Self-assembling magnetic anastomosis device having an exoskeleton
The invention is an implantable magnetic anastomosis device having an exoskeleton that directs self-assembly. The design allows the device to be delivered in a linear configuration using a minimally-invasive technique, such as endoscopy or laparoscopy, whereupon the device self-assembles into, e.g., a polygon. A coupled set of polygons define a circumscribed tissue that can be perforated, or the tissue can be allowed to naturally necrose and perforate. The device can be used to create anastomoses in a variety of tissues, such as tissues found in the gastrointestinal, renal/urinary, and reproductive tracts. New procedures for using anastomoses, e.g., surgical bypass are also disclosed.
1. An implantable exoskeleton comprising a shape memory material and adapted to direct self-assembly of at least two magnetic segments into a geometric shape comprising a plane based, at least in part, on a shape setting of the exoskeleton, wherein the exoskeleton restricts movement of the at least two magnetic segments relative to the plane and comprises:
a band that extends along an entire length of the exoskeleton and defines at least a portion of a perimeter of the geometric shape when the exoskeleton transitions from a substantially linear configuration to a non-linear configuration based, at least in part, on the shape setting;
at least two flanges disposed on a first side of the band and adjacent each other along the length of the exoskeleton, and
at least two flanges disposed on a second side of the band and adjacent each other along the length of the exoskeleton, the second side of the band being opposite the first side, wherein, when the exoskeleton is in the shape setting, the flanges contact the magnetic segments to prevent rotation of the magnetic segments outside the plane during self-assembly.
2. The exoskeleton of claim 1 , wherein the exoskeleton permits movement of the at least two magnetic segments within the plane and prohibits movement of the at least two magnetic segments out of the plane.
3. The exoskeleton of claim 1 , wherein a magnetic pole of each of the at least two magnetic segments is normal to the plane of the geometric shape.
4. The exoskeleton of claim 3 , wherein the geometric shape is a polygon.
5. The exoskeleton of claim 4 , wherein the polygon is selected from the group consisting of a square, a rectangle, a hexagon, and an octagon.
6. The exoskeleton of claim 1 , wherein the flanges are essentially parallel to the plane of the geometric shape when the exoskeleton is in the non-linear configuration based on the shape setting.
7. The exoskeleton of claim 6 , wherein:
a first flange of the at least two flanges disposed on the first side and a first flange of the at least two flanges disposed on the second side are attached to a first portion of the band and have a first width perpendicular to the portion of the band; and
a second flange of the at least two flanges disposed on the first side and a second flange of the at least two flanges disposed on the second side are attached to a second portion of the band and have a second width perpendicular to the second portion of the band, the second width being different from the first width.
8. The exoskeleton of claim 1 , wherein the flanges comprise mitered edges.
9. The exoskeleton of claim 8 , wherein an interface between the two flanges disposed on the first side of the band comprises notch radii and an interface between the two flanges disposed on the second side of the band comprise notch radii.
10. The exoskeleton of claim 1 , wherein the shape memory metal comprises a material selected from the group consisting of a nickel alloy, a copper alloy, a zinc alloy, a platinum alloy, and a cobalt alloy.
11. The exoskeleton of claim 1 , wherein the shape memory material comprises nitinol.
12. The exoskeleton of claim 1 , wherein the exoskeleton has a thickness of from about 0.001 inches to about 0.01 inches.
13. The exoskeleton of claim 1 , wherein, when the exoskeleton is in the shape memory setting, the exoskeleton comprises a channel that accommodates at least a portion of the at least two magnetic segments.
14. The exoskeleton of claim 1 , further comprising an attachment point.
15. The exoskeleton of claim 14 , wherein the attachment point comprises a suture.
16. The exoskeleton of claim 1 , wherein a portion of the exoskeleton is biodegradable.
17. The exoskeleton of claim 16 , wherein the biodegradable portion comprises one selected from the group consisting of poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA), and poly(vinyl alcohol) (PVA).