I70.645

Billable

Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of foot

HCC Category Mapping

RxHCCHCC 311 — Diabetic and Chronic Skin Ulcer

0.000

What This Code Means

This code describes a condition where fatty deposits have built up in an artificial bypass graft in the left leg, causing an ulcer (open sore) to develop on a part of the foot other than the heel or toe. This is a serious circulation problem that occurs when the synthetic graft used to bypass a blocked artery becomes narrowed by plaque.

Coding Tips

•Verify the graft type is nonbiological (synthetic) and confirm the ulceration location is documented as 'other part of foot' rather than heel, midfoot, or toe to ensure accurate code selection
•This code requires documentation of both the atherosclerosis of the bypass graft AND the presence of ulceration; if only the graft disease exists without ulceration, use a different I70.64x code

Clinical Significance

This code captures atherosclerosis affecting nonbiological (synthetic) bypass graft(s) of the extremities with ulceration of other part of the foot in the left lower extremity, indicating Fontaine Stage III-IV peripheral arterial disease. Ulceration in the setting of bypass graft atherosclerosis reflects inadequate distal perfusion despite prior surgical revascularization, suggesting graft compromise or disease progression. These patients require complex wound management, serial vascular assessments, and potential graft revision or amputation.

Documentation Requirements

✓Confirmed diagnosis of atherosclerosis affecting nonbiological (synthetic) bypass graft(s)
✓Type of bypass graft material documented (synthetic/nonbiological vs. other type such as composite or mixed-material graft)
✓Laterality clearly documented (left lower extremity)
✓History of bypass graft surgery with approximate date or timeframe
✓Current status and monitoring plan for the bypass graft
✓Ulcer location specifically documented (e.g., other part of the foot)
✓Ulcer characteristics: size, depth, stage/grade, wound bed description
✓Vascular etiology confirmed — distinguishing from diabetic, venous, or pressure ulcers
✓Wound care treatment plan and follow-up schedule
✓Consider additional code for ulcer severity (L97.- or L98.-) as applicable

Commonly Confused Codes

I70.531-I70.549 — Atherosclerosis of nonautologous biological bypass graft with ulceration; different graft material I70.431-I70.449 — Atherosclerosis of autologous vein bypass graft with ulceration; for saphenous or other autologous vein grafts I70.331-I70.349 — Atherosclerosis of unspecified bypass graft with ulceration; only when graft type is undocumented I70.231-I70.249 — Atherosclerosis of native arteries with ulceration; for native vessel disease, not bypass grafts L97.x — Non-pressure chronic ulcer of lower limb; may be needed as additional code for ulcer severity

Code Hierarchy

└I70Atherosclerosis └I70.6Atherosclerosis of nonbiological bypass graft(s) of the extremities └I70.64Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration └I70.645Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of foot

└I70.645Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of other part of foot