Chiba Needle For FNAB

Pain Points in Fine-Needle Aspiration Biopsy

Traditional biopsy instruments bring obvious clinical dilemmas for interventional radiologists. Thick trocar needles cause heavy trauma, high bleeding risk and poor patient tolerance, especially for small, deep, adjacent-vessel lesions. Standard puncture tools lack directional control; once the needle tip deviates under real-time imaging, repeated punctures become inevitable, raising pneumothorax, hematoma and seeding risks. Many low-gauge needles cannot balance flexibility and sharpness. For cytology sampling, insufficient cell acquisition often leads to non-diagnostic specimens, forcing repeated hospital visits and delayed diagnosis. In addition, many generic puncture needles have unstable surface finish, poor echogenicity under ultrasound and inconsistent batch quality, which interfere with intraoperative visualization and increase operator learning burden. Clinicians urgently require a thin, steerable, atraumatic needle optimized for cytology aspiration.

Core Working Principle of Chiba Needle

Invented by Dr. Kun Chiba, the Chiba needle adopts a hollow single-cannula structure with a 30-degree Chiba bevel tip and a matching inner stylet. The 30° angled bevel is its core design feature: when advancing, the bevel surface generates directional deflection, so operators can subtly steer the needle trajectory by rotating the hub, a unique steerable advantage unavailable for perpendicular trocar tips. The inner stylet seals the cannula lumen during penetration to block skin and soft tissue debris, preventing specimen contamination. After removing the stylet, the hollow lumen connects to a syringe for negative-pressure aspiration. Its thin stainless steel wall reduces tissue shear injury while maintaining enough structural rigidity to pass through fascia and parenchymal organs without buckling. Materials including 304 and 316 medical stainless steel deliver stable biocompatibility, corrosion resistance and mechanical performance for single-use percutaneous access.

Classification of Chiba Needle Specifications

Chiba needles are primarily classified by gauge and length for differentiated clinical scenarios. Gauge ranges cover 16G to 27G. Large gauges (16G–18G) feature larger inner lumens, suitable for thick fluid aspiration, abscess drainage and coaxial guiding sheaths. Medium gauges (19G–21G) balance stiffness and minimal trauma, widely used for liver, renal and deep abdominal lesion sampling. Fine gauges (22G–27G) are the mainstream for superficial nodules, thyroid, lymph node and lung FNAB, minimizing bleeding and air leakage. Length options include standard 90mm and custom lengths extended for deep pelvic, retroperitoneal and thoracic lesions. All products adopt standard Chiba point bevel design; customized surface echogenic coating is optional for ultrasound-guided workflows. Packaging can be standard carton or customer-specific sterile packaging to fit hospital and distributor requirements.

Standard Operation Guide for Image-Guided FNAB

The whole procedure follows standardized sterile workflow under ultrasound, CT or fluoroscopy guidance. First, complete preoperative assessment: coagulation function, platelet count, allergy screening and lesion location mapping. Mark the skin entry point, apply local anesthesia and fix the imaging probe. Hold the Chiba needle with stylet inserted, advance slowly toward the target lesion under continuous imaging monitoring. When the tip reaches the target, stop advancement, withdraw the inner stylet and connect a 10mL syringe. Apply gentle negative suction, rotate and oscillate the needle slightly within the lesion to harvest cytological materials. Once fluid or cell fragments appear at the needle hub, release suction before withdrawing the needle to avoid aspirating peripheral normal tissue. Expel specimens onto slides for immediate fixation and cytopathology review. After sampling, perform hemostasis by compression and post-procedure imaging check for bleeding or leakage. Operators must maintain suspended respiration coordination for thoracic lesions to avoid organ laceration.

Practical Clinical Experience Summary

Long-term clinical practice proves that gauge selection is the top priority for success. Most thyroid and superficial lymph node biopsies prefer 22G–23G Chiba needles, while solid visceral lesions commonly select 20G–21G. Operators should avoid excessive negative pressure, which easily mixes blood and dilutes target cells and reduces diagnostic yield. Rotation control of the bevel direction is critical: consistent rotation stabilizes trajectory, while intentional rotation can bypass vital vessels and ducts. For high bleeding-risk patients, coaxial technique with Chiba needle as the introducer is recommended, which allows repeated sampling through the same access tract and reduces multiple skin punctures. Training for junior doctors should start with superficial lesions to master bevel steering before moving to deep thoracic and abdominal targets. Disposable sterile Chiba needles eliminate cross-contamination risks; reusing is strictly prohibited.

Conclusion & Prospect Suggestions

As a foundational fine puncture instrument, the Chiba needle fills the gap between traumatic thick biopsy needles and low-precision generic puncture tools. Its steerable bevel tip, flexible gauge matrix and minimal-invasion design make it irreplaceable in cytology diagnosis. Looking forward, manufacturers can optimize echogenic coating for clearer ultrasound visualization, develop pre-connected syringe assemblies to shorten operation time, and expand traceability marking for surgical quality control. Clinical departments should build standardized Chiba needle training modules to reduce operator-dependent complication rates. With the growth of minimally invasive interventional diagnosis, standardized Chiba needle products will continue to support early, accurate cytological diagnosis for oncology and internal medicine.