ELRA & Biliary Stent Knowledge Base USA Only

ELRA — Endoluminal Radiofrequency Ablation Electrode

Flexible bipolar RF catheter for temperature-controlled endobiliary ablation. FDA 510(k) indication: "partial or complete ablation of tissue in the pancreatic and biliary tracts" (21 CFR 878.4400).

Key Features

• Temperature sensing — 80°C ablation zone with real-time feedback
• Impedance monitoring via VIVA combo generator
• Slim 7Fr with silicone tapered tip — navigates difficult anatomy
• Bipolar design — no grounding pads required (standard for endobiliary RFA)
• 4 sizes available — based on treatment location

ELRA Sizing Guide

Smaller sizes for hilar (thin walls, high vascularity). Larger for CBD (thicker tissue). Standard temp: 75-80°C.

VIVA Combo RF Generator Compatibility

• Same VIVA combo used for Star thyroid electrodes
• Power range: 5–200W (ELRA uses 7–10W)
• Auto-adjusts wattage to maintain target temperature
• No additional capital purchase if facility already has VIVA combo

ELRA Setup Checklist

• Connect ELRA electrode to VIVA combo RF Generator
• Set temperature: 75–80°C; power 7–10W per sizing guide
• Set timer: 2-minute ablation cycle
• Verify impedance before ablation start
• Position electrode under fluoroscopy/US guidance
• After ablation: balloon sweep to remove residual tissue

ELRA Probe Selection Guide (from Danny Kim Q&A)

When to use 18mm probe

• Long strictures (e.g. 4cm): Divide into 3–4 overlapping segments, ablate sequentially
• Post-surgical or clip-adjacent anatomy: Shallow ~2mm depth limits thermal spread — preferred near surgical clips
• Standard settings: 7W, 75°C, 2 minutes per segment
• Expected ablation zone: Length ~18mm (±1-2mm), Diameter ~6-7mm, Depth ~2mm

When to use 22mm / 33mm probes

• Best for straight, non-surgical bile ducts not near metal or critical structures
• Deeper ablation zone (3–3.5mm) — reduces number of treatment segments
• Example: long distal CBD stricture without prior biliary surgery
• In post-surgical or clip-adjacent anatomy, prefer 18mm for better control

Sequential (back-to-back) ablation

• Multiple segments in one session are common and safe
• Key tip: Allow 5–10 seconds between segments for tissue to settle before the next ablation cycle, ensuring uniform ablation zones
• Can be performed after balloon dilation — RFA adds thermal remodeling to mechanical disruption

Guiding sheath sizing

• ELRA catheter (7Fr) → use 8Fr guiding sheath (always 1Fr larger)
• Stent delivery (8Fr) → use 9Fr guiding sheath
• Guidewire: 0.035" stiff/supportive, 145–150cm — provides best trackability without being cumbersome

ELRA Technical Deep-Dive — Manufacturer Q&A

Why You Must Follow the Recommended Power Settings

Think of ELRA like a toaster oven with a thermostat. The system is designed to heat tissue to exactly 80°C — no more. The recommended wattage settings make this possible:

How Temperature Mode Actually Works

When the physician starts ELRA, here's what happens inside the system:

• Step 1: RF energy is delivered at the set wattage
• Step 2: Temperature sensor monitors tissue temperature in real-time
• Step 3: Once target temperature (75–80°C) is reached, the system automatically adjusts power up and down to maintain it — like cruise control in a car
• Step 4: After exactly 2 minutes, the system automatically shuts off

Why 2 Minutes Is the Sweet Spot — Not More

Manufacturer testing (ex-vivo) showed:

• At 2 minutes: Optimal ablation depth achieved (~2mm)
• After 2 minutes: Minimal additional depth gain — diminishing returns
• After 3 minutes: Tissue carbonization (charring) begins — this is bad because carbonized tissue acts as an insulator, blocks further energy delivery, and can cause tissue to stick to the electrode

Bottom line: 2 minutes is not arbitrary — it's the scientifically validated sweet spot.

Repeat Ablation at the Same Spot — Does It Go Deeper?

