Vascular filter system

Abstract

A vascular filter system comprises a vascular filter ( 1 ), a clamp device ( 50 ), and a delivery catheter ( 51 ). The filter ( 1 ) comprises filter elements ( 6 ). When used without the clamp device ( 50 ), the filter elements ( 6 ) move from a closed state to an open state upon elapse of a predetermined period of time. In the closed state the filter elements ( 6 ) capture thrombus passing through the inferior vena cava ( 2 ). The delivery catheter ( 51 ) is employed to deliver the clamp device ( 50 ) to the filter ( 1 ) after the filter ( 1 ) has been deployed in the inferior vena cava ( 2 ). The clamp device ( 50 ) engages with the filter elements ( 6 ) of the filter ( 1 ) to clamp the filter ( 1 ) in the closed state beyond elapse of the predetermined period of time. Because of the presence of the clamp device ( 50 ), the filter elements ( 6 ) are no longer free to move from the closed state to the open state upon elapse of the predetermined period of time. In this manner the period of time in which the filter ( 1 ) captures thrombus is extended either temporarily or permanently.

1 . A vascular filter system comprising:
 a vascular filter comprising at least one filter element, the filter being movable from a closed state for capturing thrombus passing through a blood vessel to an open state facilitating blood flow,   a holder for holding the filter in the closed state for a predetermined period of time, and   a member to at least temporarily extend the filtration period.   
   
   
       2 . A system as claimed in  claim 1  wherein the member comprises a retainer to at least temporarily retain the filter in the closed state beyond elapse of the predetermined period of time. 
   
   
       3 . A system as claimed in  claim 2 , wherein the retainer is extendable around at least part of the filter to retain the filter in the closed state. 
   
   
       4 . A system as claimed in  claim 2 , wherein the retainer is adapted to clamp at least part of the filter to retain it in the closed state. 
   
   
       5 . A system as claimed in  claim 2 , wherein the retainer is adapted to tie at least part of the filter to retain it in the capturing state. 
   
   
       6 - 9 . (canceled) 
   
   
       10 . A system as claimed in  claim 2 , wherein the retainer is movable between a delivery state and a retaining state. 
   
   
       11 . A system as claimed in  claim 10 , wherein the retainer is biased towards the retaining state. 
   
   
       12 . A vascular filter system comprising:
 a vascular filter comprising at least one filter element, the filter being movable from a closed state for capturing thrombus passing through a blood vessel to an open state facilitating blood flow,   a holder for holding the filter in the closed state for a predetermined period of time,   a member to at least temporarily extend the filtration period, wherein the member comprises a retainer to at least temporarily retain the filter in the closed state beyond elapse of the predetermined period of time, and   a delivery mechanism to deliver the retainer to the filter located in the blood vessel.   
   
   
       13 . A system as claimed in  claim 12  wherein the delivery mechanism is adapted to maintain the position of the filter relative to a blood vessel during delivery of the retainer. 
   
   
       14 . A system as claimed in  claim 13 , wherein the delivery mechanism is adapted to grasp the filter for delivery of the retainer. 
   
   
       15 . A system as claimed in  claim 12 , wherein the retainer is configured to releasably retain the filter in the closed state. 
   
   
       16 . A system as claimed in  claim 12 , wherein the retainer is changeable, when engaging the filter, from a non-retaining state in which the filter is not retained to a retaining state in which the filter is retained. 
   
   
       17 . (canceled) 
   
   
       18 . A system as claimed in  claim 16 , wherein the retainer is changeable by rotation on threads to move with respect to the filter. 
   
   
       19 . A system as claimed in  claim 16 , wherein the retainer is changeable by insertion of a magnetic part to retain the filter. 
   
   
       20 - 35 . (canceled) 
   
   
       36 . A method for treating a blood vessel, the method comprising the steps of:
 locating a vascular filter in the blood vessel, the vascular filter comprising at least one filter element, the filter being movable after a predetermined period of time from a closed state for capturing thrombus passing through the blood vessel to an open state facilitating blood flow, and   a retainer at least temporarily retaining the filter in the capturing state beyond elapse of the first predetermined period of time.   
   
   
       37 . A method as claimed in  claim 36 , wherein the method comprises the step of delivering the retainer to the filter. 
   
   
       38 . A method as claimed in  claim 37 , wherein the retainer is delivered to the filter after the filter has been located in the blood vessel. 
   
   
       39 . A method as claimed in  claim 37 , wherein the retainer is delivered to the filter using a delivery mechanism, and the method comprises the step of centering the delivery mechanism in the blood vessel. 
   
   
       40 . (canceled) 
   
   
       41 . A method as claimed in  claim 37 , wherein the method comprises the step of grasping the filter before delivering the retainer. 
   
   
       42 . A method as claimed in  claim 36 , wherein the method comprises the step of changing the retainer while it engages the filter from a non-retaining state in which the filter is not retained to a retaining state in which the filter is retained. 
   
   
       43 - 52 . (canceled)