Intriducer Sheath — The "Safety Access Channel" for Interventional Surgery

author: Willow Hu

2026-05-09

1. Core Structure (Indispensable Components)

Sheath Tube: A thin and smooth long tube (commonly made of PTFE/FEP). It features thin wall, large lumen and good elasticity to reduce vascular friction and injury.

Hemostasis Valve: A sealing valve at the sheath hub, preventing blood leakage during instrument insertion and withdrawal, and fixing the instruments in position.

Side Arm (Lateral Tube): A branch tube with a switch, used for heparin saline flushing, drug administration and pressure monitoring to prevent access thrombosis.

Dilator (Matching Accessory): Pre-assembled inside the sheath during puncture. With a tapered tip, it dilates subcutaneous tissue and vascular puncture opening for smooth sheath insertion. It is removed after proper placement, leaving the sheath tube as the working channel.

2. Main Functions (Indispensable Rationale)

Establish stable access: Single puncture for full-procedure use; repeated instrument insertion and withdrawal without re-puncturing, saving operation time and reducing patient pain.

Vascular protection: Avoid direct friction of vascular wall by rigid catheters/guidewires, lowering risks of arterial dissection, vasospasm and hemorrhage.

Anti-bleeding and anti-coagulation: The hemostasis valve prevents blood leakage; the side arm allows continuous flushing and anticoagulation to maintain patency of the access channel.

Rapid instrument exchange: Facilitates intra-operative replacement of catheters, balloons and stents of different specifications, improving surgical efficiency.

3. Classification by Access Site

Radial Artery Sheath: Wrist access, easy hemostasis after operation and short bed rest time; the preferred option for coronary intervention.

Femoral Artery Sheath: Groin access, large inner diameter and strong supporting force, suitable for complex procedures such as large stent implantation and aortic surgery.