WO2009036094A2

WO2009036094A2 - Magnetic prosthetic materials for implantation using natural orifice transluminal endoscopic methods

Info

Publication number: WO2009036094A2
Application number: PCT/US2008/075898
Authority: WO
Inventors: Christopher C. Thompson; Marvin Ryou
Original assignee: The Brigham And Women's Hospital, Inc.
Priority date: 2007-09-12
Filing date: 2008-09-10
Publication date: 2009-03-19
Also published as: WO2009036094A3

Abstract

Magnetically manipulatable prosthetic materials, such as magnetically manipulatable meshes, are disclosed, along with methods for implanting the materials in a body cavity using natural orifice transluminal endoscopic surgery (NOTES). Also disclosed are methods and systems for manipulating the magnetically manipulatable prosthetic material from the exterior of the body.

Description

Magnetic Prosthetic Materials for Implantation using Natural Orifice Transluminal Endoscopic Methods

Cross-Reference to Related Applications

This application claims priority to, and the benefit of, U.S. Provisional Patent Application No. 60/971,883, filed September 12, 2007, and U.S. Provisional Patent Application No. 60/975,982, filed September 28, 2007. Both of those applications are incorporated by reference herein in their entireties.

Technical Field

Generally speaking, the invention relates to the field of medical devices, and more specifically, to magnetic prosthetic materials for implantation using natural orifice transluminal endoscopic methods.

Background of the Invention

In Natural Orifice Transluminal Endoscopic Surgery (NOTES), a flexible endoscope is introduced through a natural orifice — such as the mouth, anus, or vagina— to create a controlled transvisceral incision for access into the peritoneal cavity. NOTES is potentially less invasive than laparoscopy because it eliminates abdominal incisions and incision-related complications such as wound infections, incisional hernias, post-operative pain, and adhesions.

The surgical repair of abdominal wall hernias, including inguinal hernias, represents one of the most common group of surgical procedures being performed in the United States. Over a million procedures are performed annually at an estimated cost of $2.5 billion dollars. Over the last few decades, surgical approaches to the repair of ventral wall hernias have witnessed dramatic changes driven by the introduction of two pivotal technological advances. In the mid 1980's, the use of synthetic meshes in tension free mesh repairs revolutionized the field by demonstrating superior long-term durability. With the introduction of laparoscopic approaches in the 1990's, improved surgical outcomes were achieved including a reduction in wound related complications, improved cosmesis, reduced length of stay, and lower rates of hernia recurrence. To further minimize the invasiveness of ventral wall hernia repair, a NOTES approach may represent a potentially less invasive alternative to transabdominal surgery. However, although advances in electrosurgical instruments and prototype suturing devices have allowed for dissection and resection of abdominal organs using NOTES, surgical procedures involving implants, such as hernia mesh, present challenges because of the difficulty in manipulating and securing such implants. Particular difficulties exist with respect to hernia mesh, including mesh delivery and retraction against gravity.

Summary of the Invention

One aspect of the invention relates to magnetically manipulatable prosthetic materials for implantation in human and animal bodies. The materials comprise at least one layer of a biocompatible prosthetic material and one or more magnetic elements attached to the biocompatible prosthetic material at defined locations. The prosthetic material may comprise a sheet of mesh material, and the magnetic elements may be attached around the periphery of the sheet of mesh material. Another aspect of the invention relates to a system for manipulating and securing a magnetic prosthetic material inside a body cavity. The system comprises a magnetically manipulatable prosthetic material, as described above, and a positionable magnetic manipulator. The positionable magnetic manipulator has at least one magnetic element and is constructed and arranged to exert a magnetic manipulating force on the prosthetic material while the prosthetic material is positioned within a body cavity and the magnetic manipulator is positioned outside of the body cavity.

