**3. Step-by-step explanation of the procedure**

## **3.1 First step**

Perform antisepsis, and surgical fields are placed as for any surgery in the areas that the surgeon considers (**Figure 9**).

## **3.2 Second step**

Puncture of the occluded vein guided by doppler ultrasound and positioning of the guide wire (**Figure 10**).

I prefer to puncture the vein in a place where it is as straight as possible to be able to pass the guide.

That is to say, I prefer to puncture the vein in the right internal jugular vein and both femoral veins, the left subclavian and jugular vein, we have the innominate

**Figure 9.** *All set to start, surgical drapes, fluoroscopy, and doppler ultrasound.*

**Figure 10.** *Doppler photo showing occlusion of the jugular above and orange carotid arterial flow below.*

vein curve, and for the right subcalvia a curve of almost 90 degrees to enter the cava.
