A catheter is a thin, flexible tube that can be inserted into a body cavity, duct or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments and the process of inserting a catheter is caricaturization. In this book, the authors present current research in the study of the types, applications and potential complications of catheters, including the comparison of catheter placement between laparoscopic and open surgery; the use of indwelling catheters in respiratory disease; using catheters for trans-radial coronary procedures; vascular access catheters and the complications of peripheral nerve block catheters.