https://admin1.seo.com.cn/CustomerAdmin/S_News/Create?ru=%2FCustomerAdmin%2FS_News%2F%3Fpage%3D2

Although the principle of the PTC needle (Chiba type) is unified, manufacturers offer multi-specification combinations to meet diverse patient physiques, biliary conditions, and operator preferences. Scientific selection guidance helps distributors and end-users procure correctly, reducing clinical failures caused by mismatched specifications.

Gauge (Outer Diameter) Selection:

• 22G (OD ≈ 0.7 mm, ID ≈ 0.41 mm):​ Most commonly used for PTC diagnostic cholangiography and PTCD first-pass, balancing minimal invasiveness with guidewire passage (accommodates 0.018″ micro-guidewire). Recommended as the standard configuration.
• 21G (OD ≈ 0.8 mm):​ Slightly larger lumen, suitable for significantly fibrotic livers or when stronger support is needed; still usable for first-pass followed by exchange.
• 20G (OD ≈ 0.9 mm):​ Some centers use directly for one-step PTCD (with micro-introducer), but trauma is marginally increased.
• 23G (OD ≈ 0.6 mm):​ Ultra-fine, suitable for pediatrics, extremely lean adults, or pure PTC without catheter placement; note the small lumen requires extra caution with guidewire passage.
• Length Selection:​ 150 mm (superficial / left lobe subxiphoid approach), 200 mm (standard adult right mid-axillary approach), 250–300 mm (obese patients or deeply seated target bile ducts). Manufacturers typically stock 150/200 mm as standard, with extended lengths available on demand.

Material and Performance Differences:

• SUS304:​ Low cost, good strength, satisfies most needs.
• SUS316L:​ Superior corrosion resistance, better for prolonged fluid contact; chosen for high-end lines.
• NiTi (Nitinol) shaft or full needle:​ Superelastic and kink-resistant, less prone to deformation in curved liver parenchyma, suitable for complex multi-adjustment punctures, but at higher cost.

Functional Add-ons:

• Ultrasound visibility markers (tip roughening / micro-pitting / spiral etching):​ Strongly recommended as standard to greatly enhance tip tracking under ultrasound guidance.
• Color-coded gauge rings:​ Enable quick specification identification, reducing intraoperative confusion.
• Graduated markings (every 1 cm):​ Scale markings within 5–10 cm from the tip assist in judging insertion depth.
• Hydrophilic coating (internal lumen or external surface):​ Some premium versions feature internal hydrophilic coating to reduce guidewire friction; external hydrophilic coating reduces tissue resistance.

Manufacturers' Configuration Recommendations:

Primary / teaching hospital interventional departments:22G×200 mm (with visibility marker + markings), 21G×200 mm in proportional mix, accompanied by a 0.018″ guidewire starter kit.

Pediatric / lean adult specialty:23G×150 mm as backup.

Overseas OEM customers:Customizable length, connector (Luer slip vs. Luer lock), packaging (individual paper-plastic pouch / blister box), and multilingual IFU per client drawings.

Guiding customers to order according to "22G for PTC cholangiography vs. 21G–22G for PTCD first-pass vs. extended length for obese patients" not only improves clinical satisfaction but also reduces returns/exchanges caused by specification errors.