Clinical Context
A 72-year-old male with progressive claudication, rest pain in the lower extremities, and imaging-confirmed severe aortoiliac occlusive disease (chronically occluded infrarenal aorta and bilateral common iliac arteries) is scheduled for revascularization. The vascular surgery team plans an extra-anatomic axillofemoral bypass using a synthetic graft to restore perfusion to the lower extremity by connecting the axillary artery to the femoral artery (CPT 35621). Preoperative workup includes arterial duplex ultrasound and CT angiography, cardiopulmonary risk assessment, and informed consent discussing limb salvage and graft patency expectations. The procedure is performed in an operating room under general or regional anesthesia with vascular surgery or cardiothoracic-vessel trained surgeons and perioperative vascular access and monitoring. Postoperative care includes anticoagulation management, wound and graft surveillance, and vascular imaging follow-up to assess patency and limb perfusion.
Coding Specifications
| Modifier | Description | When to Use |
|---|
00 | No specific modifier — standard reporting | Use for standard, complete procedures with no additional modifier indicated |
| 11 | Office or other outpatient setting (CMS sometimes uses for providers' internal purposes) | Rarely used for this inpatient/OR procedure; not typical but may appear for claims systems that require a default primary modifier |
| 22 | Increased procedural services | Use when the work, time, and technical difficulty substantially exceed usual for CPT 35621 (document justification) |
| 23 | Unusual anesthesia | Use when general anesthesia is contraindicated or not used and excessive difficulty of local/monitored anesthesia required (document reason) |
| 26 | Professional component | Use if reporting only the surgeon's professional component separate from technical facility billing (uncommon for most facility-based vascular surgery claims) |
| 52 | Reduced services | Use when the procedure is partially reduced or not completed as planned and documentation supports reduced service |
| 53 | Discontinued procedure | Use when the procedure is started but discontinued due to patient condition or intraoperative findings (report with documentation) |
| 62 | Two surgeons | Use when two surgeons work together as primary surgeons, each reporting their portion per payer policy (document roles) |
| 66 | Surgical team (multiple surgeons) | Use when a surgical team is required for complex open revascularization and team billing is permitted by the payer |
| 79 | Unrelated procedure or service by the same physician during the postoperative period | Use when an unrelated procedure is performed during global period and distinct from the bypass procedure |
| 80 | Assistant surgeon | Use when an assistant-at-surgery (physician) participates and assistant reporting is allowed by payer |
| 81 | Minimum assistant surgeon | Use when a minimal assistant role is documented and permitted by payer |
| AS | Physician is the primary surgeon (Medicare-specific) | Use to indicate the physician performing the primary surgery when required by Medicare billing rules |
| LT | Left side | Use to indicate laterality when applicable for laterality reporting to payers that require side-specific modifiers |
| Taxonomy Code | Specialty | Notes |
|---|
208800000X | Vascular Surgery | Primary specialty performing open axillofemoral bypass and aortoiliac revascularization |
| 207L00000X | Thoracic and Cardiac Surgery | May perform complex aortic and extra-anatomic bypass procedures in some centers |
| 207T00000X | General Surgery | General surgeons with vascular training may perform peripheral arterial bypass procedures |
| 207L0006X | Cardiothoracic Vascular Surgery | Surgeons with combined cardiothoracic and vascular expertise involved in complex thoracoabdominal vascular reconstructions |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|
I70.2 | Atherosclerosis of native arteries of the extremities | Peripheral atherosclerotic disease causing aortoiliac occlusive lesions addressed by axillofemoral bypass |
| I70.21 | Atherosclerosis of native arteries of the extremities with intermittent claudication | Symptom driving revascularization to improve functional status and walking distance |
| I70.23 | Atherosclerosis of native arteries of the extremities with gangrene | Severe ischemia risking limb loss, indication for urgent revascularization such as CPT 35621 |
| I74.3 | Embolism and thrombosis of arteries of the lower extremity | Acute or chronic thrombotic/embolic disease that may necessitate bypass if endovascular options fail |
| I77.1 | Stricture of artery | Focal arterial occlusion or stenosis in the aortoiliac segment that can be managed with bypass when anatomy is unsuitable for endovascular repair |
| Z95.2 | Presence of prosthetic arterial graft | Relevant for patients with prior grafts who require additional or revision bypass procedures |
| I96 | Gangrene, not elsewhere classified | Severe ischemic complication that may prompt revascularization to salvage limb |
| E11.51 | Type 2 diabetes mellitus with diabetic peripheral angiopathy with gangrene | Diabetes with advanced peripheral vascular disease increasing need for surgical bypass to restore perfusion |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|
36147 | Arterial catheterization or cannulation for diagnostic or therapeutic injection, percutaneous, femoral, brachial or axillary, including diagnostic angiography when performed | Commonly performed preoperatively or intraoperatively for angiographic assessment or distal run-off evaluation prior to CPT 35621 |
| 35566 | Thromboendarterectomy, iliac artery, with or without patch graft | Performed in alternative open aortoiliac reconstructions; may be performed in same patient if focal lesions are amenable to endarterectomy rather than extra-anatomic bypass |
| 35102 | Graft, bypass, or bypass graft, femoral-femoral bypass, prosthetic graft | Femoral-femoral bypass is an alternative extra-anatomic revascularization; may be considered in similar clinical workflows or performed sequentially in staged procedures |
| 36818 | Introduction of tunneled intravascular catheter, dialysis or long term | May be billed when long-term vascular access is needed in complex vascular patients (contextual ancillary service) |
| 93975 | Duplex scan of extremity arteries, bilateral study | Noninvasive testing used preoperatively and postoperatively to assess arterial disease and graft patency |