No. Manufacturer testing confirmed that ablating the same exact spot twice does NOT significantly increase depth. However, overlapping segments (moving the electrode slightly to cover adjacent areas) is both safe and standard clinical practice for treating long strictures.

Which Electrode Size for Curved Hilar Anatomy?

The electrode tip is made of metal — it's the one part that's stiff, not flexible. In the hilum where bile ducts curve sharply:

• 22mm or 33mm electrodes → too stiff for curves → the electrode presses against one wall, creating uneven ablation
• 11mm electrode → short enough to navigate curves → even ablation on all sides

When the Stricture Is Mild (Not Very Tight)

ELRA needs good contact between the electrode and the duct wall to work properly. If the stricture is mild and the duct is relatively open:

• The electrode won't press firmly against tissue → poor contact
• Temperature rises very slowly or not at all
• The 25-second auto-shutoff will trigger before reaching target temperature

This is not a product failure — it means the stricture may not need ablation, or a smaller electrode might achieve better contact.

Ablation Inside an Occluded (Blocked) Stent

When a previously placed stent gets blocked by tumor growing into it, ELRA can be used to ablate the tumor INSIDE the stent. This is called "intra-stent ablation." Critical rules:

• Use 11mm electrode — minimizes chance of touching the metal stent mesh
• The electrode must NOT touch the stent — this is the #1 rule

What happens if the electrode touches the stent:

ELRA Safety — Hilar Anatomy Warning

The Right Hepatic Duct runs very close to the Hepatic Artery (a major blood vessel). When performing ELRA ablation in the right intrahepatic duct near the hilum:

• Extra caution is required due to arterial proximity
• Use the 11mm electrode for better control
• Temperature-controlled ablation provides a safety margin, but the physician should be aware of this anatomical relationship

ELRA Regulatory & Logistics Reference

FDA Clearance Chain

Classification: 21 CFR 876.4300 — Endoscopic Electrosurgical Unit and Accessories, Product Code KNS, Class II. Indication: "partial or complete ablation of tissue in the pancreatic and biliary tracts."

3-Year Shelf Life — Sales Advantage

ELRA shelf life was extended from 1 year to 3 years (confirmed via K233113, real-time aging data). This significantly improves distributor stocking flexibility and reduces expiration-related waste. When discussing inventory with hospitals: "You can stock ELRA without worrying about rapid expiration — 3-year shelf life means minimal waste."

Model Naming Convention Decoded

STARMED America sells S (percutaneous) models only. L (endoscopic) models are Taewoong USA territory.

Patient Population

Adult patients (over 22 years). ELRA must NOT be used with other manufacturers' RF generators — VIVA combo only.

ELRA Ablation Volume Data (Ex-Vivo)

Manufacturer bench testing (ex-vivo bovine liver, 23.6°C, 27% humidity):

Lesion-to-Electrode Selection Guide

Clinical results may differ from ex-vivo data. For lesions exceeding electrode ablation length, perform overlapping ablations — start proximal (away from Ampulla), progress distally.

ELRA Contraindications & Key Warnings

Contraindications (from User Manual)

• Patients with electronic implants (pacemakers, defibrillators) — consult cardiologist before use
• Use near flammable anesthetics or oxidizing gases (N₂O, O₂) or volatile solvents
• Do NOT activate when not in contact with target tissue (capacitive coupling risk)

Required Equipment

• Fluoroscopy — required for ALL ELRA procedures (percutaneous and endoscopic)
• Guidewire — max outer diameter 0.035 inch
• Protective eyewear and filtration masks (electrosurgical byproducts)
• Smoke evacuation system recommended

Post-RFA Adverse Effects (for physician awareness)

Abdominal pain, fever, nausea, headache, right shoulder joint pain, chest discomfort. Delayed bleeding and recurrence of cancer are also listed risks.

The Niti-S D-type is STARMED America's primary biliary stent for the U.S. market. This is the stent you are selling.

