https://radiopaedia.org/articles/chiba-needle

Introduction

If medical devices act as extensions of a physician's arms, the 22G Chiba needle is undoubtedly the most dexterous and dependable fingertip tool in the hands of interventional radiologists. Since its inception, its scope of application has expanded far beyond its original role for biliary cholangiography, penetrating minimally invasive diagnosis and treatment across the thorax, abdomen, pelvis, as well as bone and soft tissues. Boasting an ultra-slender outer diameter of approximately 0.7 mm, it functions like a universal minimally invasive key, unlocking pathways for diagnosis and therapy deep within the human body. This paper systematically reviews the full range of clinical uses for the 22G Chiba needle in modern interventional medicine, and elaborates on the inherent rationale that makes it an indispensable core instrument across multiple subspecialties.

1. Hepatobiliary and Pancreatic Interventions: Foundational and Flagship Indications

1.1 Percutaneous Transhepatic Cholangiography and Drainage (PTCD/PTBD)

This is the iconic, original application that established the 22G Chiba needle's reputation. For patients with obstructive jaundice, physicians use the 22G needle to percutaneously puncture intrahepatic bile ducts under image guidance. Its ultra-fine lumen yields an extremely low hemorrhage risk even when traversing small intrahepatic blood vessels. Once bile drainage is successfully achieved, a guidewire can be advanced along the needle tract to form a definitive drainage pathway. No alternative matches the unparalleled safety profile of the 22G needle for this procedure.

1.2 Biopsy of Pancreatic Lesions

The pancreas sits deep in the abdomen surrounded by abundant vasculature, rendering biopsy inherently high-risk. Leveraging minimal trauma and superior safety, the 22G needle has become the gold-standard instrument for cytological sampling of pancreatic cancer and other pancreatic lesions under endoscopic ultrasound (EUS) or CT guidance. It effectively prevents severe complications such as hemorrhage and pancreatic leakage associated with larger-bore conventional needles.

2. Thoracic Interventions: The Gold Standard for Lung Biopsy

The 22G Chiba needle serves as the primary instrument for CT-guided percutaneous lung biopsy:

Maximized safety: Its thin gauge markedly reduces the incidence of post-procedural pneumothorax (a 5–10% relative risk reduction) and hemoptysis, a critical benefit for patients with poor pulmonary function, subpleural lesions, or emphysema.

Precise tissue sampling: With real-time CT navigation, the 22G needle accurately targets pulmonary nodules measuring only a few millimeters in size. Negative-pressure aspiration harvests sufficient cytological specimens, delivering high sensitivity and specificity for lung cancer diagnosis.

Mediastinal and chest wall lesions: It is the first-line safe biopsy option for mediastinal masses adjacent to the heart and great vessels, as well as chest wall abnormalities.

3. Abdominal and Pelvic Interventions: Minimally Invasive Diagnosis for Multiple Organs

3.1 Renal and Adrenal Biopsy

When characterization of renal masses or identification of adrenal tumor origins is required, the 22G needle safely navigates tissue planes between adjacent organs such as the liver and intestines (via paravertebral or transhepatic approaches) to reach target sites for aspiration, eliminating the need for open exploratory surgery.

3.2 Biopsy of Intra-Abdominal and Retroperitoneal Lymph Nodes

For cancer staging or workup of unexplained lymphadenopathy, CT or ultrasound guidance enables the 22G needle to precisely sample deep lymph nodes surrounding the celiac trunk and in the retroperitoneum, supplying vital pathological evidence for lymphoma, metastatic carcinoma, and other malignancies.

3.3 Drainage of Pelvic Abscesses and Cysts

For deep pelvic abscesses accessed via gluteal or presacral routes, the 22G needle localizes pathology and establishes an initial access tract-an essential safe precursor for subsequent indwelling catheter drainage.

4. Bone, Soft Tissue and Specialized Supplementary Applications

4.1 Bone Lesion Biopsy

For osteolytic lesions or bone tumors with prominent soft tissue components, the 22G needle penetrates tissue effortlessly to retrieve cellular samples for diagnosis. It is especially suitable for initial screening in anatomically challenging sites such as the spine and pelvis, where open surgery carries high risks.

4.2 Nerve Block and Pain Management

Under CT or ultrasound guidance, the 22G needle is positioned with pinpoint accuracy adjacent to target nerves (e.g., celiac plexus, spinal nerve roots, stellate ganglia). Absolute ethanol or analgesic medications are injected to treat oncologic pain and intractable chronic pain, with far less trauma than open surgical neurolysis.

4.3 Cyst Sclerotherapy

For hepatic and renal cysts, after complete aspiration of cyst fluid, sclerosants such as absolute ethanol are delivered through the 22G needle to ablate epithelial cyst lining cells and achieve curative outcomes.

4.4 Vascular Access Establishment

In cases where standard cannulation proves difficult (e.g., severe anasarca, poor venous integrity), ultrasound-directed 22G needle puncture safely establishes deep venous access for critical care support.

Conclusion

Spanning hepatobiliary-pancreatic, thoracic, abdominal and pelvic systems, covering both diagnostic and therapeutic endpoints, the broad application spectrum of the 22G Chiba needle fully embodies the core tenets of modern medicine: precision, minimal invasiveness and high efficiency. It functions not only as a powerful tool for securing pathological diagnoses, but also as a pioneering device to build therapeutic access tracts. The fundamental logic behind its widespread adoption lies in its ability to maximize diagnostic tissue yield or precisely create treatment pathways with minimal tissue injury, while upholding the highest safety thresholds possible. Mastery of 22G Chiba needle technique equips interventional physicians with a universal, safe, and effective foundational skillset to resolve a vast array of clinical challenges. As image-guidance technology continues to advance, the precision and reach of its clinical applications will undoubtedly expand even further.