15G-17G SUS304 Medical Stainless Steel AVF Cannula for Hemodialysis , Back Eye Needle Tip
15G-17G SUS304 Medical Stainless Steel AVF Cannula for Hemodialysis , Back Eye Needle Tip
An ISO 9626 SUS304 medical stainless steel AVF cannula/needle for hemodialysis with back-eye needle tip is a sterile, single-use vascular access needle assembly used to cannulate an arteriovenous fistula (AVF) or arteriovenous graft (AVG) during hemodialysis. The cannula/needle tube is made from SUS304 austenitic stainless steel needle tubing that complies with ISO 9626 — the international standard for stainless steel needle tubing used in medical devices. Back-eye refers to a secondary opening or side hole located near the needle tip, usually on the back/heel side opposite the primary bevel. This back eye helps maintain blood flow even if the primary bevel is partially occluded by the vessel wall.
An AVF (arteriovenous fistula) is a surgically created vascular access joining an artery and vein, which provides high blood flow for extracorporeal blood purification. The **back eye** means a precision-machined auxiliary side orifice near the primary bevel tip, working together with the main bevel lumen to guarantee uninterrupted blood flow even if the main bevel opening is pressed against the inner vessel wall during dialysis cannulation. This tubing is the core metal substrate for finished disposable hemodialysis fistula needles, not the complete assembled needle set with plastic wings, silicone tubing or hub.
Common Sizes:
| Gauge | Outer Diameter OD (mm) | Wall Thickness WT (mm) | Typical Length (mm) | Application Notes |
| 14G | 2.10 ±0.02 | 0.20 | 25 / 32 / 40 / 54 | High blood flow >350 mL/min |
| 15G | 1.83 ±0.02 | 0.18 | 25 / 32 / 40 / 54 | Standard high-flow dialysis |
| 16G | 1.65 ±0.02 | 0.15 | 25 / 32 / 40 / 54 | Most widely used for routine hemodialysis |
| 17G | 1.47 ±0.02 | 0.13 | 25 / 32 / 40 | For new immature fistula, lower blood flow 200–250 mL/min |
Chemical Composition:
| Element | C | Si | Mn | P | S | Cr | Ni | N |
| Min | — | — | — | — | — | 18.00 | 8.00 | — |
| Max | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 20.00 | 10.50 | 0.10 |
Key Features of Back-Eye AVF Needle Tubes:
Secondary side hole near the tip: Located opposite the primary bevel or on the heel/back side.
Maintains blood flow: If the primary bevel is against the vessel wall, the back eye still allows blood to flow.
Reduces occlusion risk: Less likely to have complete flow blockage during cannulation.
Improves dialysis adequacy: Helps maintain prescribed blood flow rates.
Reduces shear stress and hemolysis: Multiple openings can distribute flow and reduce jetting.
May reduce recirculation: Better flow patterns can help avoid recirculation in some clinical situations.
Useful in difficult accesses: Helpful in tortuous, scarred, or buttonhole fistulas.
Laser-drilled and polished: Back eye is precisely formed, deburred, and electropolished.
Available in common gauges: 14G, 15G, 16G, 17G, with customized lengths.
Main Using Areas of AVF Needles:
Hemodialysis: Arterial and venous cannulation of AVF or AVG.
Buttonhole cannulation technique: Repeated cannulation at the same site.
Apheresis and plasmapheresis: Therapeutic plasma exchange and cell separation.
Hemoperfusion, hemodiafiltration, and ultrafiltration.
Blood collection/return in extracorporeal circuits.
Pediatric or low-flow dialysis using smaller gauges such as 17G or 18G.
Vascular access in renal failure patients requiring long-term dialysis.
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