Yet another aspect of the invention relates to a method for implanting a magnetically manipulatable prosthetic material in a body cavity. The method comprises accessing the body cavity by inserting a surgical instrument into an existing bodily lumen through a natural orifice and making an opening in a tissue wall associated with the bodily lumen to define a transluminal pathway into the body cavity. The method further comprises deploying a magnetically manipulatable prosthetic material into the body cavity using the transluminal pathway, and manipulating the prosthetic material using a magnetic manipulator located outside of the body cavity. Other aspects, features, and advantages of the invention will be set forth in the description that follows.

Brief Description of the Drawings The invention will be described with respect to the following drawing figures, in which like numerals represent like features throughout the drawings, and in which:

FIG. 1 is a perspective view of a one embodiment of a magnetically manipulatable mesh according to an embodiment of the invention;

FIG. 2 is a top plan view of another embodiment of a magnetically manipulatable mesh according to another embodiment of the invention;

FIG. 3 is a top plan view of a magnetically manipulatable mesh according to yet another embodiment of the invention;

FIG. 4 is a side elevational view of a deployment device suitable for use with the meshes of FIGS. 1-3; FIG. 5 is an illustration of the magnetically manipulatable mesh of FIG. 1 in position and being manipulated using a magnetic manipulator.

FIG. 6 is a side elevational view of a magnetic manipulator;

FIG. 7 is a photograph taken using an endoscope showing a prosthetic mesh implanted on the ventral abdominal wall; and FIG. 8 is a photograph illustrating the necropsy findings of the implanted mesh site of FIG. 7.

Detailed Description

Embodiments of the invention provide magnetically manipulatable prosthetic materials suitable for implantation in human and other animal bodies. These magnetically manipulatable materials may take the form of single-layer continuous sheets, multi-layer sheets, meshes, plugs, or other shapes.

FIG. 1 is a schematic top plan view of a magnetically manipulatable material according to one embodiment of the invention, in the form of a magnetically manipulatable mesh for hernia repair, generally indicated at 10. The mesh 10 comprises one or more layers of mesh material, in the illustrated embodiment, a first layer of mesh material 12, a second layer of mesh material 14, and a layer of ferromagnetic material 16 that is secured between the first and second layers of mesh material 12, 14 around the periphery of the mesh 10.

The mesh 10 may have any size or shape that is appropriate for the particular application or procedure. The layers of mesh material 12, 14 are generally made of biocompatible materials and, for example, may be made of biocompatible polymers. For example, the layers of mesh material 12, 14 may be layers of polypropylene and expanded polytetrafluoroethylene (ePTFE) hernia mesh (e.g., COMPOSIX mesh, Davol Inc., Cranston, RI). Other examples of suitable materials for meshes include polypropylene and collagen; polyester and collagen; polypropylene, hyaluronic acid and carboxymethyl cellulose; and polypropylene, polydioxanone, and oxidized regenerated cellulose. Generally speaking, a mesh according to embodiments of the invention may have any number of layers, secured together in any suitable fashion. Magnetically manipulatable materials other than meshes may be made of any of the materials listed above or any other suitable biocompatible material.

The layers of mesh material 12, 14 may have any conventional features; for example, one layer of material 12, 14 may have a surface that is rough, barbed, textured, or otherwise adapted to facilitate tissue growth, while the other layer 12, 14 may be relatively smooth and adapted for adhesion. The overall thickness of the mesh 10 may be several millimeters, for example 2-3 millimeters. It is advantageous, however, if the mesh 10 has at least some flexibility, regardless of its particular thickness. The ferromagnetic material 16 may be any biocompatible ferromagnetic material, including surgical steels and other biocompatible ferromagnetic alloys. The ferromagnetic material 16 may also have any shape or thickness, and may extend over the entirety or only a portion of the peripheral space into which it is sewn or otherwise attached, so long as it extends over a portion of the mesh 10 sufficient to allow the mesh 10 to be magnetically manipulated. Additionally, although the ferromagnetic material 16 and the mesh 10 as a whole may have any desired thickness, it is advantageous if the ferromagnetic material 16 allows the mesh 10 to be folded, rolled, or otherwise packed for delivery. Although the ferromagnetic material 16 of the mesh 10 is shown as extending around the periphery of the mesh 10, in some embodiments, particularly with larger meshes, it may be desirable to have layers of ferromagnetic material 16 extending into the interior of the mesh 10, so as to make the mesh more easily manipulatable. For example, pockets of ferromagnetic material could be provided at particular or regularly-spaced locations along the mesh 10.

