Summary & Overview
CPT 47535: Percutaneous Conversion to Internal–External Biliary Drainage
Headline: CPT code 47535 defines percutaneous conversion of an external biliary drainage catheter to an internal–external biliary drainage catheter
Lead: CPT code 47535 covers an image-guided, percutaneous procedure that converts an external biliary drainage catheter to an internal–external catheter to permit both internal and external bile drainage; the procedure often includes cholangiography and is commonly performed by interventional radiology teams in hospital outpatient and ambulatory settings.
CPT code 47535 matters nationally because it reflects a frequently used interventional radiology service for patients with biliary obstruction, postoperative leaks, or complex biliary drainage needs. Timely conversion from external-only to internal–external drainage can affect patient care pathways, length of stay, and frequencies of outpatient follow-up.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise summary of what CPT code 47535 represents, the clinical and service context for its use, and the typical sites of service. The publication provides benchmarks and policy-relevant details where available, clarifies common billing considerations, and situates the code within interventional radiology procedural practice.
Data not provided in the input include associated taxonomies, specific ICD-10 diagnoses, related codes, and payer-specific reimbursement rates; those items are noted as unavailable and are not fabricated here.
Billing Code Overview
CPT code 47535 describes the percutaneous conversion of an external biliary drainage catheter to an internal–external biliary drainage catheter to allow both internal and external drainage of bile. The procedure is performed via a percutaneous (through the skin) access route using image guidance such as ultrasound and/or fluoroscopy, and may include cholangiography (contrast imaging of the bile ducts).
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Service type: Image-guided percutaneous biliary drainage catheter conversion
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Typical site of service: Hospital outpatient department, interventional radiology suite, or ambulatory surgical center where image-guided percutaneous procedures are performed
Clinical & Coding Specifications
Clinical Context
A 68-year-old patient with a history of cholangiocarcinoma presents with an existing percutaneous external biliary drainage catheter that is producing persistent external bile output and causing skin irritation and decreased quality of life. The interventional radiology team evaluates imaging (ultrasound and fluoroscopy) and plans conversion of the external catheter to an internal–external biliary drainage catheter to allow bile to drain internally into the duodenum while maintaining external access if needed. Under moderate sedation in the interventional suite, the provider performs image-guided access of the biliary tree, injects contrast for cholangiography to delineate ductal anatomy and level of obstruction, upsizes or exchanges the catheter over a guidewire, and places an internal–external catheter with the internal pigtail positioned across the ampulla when feasible. Postprocedure radiographs confirm position and patency. Typical site of service is the hospital-based interventional radiology suite or ambulatory surgical center using fluoroscopy and/or ultrasound guidance. Common clinical indications include malignant or benign biliary obstruction, leak management, or need for temporary internalization of long-term external drainage.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
11 | Normal (uncomplicated) service | Use when procedure is the primary, routine service without complications or unusual circumstances |