Vascular sheath placement

sometimes our IR docs are asked only to place a vascular sheath for access in the jugular vein (Cordis sheath) so the Swan-Ganz catheter can be placed by another physician (not in our group) at a later time. Is there a code for just placing an ultrasonic guided sheath placement into the IJ?
I thought of using 36000 or 37799, along with +76937 (for US guidance), but not very confident. Even I feel that may be nothing can be coded for only the placement of the vascular sheath.
Please help.