FIG. 2 is a schematic top plan view of another embodiment of a magnetically manipulatable mesh for hernia repair, generally indicated at 50. Mesh 50 comprises a layer of mesh material 52 to which ferromagnetic materials 54 have been attached at discrete locations around its perimeter. In the embodiment of FIG. 2, the ferromagnetic materials 54 may be attached, for example, by appropriate sutures 56. FIG. 3 is a top plan view of a mesh 100 according to another embodiment of the invention. Mesh 100 has ferromagnetic surgical clips 102 attached to its corners to allow it to be magnetically manipulated. Thus, the meshes 50, 100 of FIGS. 2 and 3 have removably attached ferromagnetic materials that may be detached either by severing a connector that connects the two, as in mesh 50, or by operating a mechanism to release the ferromagnetic material 102 from the mesh, as in mesh 100. These configurations may be particularly advantageous, in that the meshes 50, 100 may be implanted and manipulated magnetically, after which (for example, after suturing in place) the ferromagnetic materials 54, 102 may be detached from the mesh 50, 100 and withdrawn, so that the mesh 50, 100, as implanted, is not susceptible to electromagnetic forces.

Although FIGS. 1-3 illustrate specific examples of magnetically manipulatable meshes using distinct ferromagnetic materials, any mechanism by which a mesh may be made responsive to magnetic fields may be used in embodiments of the invention. Moreover, regardless of the particular type of magnetically manipulatable material, it may be advantageous to select magnetic materials or elements that are not mutually attracted to one another, so that the edges of the material are not attracted to one another.

A mesh 10, 50, 100 may be implanted in a body cavity by inserting a surgical instrument, such as an endoscope, into an existing bodily lumen through a natural orifice and making an incision in a tissue wall associated with the bodily lumen to define a transluminal pathway into the body cavity, a type of procedure sometimes referred to as Natural Orifice Transluminal Endoscopic Surgery (NOTES). The associated tissue wall may be contiguous or substantially contiguous with the bodily lumen. This arrangement may be most advantageously used to deploy and manipulate a mesh in the peritoneal cavity or abdomen.

In order to effect deployment, a magnetically manipulatable mesh 10, 50, 100 according to embodiments of the invention may be folded, rolled, bunched, compressed, or otherwise stowed in an appropriate deployment device. One such device 110 is illustrated in FIG. 4. The device 110 has an outer tubing member 112, formed of flexible tubing in the illustrated embodiment, an inner pusher member 114 formed of semirigid tubing in the illustrated embodiment, and a tip 116 that covers the end of the outer tubing member 112 and serves to prevent the mesh 10, 50, 100 from becoming fouled, soiled, or damaged during the insertion process prior to deployment. Once the tip 116 is positioned in the appropriate location, the pusher member 114 would be advanced to eject the mesh 10, 50, 100 from the device 110.

