35642 CPT Carotid–Vertebral Bypass Reimbursement | OpenPayer

Summary & Overview

CPT 35642: Carotid-to-Vertebral Artery Bypass with Synthetic Graft

CPT code 35642 denotes an open vascular bypass using a synthetic graft to reroute flow from the carotid artery around a blocked vertebral artery. This procedure addresses symptomatic or hemodynamically significant vertebral artery occlusion that threatens posterior circulation and may be performed when endovascular options are unsuitable. Nationally, the code represents a high-acuity vascular surgery with implications for hospital resource use, perioperative care, and neurosurgical/vascular service lines.

Key payers commonly involved in coverage and payment for this service include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise review of clinical context for the bypass procedure, expected site-of-service implications, and the categories of payers relevant to coverage decisions. The publication also summarizes where to look for benchmarks, common billing modifiers, and coding relationships for clinical documentation and claims processing. Data not available in the input will be noted where applicable.

This summary provides clinicians, coding professionals, and policy analysts with a focused overview of the procedure represented by CPT code 35642, its national relevance, and the types of payers that influence payment and utilization oversight.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 35642vascular surgeryvertebral artery bypasssynthetic graftcarotid-vertebral bypasshospital servicesoperative procedureneurovascular

Billing Code Overview

CPT code 35642 describes a surgical bypass procedure using a synthetic graft to reroute blood flow from the carotid artery around a blockage in a vertebral artery. The procedure is a vascular reconstruction intended to restore posterior cerebral circulation when vertebral artery occlusion or stenosis impairs blood flow.

Service type: Open vascular bypass with synthetic graft

Typical site of service: Hospital operating room or inpatient surgical setting

Clinical & Coding Specifications

Clinical Context

A typical patient is a 65-year-old male with symptomatic vertebrobasilar insufficiency presenting with recurrent transient ischemic attacks characterized by vertigo, ataxia, and visual disturbances despite maximal medical therapy. Diagnostic workup includes duplex ultrasonography, CT angiography, and digital subtraction angiography demonstrating a high-grade proximal vertebral artery stenosis or occlusion not amenable to endovascular stenting. After multidisciplinary vascular neurology and vascular surgery review, the patient is scheduled for surgical carotid–vertebral bypass using a synthetic (prosthetic) graft to re-establish antegrade vertebral artery flow.

Preoperative workflow includes history/physical, perioperative risk stratification, antiplatelet/anticoagulation management, and informed consent discussing benefits and risks (stroke, cranial nerve injury, graft occlusion, infection). Intraoperative steps include surgical exposure of the common carotid artery and the vertebral artery (typically at the V1 segment), heparinization, construction of the carotid-to-vertebral bypass with a synthetic graft, completion angiography or Doppler assessment of graft patency, hemostasis, and layered closure. Postoperative care includes neurologic monitoring in a step-down or intensive care setting, blood pressure control, graft surveillance with duplex ultrasound, and continuation of antiplatelet therapy.

Typical site of service is an inpatient acute care hospital operating room with postoperative monitoring in a PACU or intensive care unit. Service type is a major vascular surgical procedure (open arterial bypass) under general anesthesia, often billed by vascular surgery and/or neurosurgery teams depending on institutional practice.