Key Features — Why D-type Wins

• Two nitinol wires, "Hook and Cross" structure — superior conformability in tortuous bile ducts
• Low foreshortening (<20%) — critical for accurate placement; stent stays where you put it
• Immediate wall opposition — conforms to duct shape instantly after deployment
• Radiopaque markers — 3 at both ends + 2 in middle for precise fluoroscopic positioning

Ordering Information

D-type Stent Selection Rules (from Danny Kim Q&A)

Diameter selection

Covered vs. Uncovered

Stent length sizing rule

• Stent = tumor length + 1cm margin on each side
• Example: 3cm tumor → minimum 5cm → choose 6cm stent (next available size)
• Margin accounts for tumor growth and edema over time

Why D-type (braided) is ideal for CHD/hilar

• Low axial force — preserves natural anatomy and side-branch drainage
• Uniform radial force — consistent expansion without straightening the duct
• Laser-cut stents have very high radial force that can shift the landing zone

Deployment markers explained

• 4 total radiopaque markers on delivery system: 3 on inner catheter (distal, mid, proximal) + 1 ring marker on outer sheath
• Inner markers = final stent boundary positions
• Outer ring marker = real-time deployment progress
• Foreshortening note: Final deployed length = length printed on box (predictable)

Understanding SEMS Design — Braided vs. Laser-Cut

Braided SEMS (e.g., Niti-S D-type)

• Wire mesh woven pattern
• LOW axial force → excellent conformability
• Foreshortening occurs but is PREDICTABLE
• Uniform radial force along length

Laser-cut SEMS (e.g., some Wallflex)

• Cut from single nitinol tube
• ZERO foreshortening → precise length
• BUT higher axial force can straighten tortuous ducts and shift landing zone
• Sharp cell edges may accelerate tumor ingrowth

Covered vs. Uncovered failure modes

D-type Stent — Complete Technical Specifications

510(k) Clearance: K073667 (Nov 19, 2008)

Indication: Palliation of malignant strictures in the biliary tree. Prescription use only.

Physical Specifications (All Percutaneous TD-- Models)

Shorter stents have higher foreshortening %. Crossing profile 2.7mm is consistent across all sizes.

Article Number Convention

STARMED America sells TD-- (percutaneous) only. BD-- sold by Taewoong USA.

Stent Size Selection Rule (from User Manual)

• Select stent 20–40mm longer than measured stricture to fully cover both ends
• Unconstrained stent diameter should be 1–4mm larger than largest reference target diameter

MRI Safety

MR Conditional at 1.5T and 3.0T. Max spatial field gradient: 30 T/m. Max whole-body SAR: 2 W/kg. Scan duration: 30 min continuous with 30 min off. May produce image artifact near stent.

Guidewire Requirements

• Percutaneous: 0.035" (0.89mm), at least 180cm, stiff/extra-stiff preferred
• Endoscopic: 0.035" (0.89mm), at least 450cm, stiff/extra-stiff preferred

D-type Stent — Contraindications & Required Warnings

Contraindications

• Strictures that do not allow passage of a guidewire
• Patients for whom endoscopic techniques are contraindicated
• Patients with bleeding disorder or coagulopathy
• Patients with ascites
• Biliary obstruction preventing cholangiography

FDA-Required Labeling Warning

Key Clinical Warnings

• Stents cannot be repositioned after complete deployment
• Chemoradiation may cause tumor shrinkage → stent migration risk
• Contains nickel — potential allergic reaction in nickel-sensitive patients
• Do NOT use with Ethiodol or Lipiodol contrast media
• Do NOT expose introducer to organic solvents (e.g., alcohol)
• Full expansion may require 1–3 days post-deployment

Sterilization & Storage

Ethylene oxide (EO) sterilized. Single use only — do not resterilize or reuse. Store in dry, cool place away from sunlight.

2026 Pricing — Current Target Pricing

Note: Market is still being researched. Pricing subject to adjustment as market data is collected during Danny's Phase 1.

Revenue Per Procedure Potential

Stents are consumables — once you build an account, they reorder regularly. Focus on building relationships now; this is your future recurring income.

Clinical Indications — When Percutaneous Metal Stenting Is Used

Core principle (SIR/CIRSE): drain obstructed/infected bile quickly and safely while preserving future treatment options. ERCP is first-line; percutaneous (PTC/PTBD) is used when endoscopy fails or is impossible.

