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General product information from manufacturer documents, not medical advice and not a procedure guide.
Short answer
A Tuohy-Borst adapter is a Luer-fitted connector with a compression seal that lets an instrument pass through while resisting fluid backflow around it. Cook Medical’s instructions for use describe its version as an endoscopic adapter that connects to a standard female Luer lock fitting and accepts instruments up to 6 French.
Definition and scope
The name appears on products from several manufacturers, and each defines its own device. Cook Medical’s instructions for use (IFU) describe the Tuohy-Borst Adapter as “an endoscopic adapter designed to facilitate the passage of instruments sized up to 6 French in diameter,” connectable to “any standard female Luer lock fitting.” The same document states that it is “intended to resist the backflow of fluid around an instrument inserted through the working channel of a ureteroscope, cystoscope, or other endoscope.”
It is an accessory, not an endoscope. For the instrument it is used with, see what an endoscope is.
How it is used in practice
Per the Cook IFU, the adapter attaches at the endoscope’s working channel through the Luer lock fitting, and an instrument passes through its port. If a model has a side arm, the IFU says the side arm can be used to facilitate use of complementary devices. Qosina, a components supplier, lists a version with a tubing sideport for flushing (5 mm inner diameter) and describes the part as preventing fluid backflow around instruments in large-bore applications.
The IFU says the product is intended for physicians trained and experienced in urological procedures, and lists contraindications and warnings as “None known.” It carries the U.S. federal-law caution that sale is restricted to or on the order of a physician. Technique is the clinician’s domain and is not covered here.
Types and how sourced listings differ
The three manufacturer documents in the Sources section describe the same device class with different ranges and details. The table restates what each page says and does not rank them.
| Listing | Instrument range stated | Connector and other details stated |
|---|---|---|
| Cook Tuohy-Borst Adapter (IFU) | Up to 6 French | Standard female Luer lock; ethylene oxide sterilized; single use; physician-order caution |
| Cook Tuohy-Borst Sidearm Adapter (PTBYC-RA) | Up to 9 Fr | Product page names the spec-table type “Large Bore Rotating Male Adapter”; maximum pressure 300 psi |
| Qosina Tuohy Borst Adapter, Threaded Flare Connector (#11226) | 0 to 13 FR (up to 4.3 mm) | Tinted polycarbonate body suited to gamma sterilization; threaded flare connector; flushing sideport |
Where it matters for labs, clinics and supply decisions
Because ranges and connectors differ by product, a spec sheet is the deciding document, not the product name. A checklist built only from fields the sources above actually publish:
- Instrument range in French (Fr) (the Qosina page also gives millimetres: 13 Fr is 4.3 mm).
- Connector type: Cook states standard female Luer lock for its endoscopic adapter and a male-type rotating adapter for its large-bore sidearm; Qosina lists a threaded flare connector.
- Sideport: present or absent, and its inner diameter where given (Qosina: 5 mm).
- Pressure rating: Cook lists 300 psi for the sidearm model; the Qosina page states none.
- Sterility and reuse: Cook’s endoscopic adapter is supplied sterile by ethylene oxide and for one-time use; see sterility assurance level for what sterilization claims mean.
- Materials and sterilization method: Qosina states a polycarbonate body suited to gamma sterilization; the Cook sidearm page lists no materials.
- Labeling: whether the IFU carries a prescription caution.
Missing fields are themselves a finding: ask the manufacturer for the full specification rather than assuming. For a related supply list that touches urology consumables, see the urology clinic supply checklist.
Common misunderstandings
- One size fits all. The stated ranges above run from 6 Fr to 13 Fr, so a figure from one listing does not transfer to another.
- Same connector everywhere. Female Luer lock, male rotating and threaded flare appear across these sources.
- Reusable by default. Cook’s endoscopic adapter is labeled for one-time use; check each product’s own labeling.
Frequently asked questions
What does a Tuohy-Borst adapter do?
Per Cook’s instructions for use, its adapter is intended to resist the backflow of fluid around an instrument inserted through an endoscope’s working channel. Qosina likewise describes its part as designed to prevent backflow of fluid around instruments.
What size of instrument does it accept?
It depends on the product. The sources above state up to 6 Fr (Cook endoscopic adapter), up to 9 Fr (Cook sidearm adapter) and 0 to 13 Fr, or 4.3 mm (Qosina #11226).
What is the sideport for?
Qosina lists a tubing sideport for flushing on its part (5 mm inner diameter). Cook’s instructions say that, where a device has a side arm, it can be used to facilitate use of complementary devices.
What connector does it use?
Cook states a standard female Luer lock fitting for its endoscopic adapter. The sidearm model is listed as a large bore rotating male adapter, and the Qosina part has a threaded flare connector.
Is it sterile and single use?
Cook’s endoscopic adapter is supplied sterilized by ethylene oxide and intended for one-time use. Check the labeling of each product, since component suppliers and finished-device makers differ.
Sources
- Cook Medical, Tuohy-Borst Adapter instructions for use (English section): ifu.cookmedical.com, checked 2026-10-30.
- Cook Medical, Tuohy-Borst Sidearm Adapter product page: cookmedical.com, checked 2026-10-30.
- Qosina, Tuohy Borst Adapter, Threaded Flare Connector #11226: qosina.com, checked 2026-10-30.
