Background and approximator placement
Place the background beside the vessel, lift up on the vessel and pull the background under it.
Holding the approximator over the vessel, probe to find a good position for its clamps.
Remember to place the clamps as far apart as possible, with no collateral vessel stump midway between them and enough dissected vessel length proximal and distal to them to avoid twisting the vessel when flipping over the approximator.
Apply the proximal approximator clamp first and wait for the vessel to dilate.
Then place the distal approximator clamp.
Try to apply the clamps correctly the first time, as applying them several times or moving them along the fragile venous wall may injure the vessel.