1. Malignant Biliary Obstruction (MBO) — the primary indication

• Unresectable/metastatic tumor causing obstruction: pancreatic cancer, cholangiocarcinoma, gallbladder cancer, metastases.
• Goal: drain ≥50% of liver volume to lower bilirubin and enable chemotherapy.
• Stent choice by prognosis: expected survival <4 months → plastic can be justified; >4–6 months → self-expanding metal stent (SEMS) for longer patency and fewer re-interventions.
• Routine pre-op drainage of a resectable patient is not recommended (raises infection/complications) — limit to cholangitis, uncertain resectability, or planned neoadjuvant therapy.

2. Benign Biliary Strictures (BBS)

• Post-cholecystectomy iatrogenic injury, post-transplant anastomotic stricture, PSC, chronic pancreatitis.
• Historically metal stents were contraindicated (tissue ingrowth made them unremovable). Fully-Covered SEMS (FC-SEMS) now allow 6–12 months of remodeling then removal.

3. When percutaneous is required instead of ERCP

• Altered GI anatomy (Roux-en-Y, subtotal gastrectomy, Whipple) — scope cannot reach the ampulla.
• Complex hilar malignancy (Bismuth-Corlette III/IV) — percutaneous technical success ~97.7%.
• Failed ERCP wire passage → rendezvous procedure (+47541).

FDA Regulatory Status & Stent Types

All U.S. biliary stents clear FDA via 510(k) or De Novo. Historically metal stents were approved only for palliation of malignant strictures.

• 2016 milestone: Boston Scientific WallFlex Biliary RX Fully Covered RMV passed De Novo DEN150040 — first U.S. metal stent approved to indwell up to 12 months for benign stricture due to chronic pancreatitis (study cohort n=127). FDA created a new Class II category "Metallic Biliary Stent System for Benign Strictures."
• Label warning: not established for post-transplant anastomotic or post-surgical benign strictures (data insufficient).

Clinical Rationale: RFA + Stent vs. Stent Alone

Endobiliary RFA prior to stent placement addresses the primary cause of stent failure — tumor ingrowth. ELRA thermal ablation at the stricture site:

• Reduces tumor ingrowth into stent lumen
• Improves stent patency duration
• May extend overall survival in unresectable cholangiocarcinoma
• Serves as rescue treatment for bilateral metal stent obstruction due to tumor ingrowth

Biliary Anatomy & Disease Overview

Key anatomy (for physician conversations)

• Right/Left Hepatic Duct → Common Hepatic Duct → Cystic Duct junction → Common Bile Duct → Ampulla of Vater → Duodenum
• Pancreatic duct joins at ampulla

Malignant biliary obstruction causes

• Cholangiocarcinoma — primary bile duct cancer; 45% at hilum (Klatskin tumor), 35% mid-duct, 20% distal
• Pancreatic cancer — 75% in head/neck causing CBD compression; 4th most common cancer death
• Ampullary carcinoma — blocks drainage at ampulla of Vater
• Gallbladder carcinoma — extrinsic compression

Klatskin tumor classification (Bismuth)

• Type I: below confluence | Type II: at confluence
• Type IIIa/b: extends into R or L hepatic duct | Type IV: bilateral (unresectable)

Key Published Studies Using ELRA

ELRA Safety Profile

• Temperature-controlled at 80°C prevents over-ablation
• Impedance monitoring: real-time feedback on tissue contact
• Validated in swine models (2018 J Invest Surg; 2019)
• Potential complications: perforation, pain, fever, nausea, delayed bleeding (rare)

Clinical Insights from Field Training (Danny Kim)

Drainage success indicator

• After successful biliary drainage, bilirubin should drop from ~12 mg/dL to 3–5 mg/dL within 3–7 days
• This is a practical benchmark to share with physicians when discussing drainage effectiveness

RFA + Stent: Evidence for physician conversations

• Stent patency: RFA + stent improves patency vs. stent alone, especially in hilar CCA
• Overall survival: Pooled data shows improved survival with RFA + stent
• Safety: No significant increase in major complications with temperature-controlled systems (no perforation, no hemobilia in published series)
• Complications to discuss: Main risks are biliary infection and pancreatitis — related to stasis and instrumentation, NOT ablation depth

Modern biliary management framing

"We're not past uncovered stents — we're past stent alone as the full strategy. Modern IR approach: Ablation + Uncovered stent + functional drainage planning."

