Open structure sizing device
A system and method for sizing and imaging of cardiovascular defects generally are disclosed capable of producing model images or forms that mimic the shape of defects such as openings or breaches in cardiac septum walls, so that remedial devices of the correct size and shape can be administered to occlude defects. The system uses a three-dimensional open wire imaging structure which is flexible, easy to position and does not occlude blood flow and when expanded, can be measured in situ.
1 . A structure for imaging or sizing cardiovascular defects comprising:
(a) a three dimensional open wire structure adapted to be deployed into the cardiovascular system of a patient;
(b) an elongate device for advancing said imaging structure to the vicinity of a cardiovascular defect to be measured;
(c) a control system for controlling the operation of the open wire imaging structure in an imaging procedure;
(d) wherein said open wire imaging structure is selected from the group consisting of a generally oval braided open wire mesh structure, a generally oval braided open wire mesh structure having a defined central waist area, a plurality of radially distributed individual wire members connected between adjustably spaced proximal and distal end members, and a wire loop structure.
2 . A device as in claim 1 wherein the wire mesh structure is a braided generally oval shape.
3 . A device as in claim 1 wherein the wire mesh structure is woven.
4 . A device as in claim 1 wherein said imaging structure is memoried so as to self-expand when released.
5 . A device as in claim 1 further comprising aspects visible under fluoroscopy.
6 . A device as in claim 4 wherein said imaging structure is a nitinol mesh.
7 . A device as in claim 1 wherein said control system includes an actuating wire.
8 . A device as in claim 1 wherein said defect is an abnormal opening in a membrane and wherein said imaging structure penetrates said opening and, upon expansion, forms a waist that defines the shape and size of the opening.
9 . A device as in claim 4 wherein said defect is an abnormal opening in a membrane and wherein said imaging structure penetrates said opening in a membrane and, upon expansion, forms a waist that defines the shape and size of the opening.
10 . A device as in claim 9 wherein said imaging structure is a nitinol mesh.
11 . A device as in claim 1 wherein said control system includes an element for modulating the radial force exerted by said imaging structure.
12 . A device as in claim 1 wherein said elongate device is a guidewire.
13 . A device as in claim 7 wherein axial displacement of said actuating wire is calibrated.
14 . A device as in claim 1 wherein said open wire structure further includes markers of known separation distance visible under fluoroscopy.
15 . A device as in claim 1 wherein said elongate device is a catheter.
16 . A device as in claim 1 that is a steerable system.
17 . A device as in claim 1 wherein said open wire structure includes a polymeric material.
18 . A method of imagery or sizing cardiovascular defects comprising steps of:
(a) providing a deployment device with a three-dimensional open wire imaging structure carried near the distal end thereof;
(b) introducing the deployment device into a patient and advancing the imaging structure to the vicinity of a defect of interest to be measured;
(c) expanding the imaging structure to provide a measurement of a desired aspect of the defect;
(d) determining the dimensions of the defect in situ;
(e) collapsing the imaging structure; and
(f) withdrawing the imaging structure from the patient.
19 . A method as in claim 18 including the step of modulating radial expansion force in the imaging structure to control radial force exerted on the defect.
20 . A method as in claim 18 including the step of measuring the imaging structure expansion in situ using fluoroscopy.
21 . A method as in claim 18 including the step of measuring the imaging structure expansion in situ using ultrasound.