Av Fistulas And Dialysis Grafts

Congestive heart failure (CHF) is a condition characterized by the heart's inability to pump enough blood to meet the body's needs. One of the reasons for this is increased venous return to the heart, which means that more blood is returning to the heart than it can effectively pump out. This leads to congestion and fluid buildup in the body, causing symptoms such as shortness of breath, fatigue, and swelling. Therefore, the given answer, congestive heart failure (CHF), accurately describes the condition caused by increased venous return to the heart.

Arterial steal syndrome occurs when there is increased pressure in the arteries within a graft or fistula, causing blood flow to be redirected away from the hand. This can result in reduced blood supply to the hand and fingers, leading to symptoms such as coldness, numbness, and pain. It is important to diagnose and manage this condition to prevent further complications and ensure adequate blood flow to the hand.

Angiography is a better option than ultrasound for graft stenosis. Angiography is an imaging technique that uses a contrast dye and X-rays to visualize blood vessels, including the graft. It provides detailed information about the location, severity, and extent of the stenosis, allowing for accurate diagnosis and planning of further treatment. On the other hand, ultrasound uses sound waves to create images and may not provide as clear and precise information about the stenosis. Therefore, angiography is preferred for evaluating graft stenosis.

Venous anastomosis is more common than arterial anastomosis. This is because veins have a higher capacity for blood flow and are more flexible than arteries. Additionally, venous anastomosis is often performed in surgical procedures to bypass obstructed or damaged veins, improve blood circulation, or create alternative pathways for blood flow. Arterial anastomosis, on the other hand, is less common and typically performed in cases of arterial blockages or to restore blood flow to an area that has been deprived of oxygen and nutrients.

An AV fistula is a communication between an artery and a vein that can occur due to trauma or be a congenital finding. This abnormal connection allows blood to flow directly from the artery to the vein, bypassing the capillaries. AV fistulas can lead to various complications, such as increased blood flow in the vein, which can cause swelling and damage to surrounding tissues. They are commonly created surgically for dialysis patients to provide a reliable access point for hemodialysis treatments.

Normal grafts and fistulas have high flow and low resistance. This is because grafts and fistulas are created surgically to provide an alternative route for blood flow in patients with compromised blood vessels. The purpose of these procedures is to increase the flow of blood, and therefore, grafts and fistulas are designed to have high flow. Additionally, they are constructed with larger diameter vessels to minimize resistance to blood flow, resulting in low resistance.

The answer is higher because when the access graft is closer to the heart, such as in the arm, it means that the graft is positioned in a major blood vessel that is closer to the heart. This increases the risk because any complications or problems with the graft can directly affect the heart and its function, leading to potentially more serious consequences.

Pseudoaneurysms are most commonly found in the groin region. This is because the femoral artery, located in the groin, is frequently accessed for procedures such as cardiac catheterization and arterial angiography. These procedures can sometimes cause damage to the artery, leading to the formation of a pseudoaneurysm. Additionally, the groin area is subject to trauma and injury, which can also contribute to the development of pseudoaneurysms in this region.

A change in the renal index (RI) of greater than or equal to .15 indicates a significant venous stenosis. This means that there is a blockage or narrowing of the veins in the renal system, which can lead to reduced blood flow and potentially serious complications. Venous stenosis can cause a decrease in kidney function and may require medical intervention to restore proper blood flow.

A PSV (Peak Systolic Velocity) measurement is used to assess the severity of stenosis (narrowing) in fistulas. In this case, a PSV measurement above 250 cm/s indicates a 50% stenosis. This means that if the PSV is higher than 250 cm/s, it suggests that the fistula is significantly narrowed, potentially causing restricted blood flow.

Grafts and fistulas typically have high PSV (peak systolic velocity) values ranging between 100-400 cm/s and high EDV (end diastolic velocity) values between 60-200 cm/s.

When conducting compression of pseudoaneurysms, it is important to check the foot with a CW Doppler to ensure that the artery is not being blocked off and there is a pedal pulse. This is because the foot is the area where the pulse can be felt and the CW Doppler is a type of ultrasound that can detect blood flow in the artery. By checking the foot with a CW Doppler, one can ensure that the artery is not being obstructed and that there is a normal pedal pulse present.

Doppler imaging is a non-invasive technique that uses sound waves to measure blood flow. When compared to angiography, which is an invasive procedure that uses contrast dye to visualize blood vessels, Doppler imaging can overestimate the degree of stenosis. This is because Doppler imaging relies on the detection of blood flow velocity and may not accurately assess the actual narrowing of the blood vessel. Additionally, Doppler imaging may be affected by factors such as turbulence or calcification, leading to an overestimation of stenosis.

no they cannot be used- can blow graft

When pseudoaneurysms are visualized on ultrasound, there is a swirling pattern within the pseudo seen with color, known as the yin-yang sign and a to-fro pattern seen on Doppler.

