Absorbable vascular filter

Abstract

An absorbable vascular filter is disclosed for deployment within a vessel for temporary filtering of body fluids. A preferred embodiment is the placement of such absorbable vascular filter within the inferior vena cava (IVC) to filter emboli for the prevention of pulmonary embolism for a limited duration in time. Once protection from PE is complete, the filter is biodegraded according to a planned schedule determined by the absorption properties of the filter components. Hence the temporary absorbable vascular filter obviates the long term complications of permanent IVC filters such as increased deep vein thrombosis, neighboring organ puncture from filter fracture and embolization while also circumventing the removal requirement of metal retrievable IVC filters.

1 . An absorbable filter configured for intra vena cava deployment through the femoral or jugular vein comprising:
 a circumferential element for attaching or securing the filter to a vessel, wherein the circumferential element provides sufficient radial force to maintain placement in a vessel, the circumferential element being made from an absorbable material; and   a plurality of absorbable capture elements affixed to the circumferential element for capturing or retarding substances flowing in the vessel for a limited duration in time;   wherein the circumferential element is characterized by a first lattice spacing and the absorbable capture elements are characterized by a second lattice spacing, the first lattice spacing being smaller than the second lattice spacing;   wherein individual ones of the plurality of absorbable capture elements are linked with adjacent absorbable capture elements via an inner capture element woven through the plurality of absorbable capture elements to establish the second lattice spacing;   wherein individual ones of the plurality of absorbable capture elements intersect and wrap around other individual ones of the plurality of absorbable capture elements at a plurality of separate locations along a given absorbable capture element; and   wherein the intersecting and wrapping creates an inner petal structure having a plurality of inter petals with an inner lattice spacing, and an out petal structure having a plurality of outer petals with an outer lattice spacing that is larger than the inner lattice spacing, the plurality of absorbable capture elements configured such that the inner petal structure and the outer petal structure are located in a lumen of the vena cava to capture or retard the substances flowing in the vessel.   
     
     
         2 . The filter of  claim 1 , wherein the inner petal structure comprises a multi-pointed star shape formed by the plurality of absorbable capture elements. 
     
     
         3 . The filter of  claim 1 , wherein the outer petal structure comprises a plurality of teardrop shapes or diamond shapes formed by the plurality of absorbable capture elements. 
     
     
         4 . The filter of  claim 1 , wherein the plurality of absorbable capture elements form an absorbable capture basket affixed to the circumferential element for capturing or retarding the substances flowing in the vessel for the limited duration in time. 
     
     
         5 . The filter of  claim 4 , wherein the capture basket comprises polydioxanone. 
     
     
         6 . The filter of  claim 4 , wherein the capture basket is a biocompatible mesh. 
     
     
         7 . The filter of  claim 4 , wherein the capture basket is fabricated from a biocompatible mesh comprising polydioxanone. 
     
     
         8 . The filter of  claim 1 , wherein the circumferential element and the plurality of absorbable capture elements comprise polydioxanone. 
     
     
         9 . The filter of  claim 1 , wherein the circumferential element comprises an anchor element or barb for attachment to a vessel. 
     
     
         10 . The filter of  claim 1 , wherein the circumferential element and/or the plurality of absorbable capture elements include bioactive surfaces for anticoagulation. 
     
     
         11 . The filter of  claim 1 , wherein the absorbable filter is configured for intra vena cava deployment through the femoral or jugular vein with a balloon catheter. 
     
     
         12 . The filter of  claim 1 , wherein the circumferential element and the plurality of absorbable capture elements comprise a single, continuous, absorbable filament. 
     
     
         13 . The filter of  claim 12 , wherein the single, continuous, absorbable filament comprises polydioxanone. 
     
     
         14 . The filter of  claim 1 , wherein the circumferential element is braided to offer diametrically expandable and compressible tubular characteristics to accommodate minimally invasive deployment via a catheter. 
     
     
         15 . The filter of  claim 14 , wherein the radial force from the circumferential element exerted on the vessel is selected based on an angle of intersection of braided elements comprising the circumferential element, material composition of the braided elements, diameter of the braided elements, and an outer diameter of the circumferential element. 
     
     
         16 . The filter of  claim 1 , wherein the plurality of absorbable capture elements form a capture basket, and wherein the capture basket is formed by sequentially interlocking loops from adjacent loops distal to the circumferential element and extending loops to an apex in a periodic manner to form a conical capture basket with filter resolution determined by a periodicity of a filter braid. 
     
     
         17 . The filter of  claim 1 , wherein the circumferential element and the plurality of absorbable capture elements are sutures and are fabricated from absorbable materials comprising one or more of polydioxanone, polytrimethylene carbonate, polyglactin, polyglycolic acid, poly L lactic acid, poliglecaprone, polyglytone, or polylacticoglycolic acid. 
     
     
         18 . The filter of  claim 1 , wherein the plurality of absorbable capture elements comprise proximal capture elements, middle section capture elements, and distal capture elements configured to degrade sequentially such that filter decomposition begins with the proximal capture elements and then progresses through the middle section capture elements, the distal capture elements, and the circumferential element in sequential order. 
     
     
         19 . The filter of  claim 1 , wherein the plurality of absorbable capture elements are configured such that wrapping around comprises starting a wrap on a first side of the given individual capture element and finishing the wrap on an opposite side of the given individual capture element. 
     
     
         20 . A method for delivering a filter as claimed in  claim 1  with a delivery catheter, wherein the delivery comprises:
 inserting the filter, in compressed form, within the delivery catheter to a desired position within the vessel; and 
 deploying the filter in expanded form at the desired position within the vessel; and 
 subsequently removing delivery catheter from the vessel.