FIG. 5 illustrates the general principle of operation of a magnetically manipulatable mesh 10, 50 once deployed. Specifically, during a procedure, the mesh 10 would be deployed inside a body cavity 61 by an appropriate instrument (not shown in FIG. 5), and then a magnetic manipulator 60 having a magnet of appropriate field strength and polar orientation could be used to move and manipulate the mesh 10, 50 within the body from a position outside of the body. Specifically, in FIG. 5, the mesh 10, 50 is positioned inside the abdomen, and the abdominal wall 63 lies between the mesh 10, 50, 100 and the manipulator 60. The magnetic manipulator 60, also referred to as a magnetic retractor, may comprise one or more permanent magnets or electromagnets arranged on a jointed arm or another such movement mechanism that allows the position of the magnets to be changed so as to change the position or orientation of the mesh 10, 50, 100. FIG. 6 illustrates one example of a magnetic manipulator 60. It includes a support portion 62 that is adapted to be anchored to a fixed surface, such as an operating room table or a floor, and a positionable portion 64 connected to and supported by the support portion 62. The positionable portion 64 itself has a first end 66 and a second end 68 that is spaced from the first end 66. Between the first end 66 and the second end 68 are one or more joints 70, 72, 74, 76. In the magnetic manipulator 60 of FIG. 6, the joints 70, 72, 74, 76 are single and double ball joints; specifically, the two middle joints 72, 74 are double ball joints, while the joints proximate to the first and second ends 70, 76 are single ball joints. In other embodiments of the invention, the joints of the magnetic manipulator 60 may be of essentially any sort, including ball joints, hinge joints, and sliding joints, to name a few.

Preferably, the magnetic manipulator 60 also includes structures to fix it in a desired position once that position has been set. In the illustrated embodiment, set screws 78, 80, 82, which are also useful as positioning handles, are provided. In other embodiments, the joints 70, 72, 74, 76 may employ friction to maintain the positionable portion 64 in position, or the positionable portion 64 may include counterweights or other conventional elements to maintain position. Additionally, any combination of conventional elements may be used to maintain position, particularly of the first end 66. Generally speaking, aside from positionability and the ability to lock into or retain a particular position, the magnetic manipulator 60 is preferably of a construction that can support relatively heavy loads (e.g., about 10 kg) in a desired position. It is also advantageous if the magnetic manipulator 60 is made of a rigid, non-magnetic material, such as aluminum. At the first end 66 of the positionable portion 64 are one or more magnets 84.

The magnets 84 may be permanent magnets, conventional coil electromagnets, or superconducting magnets (i.e., electromagnets cooled by cryogenic fluids to reduce electrical resistance in the coils). If the magnets 84 are permanent magnets, then they would generally be through-magnetized, such that there are north (N) and south (S) poles, allowing two or more of them to be stacked and magnetically adhered, clamped or otherwise cooperatively attached to increase the total magnetic field and magnetic force levels incrementally. Neodymium permanent magnets are one type of magnet that is suitable for use in embodiments of the present invention. Among other advantages, neodymium magnets are capable of producing strong forces relative to their size and also have a high degree of coercivity (i.e., resistance to demagnetization) . The magnets 84 may be attached to the first end 64 using adhesives (such as epoxy), clamps, straps, mechanical fasteners, or some other conventional method of attachment. (In the illustrated embodiment, the magnets 84 are secured by straps 86.) If adhesives are used to secure permanent magnets, it is advantageous if the chemical reactions involved in curing the adhesives are not strongly exothermic, as high temperatures may have a deleterious effect on the magnetic properties of permanent magnets. Likewise, if mechanical clamping or strapping is used, it is advantageous if the clamping or strapping force is kept as low as possible to avoid mechanical damage to the magnets. In the illustrated embodiment, the first end 66 includes a generally flat attachment plate 88 that is connected to the joint 76 nearest the first end 66 and is thus itself positionable. In order to aid attachment, the attachment plate 88 may, in some embodiments, be magnetic.

Whether permanent magnet or electromagnet, the magnets 84 may be covered by an appropriate cover so as to maintain sterility, prevent corrosion, and make cleaning easier. The cover itself may be removable and replaceable for easy cleaning, or it may be disposable.

Additional disclosure of magnetic manipulators 60 and additional surgical tools and procedures that may be used with them can be found in PCT International Application No. PCT/US2008/60668, filed April 17, 2008, the contents of which are incorporated by reference herein in their entirety.

