Juxta-anastomotic stenosis is defined as stenosis that occurs within the section of the AVF that is immediately next to the artery anastomosis (within 2-3 cm). The lesion has the effect of obstructing AVF inflow. PE of the anastomosis and distal vein can easily identify this lesion (4,17,18). Duplex ultrasound may also be used to identify juxta-anastomotic lesions (19). CT angiography is the gold standard for identifying vascular abnormalities but cannot distinguish between inflammatory changes due to PVST and true neoplasm (20). MRI with gadolinium may show increased signal intensity on T1-weighted images and decreased signal intensity on T2-weighted images compared with the contralateral side (21).
Patients with symptomatic juxta-anastomotic stenosis require treatment. Endovascular intervention using balloon angioplasty or stenting are effective treatments for juxta-anastomotic stenosis (22,23). Patients who are not candidates for endovascular therapy can undergo surgical revision of the anastomosis site (24,25).
Anastomosis The joining or linking of vessels that are artery to artery or vein to vein. The overall goal of these connections is to provide additional routes for blood flow if one conduit gets clogged. An anastomosis of the arteries is called a bypass, while an anastomosis of the veins is called a shunting operation. Many types of anastomoses exist: end-to-end, end-to-side, side-to-side, patch, carotid-carotid, and carotid-subclavian. End-to-end anastomoses are the most common type of arterial anastomosis and consist of matching sections of artery that are joined together. This article focuses on bypass surgery; related articles can be found under Anatomy/General Surgery in the index.
Aortic valve area (AVA) of 1.0 cm2 and/or mean transaortic pressure gradient (MPG) of >40 mm Hg and/or peak aortic jet velocity (Vmax) of >4 m/s are presently used to characterize severe aortic stenosis (AS). AVA
Using these criteria, the average AVA is 0.6 cm2 and the prevalence of severe AS is 25%. However, there is considerable overlap in AVA between patients with and those without severe AS. Thus, it can be anticipated that many patients with mild or moderate AS will undergo aortic valve replacement because of symptoms or risk factors such as older age, higher MPG, and reduced left ventricular systolic function. This article focuses on identifying patients with severe AS.
Symptoms of severe AS include chest pain due to angina pectoris caused by increased cardiac work or heart failure due to decreased cardiac work. Asymptomatic patients with severe AS may have increased mortality rates compared with asymptomatic patients with mild or moderate AS. The presence of additional risk factors for adverse outcomes including older age, lower ejection fraction, and higher MPG further defines patients with severe AS. These patients should be identified prior to surgery so that appropriate precautions can be taken during anesthesia and surgery.
Treatment for severe AS includes medical management with beta-blockers and calcium channel blockers and surgical aortic valve replacement.
Intestinal atresia is a general phrase that refers to a full blockage or obstruction of the gut. Stenosis is a partial blockage that causes a narrowing of the intestine's aperture (lumen). The two conditions often occur together- many cases of intestinal atresia also have some degree of intestinal stenosis.
The cause of both atresias and stenoses is usually unknown. They can be found in animals of all ages, but they are most common in newborns. These disorders affect the intestines only; other parts of the gastrointestinal tract are rarely involved.
People with intestinal atresias are not able to digest certain foods because they have no working stomachs. This can lead to malnutrition if the condition is not treated promptly. If left untreated, intestinal atresias may require surgery to correct the problem or patients will need to rely on gastric juices for digestion.
In people with intestinal stenoses, part of the intestine is unable to expand like the rest of the organ. This causes pain in response to eating food that cannot fit through the narrowed area. As a result, these individuals must ingest large amounts of food daily in order to feel full.
Aortic or pulmonic valve stenosis causes a systolic murmur when blood is discharged through the restricted orifice. When ventricular pressures drop during relaxation, regurgitation of the same valves causes a diastolic murmur as blood flows backward through the sick valve. The severity of these murmurs is an indication of how much damage there is to the valve.
Pulmonary stenosis is usually found in infants and young children with left-to-right shunts such as patent ductus arteriosus or atrial septal defects. It occurs when blood pressure differences between the right and left sides of the heart cause the valve leaflets to calcify on the wrong side. This prevents them from closing completely, allowing more blood to flow toward the other side. As a result, there is increased stress on that side of the heart, leading to remodeling of the muscle fibers and eventual development of fibrosis.
The only cure for this disease is surgery to replace the defective valve. Do not confuse pulmonary stenosis with asthma, which can also cause shortness of breath upon exercise. Do not confuse it with pneumonitis, which is an inflammation of the lungs that can be caused by many things including drugs, chemicals, or infections.
Valvular stenosis is a valvular heart disease condition in which the tissues that compose the valve leaflets stiffen, narrowing the valve opening and limiting the quantity of blood that can flow through it. If the constriction is little, the heart's general function may be unaffected. But as the severity increases, it can lead to left ventricular hypertrophy (increased mass of muscle tissue in the heart), congestive heart failure, and eventually death.
The two main types of valvular stenosis are hypertrophic obstructive cardiomyopathy (HOCM) and atherosclerotic stenosis. HOCM is characterized by increased thickness of all or part of one or more of the four walls of the heart. This increase in wall thickness causes the left ventricle to become larger, making it harder for it to contract and thus reducing its efficiency. The heart tries to compensate for this reduced efficiency by becoming larger, which leads to additional pressure on other parts of the heart (such as the lungs) to work harder. This cycle can cause other problems, such as heart failure.
Atherosclerotic stenosis occurs when fatty deposits build up inside the walls of your arteries, restricting the flow of blood through them. As you age, these deposits will more likely to occur at sites where blood flows into the heart from large vessels such as the aorta and major coronary arteries.