Method for using intravenous filter and method for filter placement

Abstract

A vascular filter system and method are disclosed. In one embodiment, the filter system comprises a dispensing needle releasably attached to a filter dispenser which stores a length of filter wire. The filter wire dispenser has a guide tube which guides the filter wire into the needle and then into a vein during surgical implantation. The filter wire is configured to coil into a predetermined shape as it is deployed from the needle. The shape of the filter wire captures blood clots in the blood stream. Once the filter wire is deployed, the needle may be removed and a portion of the filter wire may be left protruding from the patient's skin surface to allow the filter wire to be secured by a fixation device. A syringe may be used to draw blood to confirm that the needle is properly positioned within a vein before the filter wire is deployed.

What is claimed is: 
     
         1 . A method for surgically implanting a vascular filter in a patient comprising:
 accessing a blood vessel with a dispensing needle;   attaching a filter wire dispenser to the needle, wherein the dispenser has a length of filter wire stored therein, the filter wire comprising a first end, a second end, and fabricated such that the filter wire coils upon deployment from a delivery end of the needle;   advancing the first end of the filter wire into the needle from the filter wire dispenser such that the first end exits the delivery end of the needle and forms a substantial filter wire coil within the blood vessel;   removing the needle and the dispenser, wherein the filter wire remains within the blood vessel and a portion of the filter wire extends out of the patient; and   securing the second end of the filter wire to a fixation device, the fixation device generally covering an exit passage from the patient for the filter wire.   
     
     
         2 . The method for surgically implanting a vascular filter of  claim 1  further comprising the step of verifying the needle is accurately located within the blood vessel. 
     
     
         3 . The method for surgically implanting a vascular filter of  claim 1  further comprising:
 attaching a syringe to the needle, wherein the syringe is releasably attached to the needle; 
 drawing blood from the blood vessel into the syringe to confirm that the needle is accurately located within the blood vessel; and 
 detaching the syringe from the needle while leaving the needle located in the blood vessel. 
 
     
     
         4 . The method for surgically implanting a vascular filter of  claim 1  wherein the length of filter wire is continuous length of filter wire. 
     
     
         5 . The method for surgically implanting a vascular filter of  claim 1  wherein the first end of the filter wire has a flexible tip. 
     
     
         6 . The method for surgically implanting a vascular filter of  claim 1  wherein the length of filter wire is stored in a spool within the filter wire dispenser. 
     
     
         7 . The method for surgically implanting a vascular filter of  claim 1  wherein the length of filter wire is stored linearly within the filter wire dispenser. 
     
     
         8 . The method for surgically implanting a vascular filter of  claim 1  wherein advancing the filter wire comprises pushing the filter wire into the blood vessel. 
     
     
         9 . The method for surgically implanting a vascular filter of  claim 1  wherein accessing the blood vessel comprises penetrating a skin layer of the patient at an acute angle in relation to the blood vessel. 
     
     
         10 . A method for surgically implanting a vascular filter in a patient comprising:
 accessing a blood vessel with a needle and verifying that the needle is within blood vessel;   inserting a length of continuous filter wire into the needle or other filter wire delivery device from a filter wire housing, the filter wire housing storing the filter wire;   advancing the filter wire into the blood vessel to cause a first end of the filter wire to exit a delivery end of the needle or other filter wire delivery device such that at least a portion of the filter wire within the blood vessel has residual stresses, surface tensions, or both that cause the filter wire when deployed in the blood vessel to form a plurality of loops;   removing the needle or the other filter wire delivery device from the blood vessel such that the filter wire remains within the blood vessel and a second end of the filter wire extends out of the patient; and   securing the second end of the filter wire to a fixation device and securing the fixation device to a patient.   
     
     
         11 . The method for surgically implanting a vascular filter of  claim 10  wherein the length of filter wire is stored in a spool within the filter wire dispenser. 
     
     
         12 . The method for surgically implanting a vascular filter of  claim 10  wherein the other filter wire delivery device comprises a catheter. 
     
     
         13 . The method of surgically implanting a vascular filter of  claim 10  wherein advancing the filter wire into the blood vessel and securing the second end of the filter wire causes the plurality of loops of filter wire to float within the blood vessel and move in a direction that is generally parallel to the blood vessel due to movement by the patent and blood flow. 
     
     
         14 . The method for surgically implanting a vascular filter of  claim 10  further comprising removing the filter by:
 detaching the second end of the filter wire from the fixation device; 
 pressing on the patient where the filter wire exits the patient; and 
 pulling the filter wire from the patient, the filter wire being an continuous length of filter wire with a uniform outer profile. 
 
     
     
         15 . The method for surgically implanting a vascular filter of  claim 1  wherein the length of filter wire is stored linearly within the filter wire housing. 
     
     
         16 . A method for filtering blood with an implanted vascular filter in a patient comprising:
 providing a vascular filter comprising a continuous length of filter wire, at least a portion of the filter wire within the blood vessel has residual stresses, surface tensions, or both that cause the filter wire when deployed in the blood vessel to form a plurality of loops;   implanting a first portion of the length of filter wire into the patient while leaving a second portion of the length of filter wire outside of the patient;   coiling the portion of the vascular filter in the blood vessel due to the residual stresses on the length of filter to form the plurality of loops;   securing the second portion of the vascular filter to the patient; and   filtering blood flow as blood flow within the blood vessel passes over the plurality of loops.   
     
     
         17 . The method of  claim 16  wherein the vascular filter is located in the common femoral vein or a continuation of the femoral vein. 
     
     
         18 . The method of  claim 16  further comprising removing the vascular filter by securing the second portion of the vascular filter from the patient and pulling on the vascular filter at a patient bedside, the pulling of the filter overcoming the residual stresses of the first portion of filter wire. 
     
     
         19 . The method of  claim 16  wherein the first portion of the filter wire has a generally uniform outer profile along the entire length of the first portion.