Catheter

Catheter disassembled

In medicine, a catheter is a tube that can be inserted into a body cavity duct or vessel. Catheters thereby allow drainage or injection of fluids or access by surgical instruments. The process of inserting a catheter is catheterization. In most uses a catheter is a thin, flexible tube: a "soft" catheter; in some uses, it is a larger, solid tube: a "hard" catheter.

The ancient Egyptians are reported to have fashioned catheters from papyrus, and the ancient Greeks from reeds. A flexible urinary catheter was invented by Benjamin Franklin for the use of his brother.

Placement of a catheter into a particular part of the body may allow:

draining urine from the urinary bladder as in urinary catheterization, i.e. Foley catheter or even when the urethra is damaged as in suprapubic catheterisation. By comparison, a Texas catheter is not inserted into the urethra, but connects to the penis via a condom-like envelope with a drainage tube at its tip.
drainage of fluid collections, e.g. an abdominal abscess
administration of intravenous fluids, medication or parenteral nutrition
angioplasty, angiography, balloon septostomy, balloon sinuplasty
direct measurement of blood pressure in an artery or vein
direct measurement of intracranial pressure
administration of anaesthetic medication into the epidural space, the subarachnoid space, or around a major nerve bundle such as the brachial plexus

A central venous catheter is a conduit for giving drugs or fluids into a large-bore catheter positioned either in a vein near the heart or just inside the atrium. A Swan-Ganz catheter is a special type of catheter placed into the pulmonary artery for measuring pressures in the heart.

Catheter

See also