In addition to the magnetic mesh embodiments described above, magnetically manipulatable prosthetic materials according to embodiments of the invention may be used to bolster anastomotic sites, re-route bypass sections in gastric bypass surgical procedures, repair fistulas, and act as a tissue plug, to name a few uses.

The following example demonstrates one potential surgical technique for implanting a magnetically manipulatable prosthetic mesh.

Example Animals Five female Yorkshire pigs (Parson's Farm, Hadley, MA) weighing 25 to 30 kg were used in the study. The research protocol was approved by the Animal Research at Children's Hospital (ARCH) animal research committee and animals were housed at the ARCH Facility, Boston, Massachusetts. Equipment

Suturing system: The suturing system consisted of a 19 gauge hollow needle and pusher wire from a standard Bard EndoCinch kit (Davol Inc., Cranston, RI). 3-0 monofilament sutures with attached T-tags were also utilized.

Composite hernia mesh: Polypropylene and expanded polytetrafluoroethylene (ePTFE) hernia mesh (Composix mesh, Davol Inc., Cranston, RI) were received sterile and cut to size ranging from 1.5 to 2 cm by 2.5 to 3 cm rectangular pieces.

Ferromagnetic endoscopic clips (Resolution^® Clip, Boston Scientific Corp., Natick,

MA) were affixed to each of the four corners of the mesh, as in FIG. 3.

Mesh delivery device: The mesh delivery device comprised a delivery tube with a pusher shaft mechanism, as in FIG. 4. The device was constructed from medical grade clear flexible plastic tubing with an outer diameter of 1.2 mm, an inner diameter of 10 mm, and a length of 50 cm. A tapered tip of soft plastic was fixed onto the end of the tube. A semi-rigid piece of plastic tubing was used as the pusher shaft.

Prepared pieces of hernia mesh were rolled and carefully back- loaded onto the end of the delivery tube prior to use.

Magnetic manipulator: The magnetic manipulator comprised a magnetic manipulator 60 similar to that shown in FIG. 6. The manipulator 60 included four rare earth neodymium block magnets measuring 4" x 2" x 8", stacked together to generate a pull force of 640.5 lbs and a surface field measuring 5120 Gauss (K&J Magnetics, Jamison, PA).

Preoperative Preparation

Preoperative preparation for transcolonic survival experiments have been previously described in detail, and are generally known in the art. Briefly, double- channel upper endoscopes (GIF 2Tl 00; Olympus, Tokyo, Japan), re-useable instruments, and the prototype mesh delivery device were treated with 2.4% glutaraldehyde (Cidex; Johnson and Johnson, Irvine, CA) for high level disinfection.

The animals were fasted for 48 hours prior to the procedure. Pre- anesthesia sedation consisted of Telazol 4.4 mg/kg intravenous (IV) (Fort Dodge, Ames, IA), atropine sulfate 0.4 mg/kg IV, and xylazine 2.2 mg/kg IV. General anesthesia was achieved with inhaled 1-3%. isoflurane. Cefazolin 1 gm IV was administered immediately before the procedure.

Colonic preparation included copious tap water enema lavage followed by the instillation of a 1 gm cefazolin suspension and 60 mL of 10% povidone-iodine solution. The external anal and gluteal surfaces were then scrubbed with 10% povidone-iodine and sterile drapes applied.

Procedure and Technique

Internal indentation from abdominal palpation was used to localize the anterior colonic wall. In survival experiments, three T-tags with attached sutures were placed in a triangular configuration flanking the proximal and distal margins of the planned incision site. At a distance of 15 to 20 cm from the anal verge, a focal colonic incision (< 2 to 3 mm) was created using a needle-knife with a brief pulse of coagulation current at 20 watts. The retracted needle-knife was then advanced through the incision followed by the endoscope over the retracted needle-knife cannula into the peritoneal cavity. After a brief survey of the anterior abdominal wall, a guidewire was advanced into the peritoneal cavity and the endoscope was removed. The loaded mesh delivery device was then advanced over the wire through the colotomy and into the peritoneal cavity. The pusher shaft was then advanced through the delivery tube to deposit the mesh into the peritoneal cavity and the device was removed.