Biliary Anatomy for IR — Expanded Reference

Normal biliary tree

• Right Posterior Sectoral Duct + Right Anterior Sectoral Duct → Right Hepatic Duct (RHD)
• Left hepatic duct drains segments II–IV
• RHD + LHD → Common Hepatic Duct (CHD)
• CHD + Cystic Duct → Common Bile Duct (CBD) → Ampulla of Vater → Duodenum

Key anatomic variants (13–19% of population)

• Crossover anomaly: Right posterior duct crosses over to drain into left hepatic duct
• Trifurcation pattern: 3 ducts join at confluence instead of the normal 2
• Aberrant right posterior duct: Drains directly into CHD

Percutaneous Access: Right vs. Left Approach

SEMS Material Science — What's Inside the Stent

Manufacturing types

• Braided type: Woven wire mesh → high conformability, but foreshortening 20–40%
• Laser-cut type: Cut from tube → zero foreshortening, but higher axial force, may straighten duct

Mechanical forces

• Axial force (AF) = straightening force on central axis → low AF = better conformability
• Radial force (RF) = expanding force → high RF = better lumen dilation
• D-type braided stent: low AF + uniform RF = ideal for tortuous/hilar anatomy

Stent Patency Data — Published Evidence

• Overall median SEMS patency: ~360 days (25-week patency 81%, 50-week 53%) — AJR 1997
• Percutaneous uncovered SEMS: Occlusion rate 13.5%, weighted mean time to occlusion 83.9 days — Frontiers in Radiology 2025 systematic review (18 studies)
• Novel dedicated hilar stent: 6-month patency 90.9%, 12-month 68.2%; median patency 165 days — PMC 2022

Factors worsening patency

• Larger cancer size
• Stones/sludge present at time of placement
• Longer stent
• Total bilirubin >2 mg/dL at 1 month post-placement
• Cholangiocarcinoma patients had lower patency rates than other diagnoses

RFA + Stent: Latest Meta-Analysis Evidence (2024)

2024 meta-analysis: 9 RCTs, 750 patients (374 RFA+stent vs 376 stent only)

• Overall survival: RFA+stent showed benefit specifically in cholangiocarcinoma patients
• Stent patency: Similar at 3 months between groups; RFA did not significantly improve patency overall

Earlier meta-analysis (2023): 5 RCTs, 370 patients

• Stent patency significantly better in RFA group
• Trend toward improved survival with RFA + plastic stents

Expert Clinical Insights — ELRA Webinar Q&A

Key insights from ELRA webinar featuring Dr. Nageshwar Reddy, Dr. Jaehee Cho, and Dr. Terry Wong:

Stent Choice After RFA — Plastic vs. Metal

• Dr. Reddy: Uses metal stents generally, but plastic stents for hilar strictures — advantage is you can repeat RFA after removing the plastic stent
• Dr. Cho: Depends on patient condition — plastic for multiple-RFA candidates, metal for advanced disease patients with limited life expectancy
• Radical view (Dr. Reddy): For patients living 3+ years who face repeated stent occlusion, consider using plastic stents with repeated changes + RFA rather than metal stents — "a total change in view"

RFA Interval Between Sessions

Dr. Cho: 2–3 months between sessions. After the first RFA, 2 months is recommended since stent occlusion occurs sooner after the initial session.

Hilar RFA Safety — Vessel Encasement

• Portal vein encasement: Not a major problem — portal vein never comes to the RFA field (Dr. Reddy)
• Hepatic artery (right intrahepatic duct): Very careful approach needed. Dr. Reddy uses intraductal ultrasound to check right hepatic artery anatomy
• Complication data: Dr. Reddy reported 2 major hemobilia cases from right hepatic artery — both with Habib catheter, not ELRA

RFA for Benign Biliary Strictures

Cholangioscopy + RFA

RFA is normally a blinded procedure. Standard nasal cholangioscope can accommodate the RFA catheter for direct visualization. However, the Spyglass scope CANNOT accommodate the RFA catheter. Some experience with percutaneous transhepatic cholangioscopy (PTC) for RFA under direct visualization.

