Patent Publication Number: US-2023147440-A1

Title: System and methods for embolized occlusion of neurovascular aneurysms

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/303,507, filed Nov. 20, 2018, which is a U.S. National Phase of International Application No. PCT/US2017/034460, filed May 25, 2017, which claims priority benefit under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 62/342,135, filed May 26, 2016, titled SYSTEM AND METHODS FOR EMBOLIZED OCCLUSION OF NEUROVASCULAR ANEURYSMS, all of which applications are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Field 
     This application is related to methods and devices for treating neurovascular aneurysms. 
     Description of the Related Art 
     The worldwide occurrence of stroke is estimated to be in the vicinity of 60,000,000 instances per year. The economic and social costs for strokes are enormous. While most strokes are fatal or debilitating, even mild strokes often result in impairment that greatly diminishes quality of life and independence while substantially increasing direct costs for healthcare and daily living. Further, indirect costs such as lost productivity, expanded burden on care provided by immediate family, and the allocation of limited resources to rehabilitative therapy and convalescence aggregate to create a significant unmet need for the prevention of stroke beyond the current standard of care. 
     While advances in medical science, standards of care, preventative actions, and an understanding of the influences of personal lifestyle have improved in the field of stroke over time, the causes of stroke are complex and not fully understood in all instances. Stroke is divided into two categories: ischemic (loss of normal blood flow) and hemorrhagic (bleeding through blood vessel rupture). 
     A brain (cerebral) aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain. If a brain aneurysm ruptures (a subarachnoid hemorrhage), it releases blood into the skull resulting in stroke. Depending on the severity of the hemorrhage, brain damage or death may result. 
     The risk factors for formation of aneurysms are recognized to include genetics, gender, age, race, elevated blood pressure, smoking, and atherosclerosis. In many cases an unruptured cerebral aneurysm may only be discovered during tests for another, usually unrelated, condition. In other cases, an unruptured cerebral aneurysm will cause problems by pressing on areas in the brain. When this happens, the person may suffer from severe headaches, blurred vision, changes in speech, and neck pain, depending on what areas of the brain are affected and how severe the aneurysm is. 
     SUMMARY 
     At present there are three treatment options for people with the diagnosis of cerebral aneurysm: (1) medical (non-surgical) therapy; (2) surgical therapy or clipping; and (3) endovascular therapy or coiling. 
     Medical therapy is usually only an option for the treatment of unruptured intracranial aneurysms. Strategies include smoking cessation and blood pressure control. These are the only factors that have been shown to have a significant effect on aneurysm formation, growth, and rupture. Periodic radiographic imaging may be used to monitor the size and growth of an aneurysm. However, because the mechanisms of aneurysm rupture are not entirely understood, and because even aneurysms of very small size may rupture, monitoring cerebral aneurysms is an incomplete solution to meeting medical needs. 
     Surgical treatment of cerebral aneurysms has existed for more than 150 years, and for more than 80 years the standard of care has included the use of aneurysm clips which have evolved into hundreds of varieties, shapes, and sizes. The mechanical sophistication of available clips, along with the advent of the operating microscope in the 1960s have made surgical clipping the gold standard in the treatment of both ruptured and unruptured cerebral aneurysms. 
     Surgical clipping remains an invasive and technically challenging procedure whereby the brain and the blood vessels are accessed through an opening in the skull. After the aneurysm is identified, it is carefully separated from the surrounding brain tissue. A small metal clip is secured to the base of the aneurysm. The choice of a particular clip configuration is based on the size and location of an aneurysm. The clip has a spring mechanism which allows the clip to close around either side of the aneurysm, thus occluding the aneurysm from the blood vessel. Normal blood vessel anatomy is physically restored by excluding the aneurysm sac from the cerebral circulation. 
     Endovascular techniques for treating aneurysms date back to the 1970s with the introduction of proximal balloon occlusion. Guido Guglielmi an American-based neuroradiologist, invented the platinum detachable microcoil, which was used to treat the first human being in 1991. 
     Endovascularly delivered coils are soft wire spirals originally made out of platinum. These coils are deployed into an aneurysm via a microcatheter that is inserted through the femoral artery of the leg and carefully advanced into the brain. The microcatheter is advanced into the aneurysm itself, and the microcoils are released in a sequential manner. Once the coils are released into the aneurysm, the blood flow pattern within the aneurysm is significantly reduced, leading to thrombosis (clotting) of the aneurysm. A thrombosed aneurysm resists the entry of liquid blood, providing a seal in a manner similar to a clip. 
     Endovascular coiling is an attractive option for treating aneurysms because it does not require opening of the skull, and is generally accomplished in a shorter timeframe, which lessens the impact of physical strain on the patient. A limitation of coiling is that eventual compression of the bolus of individual coils may compress over time and thus blood flow to the aneurysm may become reestablished. Additionally, not all aneurysms are suitable for coiling: (1) wide-necked aneurysms require a support scaffolding (usually a stent) as a structural support to prevent prolapse of the coil bolus into the blood vessel; (2) aneurysms that are located in the distal reaches of the neurovasculature may lie beyond the reach of current microcatheter sizing; and, (3) microcatheters filled with embolic coils are not always flexible enough to navigate the highly tortuous and fragile anatomy of neurovascular blood vessels. As experience with coiling grows, the indications and pitfalls continue to be refined. Endovascular and coil technology continue to improve: endovascular adjuncts, such as intracranial stents, are now available to assist in coiling procedures; the original platinum microcoil has been refined with ever-improving features such as biological coating and microengineering for efficiency in deployment. 
     More recently, endovascular devices alternative to coils have begun to open further options for the treatment of aneurysms. Blood flow diversion without coils may provide a less expensive, more efficient, and more adaptive means for the treatment of aneurysms. Nickel-titanium-based (NiTi) flow diversion structures provide further options for physicians and patients. At present, laser cut hypotube or braided wire form the structures from which flow diverters are made. Laser cut hypotubes require complex manufacturing and have limitations in the degree of expansion deformation that they can tolerate. Alternately, braided wire forms are much less complicated to manufacture, can tolerate substantial expansion deformation, but offer very limited control of structural porosity due to the localized unconstrained movement allowable between wires that are not mechanically bound together. 
     Therefore, a substantial need exists to increase minimally invasive and cost-effective solutions to improve intracranial access using systems and methods to control the risk and effects of hemorrhagic stroke through means of very small, highly capable, and reliably producible interventional tools and implants. 
     Some aspects of the present disclosure provide the means and the methods for treating cerebral aneurysms via a catheter-based, minimally invasive interventional system that includes a blood flow diverting implant that is placed within the aneurysm sac. 
     Some aspects of the present disclosure include deploying the implant from a microcatheter having an outer diameter of 0.027 inches or less, for example 0.021 inches or less at the distal working area of the microcatheter. Manufactured with polymer, metal and polymer, polymer and thin film, polymer and integrated braided material for torque control, and integrated tether mechanism or tether line for release of the implant. The release may be completed by mechanical energy, or absorbed or by delivered energy such as thermal or electrical or by environmental energy from thermal body temperature transfer. 
     Some aspects of the present disclosure provide a restraint for restraining, and optionally recapturing, an implant so as to aid in the accurate positioning and deployment of an implant in situ. 
     Some aspects of the present disclosure are directed toward an implant for treating an aneurysm that is a blood flow diverter (e.g., occluder) comprised of thin-film NiTi. When deployed, the NiTi implant may be in the martensitic (shape memory) state, the austenitic (superelastic) state, or a mixture of both or may be a multilayer of several film compositions. For example, a deployed NiTi implant is more austenitic than martensitic in situ. 
     Some aspects of the present disclosure are directed toward an implant for treating an aneurysm that is a blood flow diverter (e.g., occluder) comprised of an acceptable biocompatible metal including, but not limited to, biocompatible stainless steel, tantalum, tungsten, titanium, TiNi, platinum, or combinations or multilayers thereof. The metal shall be of a medical biocompatible material that may be delivered into the aneurysm utilizing balloon, wire or assisted delivery by other means, or encapsulated and then released. 
