Treatment of ischaemia

Abstract

An endovascular apparatus for crossing through an obstruction in a blood vessel comprises an elongate endovascular element such as a wire. The element has a proximal section, a distal tip section of smaller diameter than the proximal section; and a distally-tapering intermediate section extending between the proximal and distal tip sections. The apparatus comprises an ultrasonic transducer, mechanically coupled to the proximal section of the element for ultrasonically activating the element, hence exciting the distal tip section to facilitate crossing through the obstruction. A catheter surrounds the element, leaving at least part of the distal tip section of the element protruding distally beyond a distal end of the catheter.

1 - 52 . (canceled) 
     
     
         53 . An endovascular apparatus for crossing through an obstruction in a blood vessel, the apparatus comprising:
 an endovascular element such as a wire, the element comprising a proximal section, a distal section of smaller diameter than the proximal section; and a distally-tapering intermediate section extending between the proximal and distal sections;   an ultrasonic transducer, mechanically coupled to a proximal section of the element for ultrasonically activating the element, hence exciting the distal section to facilitate crossing through the obstruction; and   a catheter or sheath surrounding the element, at least part of the distal section of the element protruding distally beyond a distal end of the catheter or sheath;   wherein the catheter or sheath comprises a longitudinal closure or aperture extending along at least a majority of a length of the catheter or sheath, the longitudinal closure or aperture communicating with a lumen of the catheter or sheath for accommodating the element.   
     
     
         54 . The apparatus of  claim 53 , wherein the longitudinal closure or aperture is a slit or groove. 
     
     
         55 . The apparatus of  claim 53 , wherein the catheter or sheath is a catheter. 
     
     
         56 . The apparatus of  claim 55 , wherein the longitudinal closure or aperture terminates short of a distal end of the catheter. 
     
     
         57 . The apparatus of  claim 55 , wherein the catheter defines at least two parallel lumens, a first of those lumens being for housing the element. 
     
     
         58 . The apparatus of  claim 57 , wherein a second lumen of the catheter communicates with a coupling for connection to a pump for driving fluid flow along, or for pressurising fluid within, that second lumen. 
     
     
         59 . The apparatus of  claim 58 , wherein the second lumen is in fluid communication with the first lumen. 
     
     
         60 . The apparatus of  claim 59 , wherein the second lumen has a distal opening whose periphery is inclined at an acute angle to a longitudinal axis of the catheter. 
     
     
         61 . An endovascular apparatus for crossing through an obstruction in a blood vessel, the apparatus comprising:
 an endovascular element, the element comprising a proximal section that can be mechanically coupled to an ultrasonic transducer for ultrasonic activation of the element and a distal section that can be excited by said ultrasonic activation to facilitate crossing through the obstruction; and   a tube surrounding the element, at least part of the distal section of the element protruding distally beyond a distal end of the tube;   wherein the tube comprises a longitudinal closure or aperture extending along at least a majority of the length of the tube, the longitudinal closure or aperture communicating with a lumen of the tube for accommodating the element.   
     
     
         62 . The apparatus of  claim 61 , wherein the endovascular element is a wire. 
     
     
         63 . The apparatus of  claim 62 , wherein the distal section of the wire is of smaller diameter than the proximal section of the wire; and the wire further comprises a distally-tapering intermediate section extending between the proximal section and the distal section. 
     
     
         64 . The apparatus of  claim 61 , wherein the tube is a catheter or sheath. 
     
     
         65 . The apparatus of  claim 61 , wherein the longitudinal closure or aperture is a slit or groove. 
     
     
         66 . The apparatus of  claim 61 , wherein the longitudinal closure or aperture terminates short of the distal end of the tube. 
     
     
         67 . The apparatus of  claim 61 , wherein the tube comprises at least two parallel lumens, a first of those lumens housing the element. 
     
     
         68 . The apparatus of  claim 67 , wherein a second lumen of the tube has a distal opening whose periphery is inclined at an acute angle to a longitudinal axis of the tube. 
     
     
         69 . A method of handling an endovascular element, such as a wire, for crossing through an obstruction in a blood vessel of a patient's body, the method comprising:
 supporting a portion of the element outside the patient's body within a tube, such as a catheter or sheath, extending between the body and an activation unit that is coupled to the element to activate the element ultrasonically, a wall of the tube being penetrated by a longitudinal closure or aperture; and either   preliminarily, inserting at least part of that portion of the element into the tube through the longitudinal closure or aperture; or   subsequently, withdrawing at least part of that portion of the element from the tube through the longitudinal closure or aperture.   
     
     
         70 . The method of  claim 69 , wherein the longitudinal closure or aperture terminates short of a distal end of the tube and the element is constrained within a distal portion of the tube. 
     
     
         71 . The method of  claim 69 , comprising:
 coupling an ultrasonic activation unit to the element outside the patient's body; and   advancing the activation unit and the element together distally to insert the element into the patient's body, causing the tube to split longitudinally as at least part of the element exits the tube through the longitudinal closure or aperture.   
     
     
         72 . The method of  claim 71 , comprising advancing the element in a single continuous movement during which the ultrasonic activation unit remains coupled to the element.