Cook Check-Flo Long Shaft 10Fr Outer Diameter
The outer diameter of a 10 French (Fr) introducer sheath is approximately 3.3 mm.
Understanding French Size Conversion
The French catheter scale defines 1 Fr as 0.33 mm of outer diameter. 1 Therefore, a 10 Fr sheath has an outer diameter of approximately 3.3 mm (10 × 0.33 mm = 3.3 mm). This is a standardized measurement system used universally for vascular access devices.
Clinical Context for 10Fr Sheath Selection
A 10 Fr sheath is commonly used for biliary interventions, particularly for dominant stricture management in conditions like primary sclerosing cholangitis, where single 10-Fr stents are the preferred diameter for extrahepatic duct strictures 1
For hemodialysis access, larger sheaths are typically required - femoral catheters for dialysis use 11.5 Fr or larger with outer diameters exceeding 3.8 mm 2
The 10 Fr size represents a middle-ground option that can accommodate various interventional devices while maintaining reasonable vessel compatibility 3
Vessel Compatibility Considerations
When selecting any introducer sheath, the critical safety principle is the 1:3 rule: catheter outer diameter should not exceed 33% of the vessel diameter. 4, 5 For a 10 Fr sheath (3.3 mm outer diameter), the target vessel should ideally be at least 10 mm in diameter to minimize thrombotic complications.
Ultrasound assessment of vessel diameter before insertion is essential to ensure appropriate sizing and reduce endothelial damage 5
Smaller vessels may accommodate 10 Fr sheaths but carry higher complication risks, including vasospasm, thrombosis, and vessel injury 6