     In some configurations, the self-expanding implant may include NiTi thin-film, wherein the film is initially formed in a substantially flat or planar, two-dimensional form and then subsequently shaped into a three-dimensional form prior to incorporation into a catheter. In three-dimensional form, the implant may be a sphere or other enclosed or semi enclosed structure made of a hollow, semi hollow, or fully-filled thin film body. The surface area may be many times greater than volume when conformed for delivery to the specific site of treatment. 
     The thin film NiTi implant may be combined with additional wire, foil, and/or thin film elements either before or after shaping to provide added structural elements. The NiTi material would shape within the range of body temperature from as low as a set temperature 34 degrees centigrade and as high as 40 degrees centigrade. 
     In some configurations, the deployed implant may include a portion that conforms to the opening at the neck of an aneurysm. 
     In some configurations, the deployed implant may include a bottom portion that diverts blood flow away from the neck and sac of an aneurysm and is comprised to include one or more additional portions that fill at least some of the sac of an aneurysm. 
     In some configurations, the implant may include NiTi thin film, wherein the film is initially formed in a partially three-dimensional form and then subsequently further shaped into a final three-dimensional form prior to incorporation into a catheter. 
     In some configurations, the implant may include NiTi thin film, wherein the film is initially formed at least partially or at least substantially in three-dimensional form prior to incorporation into a catheter. 
     Some aspects of the disclosure are related to implants including NiTi thin film, wherein the film may be comprised of a regularly repeating pattern of meshed structures (e.g., regularly repeating porosity), wherein the meshed structures may be any pattern that optimizes the film&#39;s ability to expand from a highly compressed state that can loaded into a catheter to a substantially expanded state after release into the aneurysm while also optimizing the degree of localized stress and strain experienced by elements of the mesh. 
     Some aspects of the disclosure are related to implants including NiTi thin film, wherein the initial flat or planar form of the device may be shaped such that it can be formed into a three-dimensional shape as desired for deployment into an aneurysm prior to incorporation into a catheter and then unfolded into a different three dimensional shape conducive to loading into a catheter, such that upon deployment from the catheter the device returns to the first shape. 
     Some aspects of the disclosure are related to implants including NiTi thin film, wherein the film may be comprised of a regularly repeating pattern of meshed or perforated structures, wherein the structures may be any pattern porosity that optimizes the occlusive performance of the structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments are depicted in the accompanying drawings for illustrative purposes, and should in no way be interpreted as limiting the scope of the embodiments. Furthermore, various features of different disclosed embodiments can be combined to form additional embodiments, which are part of this disclosure. 
         FIG.  1    shows a schematic view of the interventional system of the present disclosure in a representative access pathway to a cerebral aneurysm. 
         FIG.  2 A  shows a representative example of an aneurysm, located laterally along the length of a blood vessel, with a representative example of an implant located therein. 
         FIG.  2 B  shows a representative example of an aneurysm, located at the bifurcation of a blood vessel, with a representative example of an implant located therein. 
         FIGS.  3 A- 3 E  show a schematic depiction of an implant embodiment during its forming process. 
         FIGS.  4 A and  4 B  show a schematic depiction of another implant embodiment during its forming process. 
         FIGS.  5 A- 5 E  show a schematic depiction of yet another implant embodiment during its forming process, and the compression process prior to catheterization. 
         FIGS.  6 A and  6 B  depicts a schematic representation of another embodiment of a NiTi thin film mesh structure and a unit cell thereof. 
         FIGS.  7 A- 7 D  depict a schematic representation of embodiments of NiTi thin film mesh structures in a collapsed state and in an expanded state. 
         FIG.  8    shows a schematic representation of an embodiment of a NiTi thin film mesh structure in a substantially planar state. 
         FIG.  9    depicts the embodiment of  FIG.  8    during the three-dimensional forming process. 
         FIG.  10 A  shows a schematic depiction of an exemplary embodiment of a restraint at the working end of the system shown in  FIG.  1   . 
         FIG.  10 B  shows a schematic depiction of the restraint of  FIG.  10 A  in use deploying the implant of  FIGS.  3 A- 3 D . 
         FIG.  11    shows a schematic depiction of an implant embodiment in situ. 
         FIGS.  12 A and  12 B  show a schematic depiction of an implant embodiment in a planar state and a formed three-dimensional shape. 
         FIGS.  13 A to  13 D  show yet another implant embodiment in a planar state and a partially cylindrical shape. 
         FIGS.  14 A to  14 D  show yet another implant embodiment in a planar state and a partially spherical shape. 
     
    
    
     DETAILED DESCRIPTION 
     As has been previously explained herein, there remains a need for further advancement in minimally invasive interventional treatment of cerebral aneurysms. The tortuous anatomy, small vessel diameter, and uniquely delicate anatomy of the neurovasculature provides for a particularly challenging set of constraints in which an interventional system must operate. There is little room for error given that even the smallest unintended consequences of an error often result in significant negative consequences for a patient. 
     Delivering the Implant 
     When treating a cerebral aneurysm, a system should be able to navigate the access pathway to the target site. As is shown in  FIG.  1   , a typical method is to access a femoral blood vessel at location  104  and traverse access pathway  105  through the heart and into the cranial cavity to an aneurysm location  106  that is substantially distal from access location  104 . This is done with known interventional techniques which may include system  100  of the present disclosure comprised of a complex set of features which may be subdivided into principal functional subsystems comprised of control handle  101 , catheter body  102 , and catheter distal working end  103  (further containing an implant). 
     System  100  should possess enough rigidity to traverse the torso and its circulatory system along pathway  105 , and then the more distal, tortuous, delicate and small diameter vessels of the cranium until target aneurism location  106  is reached. System  100  should be able to track to location  106  along pathway  105  through a micro guide catheter, over a guide wire, or on its own via natural shaping of catheter body  102  and/or steerable control from the proximal end via control handle  101 . 
     Access to more distally located targets becomes limited by the size and stiffness of catheter working end  103 , which in turn may be limited by the physical aspects of the implant contained therein. A solution to this problem of limitation is to provide an implant structure that provides the simultaneous abilities of compressing to a very small diameter, below 0.021 inches, e.g., smaller than 0.019 inches, while remaining flexible in its compressed state, and then being able to expand to many times its compressed diameter in order to fixate and perform safely in situ. 
     Tracking, manipulation, sheath control, compatibility with guidewires and other access tools and techniques are incorporated into the assembly and use of catheter system  100 . The implant loaded into working end  103  may be radially compressed and/or folded similar to the way that angioplasty balloons and stents are loaded to reduce the profile of the distal section of a polymer delivery system, where a guide wire lumen and an outer lumen and a working end  103  where the implant is covered with a sheath. The sheath may be retracted releasing the implant to target site  106  or the implant may be pushed or manipulated from control handle  101  at the proximal end of catheter system  100  using a mandrel, guide wire or braided shaft, or other such means providing pushable force transmission a columnar strength through tortuous anatomy such that the load bearing unit is able to effect the desired action at working end  103  to deliver an implant to target site  106 . 
     Additionally, catheter system  100  may also integrate a tethered line connected to the implant at working end  103  and extending proximally through catheter body  102  to control handle  101  which enabling catheter system  100  system to recapture or reposition the implant prior to completing deployment at target site  106 . 
     One example of tethering means may include a tether comprised of a lubricious polymer tied by a slip knot method where one end of the line is integrated with the catheter body  102  and the second end is able to be controlled an communicated with by the user at control handle  101 . 
     Another example of tethering means may include dissoluble material that interacts with blood or fluids and breaks down over the standard duration of the implant procedure such that the implant is released when the tether line is broken by erosion, the application of force, or both. 