The magnetic manipulator 60 was attached to the operating table and was then positioned externally over the anterior abdominal wall to transcutaneously manipulate the mesh. In conjunction with two endoscopic forceps internally, the external magnetic manipulator was used to position the mesh over the mid abdominal wall. Using the 19 gauge hollow needle and pusher wire, suture T-tags were used to secure the four corners of the mesh with a goal of transfascial fixation. To facilitate needle puncture, the endoscope was positioned in as much of a perpendicular orientation as possible, relative to the abdominal wall. In subsequent experiments, carefully applied external counter pressure was used to facilitate deeper needle insertion and T-tag deployment through the abdominal layers without breaching the abdominal wall. FIG. 7 is an endoscopic view of the ventral wall with an implanted mesh. Four ceramic plugs from suture T-tags are visible at the corners of the mesh.

In the three survival experiments, full thickness closure of the colonic incision was attempted by placing an endo-loop (Olympus, Tokyo, Japan) over the colonic incision. The previously placed T-tag sutures were threaded through the endo-loop and gentle tension was used to facilitate eversion of the incision margins prior to closure of the endo-loop around the base of the incision. Any residual open defects were closed with endoscopic clips as needed. During the procedure, pneumoperitoneum was achieved with CO₂ insufflation through a veress needle placed in the lower abdominal midline. Continuous CO₂ insufflation was used to create pneumoperitoneum to a pressure of less than 15 mm Hg.

Post Operative Care and Necropsy Survival animals were recovered from anesthesia and allowed to resume a regular diet immediately. Cephalexin 250mg was administered orally twice a day for three days. On day 14 the pigs were electively sacrificed and necropsies performed. Necropsies were performed immediately after surgery in the two acute experiments. Gross examination of the peritoneal cavity was performed to identify signs of organ injury and evidence of bleeding or suppurative complications. An assessment of tissue healing and incorporation of the mesh was made including presence of any adhesions. Peritoneal biopsies and tissue samples from the mesh site were obtained for histopathologic examination.

Results Composite hernia mesh was successfully transferred to the peritoneal cavity in all five attempts using the prototype mesh delivery device. Passage of the device and deployment of the mesh was rapid and uncomplicated using the introducer mechanism. In one instance, retrieval of the deposited mesh required several minutes due to difficulty finding the free mesh within the abdominal cavity. The magnetic manipulator was ultimately instrumental in locating the lost deposited mesh by floating the magnetic assembly across the abdomen. Transcutaneous magnetic manipulation with the prototype magnetic manipulator facilitated positioning of the mesh along the abdominal wall. The magnetic retraction allowed the mesh to lie flat against the abdominal wall while forceps in each of the biopsy channels were used to make lateral position adjustments. The magnetic pull of the magnets did have an unintended impact on the control of the endoscopic forceps and this magnetic attraction required intermittent repositioning of the magnets away from the abdominal wall to modulate magnetic forces.

Fixation of the mesh using the T-tag suturing system was successful in all five animals. During this stage of the procedure, the magnetic manipulator also proved to be helpful in stabilizing mesh while the first few T-tags were being secured. In each animal, suture tags were placed at each of the four corners without complications.

The total time for suture placement ranged from 15 to 25 minutes.

Closure of the colonic incision was greatly facilitated by the placement of suture T-tags proximal and distal/lateral to the incision site. In previous work by the present inventors using an endo-loop over forceps technique, closure was often challenging due to difficulty bringing the incision margins completely into the endo- loop with a single grasping forcep. Modification of this technique with the suture T- tags allowed for enhanced eversion of the incision margins into the open endo-loop. In one animal, a single endoscopic clip was used to close a residual defect. Closure times ranged from 5 to 10 minutes in this study. Total procedure times from scope insertion to closure ranged from 45 to 60 minutes.

