Athscl nonbiol bypass of the extrm w gangrene, unsp extrm

This code signifies a severe form of peripheral artery disease where a synthetic (nonbiological) bypass graft in an extremity has developed atherosclerosis, leading to tissue death (gangrene). It indicates a compromised blood supply to the limb due to plaque buildup within the artificial vessel, resulting in irreversible tissue damage.

Apply this code when documentation explicitly states atherosclerosis affecting a nonbiological bypass graft in an extremity, complicated by gangrene. This typically occurs in patients with a history of peripheral revascularization using synthetic grafts who present with signs of critical limb ischemia and tissue necrosis. Supporting documentation includes operative reports detailing graft placement, imaging studies confirming atherosclerosis, and physician notes describing gangrenous changes.

• Ensure the graft is specifically identified as "nonbiological" or "synthetic"; do not use for autogenous grafts.
• Confirm the presence of gangrene; this code is not for atherosclerosis of the graft without gangrene.
• If the specific extremity (e.g., right leg, left arm) is documented, a more specific code within the I70.66 series should be used.