     Additionally referring to  FIGS.  10 A- 10 B , yet another example of a tether or restraint may be comprised of a mesh thin film or braided material  108  connected to a delivery wire  107  inside of catheter body  102  at working end  103 , wherein delivery wire  107  and restraint  108  may be joined using any means of attachment known in the art, such as: energy-based fusion (such as heat); chemical bonds and adhesives; mechanical means such as crimping, interference fits, swaging, press fitting; and the like. A suitable connection joint should be able to withstand tensile loads equal to or greater than 0.1 Newtons. 
     Restraint  108  may further double as a snare which may be configured as a cone (as shown by example  108 ), a collet, a leaflet of 3 sides, or other such structures that expand and collapse with minimal outward force but shall open when released and/or not bound by the constraint of working end  103 . The material of restraint  108  in such application may be of any medical-grade engineering material such as metals, polymers, textiles and the like, for example NiTi and further optionally being at least partially in the austenitic phase. 
     As is illustrated by  FIG.  10 B , restraint  108  may be compressed into the inside diameter of working end  103  of catheter body  102  of delivery system  100  while maintaining a sufficient grip on implant  300  stored and deployed from the inner diameter of working end  103 . As is shown, upper portion  301  and middle portion  302  are in mid-deployment while the majority of restraint  108  and lower portion  303  of implant  300  remain constrained inside catheter body  102  until delivery wire  107  is advanced distally to further expose them. Optionally, an implant may be comprised to include a structure to mechanical interface with restraint  108  through structures such as: a formed nipple; a shaped eyelet; a nodule shape; round or non-round protrusions or recesses. While restraint  108  and implant  300  are constrained by working end  103 , both are in a state of mechanical interaction that allows the implant to not be fully released and deployed to target location  106 . The ability to recapture, reposition, or otherwise positionally manipulate an implant prior to being fully deployed from working end  103  to target site  106  is particularly advantageous for vascular interventional procedures where the accuracy of a permanent implant is of critical importance and the physician is limited by the tools that may be used in such minimally invasive methods. When doubling as a snare, restraint  108  should provide sufficient retention force on the implant at working end  103  so as to provide the structural strength to allow for recapture of an implant until it is released, with up to as much as two-thirds of the implant being exposed from working end  103  while maintaining recapturability. 
     The implant may also be non-tethered and placed at the end of a push rod and affixed thereto via a chemical bond, such as a layer of polymer bonded by heat or chemical, allowing for sufficient attachment force during the delivery and deployment procedure but is releasable upon erosion, the application of force, or both. 
     The delivery system may have an attached mesh, cage, or sheath like material made from thin film NiTi, braided metallic wire of biocompatible material or braided polymer and connecting to an inner shaft and the ID of the outer shaft which when both are manipulated the interaction in two directions cause the release of the implant from its constrained state into the selected site of delivery. 
     The outer shaft may also be maintained stationary in the selected position and only the inner shaft is moved to release the implant from its constrained position. The outer and inner shaft may also be held static in selected positions and a third shaft of smaller configuration than the inner ID be used as a pusher shaft to release the thin film from its constrained condition. The outer and inner shaft may also be static in selected positions and the temperature change enables the thin film to free itself from its constrained position and spring forward into the delivery site. 
     All of these possible configurations shall be compatible with other common methods of treatment to ensure the product is able to be used without limitation. Such treatments include gamma radiation, EO sterilization, and E-Beam. These shall not hinder but may complement the complete device in its function to deliver the implant from its constrained configuration. 
     Loading the implant into the delivery system may be done to enable the compete loaded device to be sterilized as a fully assembled item or the sterilized implant may be provided in a loading device—similar to a syringe (but with a augmented cannula) where the sterilized NiTi implant is loaded into the delivery system distal end at the time of use thus enabling delivery to the desired treatment site within the body by the delivery system. 
     The occluder may be retained in an outer lumen or double lumen with the delivery system push rod in tracking to the delivery site and then the push rod shall be moved in reference to the lumen for release. 
     Methods of Delivering an Implant 
     The occluder shall be able to loaded into a delivery system that shall be of specific length based on the vascular system access location to reach the location of the aneurysm or area of disrupted blood flow created by a primary artery with a non-uniform wall (a disproportionate wall caused by disfiguration of the artery) while still maintaining the blood flow. The Thin Film implant device is compressed to comply with the inner diameter of the delivery system and may be carried on a rigid, semi-rigid, or completely flexible spine system made from different implantable materials or similar or equivalent implantable material able to contain and release the device, as depicted in  FIGS.  5 C,  5 D,  5 E and  10 A . 
     At this location, placement of an occluder in the primary artery/capillary to fill the disproportionate wall volume and enabling the human body natural endothelization, or clotting, to clot and seal off the disproportional wall section from the primary vessel. 
     The retention of the occluder in the delivery system shall be achieved by an interference fit to the inner push rod and the extended area created by a shape material which can be integrated to the inner delivery push rod and with the occluder mated with the delivery push rod such that when finished crimping the distal end of the delivery system push rod shall maintain a retention, measurable by the tension force to pull the occluder from the delivery system push rod and when the delivery push rod end, retaining the occluder, achieves desired and material set temperature, the delivery retention shall open allowing the release of the occlude. The delivery may be an action of 2 opposing motions, with dual action vectors, to release the implant from its cradling mechanism in the delivery system or a simple single action, mono directional vector. 
     Implant 
     Any of the implants described below can be used with the delivery systems and methods described above. 
     Referring now to  FIGS.  2 A and  2 B , cerebral aneurysms come in differing types. Two representative examples are the aneurysm  106 ( a ) formed laterally along the side of neurovascular vessel  107 , and the aneurysm  106 ( b ) formed at the bifurcation of neurovascular vessel  108  into branch vessels  109  and  110 . In either case, an implant  200  representative of at least one aspect of the present disclosure is shown in situ in its deployed and fixed state. Any of the features described with respect to these representative implants can apply to any of the embodiments described below. 
     Blood flow diversion is an aspect of implant  200 , which does not require an absolutely solid surface in order to be effective. The ideal result is to provide a structure that is supple enough to avoid placing harmful pressure on the inner wall of the aneurysm sac  106 ( a ) or  106 ( b ), while occluding blood flow within the sac, and while diverting blood flow back into the healthy normal pathways of the native vessel(s), and while having enough mechanical strength to safely fix in place. 
     A fine mesh is well suited to such requirements, where the porosity of the mesh (e.g., open area of each pore) may range from about, 50 microns to about 1500 microns, and most ideally about 100 microns to about 1000 microns. Each of the implants described herein can include a mesh structure for blood flow diversion is that the mesh be of a substantially uniform porosity in the two-dimensional configuration and the three-dimensional configuration. When transformed from a two-dimensional configuration to a three-dimensional configuration, the pore size or open area of each pore in the three-dimensional configuration changes less than 20% (or less than 15%, or less than 10%, or less than 5%) than the pore size or open area of the same pore in the two-dimensional configuration. In each of the two-dimensional configuration and the three-dimensional configuration, there is less than 20% (or less than 15% or less than 10% or less than 5%) variation between the pore size or open area of any two openings. In each of the two-dimensional configuration and the three-dimensional configuration, there is less than 20% (or less than 15% or less than 10% or less than 5%) variation between the pore size of any opening and the mean pore size of the entire porosity. In some configurations, every pore and opening has a uniform size in the two-dimensional configuration and/or three-dimensional configuration. 
     Currently, meshes of this nature are constructed from braided NiTi wire. However, a braided structure inherently allows the individual wires of the braid to move past one another such that the unit cells formed by individual braided strands are inconsistent (uncontrolled) in size due to deformations that naturally occur during shaping and/or handling prior to deployment. Additionally, as layers of wire stack up in a compressed and catheterized braided implant, stiffness develops that may lead to limitations in distal vascular access and/or further localized deformations of an implant&#39;s braided unit cells. 