Cytokine Surge & Immunomodulation

Local cytokine surge observed in bile after RFA. Immunomodulation appears to work in addition to the coagulation/ablation effect in tissue. More study needed, but this may explain why RFA benefits extend beyond simple tumor debulking. (Dr. Reddy)

RFA Inside Occluded Metal Stent — No Plastic Stent Needed?

Study (Kadayifci A et al, Endoscopy 2016) showed good stent patency after RFA without placing a plastic stent inside. Next research step: compare plastic stenting vs. no stenting post-RFA since ablation quality may be sufficient alone. (Dr. Terry Wong)

IR Biliary Stenting: Step-by-Step

Procedural Tips (from Danny Kim Q&A)

Pre-dilation

• Selective only — not routine. Pre-dilate only for very tight strictures.
• Post-dilation ELRA is safe: balloon disrupts fibrotic ring mechanically, ELRA adds controlled thermal remodeling

Guidewire & sheath selection

• Wire: 0.035" stiff/supportive, 145–150cm — best trackability, prevents catheter kinking
• Sheath for ELRA (7Fr catheter): 8Fr | Sheath for stent delivery (8Fr): 9Fr
• Rule: always size up guiding sheath by 1Fr vs. catheter OD

Post-RFA stenting

• Stenting immediately after ELRA is safe — temperature-controlled RFA prevents overheating
• Standard sequence: ELRA ablation → balloon sweep → stent deployment in same session

Hilar bilateral stenting strategy

• Key: cover both ducts proportionally to lesion to reduce flow imbalance
• Uncovered D-type preferred — preserves segmental flow and re-intervention access
• Primary goal: preserve side-branch flow + secure main drainage

Re-occlusion management (modern approach)

• Old: Balloon dilation ± plastic stent through metal stent (short-lived)
• Current trend: Intra-stent ELRA ablation + re-stenting — debulks ingrowth tumor, then new uncovered stent
• Meta-analyses: RFA+stent > stent alone for patency and survival in hilar CCA

Pre-Procedure Requirements & Contraindications

Absolute contraindications

• Irreversible coagulopathy (must correct INR ≤1.5, platelets ≥50,000)
• Uncorrectable clopidogrel use
• Massive ascites (consider transjugular approach or left-sided access instead)

Relative contraindications

• Moderate ascites (perform paracentesis first; prefer left subxiphoid approach)
• Altered surgical anatomy (Roux-en-Y) — actually an INDICATION for percutaneous over endoscopic approach

SIR Quality Thresholds (JVIR 2021)

Unilateral vs. Bilateral Stenting — Hilar Decision

Post-Ablation Protocol — What Happens After ELRA

Rule #1: Always Place a Stent After ELRA — No Exceptions

After ELRA ablation, the treated tissue swells (called edema — think of it like how your skin puffs up after a burn). This swelling temporarily makes the stricture WORSE, not better. If no stent is placed:

• The bile duct narrows further from swelling
• Bile cannot drain → patient gets worse, not better
• This is dangerous and defeats the purpose of the procedure

Stent Choice After ELRA: Plastic vs. Metal

Both plastic and metal stents can be placed after ELRA. The choice depends on the treatment plan:

Guidewire Contact During Bilateral Procedures

In bilateral hilar stenting, there are often two guidewires in the bile duct at the same time — one in the left duct and one in the right. A common concern: "Will ELRA damage the other guidewire?"

Answer: No. Manufacturer ex-vivo testing confirmed:

• ELRA electrode touching a guidewire during ablation causes no problems
• Ablation quality remains normal
• Guidewire insulation is not damaged
• No adverse events in clinical use either

This means physicians can safely perform ELRA even with multiple wires in place — no need to remove the contralateral wire first.

