Question

A 55-year-old male underwent a common femoral artery to below knee popliteal artery bypass using reversed great saphenous vein graft one month ago.
How are the lesions in the venous grafts categorised based on PSV and velocity ratios (Vr)?

Hint:

PSV and Vr are key indicators of graft health. A higher PSV and Vr typically suggest more severe stenosis, which requires prompt attention.

Answer 1

Step 1: Understanding the classification of lesions.
Lesions in venous grafts are typically assessed based on Peak Systolic Velocity (PSV) and Velocity Ratio (Vr). These parameters are used to determine the degree of stenosis and help in classifying graft lesions.

Step 2: PSV and Vr classification.
- Normal graft: PSV less than 100 cm/s and a Vr of less than 2.0. This indicates that the graft is patent with no significant stenosis.
- Mild stenosis: PSV between 100 and 200 cm/s with a Vr between 2.0 and 3.0. This suggests a minor narrowing that is likely not causing significant blood flow reduction.
- Moderate stenosis: PSV between 200 and 300 cm/s with a Vr of 3.0 to 4.0. This indicates moderate narrowing, which may be associated with some symptoms of claudication.
- Severe stenosis: PSV greater than 300 cm/s with a Vr greater than 4.0. This is indicative of significant stenosis or impending graft failure, and intervention is likely needed.
- Graft occlusion: If the PSV is absent or significantly reduced and there is no flow detected, the graft is considered occluded.

Step 3: Conclusion.
Lesions in venous grafts are classified into normal, mild, moderate, or severe stenosis based on PSV and Vr values. Timely intervention is needed for moderate or severe stenosis to prevent graft failure.