     These problems may be improved by creating a mesh structure from a monolithic material which may include any medical grade material (metal, polymer, etc.) that is suitable for meeting the competing criteria previously described. One particular material is NiTi which has been formed in a film-like thickness and patterned to have a mesh structure therein. The thin film may further be created by using film deposition and patterning processes. Moreover, intraluminal devices such as stents require aggressive antiplatelet therapy and are associated with higher thromboembolic (TE) complication rates. Intravascular flow disrupters (IFD) are currently braided-wire devices designed to achieve flow disruption at the aneurysm neck without placing material in the parent vessel and without the need of antiplatelet therapy. In addition to the limitations of braided wire structures previously described herein, better system performance may be achieved by producing IFDs made from NiTi thin films. As opposed to a braided structure, a thin film structure may be patterned such that the mesh is either symmetrically repetitive or otherwise preferentially patterned in an asymmetric way so as to account for surface performance optimization for a three dimensional shape based on the portion against the wall of the aneurysm sac and the portion in contact with, and diverting, blood flow. One or more of these thin film features can be applied to any of the implant embodiments described herein. 
     The implants described herein can transform from a first, substantially flat or planar configuration to a second, three-dimensional configuration having an internal volume. The implant can be formed from a continuous or monolithic sheet (e.g., thin film layer). The continuous or monolithic sheet can have a substantially uniform thickness. The thickness can be less than or equal to 0.005 inches, less than or equal to 0.003 inches, less than or equal to 0.002 inches, or less than or equal to 0.001 inches. 
     The implant can be patterned with a structural mesh that maintains substantially uniform porosity. The implant can be shape set to achieve the designated configuration (e.g., spherical, partially spherical, elliptical, etc.) with a major and minor diameter, or a three-axis diameter with equal diameters, or two equal diameters and one unequal, or two unequal diameters, or all unequal diameters, that when released into the treatment site shall optimally fill the aneurysm and fill, block, or shield the neck transition (primary artery to aneurysm void from the same vessel wall) to the aneurysm space. In the three-dimensional configuration, the implant has sufficient structural support to maintain its shape in a fluid pressure environment equivalent or greater to the level of high blood pressure (e.g., 3/2 psig; similar to diastolic/systolic in mm of HG for high blood pressure). 
     The substantially flat or planar configuration can include rounded, circular, elliptical, cone, and other polygonal segments. Three dimensional configurations may comprise all the facets of the 2 dimensional configurations with the introductions of additional axes at defined points as determined by how the film is manipulated prior to shape setting to create a three dimensional structure. 
     The implants described herein can be compressed into a small configuration by crimping in a circle or folding as a two fold, three fold, four fold and/or more folds, similar to angioplasty balloon folding, without significantly work hardening the material to change its desired properties for filling and acting as the neuro-aneurysm filler. 
     Referring now to  FIGS.  3 A- 3 C , an example of a thin film NiTi mesh structure  300  is shown.  FIG.  3 A  shows a deposited and patterned sheet of thin film NiTi in a substantially flat or planar state. An upper segment  301  and a lower segment  303  are joined by connecting segment  302 . Segments  301  and  303  may be symmetrical to one another or asymmetrical. The representative example in  FIGS.  3 A- 3 C  is symmetrical but will be appreciated as including the dimensional variations that would accommodate asymmetry. In the example, implant  300  is comprised of a mesh having the segments described. Segments  301  and  303  are circular, having a circumference of “C”, and are connected by element  302  having a length “L” which is equal to C when measured at the points of outer surface tangency between elements  301 ,  303 , and  302 . 
     As the substantially flat or planar configuration of  FIG.  3 A  is shaped into the three dimensional shape shown in  FIGS.  3 B and  3 C , it can be seen how a planar structure evolves through shaping. Shaping may be achieved through the combination of mechanical deformation and heat treatment. Very often, successive incremental steps are required to transform the structure from its initial to its final shape. The forming steps and heat treatment process are a function of the strains involved in forming and the desired final mechanical properties of the three dimensional structure. In this example, structure  300 , when in its compressed state, forms the spheroid shape of  FIG.  3 C  while continuing to possess flexibility (e.g, some degrees of freedom offered by the segmented design), as illustrated in a not-fully-compressed state shown in  FIG.  3 B . While a spheroid shape is used for example purposes, other three dimensional shapes, such as partially spherical shapes, and segment combinations may be used to achieve the concept of this aspect of the present disclosure. 
     Referring now to  FIGS.  12 A and  12 B , another example of an implant  1200  which, when shaped to a three-dimensional configuration, may include a hemispherical bottom portion  1201  (omitting a hemispherical top portion) and include one or more filler portions  1203  and  1205 , respectively interconnected by portions  1202  and  1204  terminating and at least partially filling hemispherical portion  1201  shaped to cover the aneurysm neck entrance, where bottom portion  1201  is greater in diameter than the aneurysm neck entrance. Bottom portion  1201  may be shaped as any hemispherical shape or shape combination, such as: largest planar section  1205  is described by a cord; having a major and minor diameter equal or unequal, with a deflection from an axial centerline to the outer tip of the cord shaping the component to act as a base internal cap at the arterial vessel neck to the entrance of the aneurysm base; and the like. 
     Referring now to  FIG.  11   , the optional addition of an exterior contoured portion  1102  may be continuously connected or fused to the implant which may be configured to cover the aneurysm neck. In the example of  FIG.  11   , implant  1100  is situated inside aneurysm location  106 ( c ) along blood vessel  111 , having aneurysm neck  112 . The upper portion  1101  of implant  1100  is monolithically attached to lower portion  1102 . For the purposes of illustration, lower portion  1102  is shown as a saddle-shaped element, however, lower portion  1102  may be any shape that conforms to at least a portion of the contour of neck  112  such that localized blood flow diversion and stability are provided for in the spirit of the present disclosure. Furthermore, implant  1100  contours may be shaped to the major/minor of the primary vessel and/or aneurysm, and even the radial diameters of not just the aneurysm  106 ( c ) but even neck  112  to optimize the blood flow diversion. 
     In some of the implant shape variants, implant surface area may be many larger than implant volume, for example, in the case of a spheroid, such a surface area to volume relationship may be managed by the major and minor diameter of the spheroid where the major diameter may be as small as 0.1 mm and the minor diameter may be as small as 0.1 mm (e.g., spherical, partially spherical, elliptical, etc.). The surface area of a surface of the implant may be many times greater than volume, such that portions of the implant overlap each other. The surface area of a surface (one side) of the implant can be at least 1.5 times greater (or at least 2.0 times greater, or at least 2.5 times greater, or at least 3.0 times greater) than an internal volume formed when the implant is in the three-dimensional configuration. 
     In any of the implant shape variants, various locations along the surfaces of the implant may also include varying thickness at designed points on the inside or outside surface to provide structural support for radial strength or the implant. For example, hemispheres, disks and cords may be shaped with grooves, channels, or rails to add to the structural strength in the radial and axial directions for improved device stiffness and load carrying ability once deployed in situ. 
     In any of the implant shape variants, there may be reinforcing portions with no porosity. The reinforcing portions may extend at least partially or entirely around a perimeter of the implant. The reinforcing portion may extend at least partially or entirely across a width or length of the implant (e.g., similar to struts). The reinforcing portions may include a same thickness as the porous or mesh portions of the implant. 
       FIGS.  3 D and  3 E  show an exemplar NiTi thin film made in the form of  FIGS.  3 A- 3 C . The spheroid implant  300  may be made with one sheet or multiple sheets layered to increase thickness, where shaping can be completed with the sheet(s) layered onto a shaping tool for heat treatment. 
     In addition to thin film mechanical properties such as material phase and phase transition temperature, residual strain, and mesh structural pattern, further mechanical stiffness may be derived from film thickness from layering of two or more thin film layers, and from formed stiffeners such as pleats or spines and the like. The spines can be used to elongate the thin film material to act as a compression mechanism in reducing the shape set to a different shape that can be placed in a lumen of smaller size then the sphere for delivery to the determined artery site. 