Post-Ablation Balloon Sweep (Recommended, Not Required)

After ELRA ablation creates dead tissue (debris), it's recommended to sweep an 8mm balloon through the ablation zone before stent placement. This clears debris and gives a cleaner surface for the stent to sit on. It's not mandatory, but most experienced operators do it.

ELRA vs. Habib EndoHPB (EMcision) — Head-to-Head

ELRA vs. Habib — Expert KOL Perspectives (Webinar)

Dr. Terry Wong's Experience

"ELRA advantage is the cut-off point — RFA cuts off at very high impedance (e.g., when touching metal stent), providing safety confidence." No experience with Habib to compare directly.

Dr. Jaehee Cho's Comparison

• Habib is single-size (22mm only); ELRA has four sizes (11, 18, 22, 33mm)
• RFA inside metal stent is difficult due to electric shunt — short 11mm ELRA probe reduces shunt rate
• To avoid short circuit in metal stent: use the short RFA probe and do multiple ablations. Longer probes have higher chance of contacting the metal stent

Dr. Reddy's Safety Data

• Reported 2 major hemobilia cases from right hepatic artery — both occurred with the Habib catheter
• Uses intraductal ultrasound to check anatomy when ablating near the right intrahepatic duct

Niti-S vs. Boston Scientific Stents

Stent Complication Comparison

Early complications (all stents, ~5%)

Biliary infection (35%), pancreatitis (29%), bleeding (23%), perforation (6%), migration (3%), renal failure (3%)

Late complications — stent dysfunction

• Plastic stents: 2x more frequent dysfunction; sludge occlusion
• Uncovered SEMS: Tissue ingrowth (→ ELRA ablation can rescue)
• Covered SEMS: Lower ingrowth but higher migration risk
• ComVi advantage: Triple-layer reduces both ingrowth AND migration

Market Context — Stent Failure Modes by Type

ELRA (Biliary RFA) — CPT Coding

Unlike thyroid RFA (CPT 60660/60661 from Jan 2025), biliary RFA uses the unlisted code 47999:

• Narrative notes required with claims
• Case-by-case, payer-dependent reimbursement
• Prior authorization typically required

Biliary Stent — Base CPT Codes (47538–47540)

The three percutaneous biliary metal stent placement codes are chosen by (1) access route — existing vs. new percutaneous puncture — and (2) whether a drainage catheter is left in place at the end. All three are bundled: they already include diagnostic cholangiography, fluoro/US imaging guidance, balloon dilation (cholangioplasty), catheter exchange/removal, and all radiological S&I.

47540 use case: stent placed via new puncture, but a safety drain is intentionally left across/near the stent due to sepsis risk, bleeding, or uncertain patency. Once bilirubin normalizes and a capping trial passes, the drain is removed later at a separate outpatient visit (CPT 47537). Do not bill 47537 separately when the catheter is removed as part of the same stent procedure — that is unbundling.

Add-on Codes (+47542 / +47543 / +47544)

Add-on codes are billed in addition to a primary biliary code (47531–47541). They cannot be billed alone.

+47541 = rendezvous procedure (percutaneous access created so an endoscopist can complete the case). +47542 if billed with a stent code requires Modifier 59/XS to prove a separate anatomic site.

Multiple Stents & Required Modifiers

Billing rule for multiple stents = count anatomic sites treated, NOT the number of stents used.

• Overlapping stents in the same duct (e.g. two stents to cover one long CBD lesion) → single lesion → bill 47538/47539/47540 once.
• Separate strictures in right + left hepatic ducts (Y-stent / side-by-side, two access routes or two independent ducts) → bill the stent code twice, second one with Modifier 59 or XS (distinct/separate structure) to avoid auto-denial.

Reimbursement & Payment Landscape

Biliary metal stenting is a device-intensive service (device >30% of cost). Because of this, ASCs are reimbursed for the device portion at the same rate as hospital outpatient (OPPS), even though ASC rates are normally lower.

Figures are payer- and geography-dependent; always defer to the facility coding department for actual claims.