Coding Specifications

Modifier	Description	When to Use

CPT 35661: Femoral–Femoral Bypass with Synthetic Graft

CPT-35621-AXILLOFEMORAL-BYPASS-SYNTHETIC-GRAFT

CPT 35621: Axillofemoral Bypass Using Synthetic Graft

CPT-35656-FEMORAL-TO-POPLITEAL-BYPASS-SYNTHETIC-GRAFT

CPT 35656: Femoral-to-Popliteal Bypass with Synthetic Graft

CPT-35601-CAROTID-COMMON-ARTERY-BYPASS-SYNTHETIC-GRAFT

CPT 35601: Common Carotid Artery Bypass with Synthetic Graft

CPT-35671-POPLITEAL-TO-TIBIAL-PERONEAL-BYPASS-SYNTHETIC-GRAFT

CPT 35671: Popliteal to Tibial/Peroneal Bypass with Synthetic Graft

CPT-35654-AXILLARY-FEMORAL-BYPASS-NON-VEIN-GRAFT

CPT 35654: Axillary to Femoral Bypass Using Non-Vein Graft

CPT-35626-AORTIC-TO-SUBCLAVIAN-INNOMINATE-CAROTID-BYPASS-GRAFT

CPT 35626: Aortic-to-Subclavian/Innominate/Carotid Bypass with Synthetic Graft

CPT-35666-FEMORAL-TO-TIBIAL-OR-PERONEAL-BYPASS-SYNTHETIC-GRAFT

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

CPT-35638-AORTO-BILATERAL-ILIAC-BYPASS-SYNTHETIC-GRAFT

CPT 35638: Aorto to Bilateral Iliac Bypass with Synthetic Graft

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
2080S0200X	Vascular Surgery	Primary specialty performing open carotid–vertebral bypass procedures.
2084P0800X	Neurological Surgery	May perform bypass when vertebral pathology involves posterior circulation requiring neurosurgical access.
207R00000X	Thoracic and Cardiovascular Surgery	May be involved when complex cervical vascular reconstruction overlaps with thoracic vasculature.
207L00000X	General Surgery	In some centers, vascular-trained general surgeons perform arterial bypass procedures.
363LF0000X	Interventional Radiology	Performs preoperative diagnostic angiography and potential intraoperative imaging support.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I65.29`	Occlusion and stenosis of unspecified carotid artery	High-grade cervical arterial atherosclerotic disease indicating need for bypass to restore posterior circulation flow when vertebral involvement present.
`I66.9`	Occlusion and stenia of unspecified cerebral artery	Represents cerebrovascular occlusive disease affecting posterior circulation that may lead to surgical bypass consideration.
`I63.03`	Cerebral infarction due to thrombosis of vertebral artery	Acute or prior vertebral territory infarction prompting revascularization to prevent recurrent ischemia.
`G45.8`	Other transient cerebral ischemic attacks and related syndromes	Recurrent TIAs of vertebrobasilar origin are a common indication for carotid–vertebral bypass when medical therapy fails.
`I77.6`	Dissection of artery of neck	Cervical vertebral artery dissection not amenable to endovascular repair may require surgical bypass.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`35206`	Excision, vessel, other than head and neck; with graft (e.g., carotid)	May be performed if concomitant resection of diseased segment with interposition graft is required during exposure or reconstruction.
`36010`	Introduction of needle or intracatheter, for diagnostic angiography of extremity vessels; arterial, unilateral	Used for diagnostic catheter angiography of cervical vessels when preoperative invasive angiography is performed.
`36215`	Selective catheter placement, vertebral artery, unilateral, with diagnostic angiography	Used when selective vertebral artery angiography is obtained preoperatively or intraoperatively to define lesion and confirm bypass patency.
`35221`	Bypass graft, with vein or prosthesis; carotid-subclavian or subclavian-carotid	Related extracranial carotid-subclavian bypass codes that reflect similar open bypass techniques and graft handling.
`37718`	Ligation, femoral artery branches or other peripheral vessels (not exact match)	May be used for adjunctive vessel control/ligation in complex exposures; included here as related peripheral vascular surgical techniques.

`00`	No modifier — standard reporting	Use as the primary claim submission when no special circumstances apply.
`11`	Primary procedure performed by the billing provider	Use when the reporting surgeon performed the primary service and no modifiers indicating other circumstances are applicable.
`22`	Increased procedural services	Use when the procedure requires substantially greater work or time than typical (document rationale in operative note).
`23`	Unusual anesthesia — medically necessary	Use when additional anesthesia was required due to patient condition beyond routine general anesthesia.
`26`	Professional component	Use if splitting professional and technical components when applicable for intraoperative imaging read separately by another provider.
`50`	Bilateral procedure	Use only if a bilateral bypass were performed (rare for this procedure) and supported by documentation.
`52`	Reduced services	Use when the procedure was partially reduced or not completed as planned (with documentation explaining limitations).
`53`	Discontinued procedure	Use when the procedure is terminated before completion for documented extenuating circumstances.
`62`	Two surgeons	Use when two surgeons documented active, concurrent participation and shared operative work.
`78`	Unplanned return to the operating room following initial procedure	Use for a related, unplanned subsequent operation during the postoperative period.
`80`	Assistant surgeon — general assistant	Use when an assistant surgeon was required and documented.
`81`	Minimum assistant surgeon	Use when a minimal assistance role is documented and appropriate.
`82`	Assistant surgeon — qualified resident or assistant when no qualified surgeon available	Use per CMS rules when an assistant is a resident/assistant and direction was provided per payer policy.
`76`	Repeat procedure by same physician (not listed in raw modifiers)	Data not available in the input.

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