The invention provides an inflatable insertion device capable of being percutaneously introduced into a patient's body. The insertion device comprises an inflatable element having a distal end and a proximal end and which is operable between a collapsed condition and an inflated condition by introducing an inflating fluid therein. An elongate member extends internally of the inflatable element from its distal end. The internal member is capable of being withdrawn towards the proximal end of the inflatable element to result in the distal end of the element being withdrawn towards the proximal end internally of the element. The invention further provides a locating device comprising a catheter having a catheter tube fitted with one or more inflatable insertion devices at a distal end thereof.
