Catheter

Catheter (Gr. kathēmi, 'I thrust into') was a name applied indifferently to all instruments for passing along mucous canals. In modern times, however, it has generally been reserved for tubular rods through which fluids or air may pass, and is now restricted to those used for emptying the urinary bladder, and those used for injecting air or fluids into the Eustachian tube (Eustachian Catheter). The catheter for the former purpose is a very old surgical instrument. The ancients made theirs of copper, which accumulated verdigris. In the 9th century silver was substituted by the Arabian surgeons as a cleaner metal, and is still used by all who are not obliged, for economical reasons, to have their catheters made of German silver or pewter. The urinary catheter for the male varies in length from 10 to 11 inches; the female catheter need not be more than 4 or 5 inches. The form is a matter of less importance, but most surgeons prefer an instrument straight to within the last few inches of its length; the latter should be curved into the segment of a small circle. Others, however, use a double curve, and indeed nearly every surgeon has a peculiar fancy in this respect. Flexible catheters are made of gum elastic (see BOUGIE), which may be used either alone or supported on a wire. Many other materials have been proposed, but vulcanised india-rubber is the only one generally in use. The Eustachian catheter is generally made of metal or vulcanite, 6 or 7 inches in length, with the last inch or less slightly curved. It is introduced into the Eustachian tube along the floor of the nose, and air or fluid, as may be necessary, forced along it by an india-rubber bag which can be attached to it. See EAR, Vol. IV. p. 158.