All three survival animals thrived for 14 days prior to elective sacrifice. At necropsy, the mesh sites were well peritonealized without adhesions or gross suppurative findings. After careful dissection, suture placement through the posterior fascia (transfascial) was confirmed in 10 of 12 sutures. Of these transfascial sutures, four sutures were within the pre-peritoneal space, four sutures were within the abdominal musculature, and two sutures were through the anterior fascia and into the subcutaneous tissue layer. Histopathologic examination of peritoneal biopsies and tissues from the mesh revealed evidence of collagen deposition, lymphocytic infiltration, and foreign body giant cell reaction around the mesh material consistent with the expected stage of tissue healing and mesh incorporation. There were no micro-abscesses or evidence of infectious complications associated with the mesh. Random peritoneal biopsies did not show peritonitis. FIG. 8 is a photograph illustrating the necropsy findings of the implanted mesh site. The white arrows in FIG. 8 illustrate the outlines of the endoscopic clips at the corners of the mesh; the black arrow illustrates the ceramic plug from the suture T-tag. Thus, as an experimental technique, Natural Orifice Transluminal Endoscopic

Surgery or NOTES holds the potential to further minimize the invasiveness of transabdominal surgery with the goal of improving upon already safe and effective surgical options. A NOTES approach to ventral wall hernia repair may yield two distinct advantages. Since the site of luminal breach is posterior to the parietal surface, the entire abdominal fascia at risk for herniation can be readily visualized. In addition, abdominal incisions are avoided which may reduce the risk of further incisional hernias and abdominal wound related complications.

With this approach, the delivery of surgical implants is preferably done by aseptic passage through the gastrointestinal tract. The pusher mechanism and delivery tube proved to be an effective conduit for the rolled mesh. Strengths of this design include the simplicity and adaptability to other collapsible or compressible objects that can be back-loaded into a tube. The flexible nature of the plastic tubing also allowed for the creation of a gentle curve to facilitate passage. Although the device was designed to minimize potential contamination, the extent to which "aseptic" transfer was achieved is unclear. A workable transgastric mesh delivery device may also potentially allow for a transgastric NOTES approach.

The system was highly effective in facilitating mesh positioning within the abdominal cavity. The magnet also served to stabilize the mesh during suture T-tag placement. The ability to stabilize the mesh would likely be useful in formal hernia repairs since precise and stable positioning will be highly advantageous during fixation of the mesh. One unexpected benefit of the magnetic manipulator was that it also proved to be instrumental in locating deposited mesh within the abdominal cavity by simply "floating" the magnet across the abdomen. One unintended consequence of the powerful magnets was the magnetic pull on the ferromagnetic forceps, which necessitated intermittent repositioning of the magnets in order to limit the unintended instrument pull. Therefore, it may be advantageous to use non-ferromagnetic surgical instruments with this system, for example, titanium instruments.

A true ventral wall hernia repair would involve the creation of a ventral wall hernia, the precise placement of mesh over the ventral wall defect, and secure fixation with both transfascial sutures and the equivalent of tacking sutures to seal the borders of the mesh. The pieces of mesh used in this example were small, and much larger pieces of mesh would be used for formal repairs.

In addition, the pieces of hernia mesh were all implanted in relatively midline positions, which likely facilitated transfascial suture placement. To optimize pushing forces along a perpendicular axis, every attempt was made to keep the endoscope in as much of a perpendicular orientation as possible during needle puncture. Transfascial T-tag placement in challenging locations away from midline will presumably present greater technical challenges since a perpendicular orientation will be harder to achieve, although this may be partially offset with the use of external counter pressure or a "shape-lock" device.

