Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
A nephrostomy tube is the drainage catheter placed through the skin into the kidney, and a nephrostomy tube set is the catheter plus the access and connection components packaged with it. This guide lists the parts as one manufacturer’s instructions for use (IFU) names them, the sizes catalogued in FDA device records, and the regulatory and handling facts printed on the labelling. It is written for clinic staff, buyers and students who need to tell the parts of a nephrostomy set apart and read its size designations.
What a nephrostomy tube is
The Global Medical Device Nomenclature (GMDN) definition used in FDA device records describes a nephrostomy catheter as a sterile, flexible tube intended to be inserted percutaneously into the renal pelvis to gain access to the upper urinary tract. It consists of a large-bore, thin-walled tube, usually with a self-retained tip, and sometimes has expanding wings on the tip. It is used for drainage to relieve obstructions above the bladder and may also be intended for other upper-urinary-tract procedures. The same definition states that it is a single-use device.
Who uses it: physicians trained in percutaneous access place these devices (the Cook IFU states this directly), and clinic and hospital staff handle, store and stock them.
Parts of a nephrostomy tube set
A set is more than the tube. The Cook Medical IFU for the Ultrathane Nephrostomy Set with Mac-Loc (T_CMLC_REV3) lists these components in its device description:
- Catheter: an Ultrathane nephrostomy catheter with a Mac-Loc locking loop mechanism, a hydrophilic (AQ) coating on the distal 5 cm and a radiopaque band at the base of the pigtail.
- Wire guides: a .038 in (0.97 mm) TFE-coated stainless steel Safe-T-J wire guide, 100 cm, and a .018 in (0.46 mm) Cope mandril wire guide, 60 cm.
- Stylets: a non-radiopaque polyethylene flexible stylet and a stainless steel rigid stylet.
- Dilators: radiopaque polyethylene dilators, 20 cm.
- Needle: a 21 gage thinwall needle, 15 cm.
- Introducing catheter and cannula: a 6.3 French radiopaque polyethylene introducing catheter, 22 cm, and a 20 gage stainless steel stiffening cannula, 22 cm.
- Catheter support: a soft, low-profile catheter support with a pull tie.
- Connecting tube: a 14.0 French polyvinylchloride connecting tube, 30 cm, with a one-way stopcock.
The practical point for buyers and stock-keepers: the catheter, the access components and the connecting tube are separate items in the set, and the set’s French sizes refer to different parts (the introducing catheter is 6.3 French, the connecting tube 14.0 French).
Types and variants
| Type | Typical use | Key difference | Source |
|---|---|---|---|
| Locking loop (pigtail) nephrostomy catheter | Percutaneous nephrostomy drainage from the renal pelvis (Cook IFU intended use) | A locking loop mechanism forms the retained loop at the tip; the Cook catheter carries a radiopaque band at the base of the pigtail | Cook IFU T_CMLC_REV3; FDA UDI records (Percuflex Locking Loop) |
| Malecot-type catheter | Drainage using an expanding-wing tip | Wings on the tip, which the GMDN definition notes some nephrostomy catheters have; see Malecot catheter design, sizes and set contents | GMDN definition in FDA UDI records |
For how nephrostomy catheters sit among other drainage catheters, see the drainage catheter types and institutional stocking guide.
Nephrostomy tube sizes
Catheter sizes are given in French (F), and FDA device records list the equivalent diameter in millimetres. The GMDN definition states that large-bore sizes from 14 to 24 Fr are typical for nephrostomy catheters. The Boston Scientific Percuflex Locking Loop records in FDA’s device identification database (AccessGUDID data, accessed through openFDA, last updated 2026-10-01) list these catalogued sizes:
| Model | Diameter (F) | Diameter (mm) | Effective length |
|---|---|---|---|
| M0064102020 | 8.3 | 2.8 | 19 cm |
| M0064102040 | 8.3 | 2.8 | 26 cm |
| M0064101110 | 8.3 | 2.8 | 26.5 cm |
| M0064102030 | 10.3 | 3.4 | 19 cm |
| M0064102050 | 10.3 | 3.4 | 27.6 cm |
| M0064101120 | 10.3 | 3.4 | 28.3 cm |
| M0064102060 | 12 | 4.0 | 27 cm |
The seven records above and the GMDN 14 to 24 Fr range are reported as each source states them. The records describe some models as “Nephrostomy Catheter” and others as “All Purpose Drainage Catheter”, so a catalogue size does not by itself tell you the intended use; the labelling does. The Cook set in the previous section is a second sizing reference: a 6.3 French introducing catheter and a 14.0 French connecting tube.
