Athscl unsp type bypass of the extrm w gangrene, bi legs

This code signifies a severe form of peripheral artery disease affecting both legs, specifically involving atherosclerosis within a previously placed bypass graft. The condition has progressed to gangrene, indicating tissue death due to critical ischemia. This diagnosis points to a failed or failing revascularization attempt in the lower extremities.

Apply this code when documentation clearly states atherosclerosis of a bypass graft in both legs, complicated by gangrene. This typically occurs in patients with a history of lower extremity revascularization who present with non-healing wounds, black/necrotic tissue, and signs of critical limb ischemia. Supporting documentation includes operative reports detailing bypass graft placement, vascular studies confirming graft stenosis/occlusion, and clinical notes describing gangrenous changes.

• Ensure documentation specifies "bypass graft" involvement, not native vessel atherosclerosis.
• Verify the laterality is explicitly "bilateral legs" and that gangrene is present.
• Sequence this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if treating a complication of the gangrene.