Summary & Overview
CPT 49427: Contrast Injection for Peritoneal Venous Shunt Evaluation
CPT code 49427 identifies a diagnostic procedure in which contrast is injected into the reservoir of an existing peritoneal venous shunt in the peritoneal cavity to evaluate flow through the device. The code captures a targeted imaging intervention used to assess shunt patency and function, which influences subsequent clinical management such as revision, replacement, or conservative monitoring. Nationally, this procedure is relevant across hospital outpatient departments and imaging centers where patients with implanted shunts receive follow-up and diagnostic care.
Key payers included in typical coverage discussions are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical purpose of the code, common sites of service, and the payer landscape. The publication outlines standard billing context, commonly reported modifiers (provided in the input), and areas where coding clarity matters for claims adjudication.
This article provides clinicians, coders, and billing professionals with concise benchmarking context, clinical interpretation of the service, and policy-relevant notes on coding practice. Data not available in the input is identified where applicable, and readers will learn where to look for payer-specific edits, coverage criteria, and claim documentation expectations.
Billing Code Overview
CPT code 49427 describes injection of contrast into the reservoir of an existing peritoneal venous shunt within the peritoneal cavity to evaluate flow through the shunt. This procedure is a diagnostic imaging intervention performed on patients who have an implanted peritoneal venous shunt and require assessment of shunt patency or flow dynamics.
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Service type: Diagnostic contrast injection into implanted peritoneal venous shunt reservoir
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Typical site of service: Hospital outpatient departments, outpatient imaging centers, or procedural suites where imaging-guided diagnostic evaluations of implanted shunts are performed
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with an existing peritoneovenous (Denver-type) shunt implanted for refractory ascites who presents with signs of shunt malfunction (eg, recurrent abdominal distension, worsening edema, decreased urine output) or for routine evaluation after symptoms suggest poor flow. The patient is usually evaluated in an outpatient interventional radiology or specialty clinic. After review of history, physical exam, and prior imaging, the clinician explains that fluoroscopic contrast injection into the shunt reservoir will assess patency and directional flow.
The procedure workflow: the patient is positioned on a fluoroscopy table; sterile prep and drape are performed over the subcutaneous shunt reservoir. Local anesthesia is applied and a small-gauge needle is used to access the reservoir. Contrast is injected under live fluoroscopy while the operator observes for antegrade flow into the venous system, retrograde leak into the peritoneal cavity, occlusion, or catheter fracture. Images and cine fluoroscopy are documented. If obstruction is identified, additional maneuvers (eg, thrombolytic infusion, catheter aspiration, or referral for revision) may be planned, but those are separate procedures and coded accordingly. Post-procedure monitoring occurs for a short period; discharge instructions include signs of infection and bleeding to report.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when only the physician's interpretation is billed and the facility bills separately. |