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Create a new sketch, move to one end of the obstruction
Use Spline to mimic the artery boundary (just click on the edge of the artery that is visible and follow the dots that show up)
Use Offset Curve to create two more curves: one inside and one outside the artery
Return to 3D mode
Hide the artery
Delete the inner portions of the resulting surfaces leaving only the outer ring
Unhide the artery
Do the same on the other end of the obstruction
Hide the artery
Use Blend and then control + click the two faces that remain
Unhide the artery
Ctrl + Click the missing ellipse and fillet and click Fill if you haven’t already (Note, if a curve is made instead, use the stitch tool to combine the surfaces into a surface)
Use Combine as before to create three solids
Delete or suppress all entities except the artery
Use pull to smooth any sharp edges as desired
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