I70.642
BillableAtherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of calf
HCC Category Mapping
RxHCCHCC 311 — Diabetic and Chronic Skin Ulcer
0.000What This Code Means
Hardening of arteries in a synthetic bypass graft of the left leg with an open sore on the calf.
Coding Tips
- •Verify documentation specifies left leg and calf location to ensure correct code selection
- •Calf ulceration differs from thigh or ankle; confirm anatomical site in clinical notes
Clinical Significance
This code captures atherosclerosis affecting nonbiological (synthetic) bypass graft(s) of the extremities with ulceration of calf 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., calf)
- ✓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 materialI70.431-I70.449 — Atherosclerosis of autologous vein bypass graft with ulceration; for saphenous or other autologous vein graftsI70.331-I70.349 — Atherosclerosis of unspecified bypass graft with ulceration; only when graft type is undocumentedI70.231-I70.249 — Atherosclerosis of native arteries with ulceration; for native vessel disease, not bypass graftsL97.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└I70.642Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of calf
└I70.642Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of calf