https://www.chamfondbiotech.com/4-types-of-bone-marrow-biopsy-needles/

In their daily management, the equipment department of the hospital, the procurement department of consumables, and the head nurses of the operating room and the hematology department need to establish a scientific inventory and requisition list based on "what size of the bone marrow biopsy needle is needed," in order to avoid situations where the specifications are confused (for example, an aspiration needle is mistakenly used as a biopsy needle), which could result in the return of pathological applications or the need for a second puncture.

1. Clearly Distinguish the Scale Differences Between the Aspiration Needle and the Biopsy (Trephine) Needle

• Aspiration type bone marrow puncture needle (Aspiration): Marked as 16G (1.6mm), 18G (1.2mm), 20G (0.9mm), with a length usually ranging from 50 to 100mm (BMT-A type package). It is only used for smears, flow cytometry, staining, and molecular testing and cannot replace the biopsy needle for obtaining tissue strips.
• Trephine/Biopsy type bone marrow puncture needle (Trephine/Biopsy): Marked as 11G/12G/13G/14G, clearly indicating "biopsy needle," "Trephine," "tissue core sampling," with a length of 70/100/120/150mm (BMT-B type package or separate biopsy needle set). Some "one needle for two uses" BMT-A/B packages contain a thick needle that can be used successively for aspiration and biopsy.
• Pediatric-specific package (BMT-C type): Includes fine aspiration needles (16G-20G × 15-25mm) or pediatric biopsy needles (13G × 40-65mm).

The technical parameters for the procurement and bidding should include: ① One-time use sterile bone marrow biopsy (trephine) needle; ② Outer diameter ≥ 2.4mm (i.e., ≤ 13G), preferably providing 11G and 13G options; ③ Effective working length covering 100mm and 150mm (for adults) and 65mm (for children as an alternative); ④ Equipped with adjustable depth limiter and extraction tool (probe/stick); ⑤ Compliant with YY/T 0321.3-2020 and ISO 11070; ⑥ EO sterilization with SAL = 10⁻⁶.

II. Recommended Inventory Size Combinations (For Tertiary Hospitals' Hematology/Oncology Departments)

Adult Standard Trephine Biopsy Needle 11G × 100mm or 13G × 100mm 30% Routine adult iliac bone biopsy Adult Extended Trephine Biopsy Needle 11G × 150mm or 13G × 150mm 20% Obese/BMI high patients Children Trephine Biopsy Needle (Optional) 13G × 65mm or 14G × 50mm 10% Pediatrics/adolescents Adult Aspiration Needle (Companion) 16G or 18G × 70-100mm Each portion Bone marrow fluid aspiration in the same operation Pediatric Aspiration Needle (Companion) 20G × 25mm or 18G × 25mm Small amount Infants and toddlers tibial puncture

Note: The specific ratio will be adjusted according to the annual biopsy volume and patient population of this hospital. In most centers, the usage rate of 11G is higher than that of 13G because the specimen quality is better, but the bleeding risk of 13G is slightly lower.

III. Key Points of Warehouse Inspection and Expiry Period Management

• Opening and inspection: The outer packaging clearly indicates Gauge (including mm conversion), effective length, batch number, expiration date, STERILE mark, and "For single use only." - Checking the actual items: Before unpacking, a random inspection is conducted to confirm that the syringes are not flattened, the needle cores can be smoothly inserted and removed, and the depth limiters can be locked. - Defects related to size (bent syringes, stuck needle cores) are directly rejected.
• Expiration warning: Set a 3-month warning for the near expiration date, following the First-In-First-Out (FIFO) principle. Bone marrow biopsy needles usually have an expiration period of 3 to 5 years. Pay attention to storing them in a dry and pressure-free environment.
• Reporting of adverse events: If during the operation, the needle body breaks (often related to repeated use or excessive torque - now all single-use should not be reused), or the tissue cannot be extracted (sampling window size is abnormal / inner cavity is rough), report it to the national adverse event monitoring system.

IV. Key Points of Dimensional Understanding in Clinical Use Training

When conducting bone marrow puncture training for new doctors and residents in training, it is emphasized that:

• Selecting the needle: Make sure to check the Gauge number and length on the packaging. The biopsy must use a ≥13G trephine needle; do not use an 18G aspiration needle instead.
• Determining the length: For obese patients, estimate the length in advance at 150mm. If it is too short, it will result in "being able to touch the bone but not being able to enter the medullary cavity."
• Determining the depth: Install the depth limiter and lock it. Usually, insert 1.5 to 2cm into the bone; do not blindly go deeper.
• Selecting the withdrawal: After reaching the depth, slightly retract the needle by half a turn before withdrawing it to prevent the tissue core from getting stuck at the window and breaking.

By standardizing the creation of the directory based on size, implementing strict quality control during acceptance, and conducting clinical education, the rate of re-examination due to "selecting the wrong needle size" can be significantly reduced, the satisfaction rate of pathological diagnosis can be improved, and the additional suffering of patients can be alleviated.