been introduced and currently staged, total cavopulmonary connection with fenestration has become the most commonly used multistage surgery in diverting the vena caval blood flow into the lungs. The existing ventricle, whether it is left or right, is utilized to supply systemic circuit. During Stage I, palliative surgery is performed, usually at presentation in the neonatal period/early infancy, on the basis of pathophysiology of the cardiac defect. During Stage II, a bidirectional Glenn procedure is undertaken in which the superior vena caval flow is diverted into the lungs at an approximate age of 6 months. During Stage IIIA, the blood flow from the inferior vena cava (IVC) is rerouted into the pulmonary arteries, typically by an extra-cardiac conduit along with a fenestration, generally around 2 years of age. During Stage IIIB, the fenestration is closed by transcatheter methodology 6–12 months after Stage IIIA. The evolution of Fontan concepts, the indications for Fontan surgery, and the results of old and current types of Fontan operation form the focus of this review

Derived Properties of Surface Tension for Hard Sphere Liquids from an Equation of State

Analytical expressions for surface tension, derived by using the equation of state from the scaled particle theory and that from sound propagation through liquids, have boon subjected to arrive at Eotvos constant and compressibility coefficient by forming the derivatives of surface energy and pressure coefficient of surface tension respectively. It is gratifying to note that value so obtained are in fair agreement with experiment, especially when it is noted that they are obtained as the second derivatives of Helmholtz free energy

Five- to nine-year follow-up results of balloon angioplasty of native aortic coarctation in infants and children

AbstractObjectives. To evaluate the usefulness of balloon angioplasty for relief of native aortic coarctation, we reviewed our experience with this procedure, with special emphasis on follow-up results.Background. Controversy exists with regard to the role of balloon angioplasty in the treatment of native aortic coarctation.Methods. During an 8.7-year period ending September 1993, 67 neonates, infants and children underwent balloon angioplasty for native aortic coarctation. A retrospective review of this experience with emphasis on long-term follow-up forms the basis of this study.Results. Balloon angioplasty produced a reduction in the peak-to-peak coarctation gradient from 46 ± 17 (mean ± SD) to 11 ± 9 mm Hg (p < 0.001). No patient required immediate surgical intervention. At intermediate-term follow-up (14 ± 11 months), catheterization (58 patients) and blood pressure (2 patients) data revealed a residual gradient of 16 ± 15 mm Hg (p > 0.1). When individual results were scrutinized, 15 (25%) of 60 had recoarctation, defined as peak gradient >20 mm Hg. Recoarctation was higher (p < 0.01) in neonates (5 [83%] of 6) and infants (7 [39%] of 18) than in children (3 [8%] of 36), respectively. Two infants in our early experience had surgical resection with excellent results. Three patients had no discrete narrowing but had normal arm blood pressure and had no intervention. The remaining 10 patients had repeat balloon angioplasty with reduction in peak gradient from 52 ± 13 to 9 ± 8 mm Hg (p < 0.001). Reexamination 31 ± 18 months after repeat angioplasty revealed a residual gradient of 3 to 19 mm Hg (mean 11 ± 6). Three (5%) of 58 patients who underwent follow-up angiography developed an aneurysm. Detailed evaluation of the femoral artery performed in 51 (88%) of 58 patients at follow-up catheterization revealed patency of the femoral artery in 44 (86%) of 51 patients. Femoral artery occlusion, complete in three (6%) and partial in four (8%), was observed, but all had excellent collateral flow. Blood pressure, echocardiography-Doppler ultrasound and repeat angiographic or magnetic resonance imaging data 5 to 9 years after angioplasty revealed no new aneurysms and minimal (2%) late recoarctation.Conclusions. On the basis of these data, it is concluded that balloon angioplasty is safe and effective in the treatment of native aortic coarctation; significant incidence of recoarctation is seen in neonates and infants; repeat balloon angioplasty for recoarctation is feasible and effective; and the time has come to consider balloon angioplasty as a therapeutic procedure of choice for the treatment of native aortic coarctation

Histochemical changes in pearl millet plants grown from Sg-Toxin treated seeds

Histochemical changes in the pearl millet seeds soaked in 2 percent Sg toxin and in the leaves seedlings of raised from treated seeds were studied. No noticeable changes occurred in the embryo and endosperm in the seed at the time of germination. However, the number of polysaccharide granules increased during the initial symptoms (stage I) in the bundle sheath cells of leaves. Subsequently at stage II, the number of PAS positive granules decreased and disappeared at stage III. The proteinoplasts Were less stained at stage I, which gradually disintegrated and ultimately disappeared. From stage I to III symptom development nucleic acids gradually decrease