CPT 35537 Aorto‑iliac Bypass Reimbursement | OpenPayer

Summary & Overview

CPT 35537: Aorto‑iliac Bypass with Vein Graft

CPT code 35537 denotes an open vascular bypass procedure in which a vein graft connects the aorta to an iliac artery segment to bypass an occlusion. This operation is a key option for revascularization in patients with significant aortoiliac occlusive disease and has implications for surgical capacity, inpatient utilization, and high-acuity vascular care nationally. Payers commonly managing coverage for this service include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will find clinical and billing context for CPT code 35537, including the procedure’s role in aortoiliac revascularization, typical site-of-service expectations, and an overview of common modifiers and payer considerations. The publication provides benchmarks and policy-relevant discussion for hospitals and vascular surgery practices, outlines coding and documentation priorities, and summarizes areas where payers may apply utilization management or prior authorization. Data not available in the input is noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare35537CPTaortoiliac bypassvascular surgeryvein graftinpatient surgeryrevascularizationsurgical procedure

Billing Code Overview

CPT code 35537 describes a surgical aortobiliac bypass using a vein graft to bypass an arterial obstruction. The procedure involves creating a bypass graft that connects the aorta to a portion of the iliac artery with a vein graft, restoring blood flow around a blocked vessel.

Service type: Open vascular bypass surgery
Typical site of service: Inpatient hospital operating room

Clinical & Coding Specifications

Clinical Context

A typical patient is an older adult with peripheral arterial disease and symptomatic aortoiliac occlusive disease presenting with lifestyle-limiting claudication or critical limb ischemia (rest pain, nonhealing ulcer). Preoperative workup includes vascular laboratory studies (ABI, arterial duplex), CT angiography or catheter-based angiography to define aortoiliac anatomy and confirm a proximal aortic inflow site and target iliac outflow. The vascular surgeon obtains informed consent, reviews comorbidities (coronary artery disease, diabetes, chronic kidney disease), and plans for an open aortobiiliac/ aortofemoral-type bypass using an autologous vein graft or prosthetic conduit as indicated.

Intraoperative workflow: general or regional anesthesia, midline or retroperitoneal exposure of the distal abdominal aorta and iliac arteries, systemic heparinization, proximal aortic clamp and distal control of the iliac segment, construction of an aortobi-iliac bypass with a reversed greater saphenous vein or synthetic graft, release of clamps with assessment of distal pulses and graft patency. Postoperative care includes monitoring in a step-down or ICU setting for hemodynamics, graft surveillance with duplex ultrasound, anticoagulation or antiplatelet therapy, wound care, and coordination of secondary prevention (smoking cessation, lipid management, diabetes control). Typical site of service is an inpatient hospital operating room; the procedure is commonly billed under vascular surgery services.

Coding Specifications

Modifier	Description	When to Use
`62`

CPT 35509: Carotid-to-Carotid Bypass with Vein Graft

CPT-35538-AORTO-ILIAC-VEIN-BYPASS

CPT 35538: Aorto-Iliac Bypass with Vein Graft

CPT-35566-FEMORAL-TO-TIBIAL-PERONEAL-BYPASS

CPT 35566: Femoral-to-Tibial/Peroneal Arterial Bypass

CPT-35523-BRACHIAL-TO-ULNAR-OR-RADIAL-VEIN-BYPASS

CPT 35523: Brachial to Ulnar or Radial Vein Bypass

CPT-35518-AXILLARY-ARTERY-TO-AXILLARY-ARTERY-BYPASS-VEIN-GRAFT

CPT 35518: Axillary-to-Axillary Artery Bypass with Vein Graft

CPT-35510-CAROTID-TO-BRACHIAL-ARTERY-BYPASS-VEIN-GRAFT

CPT 35510: Carotid-to-Brachial Artery Bypass with Vein Graft

CPT-35506-CAROTID-TO-SUBCLAVIAN-BYPASS-GRAFT

CPT 35506: Carotid-to-Subclavian Bypass Graft

CPT-35535-HEPATIC-TO-RENAL-ARTERY-BYPASS-VEIN-GRAFT

CPT 35535: Hepatic-to-Renal Artery Bypass with Vein Graft

CPT-35563-ILIAC-ARTERY-TO-ILIAC-ARTERY-VEIN-BYPASS

CPT 35563: Iliac-to-Iliac Artery Bypass with Vein Graft

CPT-35558-FEMORAL-FEMORAL-VEIN-BYPASS

CPT 35558: Femoral–Femoral Bypass with Vein Graft

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Taxonomy Code	Specialty	Notes
207VG0300X	Vascular Surgery	Primary specialty performing open aortoiliac bypass procedures; manages perioperative vascular care.
207K00000X	General Surgery	Performs vascular procedures in settings where general surgeons have vascular training.
207R00000X	Thoracic and Cardiac Surgery	May perform complex aortic inflow procedures when combined thoracoabdominal approaches are required.
2080P0001X	Interventional Cardiology	Related for preoperative or adjunct endovascular interventions, though open bypass is a surgical service.
2084P0800X	Interventional Radiology	Performs diagnostic and endovascular interventions that may precede or complement open surgery.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I70.2`	Atherosclerosis of native arteries of the extremities	Common underlying etiology causing aortoiliac occlusive disease prompting bypass.
`I70.201`	Unspecified atherosclerosis of native arteries of right leg with intermittent claudication	Typical presentation leading to surgical revascularization when lifestyle-limiting.
`I70.203`	Unspecified atherosclerosis of native arteries of bilateral legs with intermittent claudication	Reflects multilevel disease potentially requiring aortoiliac bypass.
`I70.231`	Atherosclerosis of aorta with ulceration of other part of lower limb	Indicates advanced disease with tissue loss risk that may require bypass.
`I74.3`	Embolism and thrombosis of arteries of lower extremities	Acute presentations where bypass may be needed if thrombolysis or embolectomy is inadequate.
`I70.239`	Atherosclerosis of aorta with rest pain of unspecified lower limb	Critical limb ischemia indication for prompt revascularization including bypass.
`Z95.2`	Presence of prosthetic heart valve	Example comorbidity relevant for perioperative anticoagulation management (not a direct indication).

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`34001`	Direct repair or replacement of aortoiliac segment with graft, abdominal aorta to iliac artery bypass	Closely related open aortoiliac bypass procedures; may be used for different anatomic extents or approaches.
`35566`	Bypass graft, with vein; femoral to popliteal (below-knee)	Represents peripheral bypass that may be performed in conjunction with aortoiliac revascularization for multilevel disease.
`35476`	Bypass graft, with vein; axillobifemoral bypass	Alternative extra-anatomic bypass option when aortic exposure is contraindicated.
`34701`	Endarterectomy, iliac artery	Performed for focal iliac disease as an alternative or adjunct to bypass; may be staged with bypass.
`36247`	Transcatheter placement of stent(s), iliac artery	Endovascular option that may be performed before or instead of open bypass; used in hybrid procedures.

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