     Referring now to  FIGS.  8  and  9   , another exemplar embodiment is shown. An implant  900  is comprised of a thin film mesh in a substantially flat or planar form having a plurality of segments that may be shaped into a three dimensional form such as a spheroid. An upper segment  901  is joined to a middle segment  903  by connector segment  902 , and a lower segment  905  is joined to a middle segment  903  by connector segment  904 . Any number of middle segments and connectors may be used to fill and stiffen the central volume of the implant  900 , here, a single middle segment  903  with connector segments  902  and  904  are shown for simplicity of communication. Any variety of shape combinations or permutations may be employed, such as: equal major and minor diameters, or unequal major and minor diameters, and the like. The one or more inner segments may also be of any other geometric shape that acts as a volumetric filler within the implant and the aneurysm sac. Most preferably volumetric filling is preferentially positioned nearer the aneurysm neck. In other embodiments, the volumetric filler is a separate component (e.g., a coil). 
     In  FIG.  9    a multi-piece shaping tool is shown shaping upper segment  901 , connector segment  902 , middle segment  903 , connector segment  904 , and lower segment  905  into a spheroid shape. A top, outer tool piece  906  sandwiches segment  901  over hemispherical forming piece  907 . Connector segment  902  serves as the bending transition to middle segment  903  which is sandwiched between tool pieces  908  and  909 . Connector segment  904  serves as the bending transition to lower segment  905  which is sandwiched between lower hemispherical forming piece  910  and bottom outer tool piece  911 . The various pieces of the forming tool may be secured together via a threaded hole and screw, an outer clamp, or other such means of mechanical securement prior to the tool and implant  900  being heat treated for shape setting. Heat treatment may occur in a vacuum or non-vacuum inert environment (inert created by using nitrogen, argon or helium gas), fluidized bed, molten salt bath, furnace, or the like, heated to the necessary shaping temperature. For example, the shape setting temperature may be greater than 450 C with subsequent quenching in a cooler media so that the thin film material takes on a 3 dimensional shape. This process may be assisted by wrapping the thin film around tooling or constraining it with wires or other structural elements to conform it to the desired final shape during the forming process. A post descaling or passivation process may be implemented to optimize the surface finish and minimize the possibility of fraction or corrosion. 
     Corrosion resistance and biocompatibility may be enhanced by placement of an inert micro layer of metallic or non-metallic material at an atomic level, or greater thickness, to ensure of a surface passivation that is robust and can resist corrosion or leach ions into the blood system. The final outer surface may have a final surface finish of material that will be inert to the body and resist corrosion by placing an ionic layer of (Ti) titanium, (Pt) Platinum, (Pd) palladium, (Ir) iridium, (Au) Gold, or other biocompatible metals or may be passivated by the formation of a surface titanium oxide layer. Stainless steel thin films shall be consistent with the medical grade ISO standard requirements of 316, 316L, 316 LVM, 17/7 and any other long term implant materials. 
     Referring now to  FIGS.  4 A and  4 B , an implant embodiment  400  is shown as being comprised of a thin film mesh  401  formed in a substantially three dimensional state with open ends  402  where a target mandrel would be positioned during the film deposition and patterning processes. Upon further shaping and expansion of mesh  401 , implant  400  takes on a three dimensional form of the final implant, a spheroid for example, where some evidence of open ends  402  may remain after shape setting. Referring now to  FIGS.  5 A- 5 E , an implant embodiment is described during its forming process, and, during the compression process prior to catheterization. 
     Implant structure  500  begins in a substantially two dimensional flat or planar form comprised of a plurality of struts with eyelets collectively referred to as element  501  which commonly terminate at a central eyelet  501 ′, the strut structure  501  and  501 ′ being layered over and attached to a thin film mesh  502 . Common structural eyelet  501 ′ and individual strut eyelets  501  may be used as part of the three dimensional forming process. 
     A three dimensional forming tool  510 , which for purposes of illustration is a sphere but may be of any shape so desired, may be comprised to include a central passageway  511  through which wire  512  may be passed. As is shown in  FIG.  5 C , the hole formed by central eyelet  501 ′ may be positioned concentrically with the opening of passageway  511  such that wire  512  may be passed through central eyelet  501 ′ and into passageway  511  in shaping tool  510 . The plurality of struts with eyelets  501  may be forced to conform around the outer surface of forming tool  510  and secured in place by positioning the plurality of strut ends with eyelets  501  over the opening of passageway  511  on the opposite end of forming tool  510  before wire  512  is then positioned through eyelets thereby securing them in position to assume a three dimensional shape. Thin film mesh  502  being joined to the plurality of struts  501  also follows the contour of forming tool  510 . The joining of mesh  502  to the plurality of struts  501  may be accomplished by laser welding, resistance welding, mechanical crimping, clipping, riveting, and the like, or, may be attached after shape setting heat treatment through means of adhesion by brazing, or chemical bonding. Alternatively, mesh  502  and struts  501  may be formed as an integrated thin film structure. 
       FIGS.  5 D and  5 E  show schematic representations of another embodiment. An optional s-shaped wire segment  503  may be included in the structure of implant  500  to facilitate collapsing its structure for insertion into a catheter. Wire  503  may be comprised of any implant-grade material, with one choice being a wire comprised of shape set NiTi which may be is inserted down the center of implant  500  and fixed in place with metal clips  504  on either end of the plurality of struts  501  and central eyelet  501 ′. The clips may be of a metal or metal alloy with good x-ray contrast to assist in visualization of the location of the implant while it is being inserted into position, such materials may be selected from any of the groups known in the art such as noble metals, tantalum, palladium, bismuth, and the like. Where galvanic corrosion is of concern, an insulating layer may be used between the surfaces of clips  504  and the surfaces of elements  501  and  501 ′ so as to prevent the formation of a galvanic couple. The size of clips  504  should fit into the inner diameter of the microcatheter that will be used for delivery in vivo. The expanded, three dimensional shape of implant  500  may then be diametrically collapsed by pulling on central wire  503  to stretch the plurality of struts  501  and mesh  502  along the central axis so that it forms a thin oblong structure that will fit into the catheter. When the implant  500  is released from the microcatheter into the aneurysm sac, the entire structure of implant  500  will spring back into its three dimensionally formed shape. 
     Additionally, a radiopaque marker band (or clip  504 ) may be made by crimping, bonding or fusing to mesh  502 . Mesh  502  may also be configured into a small ball and fused together by energy that initiates a molten state of the material of mesh  502  but controlled by the intensity of energy delivery through means such as laser, acoustic or vibration, and the like. 
     Reference is now made to  FIGS.  6 A and  6 B , which depict a schematic representation of an embodiment of a NiTi thin film mesh structure and a unit cell thereof. The geometry of the NiTi mesh and its mechanical properties are important factors influencing how well the implant performs its variety of functions. The porosity of the mesh  600  may also be generated to provide impedance to blood flow dynamics so as to allow the natural blood clotting mechanism take over to close off the aneurysm. 
     An outer Titanium atomized layer deposited on the surface of thin film mesh  600  may act as a passivation layer to enhance biocompatibility, or, other surface passivation processes may be used as needed depending on the nature and composition of the mesh structure  600 . 
     Thermomechanical properties of the thin film mesh structure  600  also play an important part of overall implant performance. While any engineering material suitable for permanent implantation may be a constituent comprising the mesh, one particularly suitable material is NiTi. Mesh  600  may be comprised of NiTi in a martensitic phase, austenitic phase, or a phase mixed between the two, or may be a multilayer of several NiTi film compositions. In some embodiments the NiTi thin film may be combined in a multilayer structure with other acceptable biocompatible metals including, but not limited to, biocompatible stainless steel, tantalum, tungsten, titanium, or platinum or combinations or multilayers. 
     In some embodiments, the mesh  600  of an implant is substantially or predominantly in the austenitic phase so as to provide the best superelasticity and load carrying strength. The greater the difference between body temperature and the temperature at which an implant and the structure of mesh  600  transform into the austenitic stage, the “Af temperature”, and the greater the stiffness of the mesh  600 . However, with increased stiffness come tradeoffs in fatigue resistance. Therefore, an optimized structure of mesh  600  offers a good combination of thermomechanical properties and mesh geometry to allow for localized distortions during expansion during and after deployment in situ, during manufacturing manipulations, and during catheterized delivery through tortuous vasculature. Af temperatures may range from 10 degrees Celsius to 37 degrees Celsius. The film thickness can be in a range from 1 micron to 200 microns, with a preferable range of about 6 microns to about 12 microns, wherein the thickness is a factor in the outward force and the controlled resistance to compression forces of the applied radial pressure from the blood vessel, a factor in catheter profile, and the like. 
