CPT 35638 Aorto-Bilateral Iliac Bypass Reimbursement | OpenPayer

Summary & Overview

CPT 35638: Aorto to Bilateral Iliac Bypass with Synthetic Graft

CPT code 35638 defines an open vascular bypass procedure in which a synthetic graft is used to reroute flow from the aorta to bypass occlusions in both iliac arteries. This code captures a definitive surgical treatment for bilateral iliac arterial disease and matters nationally because it represents a high-acuity vascular intervention with significant implications for hospital surgical services, perioperative management, device utilization, and payment policy. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn what CPT code 35638 represents clinically and operationally, the typical care setting and service line, and the context needed for billing and coding alignment. The publication provides benchmarks and reference points for utilization and payment patterns, summarizes relevant policy updates affecting vascular surgical reimbursements, and outlines clinical context such as indications for aorto-bifemoral or aorto-iliac bypass procedures. Data not available in the input is noted where specific payer policies, associated taxonomies, and ICD-10 diagnoses were not provided.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 35638aorto-iliac bypassvascular surgerysynthetic graftbypass surgeryinpatient surgeryoperating roomsurgical coding

Billing Code Overview

CPT code 35638 describes a surgical arterial bypass using a synthetic graft to bypass blockages in both iliac arteries by rerouting the connection from the aorta around the blocked segments of each iliac artery. This procedure is a vascular surgical intervention to restore blood flow to the lower extremities when bilateral iliac occlusive disease is present.

Service type: Open vascular bypass surgery using a synthetic graft
Typical site of service: Inpatient or outpatient hospital operating room (vascular surgery service line)

Clinical & Coding Specifications

Clinical Context

A 68-year-old male with a history of long-standing peripheral artery disease, hypertension, hyperlipidemia, and tobacco use presents with progressive bilateral buttock and thigh claudication and decreased ankle-brachial indices despite maximal medical therapy and supervised exercise. Imaging with CT angiography demonstrates severe atherosclerotic occlusive disease of both common and external iliac arteries with long-segment stenoses and occlusions unsuitable for endovascular repair. The vascular surgery team schedules an open aorto-bifemoral bypass using a synthetic graft to revascularize both lower extremities.

The clinical workflow includes preoperative cardiovascular risk assessment and optimization, arterial imaging review, informed consent discussing open bypass risks and alternatives, general anesthesia, midline laparotomy or retroperitoneal approach to expose the distal aorta, anastomosis of a synthetic bifurcated graft from the infrarenal aorta to both iliac/femoral targets to bypass the bilateral iliac blockages, hemostasis, wound closure, and postoperative monitoring in a step-down or intensive care setting. Postoperative management includes pain control, anticoagulation or antiplatelet therapy as indicated, graft surveillance with duplex ultrasound, and rehabilitation for ambulation.

Coding Specifications

Modifier	Description	When to Use
`00`	Default billing indicator (no modifier)	Used when no other modifier applies and the service is reported normally

CPT 35645: Subclavian-to-Vertebral Artery Bypass with Synthetic Graft

CPT-35661-FEMORAL-FEMORAL-BYPASS-SYNTHETIC-GRAFT

CPT 35661: Femoral–Femoral Bypass with Synthetic Graft

CPT-35646-AORTO-FEMORAL-BYPASS-SYNTHETIC-GRAFT

CPT 35646: Aorto-Femoral Bypass with Synthetic Graft

CPT-35606-SUBCLAVIAN-ARTERY-BYPASS-SYNTHETIC-GRAFT

CPT 35606: Subclavian Artery Bypass with Synthetic Graft

CPT-35634-ILIAC-TO-RENAL-ARTERY-BYPASS-SYNTHETIC-GRAFT

CPT 35634: Iliac-to-Renal Artery Bypass Using Synthetic Graft

CPT-35633-ILIAC-TO-MESENTERIC-ARTERY-BYPASS-SYNTHETIC-GRAFT

CPT 35633: Iliac-to-Mesenteric Artery Bypass with Synthetic Graft

CPT-35612-SUBCLAVIAN-ARTERY-BYPASS-SYNTHETIC-GRAFT

CPT 35612: Subclavian Artery Bypass with Synthetic Graft

CPT-35663-ILIAC-ARTERY-CROSS-FEMORAL-BYPASS-SYNTHETIC-GRAFT

CPT 35663: Iliac Artery Cross-Femoral Bypass with Synthetic Graft

CPT-35632-ILIAC-TO-CELIAC-SYNTHETIC-GRAFT-BYPASS

CPT 35632: Iliac-to-Celiac Synthetic Graft Bypass

CPT-35665-ILIAC-TO-FEMORAL-SYNTHETIC-GRAFT-BYPASS

CPT 35665: Iliac-to-Femoral Bypass with Synthetic Graft

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Taxonomy Code	Specialty	Notes
207RG0100X	Vascular Surgery	Primary specialty performing aorto-iliac bypass procedures
207RH0000X	Thoracic and Cardiac Surgery	Occasionally involved when aortic exposure or complex aortic disease requires cardiac/thoracic expertise
207RC0000X	General Surgery	Often performs peripheral vascular procedures in centers without dedicated vascular surgeons
208000000X	Surgery (Group/Other)	Applicable for multispecialty surgical groups participating in complex open vascular reconstructions

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I70.2`	Atherosclerosis of native arteries of the extremities	Primary indication for aorto-iliac bypass when advanced iliac atherosclerosis causes limb ischemia
`I70.31`	Atherosclerosis of native arteries of the extremities with intermittent claudication, right leg	Describes symptomatic claudication prompting revascularization on one side; bilateral disease often present
`I70.32`	Atherosclerosis of native arteries of the extremities with intermittent claudication, left leg	As above for the contralateral limb when bilateral symptoms occur
`I70.21`	Atherosclerosis of native arteries of the extremities with rest pain	Advanced ischemia signifying need for urgent revascularization to relieve rest pain and prevent tissue loss
`I74.3`	Embolism and thrombosis of arteries of lower extremities	Acute embolic or thrombotic events may necessitate bypass if endovascular or thromboembolectomy is insufficient
`I73.9`	Peripheral vascular disease, unspecified	General diagnosis code capturing PAD when more specific coding is not available
`E78.5`	Hyperlipidemia, unspecified	Contributing risk factor; relevant to perioperative medical optimization
`Z79.01`	Long term (current) use of anticoagulants	Medication history relevant to perioperative management and billing considerations

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`35631`	Axillobifemoral bypass, with or without prosthetic graft; single limb	Alternative extra-anatomic revascularization when aortic exposure is contraindicated; may be considered instead of an aorto-bifemoral bypass
`35566`	Endarterectomy, iliac artery	Performed when localized atherosclerotic plaque is amenable to direct endarterectomy rather than bypass; may be done in combination or as an alternative
`35301`	Extra-anatomic bypass, obturator or iliofemoral bypass	Related peripheral bypass options for unilateral iliac disease or as adjuncts when segmental reconstruction is required
`36200`	Selective catheter placement, arterial system, initial	Preoperative or intraoperative angiography/angioplasty procedures to define or attempt endovascular therapy prior to open bypass
`76000`	Fluoroscopic guidance; simple	Intraoperative imaging support during graft placement or angiography
`99238`	Hospital discharge day management	Postoperative inpatient discharge service following hospitalization after `35638`

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