Medical Necessity & Payer Policy

• Malignant biliary obstruction (jaundice palliation): established standard of care — approved with little dispute by most commercial payers (Aetna, Cigna, Highmark BCBS follow Medicare NCD/LCD).
• Benign stricture / recurrent stones: payers require documented evidence that ERCP failed or is anatomically impossible, and the patient is a high surgical risk.
• Biodegradable / bioresorbable stents: classified Experimental / Investigational (e.g. Aetna) — coverage restricted pending long-term data.

ICD-10 Diagnosis & Procedure Codes

Common Objections & Responses

"We already use the Habib catheter"

"Stent-only is sufficient"

"I don't do biliary RFA — that's GI"

"No capital budget for new equipment"

"Reimbursement is unclear"

"Why Niti-S over Boston Scientific stents?"

"The equipment is too expensive for us"

"We're not seeing enough biliary cases to justify this"

"What about the pricing?"

"I'm not comfortable with stents that have shortening"

"Which U.S. hospitals are currently using this stent?"

"Does RFA really change patency/survival, or is it just extra work?"

"Are we past the era of uncovered stents in the hilum?"

Advanced Scenarios — Complex Physician Conversations

These scenarios come up with experienced IR physicians. Understanding the concepts will help you hold your ground in sophisticated clinical discussions.

"My bilateral uncovered stents are occluded from ingrowth. I'll just push a plastic stent through."

Context: The physician has a Bismuth III hilar patient with previously placed bilateral uncovered metal stents. One side is now blocked because tumor grew through the mesh (ingrowth).

"For re-occlusion, are people still just doing balloon dilation + another stent?"

Context: Physician is asking about the standard of care for when a stent gets blocked again (re-occlusion).

"This is a complex hilar CCA. I'm going percutaneous. Is ablation before stenting really worth it?"

Context: IR physician with a difficult case — multiple segmental ducts, going through the skin (percutaneous), considering whether to add RFA before stenting.

"Does RFA really change patency or survival, or is it just extra work?"

Context: Skeptical physician who sees RFA as unnecessary added complexity.

"Are we past the era of just uncovered stents in the hilum?"

Context: Physician questioning whether the field has moved beyond uncovered stents.

Reference (Taewoong) — Product Knowledge Library

The following content covers Taewoong Medical's products and procedures used outside STARMED America's direct sales. Included for product knowledge and physician conversations only.

ERCP Approach (GI)

For GI physicians using endoscopic approach:

• Standard duodenoscope (side-viewing) + fluoroscopy
• Mouth → esophagus → stomach → duodenum
• Cannulate papilla; inject contrast for cholangiogram
• Guidewire across stricture → sphincterotomy if needed
• Stent selection based on stricture length measurement
• Deploy stent (B-prefix Niti-S for endoscopic approach)

EUS-Guided Approaches

IR Market Reality — What You Need to Know

Understanding the IR market is critical for setting realistic expectations and choosing the right approach. Here's what 2 months of field analysis revealed:

• IR is conservative and relationship-centered — decisions are based on trust built through clinical cases, not product demos
• Hospital internal decision-making is slow — capital equipment purchase cycles can take 6–12 months
• Growth appears slow but is normal — even Taewoong took years to establish its U.S. stent presence. STARMED's entry speed is healthy by IR standards
• Equipment-based products face the highest barrier — this is why the ELRA-first strategy at thyroid hospitals is so powerful (see below)

Key Insight: Thyroid Equipment = ELRA Equipment

This is the single biggest opportunity for STARMED in IR.

If a hospital already has the VIVA combo generator for thyroid RFA, ELRA requires zero additional capital investment. The same generator powers both thyroid electrodes and ELRA biliary electrodes.

ELRA-First Entry Strategy

The recommended market entry sequence based on field analysis:

Common Field Challenges & How to Overcome Them

Connecting product specs to real cases

Understanding hospital equipment ownership

Navigating IR/GI department dynamics

Wide territory coverage

Market Entry Progress

Questions — Quality Pipeline

Every question is tracked. Mark helpful answers with 👍. Unanswered questions can be resolved by adding an answer.

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Source Files — ELRA_Stent_KB + Training Rev.3

49 files across 6 categories + 1 comprehensive training deck (196 slides)