     The mesh structure  600  of  FIGS.  6 A and  6 B  is comprised of a series of arc-like shaped struts  602  connected at a central node  601  that collectively form a “pinwheel”. The plurality of struts  602  form a unit cell pinwheel structure that is capable of expansion or contraction. In the instant example, the unit cells of mesh  600  are interconnected by a plurality of secondary nodes  603  that are formed by the intersection of struts  602  of adjacent cells. Thus each unit cell of  600  is connected to an adjacent cell via secondary node  603 . The roughly hexagonal shape of the unit cells of mesh  600  allow for a dense packing factor. The expansion or contraction of unit cells induces a rotational deflection that causes struts  602  to either expand or contract about central node  601  allowing the mesh  600  to have a high capacity for dimensional growth, shrinkage, and localized distortion while maintain a high degree of uniformity and density. 
     Alternately, and referring now to  FIGS.  7 A- 7 D , a simple perforated mesh  700  pattern such as the one shown may be employed. In this exemplar embodiment, a symmetrically repeating plurality of struts  701  are connected to adjacent struts  701  by nodes  702 .  FIG.  7 ( a )  shows mesh  700  in a generally unexpanded state while  FIG.  7 ( b )  shows the same mesh  700  in an expanded state where the plurality of struts  701  and plurality of nodes  702  form a substantially diamond-shaped unit cell. The dimensions of struts  701 , nodes  702 , and their resultant unit cells may be optimized to provide for the most desired mechanical and porosity characteristics; a variation in the geometry of mesh  700  is shown in  FIGS.  7 C  (unexpanded) and  7 D (expanded), the mesh being elongated in one dimensional direction so as to allow for greater expansion and reduced porosity. An optional additional feature for any of the meshes of the present disclosure is an eyelet or “tab” such as the general example shown by element  703 . Tab  703  may be used to convenience during manufacturing manipulation, for attachment of radiopaque markers, as a sacrificial surface for joining by welding, as a marker visible in the implantation procedure by x-ray or other methods for placement and location confirmation, and the like. 
     Any of the embodiments described herein may include radiopaque marker bands that can be made from tantalum, titanium or precious metal and placed on the occluder at any specific location where an eyelet or nodule is formed by the thin film process or configuring the thin film into a thicker section then the standard wall thickness. The marker may be crimped, swaged, fused or adhered to the eyelet or the frame based on the optimum location for the identification of placement of the occlude in the body by x-ray (fluoroscopy). The marker may also be plated onto the specific location or dip plated to ensure the patency of a specific area of the Occluder is visible under fluoroscopy. Alternatively, radiopacity may be achieved by adding high brightness metals either as a surface coating or by inclusion into a multilayer structure in such amounts that do not compromise the shaping of the material into desired 3 dimensional forms or its mechanical robustness as required for successful deployment. 
     The occluder shall be sized based on the fluoroscope sizing and then the appropriate size for treatment shall selected by the neurovascular surgeon. The device shall be preloaded with the specific occlude and sterilized by means of gamma, e-beam or ETO, without impacting the overall device capability for a one-time-use and achieving the trackability to the specific location without any friability to the delivery system or the occlude. Once in position, confirmed by the neurovascular surgeon by fluoroscopy, the center delivery wire can be manipulated by torque and axial pushing to ensure the delivery system tip is at the neck of the aneurysm area. The release shall be completed by moving the inner delivery wire distally, or by moving the outer sheath proximally or by both at the same time. The occluder shall change from the configured loaded shape to the final configured shape partially as it exits the sheathed state but will achieve its final shape once fully released from the delivery system. 
       FIGS.  13 A- 13 D  show another embodiment of an occlusion device  1300  that is configured to transition between a first, two-dimensional configuration (see  FIG.  13 A ) and a second, three-dimensional configuration (see  FIG.  13 D ). In some configurations, the occlusion device can be constructed from thin-film nitinol. 
     The occlusion device includes a mesh structure having a porosity  1318  with a substantially uniform or uniform pore size (see  FIG.  13 C ). Any single pore size can be within at least about 5% of a pore size of any other pore or the mean pore size. The size of the perforation holes and the dimensions of the supporting mesh are chosen to maximize the occlusive performance in the device while maintaining sufficient structural strength to enable handling and deployment of the device without tearing. 
     In the first configuration, the occlusion device  1300  is in a flat, planar configuration with parallel surfaces. At rest, the occlusion device  1300  has a substantially uniform or uniform thickness, for example, a thickness of the occlusion device  1300  is at least about 0.2 mils and/or less than or equal to about 2.0 mils, such as between about 0.5 mils to about 1.5 mils or between about 1.0 mils to about 2.0 mils. 
     As shown in  FIG.  13 A , the occlusion device  1300  extends from a first end portion  1302  to a second end portion  1304 . The occlusion device can include one or more petals or segments  1314   a - 1314   d  (e.g., at least two, at least three, at least four, or more) extending along a longitudinal axis of the occlusion device  1300 . The one or more segments  1314   a - 1314   d  can be arranged such that a longitudinal axis of each of the one or more segments  1314   a - 1314   d  extends along a longitudinal axis of the occlusion device  1300 . 
     A length of each segment  1314   a - 1314   d  can be greater than a width of the respective segment  1314   a - 1314   d.  The length of each segment  1314   a - 1314   d  can be at least about 1.5×, at least about 2.0×, at least about 2.5×, or at least about 3.0× greater than the width of the respective segment  1314   a - 1314   d.    
     One or more of the segments  1314   a - 1314   d  can be the same size and/or be differently sized from one or more other segments  1314   a - 1314   d.  For example, in some configurations, the segments  1314   a - 1314   d  can be the same size. In other configurations, each of the segments can be differently sized. In yet other configurations, a subset of the segments can be differently sized from another subset of the segments. 
     For example, as shown in  FIG.  13 A , segments  1314   a,    1314   d  can be larger than segments  1314   b,    1314   c.  Smaller segments  1314   b,    1314   c  can be positioned longitudinally between larger segments  1314   a,    1314   d.  The length and/or width of segments  1314   a,    1314   d  can be greater than the length and/or width of segments  1314   b,    1314   c.  As shown, the lengths and the widths of segments  1314   a    1314   d  are greater than the lengths and the widths of segments  1314   b,    1314   c.    
     The length and/or width of each segment  1314   a - 1314   d  can be greater than the length and/or width of first and/or second end portions  1302 ,  1304 . As shown, a length and width of each segment  1314   a - 1314   d  is greater than the length and width of first and second end portions  1302 ,  1304 . 
     The occlusion device  1300  can be formed as a monolithic structure with each of the segments  1314   a - 1314   d  joined by connecting portions  1306 . The length and/or width of each segment  1314   a - 1314   d  can be greater than the length and/or width of each connecting portions  1306 . 
     The occlusion device can include reinforcing portions with no porosity to provide smooth edges and structural support. The reinforcing portions can have the same thickness as the porous portions of the occlusion device. The reinforcing portions can be monolithically formed with the porous portions. 
     The occlusion device can have peripheral reinforcing portions  1308 , horizontal reinforcing portions  1310 , and/or vertical reinforcing portions  1312 . Each reinforcing portion  1308 ,  1310 ,  1312  can have a width of at least about 0.2 mil and/or less than or equal to about 1 mil, such as between about 0.2 mil and about 0.5 mil or between about 0.5 mil and about 1.0 mil. 
