In medicine, a catheter is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. By modifying the material or adjusting the way catheters are manufactured, it is possible to tailor catheters for cardiovascular, urological, gastrointestinal, neurovascular, and ophthalmic applications.
Catheters can be inserted into a body cavity, duct, or vessel. Functionally, they allow drainage, administration of fluids or gases, access by surgical instruments, and also perform a wide variety of other tasks depending on the type of catheter. The process of inserting a catheter is “catheterization”. In most uses, a catheter is a thin, flexible tube (“soft” catheter) though catheters are available in varying levels of stiffness depending on the application. A catheter left inside the body, either temporarily or permanently, may be referred to as an “indwelling catheter” (for example, a peripherally inserted central catheter). A permanently inserted catheter may be referred to as a “permcath” (originally a trademark).
The catheter used for hemodialysis is a tunneled catheter because it is placed under the skin. There are two types of tunneled catheters: cuffed or non-cuffed. Non-cuffed tunneled catheters are used for emergencies and for short periods (up to 3 weeks). Tunneled cuffed catheters, a type recommended by the NKF for temporary access, can be used for longer than 3 weeks when: – An AV fistula or graft has been placed but is not yet ready for use.