Transfascial suture placement through the posterior fascia was achieved in 10 of 12 sutures using the 19 gauge needle, pusher wire, and T-tags suture system from a Bard EndoCinch device. However, only two of the ten transfascial sutures were anchored through the anterior fascia, which would have been preferred. Although the invention has been described with respect to certain exemplary embodiments and particular examples, the embodiments and examples are intended to be illuminating, rather than limiting. Modifications and changes may be made within the scope of the invention, which is determined by the claims.

Claims

What is Claimed is:

1. A magnetically manipulatable prosthetic material, comprising: at least one layer of a biocompatible prosthetic material; and one or more magnetic elements attached to the at least one layer of biocompatible prosthetic material at defined locations.

2. The magnetically manipulatable prosthetic material of claim 1, wherein the biocompatible prosthetic material comprises a sheet of mesh material.

3. The magnetically manipulatable prosthetic material of claim 2, wherein the one or more magnetic elements are attached around the periphery of the sheet of mesh material.

4. The magnetically manipulatable prosthetic material of claim 3, wherein the material comprises: two layers of mesh material superimposed on one another and secured together with the one or more magnetic elements interposed and secured therebetween such that the one or more magnetic elements lie around the periphery of the magnetically manipulatable mesh.

5. The magnetically manipulatable prosthetic material of claim 4, wherein the one or more magnetic elements comprise strips of ferromagnetic material.

6. The magnetically manipulatable prosthetic material of claim 3, wherein the one or more magnetic elements comprise ferromagnetic elements detachably secured to edge portions of the sheet of mesh material.

7. A system for manipulating and securing a magnetic prosthetic material inside a body cavity, comprising: a magnetically manipulatable prosthetic material, including: at least one layer of a biocompatible prosthetic material, and one or more magnetic elements attached to the at least one layer of biocompatible prosthetic material at defined locations; and a positionable magnetic manipulator having at least one magnetic element, the magnetic element being constructed and arranged to exert a magnetic manipulating force on the prosthetic material while the prosthetic material is positioned within a body cavity and the magnetic manipulator is positioned outside of the body cavity.

8. The system of claim 7, wherein the biocompatible prosthetic material comprises a sheet of mesh material.

9. The system of claim 8, wherein the one or more magnetic elements are attached around the periphery of the sheet of mesh material.

10. The system of claim 9, wherein the biocompatible prosthetic material comprises: two layers of mesh material superimposed on one another and secured together with the one or more magnetic elements interposed and secured therebetween such that the one or more magnetic elements lie around the periphery of the magnetically manipulatable mesh.

11. The system of claim 10, wherein the one or more magnetic elements comprise strips of ferromagnetic material.

12. The system of claim 9, wherein the one or more magnetic elements comprise ferromagnetic elements detachably secured to edge portions of the sheet of mesh material.

13. The system of claim 7, wherein the at least one magnetic element of the magnetic manipulator comprises one or more permanent magnets.

14. The system of claim 13, wherein the permanent magnets comprise neodymium permanent magnets.

15. A method for implanting a magnetically manipulatable prosthetic material in a body cavity, comprising: accessing the body cavity by inserting a surgical instrument into an existing bodily lumen through a natural orifice and making an opening in a tissue wall associated with the bodily lumen to define a transluminal pathway into the body cavity; deploying a magnetically manipulatable prosthetic material into the body cavity using the transluminal pathway; and manipulating the magnetically manipulatable prosthetic material using a magnetic manipulator located outside of the body cavity.

16. The method of claim 15, wherein the body cavity is the peritoneal cavity.

17. The method of claim 15, wherein the magnetically manipulatable prosthetic material is a magnetically manipulatable prosthetic mesh.

18. The method of claim 17, wherein the magnetically manipulatable prosthetic mesh includes removably attached ferromagnetic materials.

19. The method of claim 18, further comprising detaching the removably attached ferromagnetic materials.

20. The method of claim 17, wherein the magnetically manipulatable prosthetic mesh includes incorporated ferromagnetic materials.