Method and apparatus for insertion of elongate instruments within a body cavity

Abstract

A sheath is composed of a biocompatible material which has a stiffness and moldability such that it can easily be deformed by hand by the physician prior to implantation, or by means of a guiding or shaping tool such as the dilator, stylet and or guide wire during placement within the body cavity. Similarly, it has a suppleness such that it may be molded by its disposition within the body cavity without trauma to the tissues. Yet, it has sufficient stiffness and moldability such that it retains a shape which has been imparted to it by a shaping tool when in the body cavity, even when left unsupported or unconfined in a body cavity or subject to normal bodily fluid, blood or air flow. However, once the shaping or forming tool has been removed, the sheath will tend to stay in its molded shape in a body cavity without generating a resilient force or displacement which returns it to its original shape. A medical instrument can then be telescopically disposed through the sheath and thus correctly delivered within the body cavity according to the molded shape imparted to the sheath by the shaping tool. Further, the removal of the sheath similarly will not dislodge the medical instrument from its implanted position by the application of resilient forces or displacement arising during the removal of the sheath.