A PSV (Peak Systolic Velocity) of less than 45 cm/s indicates impending graft failure. This means that the blood flow through the graft is significantly reduced, which can be a sign of a blockage or narrowing in the graft. It is important to monitor the PSV regularly to detect any potential issues with the graft and take appropriate measures to prevent graft failure.

If there is increased resistance flow in the inflow artery, it indicates that there is a blockage or narrowing in the graft outflow vein. This is because when there is stenosis or occlusion in the graft outflow vein, the resistance to blood flow increases in the inflow artery. Therefore, the statement is true.

The correct answer is that compression of a pseudoaneurysm is attempted at 10-minute intervals for up to 1 hour.

With mild graft stenosis, velocities are increased but not by more than 50% from the preceding segment. With moderate stenosis, velocities are increased between 50-99% from the preceding segment, and with severe stenosis, velocities increase more than 100% from the preceding segment.

The two most common sites of stenosis in a hemodialysis access graft are the venous anastomosis and the outflow vein. Stenosis refers to the narrowing or constriction of a blood vessel, and in the case of a hemodialysis access graft, it can occur at the point where the graft is connected to the patient's vein (venous anastomosis) as well as along the path of the outflow vein. These areas are prone to stenosis due to the high flow rates and turbulence of blood in these regions, which can lead to the formation of scar tissue and narrowing of the blood vessel.

The most common sites of stenosis in a hemodialysis graft are the venous anastomosis, outflow vein, and arterial vein. This is secondary to intimal hyperplasia and increased arterial pressure into the outflow vein.

In cases of severe graft stenosis, the peak systolic velocity (PSV) is expected to be greater than 300 cm/s. Additionally, a significant drop of approximately 50% in distal velocities can be observed. This is indicative of a significant obstruction or narrowing in the graft, leading to increased blood flow velocity proximally and decreased flow distally.

fistula velocites are not as high as graft velocities

The two hemodynamic complications mentioned in the answer are CHF (Congestive Heart Failure) and arterial steal syndrome. The answer also includes the different combinations of these complications, such as CHF and arterial steal syndrome, arterial steal syndrome and CHF.

The limitations of compression of a pseudoaneurysm include the presence of a patient on anticoagulant therapy, which can increase the risk of bleeding during the compression procedure. Additionally, patient discomfort can limit the effectiveness of compression as it may be difficult for the patient to tolerate the procedure. However, a decrease in blood pressure due to pain is not a limitation of compression, as it is not directly related to the effectiveness or feasibility of the procedure.

AV fistulas commonly form between the common femoral artery (CFA) and the common femoral vein (CFV). This is because catheter procedures, such as cardiac catheterization or angiography, often involve accessing the femoral artery and vein in the groin area. The close proximity of these vessels during the procedure increases the likelihood of an AV fistula forming between them. Therefore, the correct answer is "between CFA and CFV".

pulsatile flow is visualized

The normal findings of grafts and fistulas include a PSV (Peak Systolic Velocity) that is not greater than 300-400cm/s. Additionally, there should be a high diastolic velocity in both the inflow artery and the graft.

The correct answer is PSV >4m/s, plus ratio of >3:1, outflow in cephalic vein with ratio of 3:1. This answer indicates that in a radial artery - cephalic vein anastomosis, the peak systolic velocity (PSV) should be greater than 4m/s and the ratio of PSV in the radial artery to the cephalic vein should be greater than 3:1. Additionally, there should be outflow in the cephalic vein with a ratio of 3:1. These criteria suggest that the anastomosis is functioning properly and there is adequate blood flow through the radial artery into the cephalic vein.

Signs and symptoms of arterial steal syndrome include retrograde flow in the artery distal to the fistula or graft anastomosis, decreased blood flow to the hand distal to the graft or fistula, pain on exertion, pallor and coolness of the hand, digit/limb ischemia, stealing blood from the hand, and digital pressures are useful.

The correct answer includes three possible methods for resolving pseudoaneurysms: surgical repair, compression, and thrombin injection. Surgical repair involves physically repairing the damaged blood vessel through a surgical procedure. Compression involves applying pressure to the pseudoaneurysm to stop the bleeding and promote healing. Thrombin injection involves injecting thrombin, a clotting agent, into the pseudoaneurysm to promote clot formation and stop the bleeding. These three methods are commonly used in clinical practice to treat pseudoaneurysms depending on the specific case and patient's condition.

Occlusion refers to the blockage or obstruction of blood flow in a graft or fistula. The given correct answer includes several indicators of occlusion. "No flow in detected graft" suggests that there is a lack of blood flow through the graft, indicating a possible occlusion. The absence of a "thrill" sensation, which is a vibrating sensation felt over the graft, also suggests occlusion. "No flow with color and spectral doppler" indicates a lack of blood flow visualization using these imaging techniques, further supporting the presence of occlusion. Additionally, "no flow in outflow vein distal to graft or fistula" and "high resistance is seen in artery leading to graft or fistula" are both signs of occlusion. Lastly, the statement regarding the inability to visualize flow with color due to air in the graft wall is an exception that can occur in newly placed grafts.