Introducer Sheaths for Endoscopes and Related Methods

Abstract

A sheath for inserting a cannula of an endoscope into a cavity of a patient is described herein. The sheath comprises an introducer, a support channel and a pull-tab. The introducer has an open end being sized and shaped to accept a tip of the cannula and a tip end adapted to be deflected in an outward direction by the tip of the cannula passing into the introducer. The support channel is adapted to receive a shaft of the cannula and guide the tip of the cannula into the introducer; and the pull provides a finger hold for a user to grasp the sheath. In some aspects, the introducer includes a plurality of extending segments having a normally closed position defining a conical exterior shape of the introducer, with the plurality of tapered segments adapted to be separated by the tip of the cannula passing through the introducer.

1 . A method of inserting a cannula of an endoscope into an internal space of a patient, the method comprising:
 placing the cannula of the endoscope within a support channel of a sheath, proximal to a collapsed introducer at the insertion end of the sheath;   advancing the cannula and sheath through a cavity of a patient until the collapsed introducer is inserted into an internal space of a patient, the introducer at least partially dilating the internal space;   advancing the cannula along the support channel and through the introducer;   advancing the cannula within the support channel to a desired distance within a cavity; and   removing the cannula and sheath from the patient.   
     
     
         2 . The method of  claim 1  wherein advancing the cannula through the introducer expands the introducer and further dilates the internal space. 
     
     
         3 . The method of  claim 1 , further including, advancing an inner sleeve of the sheath along the support channel and into the introducer, the advancing of the inner sleeve expanding the introducer and further dilating the internal space to enable the advancing of the cannula through the introducer and into the cavity. 
     
     
         4 - 10 . (canceled) 
     
     
         11 . A method of inserting a cannula of an endoscope into a cavity of a patient, the method comprising:
 mounting a coiled sheath on a distal end of the cannula of the endoscope;
 advancing the cannula and coiled sheath through a cavity of the patient until a distal end of the coiled sheath is inserted into an internal space of a patient, the distal end of the coiled sheath partially dilating the cavity; and 
   removing the cannula and coiled sheath from the patient.   
     
     
         12 - 14 . (canceled) 
     
     
         15 . A sheath for facilitating insertion of a cannula of an endoscope into an internal space of a patient, the sheath comprising:
 a support member adapted to receive a shaft of the cannula; and   an introducer positioned at a distal end of the sheath, the introducer having a tip end and an open end at a distal end of the introducer, the open end being sized and shaped to accept a tip of the cannula, the tip end adapted to be deflected in an outward direction.   
     
     
         16 . The sheath of  claim 15 , wherein the introducer is biased in a normally closed position. 
     
     
         17 . The sheath of  claim 15 , wherein the introducer is biased in a normally deflected position, and the tip end adapted to be deflected inwardly prior to insertion of the sheath. 
     
     
         18 . The sheath of  claim 15 , wherein the tip end is adapted to be deflected in the outward direction by the tip of the cannula when the tip of the cannula is inserted into the introducer. 
     
     
         19 . The sheath of  claim 15 , wherein the support member comprises an outer sleeve and an inner sleeve, the inner sleeve being in slidably disposed in the outer sleeve, and wherein the tip end of the introducer is adapted to be deflected in the outward direction by the inner sleeve when a distal end of the inner sleeve is inserted into the introducer. 
     
     
         20 . The sheath of  claim 15 , further including a pull-tab extending from the sheath, the pull-tab providing a finger hold for a user to grasp the sheath. 
     
     
         21 . The sheath of  claim 15 , wherein the support member defines a support channel and includes a retention clasp adapted to removeably secure the shaft of the cannula to the support channel. 
     
     
         22 . The sheath of  claim 15 , wherein the sheath is constructed from a lubricious material or coated in a lubricious material. 
     
     
         23 . The sheath of  claim 15 , wherein the introducer has a length between 127 mm to 304.8 mm 
     
     
         24 . The sheath of  claim 15 , wherein the introducer has an exterior diameter of 2 mm to 30 mm. 
     
     
         25 . The sheath of  claim 15 , wherein the introducer defines a tapered or conical exterior surface. 
     
     
         26 . The sheath of  claim 15 , wherein the introducer includes:
 a ring that at least partially defines the open end; and   a plurality of segments extending from the ring to the tip end, the plurality of tapered segments having a normally closed position defining a conical exterior shape of the introducer, the plurality of tapered segments adapted to be separated in a radial direction by the tip of the cannula when the tip of the cannula is passes through the introducer.   
     
     
         27 . The sheath of  claim 26 , wherein each of the plurality of tapered segments defines a triangular shape. 
     
     
         28 . The sheath of  claim 27 , wherein each of the plurality of tapered segments defines outside edges, the outsides edges of each of the plurality of tapered segments positioned adjacent to the outside edge of an adjacent tapered segment in the normally closed position, and the outsides edges of each of the plurality of tapered segments adapted to be separated by the tip of the cannula when the tip of the cannula is passes through the introducer. 
     
     
         29 . The sheath of  claim 15 , wherein the support member is a support tube constructed from a coiled segment, the introducer includes:
 the coiled segment extending from the support tube to the tip end in an overlapping spiral, the coiled segment having a nominal position defining a conical exterior shape of the introducer.   
     
     
         30 . The sheath of claim  12 , wherein the support member includes one or more depth markings located on the support channel to identify how far the cannula tip has been inserted into an internal space