Neurosurgical apparatus and methods

Abstract

This invention concerns a neurosurgical kit comprising a catheter (1) and a guide tube (2). The catheter (1) comprises a distal section of tubing (11) having a distal end with a port or ports for delivering fluid to a target site within the brain. The distal section of tubing (11) has an outer diameter that is smaller than an internal diameter of the guide tube (2). The catheter (1) and guide tube (2) are arranged such that, when the catheter (1) is inserted into the guide tube (2) to locate the port or ports at the target site, a recess (14) is provided in a distal end section of the guide tube (2) between the guide tube (2) and the distal section of tubing (11) of the catheter (1).

1 . A neurosurgical kit comprising a catheter and a guide tube, the guide tube having a guide tube opening in a distal end thereof and the catheter comprising a distal section of tubing having a distal end with a port or ports for delivering fluid to a target site within the brain, the catheter and guide tube are arranged such that, when the catheter is inserted into the guide tube to locate the port or ports at the target site, a recess is provided in a distal end section of the guide tube between the guide tube and the distal section of tubing of the catheter that passes through the recess to locate the port at the target site, wherein an open end of the recess is defined by the guide tube opening and a closed end of the recess is contained within the distal end section of the guide tube. 
     
     
         2 . A neurological kit according to  claim 1 , comprising an indication indicating an extent of the catheter that should be inserted into the guide tube, in use, to locate the port or ports at the target site in the brain, the catheter and guide tube arranged such that, when the catheter is inserted into the guide tube to the extent indicated by the indication, the recess is provided in the distal end section of the guide tube between the guide tube and the distal section of tubing of the catheter. 
     
     
         3 . A neurological kit according to  claim 2 , wherein the indication comprises a stop located on the catheter and a formation on the guide tube that is engaged by the stop to define an extent the catheter can be inserted into the guide tube. 
     
     
         4 . A neurological kit according to  claim 2 , wherein the indication is an indicium on the catheter, which, when aligned at a specified location during insertion of the catheter into the guide tube identifies a position of the catheter in which the port or ports are located at the target site. 
     
     
         5 . A neurological kit according to  claim 1 , wherein the recess is dimensioned to retain a volume of brain tissue sufficient to act as a seal against reflux along the guide tube of fluid delivered using the catheter. 
     
     
         6 . A neurological kit according to  claim 1 , wherein the recess extends at least 0.5 mm into the guide tube. 
     
     
         7 . A neurological kit according to  claim 6  wherein the recess extends about 3 mm into the guide tube. 
     
     
         8 . A neurological kit according to  claim 1 , comprising a length of tubing having an outer diameter greater than the outer diameter of the distal section of the catheter that defines the recess and an internal diameter less than the internal diameter of the guide tube that defines the recess, the length of tubing located or locatable in the guide tube with a distal end of the length of tubing spaced from a distal end of the guide tube. 
     
     
         9 . A neurological kit according to  claim 8 , wherein the length of tubing is an intermediate section of the catheter, the catheter comprising an outer diameter that increases from the distal section to an intermediate section of the catheter. 
     
     
         10 . A neurological kit according to  claim 9 , wherein the increase in internal diameter is a step between the intermediate section and the distal section of the catheter. 
     
     
         11 . A neurological kit according to  claim 9 , wherein the increase in diameter is a gradual increase from the distal section to the intermediate section of the catheter. 
     
     
         12 . A neurological kit according to  claim 8 , wherein the length of tubing is an intermediate section of the guide tube, the guide tube comprising an internal diameter that decreases from the distal end section to an intermediate section. 
     
     
         13 . A neurological kit according to  claim 12 , wherein the decrease in internal diameter is a step between the distal end section and the intermediate section of the guide tube. 
     
     
         14 . A neurological kit according to  claim 12 , wherein the decrease in diameter is a gradual decrease from the distal end section to the intermediate section of the guide tube. 
     
     
         15 . A neurological kit according to  claim 1 , wherein the distal section of the catheter comprises a stiff, non-porous tip and wherein the catheter comprises a flexible tube leading to the stiff, non-porous tip, the flexible tube having a diameter greater than a diameter of the stiff, non-porous tip. 
     
     
         16 . A neurological kit according to  claim 1 , wherein an internal diameter of an intermediate section of the guide tube and an outer diameter of an intermediate section of the catheter are such that the intermediate section of the catheter is a snug fit in the intermediate section of the guide tube. 
     
     
         17 . A neurological kit according to  claim 16 , wherein, the intermediate section of the catheter is positioned such that, when the catheter is inserted into the guide tube to the extent indicated by the indication, the distal end of the guide tube is located at least 0.5 mm from an interface at which the catheter first engages the guide tube. 
     
     
         18 . A neurological device comprising a catheter comprising a distal section of tubing having a distal end with a port or ports for delivering fluid to a target site within a brain, the catheter received in a guide tube such that the port or ports are located at the target site in the brain, wherein the distal section of tubing has an outer diameter that is smaller than an internal diameter of the guide tube and is located to provide a recess in a distal end portion of the guide tube between the guide tube and the distal section of tubing of the catheter. 
     
     
         19 . A neurological device according to  claim 18 , wherein the recess contains compressed brain tissue. 
     
     
         20 . A neurological kit comprising a guide tube that can be cut to the required length, a catheter comprising a distal section of tubing having a distal end with a port or ports for delivering fluid to a target site within the brain, the distal section of tubing having an outer diameter that is smaller than an internal diameter of the guide tube, and an indication for indicating an extent of the catheter that should be inserted into the guide tube, in use, to locate the port or ports at the target site in the brain and to provide a recess in a distal end section of the guide tube between the guide tube and the distal section of tubing of the catheter, the indication adjustable along a length of the catheter.