     Peripheral reinforcing portions  1308  can extend at least partially or entirely around a periphery of the occlusion device  1300 . A horizontal reinforcing portion  1310  can extend at least partially or entirely across the longitudinal axis of the occlusion device  1300 . One or more vertical reinforcing portions  1308  can extend perpendicular to the longitudinal axis of the occlusion device  1300 . For example, a vertical reinforcing portion  1308  can extend across a central axis of a segment (see e.g., segments  1314   a,    1314   c,    1314   d ), or multiple vertical reinforcing portions  1308  can extend parallel to each other in a single segment (see, e.g., segment  1314   b ). 
     Optionally, the occlusion device  1300  can have one or more holes  1316  for use as grommets to facilitate attachment of support wires or other structures for delivery. Each hole  1316  can be centered on a horizontal reinforcing portion  1310  and/or vertical reinforcing portion  1308 . Each of the holes  1316  can have a larger open area than a pore of the porous portion  1318 . 
     The occlusion device  1300  can be shape-set such that the occlusion device  1300  can transition from the two-dimensional configuration to the three-dimensional configuration. In the three-dimensional configuration, the occlusion device  1300  forms a volumetric filler. As shown in  FIG.  13 D , the occlusion device  1300  can spiral to form a cylindrical form with open ends. 
     When transformed from the two-dimensional configuration to the three-dimensional configuration, the pore size or open area of each pore in the three-dimensional configuration changes less than 20% (or less than 15%, or less than 10%, or less than 5%) than the pore size or open area of the same pore in the two-dimensional configuration. In each of the two-dimensional and three-dimensional configurations, there is less than 20% (or less than 15% or less than 10% or less than 5%) variation between the pore size or open area of any two openings. In each of the two-dimensional configuration and the three-dimensional configuration, there is less than 20% (or less than 15% or less than 10% or less than 5%) variation or between the pore size of any opening and the mean pore size of the entire porosity. In some configurations, every pore and opening has a uniform size in the two-dimensional configuration and/or three-dimensional configuration. 
     The surface area of a surface (one side) of the implant can be at least 1.5 times greater (or at least 2.0 times greater, or at least 2.5 times greater, or at least 3.0 times greater) than an internal volume formed when the implant is in the three-dimensional configuration. 
       FIGS.  14 A- 14 D  show yet another embodiment of an occlusion device  1400  that is configured to transition between a first, two-dimensional configuration (see  FIG.  14 A ) and a second, three-dimensional configuration (see  FIGS.  14 C and  14 D ). In some configurations, the occlusion device can be constructed from thin-film nitinol. 
     The occlusion device includes a mesh structure having a porosity  1418  with a substantially uniform or uniform pore size (see  FIG.  14 B ). Any single pore size can be within at least 5% of a pore size of any other pore or the mean pore size. The size of the perforation holes and the dimensions of the supporting mesh are chosen to maximize the occlusive performance in the device while maintaining sufficient structural strength to enable handling and deployment of the device without tearing. 
     In the first configuration, the occlusion device  1400  is in a flat, planar configuration with parallel surfaces. At rest, the occlusion device  1400  has a substantially uniform or uniform thickness. For example, a thickness of the occlusion device  1300  can be at least about 0.2 mils and/or less than or equal to about 2.0 mils, such between about 0.5 mils and about 1.5 mils or between about 1.0 mils and about 2.0 mils. 
     As shown in  FIG.  14 A , the occlusion device  1400  extends from a first end  1402  to a second end  1404 . The occlusion device  1400  can include one or more petals or segments  1414  (e.g., at least two, at least three, at least four, or more) connected end-to-end. The one or more segments  1414  may be arranged such that segments are arranged at an angle with respect to adjacent segments. However, in other configurations, a longitudinal axis of each segment  1414  can extend along a longitudinal axis of the occlusion device  1400 . 
     A length of each segment  1414  can be greater than a width of the respective segment  1414 . The length of each segment  1414  can be at least about 1.5×, at least about 2.0×, at least about 2.5×, or at least about 3.0× greater than the width of the respective segment  1414 . 
     As shown, each of the segments  1414  is the same size with equal lengths and widths. However, in other configurations, one or more of the segments  1414  can be differently sized from one or more other segments  1414 . 
     The occlusion device  1400  can be formed as a monolithic structure with each of the segments  1414  joined to an adjacent segment. Optionally, the occlusion device  1400  can include a hole or grommet  1416  at a transition between adjacent segments. Each of the holes  1416  can have a larger open area than a pore of the porous portion  1418 . The holes  1416  can be used to facilitate attachment to support wires or other structures for delivery. 
     The occlusion device  1400  can include reinforcing portions with no porosity to provide smooth edges and structural support. The reinforcing portions can have the same thickness as porous portions of the occlusion device. The reinforcing portions can be monolithically formed with the porous portions. 
     The occlusion device can have peripheral reinforcing portions  1408 , horizontal reinforcing portions  1410 , and/or vertical reinforcing portions  1412 . Each reinforcing portion  1408 ,  1410 ,  1412  can have a width of at least about 0.2 mil and/or less than or equal to about 1 mil, such as between about 0.2 mil and about 0.5 mil or between about 0.5 mil and about 1.0 mil. 
     Peripheral reinforcing portions  1408  can extend at least partially or entirely around a periphery of the occlusion device  1400 . A horizontal reinforcing portion  1410  can extend at least partially or entirely across the longitudinal axis of one or more segments  1414 . One or more vertical reinforcing portions  1408  can extend perpendicular to the longitudinal axis of one or more segments  1414 . For example, a vertical reinforcing portion  1418  can extend across a central axis of each segment  1414 . 
     The occlusion device  1400  can be shape-set such that the occlusion device  1400  can transition from the two-dimensional configuration to the three-dimensional configuration. As shown in  FIGS.  14 C and  14 D , the occlusion device  1400  can include a closed portion  1420  and an open portion  1422 . The occlusion device  1400  can fold such that a longitudinal dimension of each segment can extend from one side of the open portion  1422  and around to the other side of the open portion  1422  to form the closed portion  1420 . The open portion  1422  can be formed by the longitudinal edges of two adjacent segments (see  FIG.  14 C ). When completely folded, adjacent longitudinal edges of segments  1414  overlap each other such that there are no gaps between adjacent segments  1414  (see  FIG.  14 D ). 
     When transformed from the two-dimensional configuration to the three-dimensional configuration, the pore size or open area of each pore in the three-dimensional configuration changes less than 20% (or less than 15%, or less than 10%, or less than 5%) than the pore size or open area of the same pore in the two-dimensional configuration. In each of the two-dimensional configuration and the three-dimensional configuration, there is less than 20% (or less than 15% or less than 10% or less than 5%) variation between the pore size or open area of any two openings. In each of the two-dimensional configuration and the three-dimensional configuration, there is less than 20% (or less than 15% or less than 10% or less than 5%) variation or between the pore size of any opening and the mean pore size of the entire porosity. In some configurations, every pore and opening has a uniform size in the two-dimensional configuration and/or three-dimensional configuration. 
     The surface area of a surface (one side) of the implant can be at least 1.5 times greater (or at least 2.0 times greater, or at least 2.5 times greater, or at least 3.0 times greater) than an internal volume formed when the implant is in the three-dimensional configuration. 
     When implanted, the open portion  1422  can face the aneurysm neck such that blood can flow into the internal volume formed by the closed portion  1420 . In some embodiments, fillers (e.g., coils) can be released in the internal volume of the occlusion device  1400 . 
     Although certain embodiments have been described herein with respect to neurovascular aneurysms, the devices described herein can be used to treat other types of aneurysms, e.g. aortic aneurysms, ventricular aneurysms, etc. 
     As used herein, the relative terms “proximal” and “distal” shall be defined from the perspective of the delivery system. Thus, proximal refers to the direction of the handle portion of the delivery system and distal refers to the direction of the distal tip. 
     Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments. 
     The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. 
     Although certain embodiments and examples have been described herein, it will be understood by those skilled in the art that many aspects of the delivery systems shown and described in the present disclosure may be differently combined and/or modified to form still further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or indispensable. 