How to read the labelling
The labelling and records cited here show these things:
- Match the labelled intended use. The Cook IFU states the intended use as percutaneous placement of a loop catheter in the renal pelvis for nephrostomy drainage. FDA records show products with the same catheter family labelled differently (“Nephrostomy Catheter” versus “All Purpose Drainage Catheter”).
- Use the IFU of the exact product. Labelled limits and handling statements are product-specific, so a statement for one locking-pigtail catheter does not carry over to another.
- Compare set contents. Sets differ in which wire guides, dilators and connecting components they include, as the device description of each IFU shows.
Safe use and handling basics
- Single use. The GMDN definition and the Cook IFU both describe the device as single-use.
- Supplied sterile. The Cook set is supplied sterilized by ethylene oxide gas. Percuflex Locking Loop records list the product as sterile.
- Prescription device. US federal law restricts the Cook set to sale by or on the order of a physician. The Percuflex records also carry a prescription flag.
- Storage. The Cook IFU says to store the set in a dark, dry, cool place.
- Trained users. The Cook IFU is directed to physicians trained in percutaneous access techniques.
Regulatory class. FDA classifies the nephrostomy catheter under product code GBO, “Catheter, Nephrostomy, General & Plastic Surgery”, as a Class 1 device under 21 CFR 878.4200 (openFDA classification database, last updated 2026-10-19).
Common mistakes
- Treating French size as the size of the whole set. A set can include a 6.3 French introducing catheter and a 14.0 French connecting tube alongside the nephrostomy catheter itself.
- Assuming one product’s labelling applies to every locking-pigtail catheter. Each product’s own IFU governs.
- Treating “drainage catheter” and “nephrostomy catheter” as interchangeable. The same model family appears under both descriptions in FDA records.
- Confusing a nephrostomy catheter with urethral or ureteral devices. A Foley catheter and a ureteral stent are different devices with their own size conventions.
FAQ
What are the parts of a nephrostomy tube?
In the Cook Ultrathane Nephrostomy Set, the parts are a locking loop catheter with a radiopaque band and hydrophilic coating, two wire guides, a flexible and a rigid stylet, dilators, a needle, an introducing catheter, a stiffening cannula, a catheter support with a pull tie, and a connecting tube with a one-way stopcock.
What sizes do nephrostomy tubes come in?
The GMDN definition states that 14 to 24 Fr is typical. FDA device records for the Percuflex Locking Loop list 8.3 F (2.8 mm), 10.3 F (3.4 mm) and 12 F (4.0 mm) catheters, with effective lengths from 19 cm to 28.3 cm.
Is a nephrostomy tube a single-use device?
Yes. Both the GMDN definition and the Cook IFU describe it as single-use.
Is a nephrostomy tube a regulated device?
Yes. FDA product code GBO classifies it as a Class 1 device under 21 CFR 878.4200, and the sets discussed here are prescription devices.
Drainage catheters for urology are also listed in the drainage catheters category.
Sources
Each source was checked on 2026-10-30.
- Cook Medical, Instructions for Use, Ultrathane Nephrostomy Set with Mac-Loc, T_CMLC_REV3, ifu.cookmedical.com, checked 2026-10-30.
- U.S. FDA, openFDA Device UDI API (AccessGUDID data), Boston Scientific Percuflex Locking Loop records and GMDN 10735 definition, api.fda.gov, checked 2026-10-30.
- U.S. FDA, openFDA Device Classification, product code GBO, api.fda.gov, checked 2026-10-30.
- Code of Federal Regulations, 21 CFR 878.4200, law.cornell.edu, checked 2026-10-30.
