Summary & Overview

CPT 35666: Femoral-to-Tibial/Peroneal Bypass with Synthetic Graft

CPT code 35666 denotes a lower-extremity arterial bypass using a synthetic graft from the femoral artery to a tibial or peroneal target in the calf. This revascularization procedure is a key intervention for limb-threatening ischemia and symptomatic peripheral arterial disease, aiming to restore distal perfusion and prevent amputation. Nationally, such operations are central to vascular surgery practice and influence hospital surgical volumes, device utilization, and post-operative care pathways.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise view of clinical context, expected sites of service, and commonly associated billing considerations.

Readers will learn the procedural intent and clinical indications for the bypass, the typical settings where the service is delivered, and which major payers include this service line in coverage frameworks. Where available, readers will find benchmarks and reimbursement context, documentation and coding considerations, and policy updates that affect preauthorization and coverage determinations. Data not available in the input is noted explicitly in applicable sections.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 35666vascular surgerylower extremity bypasssynthetic graftperipheral arterial diseaserevascularizationoperating roominpatient surgery

Billing Code Overview

CPT code 35666 describes a surgical bypass procedure using a synthetic graft to reroute blood flow around a blockage in the femoral artery, with the distal anastomosis to the anterior tibial, posterior tibial, or peroneal artery in the calf (the back part of the leg below the knee). This procedure establishes an alternate conduit to restore arterial perfusion to the lower leg and foot.

Service type: Arterial bypass surgery (lower extremity)

Typical site of service: Inpatient or outpatient hospital operating room for vascular surgery procedures

Clinical & Coding Specifications

Clinical Context

A 68-year-old patient with long-standing peripheral arterial disease presents with rest pain and a nonhealing plantar ulcer of the right foot. Noninvasive testing (ankle-brachial index and arterial duplex) demonstrates a significant right superficial femoral artery occlusion with poor runoff to the calf and foot. After medical optimization and unsuccessful endovascular attempts or when lesion anatomy is unsuitable for angioplasty/stenting, the vascular surgery team schedules an open femorotibial bypass using a synthetic graft from the common femoral or superficial femoral artery to a tibial artery (anterior tibial, posterior tibial, or peroneal) to restore distal perfusion.

Preoperative workflow includes vascular laboratory imaging, cross-sectional imaging as indicated, anesthesia preop evaluation, and informed consent documenting goals (limb salvage, wound healing, relief of rest pain). Intraoperative workflow includes general or regional anesthesia, surgical exposure of the femoral artery and chosen tibial target, preparation and anastomosis of a synthetic prosthetic graft, completion angiography or Doppler assessment of graft patency, and wound closure. Postoperative workflow includes monitoring in a recovery or step-down unit, antiplatelet/anticoagulation management per protocol, graft surveillance with duplex ultrasound, wound care, and staged outpatient follow-up for wound healing and graft function assessment.

Coding Specifications

Modifier	Description	When to Use
`LT`	Left side	When the bypass is performed on the left lower extremity.
`RT`	Right side	When the bypass is performed on the right lower extremity.
`50`	Bilateral procedure	When bilateral femorotibial bypasses are performed during the same operative session.
`62`	Two surgeons	When two surgeons perform distinct portions of the procedure concurrently and both are reporting their work.
`78`	Unplanned return to OR for related procedure during global period	When the patient requires an unplanned reoperation related to the original bypass within the global period.
`79`	Unrelated procedure or service by same physician during global period	When an unrelated procedure is performed by the same surgeon during the global period.
`52`	Reduced services	When part of the procedure is intentionally not completed or performed to a lesser extent.
`53`	Discontinued procedure	When the procedure is started but discontinued due to extenuating circumstances or patient condition.
`22`	Increased procedural services	When the procedure requires substantially greater work than typical (document rationale).
`26`	Professional component	When reporting only the physician’s professional component separate from technical services (rare for surgical reporting).
`62`	Two surgeons	(listed to emphasize applicability to complex reconstructions requiring dual surgeons).
`79`	Unrelated procedure	(reiterated for complex inpatient settings where unrelated procedures occur).

Taxonomy Code	Specialty	Notes
207RG0100X	Vascular Surgery	Surgeons who most commonly perform open femorotibial bypass procedures.
207RI0200X	Thoracic and Cardiovascular Surgery	Cardiovascular surgeons with peripheral vascular expertise may perform these bypasses.
2080P0006X	General Surgery	General surgeons with vascular privileges in some centers perform peripheral bypass surgery.
2084P0800X	Interventional Cardiology	May be involved in preoperative endovascular attempts or hybrid procedures.
225100000X	Podiatric Surgery	Podiatric surgeons may participate in distal target selection, wound care, and limb salvage teams.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I70.213`	Atherosclerosis of native arteries of extremities, right leg with intermittent claudication	Common indication for femorotibial bypass when lifestyle-limiting claudication or progression to critical ischemia occurs.
`I70.214`	Atherosclerosis of native arteries of extremities, left leg with intermittent claudication	As above for the left leg.
`I70.241`	Atherosclerosis of native arteries of extremities, right leg with rest pain	Rest pain indicates critical limb ischemia and is an indication for revascularization such as bypass.
`I70.242`	Atherosclerosis of native arteries of extremities, left leg with rest pain	As above for the left leg.
`I70.23`	Atherosclerosis of native arteries of extremities with intermittent claudication, bilateral legs	Bilateral disease that may necessitate staged or bilateral interventions.
`I70.25`	Atherosclerosis of native arteries of extremities with ulceration	Nonhealing ulcers are a frequent reason to pursue distal bypass for limb salvage.
`I96`	Gangrene, not elsewhere classified	Advanced ischemic tissue loss that may prompt urgent revascularization to avoid amputation.
`E11.51`	Type 2 diabetes mellitus with diabetic peripheral angiopathy without gangrene	Diabetes is a common comorbidity contributing to peripheral arterial disease and poor wound healing.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`93925`	Noninvasive physiologic studies of arterial circulation, duplex scan of lower extremity arteries, complete bilateral or unilateral study	Preoperative and postoperative graft surveillance and evaluation of inflow/outflow.
`36147`	Introduction of catheter, arterial system, radiological supervision and interpretation, selective catheter placement, extremity, diagnostic; radiological evaluation with angiography	Diagnostic or intraoperative angiography to define lesion anatomy prior to or during bypass.
`75710`	Angiography, extremity, unilateral, radiological supervision and interpretation	Contrast angiography performed to assess run-off vessels and confirm bypass flow.
`36478`	Endovenous ablation therapy of incompetent veins (separate procedure example)`	Data not available in the input.
`34802`	Vascular graft; crural or pedal bypass, with autogenous vein when used	Alternative conduit option (autogenous vein) often considered or used in bypass procedures to tibial vessels.