     For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
     Moreover, while illustrative embodiments have been described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. Further, the actions of the disclosed processes and methods may be modified in any manner, including by reordering actions and/or inserting additional actions and/or deleting actions. It is intended, therefore, that the specification and examples be considered as illustrative only, with a true scope and spirit being indicated by the claims and their full scope of equivalents. 
     The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “about” or “approximately” include the recited numbers and should be interpreted based on the circumstances (e.g., as accurate as reasonably possible under the circumstances, for example ±1%, ±5%, ±10%, ±15%, etc.). For example, “about 100 microns” includes “100 microns.” Phrases preceded by a term such as “substantially” include the recited phrase and should be interpreted based on the circumstances (e.g., as much as reasonably possible under the circumstances). For example, “substantially uniform” includes “uniform.” 
     EXAMPLE EMBODIMENTS 
     The following example embodiments identify some possible permutations of combinations of features disclosed herein, although other permutations of combinations of features are also possible.
         1. An occlusion device comprising:
           a mesh structure comprising a first surface and a second surface, at least a portion of the mesh structure comprises porosity, the mesh structure being configured to transition between a two-dimensional configuration and a three-dimensional configuration,   wherein in the two-dimensional configuration and at rest, the first surface is parallel to the second surface, and   wherein in the three-dimensional configuration, the occlusion device comprises an internal volume.   
           2. The occlusion device of Embodiment 1, wherein the mesh structure is a monolithic sheet.   3. The occlusion device of Embodiment 1 or 2, wherein the mesh structure comprises a thickness of no more than 0.002 inches.   4. The occlusion device of any one of Embodiments 1 to 3, wherein in the three-dimensional configuration, the occlusion device is at least partially spherical.   5. The occlusion device of any one of Embodiments 1 to 3, wherein in the three-dimensional configuration, the occlusion device is at least partially cylindrical.   6. The occlusion device of any one of the preceding Embodiments, wherein the mesh structure comprises a uniform thickness.   7. The occlusion device of any one of the preceding Embodiments, wherein a surface area of the first surface is at least 2× greater than the internal volume.   8. The occlusion device of Embodiment 7, wherein the surface area of the first surface is at least 3× greater than the internal volume.   9. The occlusion device of any one of the preceding Embodiments, wherein the mesh structure comprises a reinforcing portion with no porosity.   10. The occlusion device of Embodiment 9, wherein the reinforcing portion extends around a periphery of the mesh structure.   11. The occlusion device of Embodiment 10, wherein the reinforcing portion extends around the entire periphery of the mesh structure.   12. The occlusion device of any one of the preceding Embodiments, wherein in the three-dimensional configuration, the occlusion device has an open portion to provide access to the internal volume.   13. The occlusion device of any one of the preceding Embodiments, wherein in the two-dimensional configuration, the entire porosity has a uniform pore size.   14. The occlusion device of any one of the preceding Embodiments, wherein in the two-dimensional configuration, any pore size of the porosity is within 10 percent of a first mean pore size of the entire porosity of the two-dimensional configuration.   15. The occlusion device of Embodiment 14, wherein in the two-dimensional configuration, any pore size of the porosity is within 5 percent of the first mean pore size.   16. The occlusion device of any one of the preceding Embodiments, wherein in the three-dimensional configuration, any pore size of the mesh structure is within 10 percent of a second mean pore size of the entire porosity of the two-dimensional configuration.   17. The occlusion device of Embodiment 16, wherein a first pore size of any pore in the two-dimensional configuration is within 5 percent of a second pore size of the same pore in the three-dimensional configuration.   18. The occlusion device of any one of the preceding Embodiments, wherein in the three-dimensional configuration, the mesh structure is partially austenitic and partially martensitic.   19. The occlusion device of claim  18 , wherein the mesh structure is more austenitic than martensitic.   20. The occlusion device of any one of the preceding Embodiments, further comprising a volumetric filler disposed in the internal volume of the mesh structure.   21. The occlusion device of Embodiment 20, wherein the mesh structure comprises the volumetric filler.   22. An occlusion device comprising:
           a monolithic structure comprising porosity, the monolithic structure being configured to transition between a first configuration and a second configuration,   wherein in the first configuration, any pore size of the porosity is within 10 percent of a first mean pore size of the entire porosity of the first configuration;   wherein in the second configuration, any pore size of the porosity is within 10 percent of a second mean pore size of the entire porosity of the second configuration.   
           23. The occlusion device of Embodiment 22, wherein the monolithic structure is a monolithic sheet.   24. The occlusion device of Embodiment 22 or 23, wherein the monolithic structure comprises a thickness of no more than 0.002 inches.   25. The occlusion device of any one of Embodiments 22 to 24, wherein in the second configuration, the occlusion device is at least partially spherical.   26. The occlusion device of any one of Embodiments 22 to 24, wherein in the second configuration, the occlusion device is at least partially cylindrical.   27. The occlusion device of any one of Embodiments 22 to 26, wherein in the three-dimensional configuration, the occlusion device has an open portion to provide access to the internal volume.   28. The occlusion device of any one of Embodiments 22 to 27, wherein the monolithic structure comprises a uniform thickness.   29. The occlusion device of any one of Embodiments 22 to 28, wherein a surface area of the first surface is at least 2× greater than the internal volume.   30. The occlusion device of Embodiment 29, wherein the surface area of the first surface is at least 3× greater than the internal volume.   31. The occlusion device of any one of Embodiments 22 to 30, wherein the monolithic structure comprises a reinforcing portion with no porosity.   32. The occlusion device of Embodiment 31, wherein the reinforcing portion extends around a periphery of the mesh structure.   33. The occlusion device of Embodiment 32, wherein the reinforcing portion extends around the entire periphery of the mesh structure.   34. The occlusion device of any one of Embodiments 22 to 33, wherein a first pore size of any pore in the first configuration is within 5 percent of a second pore size of the same pore in the second configuration.   35. The occlusion device of any one of Embodiments 22 to 34, wherein in the two-dimensional configuration, any pore size of the mesh structure is within 5 percent of the first mean pore size.   36. The occlusion device of any one of Embodiments 22 to 35, wherein in the three-dimensional configuration, any pore size of the mesh structure is within 5 percent of the second mean pore size.   37. The occlusion device of any one of Embodiments 22 to 36, wherein in the first configuration, the porosity has a uniform pore size.   38. The occlusion device of any one of Embodiments 22 to 37, wherein in the second configuration, the mesh structure is partially austenitic and partially martensitic.   39. The occlusion device of Embodiment 38, wherein the mesh structure is more austenitic than martensitic.   40. The occlusion device of any one of Embodiments 22 to 39, further comprising a volumetric filler disposed in the internal volume of the mesh structure.   41. The occlusion device of Embodiment 40, wherein the mesh structure comprises the volumetric filler.   42. A method of deploying an occlusion device, the method comprising:
           releasing the occlusion device from a catheter and into an aneurysm sac, the occlusion device comprising:
               a mesh structure having porosity,   a first configuration in which the occlusion device is planar, and   a second configuration in which the occlusion device is partially folded, wherein when the occlusion device is in the catheter, the occlusion device is in the second configuration; and   
               transforming the occlusion device from the second configuration to a third configuration in which the occlusion device comprises an internal volume;   wherein a first pore size of any pore in the first configuration is within 5 percent of a second pore size of the same pore in the second configuration.   
           43. The method of Embodiment 42, further comprising filling the internal volume of the occlusion device with a volumetric filler.   44. The method of Embodiment 43, wherein filling the internal volume comprises folding a portion of the mesh structure into the internal volume of the occlusion device.   45. The method of any one of Embodiments 42 to 44, wherein in the first configuration, the mesh structure comprises a uniform pore size.   46. The method of any one of Embodiments 42 to 45, wherein in the third configuration, the occlusion device is at least partially spherical.   47. The method of any one of Embodiments 42 to 45, wherein in the third configuration, the occlusion device is at least partially cylindrical.   48. The method of any one of Embodiments 42 to 47, the mesh structure comprises a monolithic sheet.