Great saphenous vein cutdown for sheath placement

(A) Make a small incision overlying the course of the great saphenous vein. Isolate the vein by blunt dissection (proximal to distal, paralleling the course of the vein) using a curved hemostat, taking care to avoid injury to the saphenous nerve, which is in close proximity. Place a small vessel loop around the vein proximally and distally. Double-looping the proximal vessel helps control back bleeding from the incompetent vein.
(B) Apply traction to the vein and make a transverse venotomy by inserting a No. 11 scalpel blade into the vein perpendicular to its long axis and pulling the blade up through the vein wall. If needed, the venotomy can be widened to facilitate sheath insertion using a small Jacobson clamp.  
(C) Direct the sheath into the vein opening directly or with the aid of a cannulation tool, if needed, and advance the sheath to its hub. Maintain traction on the proximal and distal vessel loops to minimize back bleeding.
(D) At the completion of the procedure, replace the vessel loops with sutures proximally and distally, and then tie down the sutures as the sheath is removed.