METHODS AND DEVICES FOR REDUCING GASTRIC VOLUME
The present invention involves new interventional methods and devices for reducing gastric volume, and thereby treating obesity. The procedures are generally performed laparoscopically and may generally be described as laparoscopic plication gastroplasty (LPG) in which, after obtaining abdominal access, spaced apart sites on a gastric wall are engaged and approximated to create one or more tissue folds that are then secured by placing one or more tissue fasteners to produce one or more plications projecting into the gastrointestinal space. The serosal tissue may optionally be treated during the procedure to promote the formation of a strong serosa-to-serosa bond that ensures the long-term stability of the tissue plication. These procedures are preferably carried out entirely extragastrically (i.e. without penetrating through the gastrointestinal wall), thereby minimizing the risks of serious complications. Minimally invasive devices for approximating and fastening soft tissues are disclosed that enable these new interventional methods to be carried out safely, efficiently and quickly. Methods for reversing the procedure are also disclosed.
This application is a continuation of U.S. patent application Ser. No. 12/184,173 filed Jul. 31, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 12/048,206, filed Mar. 13, 2008, which issued as U.S. Pat. No. 8,142,450 on Mar. 27, 2012 and claims priority to U.S. Provisional Patent Application Nos. 60/894,626 filed Mar. 13, 2007, 60/952,871 filed Jul. 31, 2007, and 60/990,968 filed Nov. 29, 2007. U.S. patent application Ser. No. 12/184,173 also claims priority to U.S. International Patent Application No. PCT/US08/56921 filed Mar. 13, 2008. These patent applications are incorporated herein by reference in their entireties.
FIELD OF THE INVENTIONThe present invention relates generally to methods and devices for reducing the volume of a hollow body organ, such as gastric volume. One application of methods and devices of the present invention is treating obesity in a patient by effectively reducing the functional volume of the stomach.
BACKGROUND AND DESCRIPTION OF THE PRIOR ARTObesity is rapidly reaching epidemic proportions in developed societies worldwide. There are currently over 1 billion overweight people globally, with 300 million of these people considered clinically obese. In the United States alone there are more than 50 million obese adults, and the numbers are expected to increase by more than 50% in the next decade. Morbid obesity (i.e. obesity in which there are secondary complications such as hypertension, diabetes, coronary artery disease, stroke, congestive heart failure, orthopedic problems and pulmonary insufficiency) not only affects quality of life, but also shortens life expectancy and costs the health care industry billions of dollars annually.
Interventional procedures and associated medical devices for treating morbid obesity in patients are well known in the art. In general, these interventional procedures promote weight loss by either (a) gastric restriction or volume reduction, (b) malabsorption, or (c) a combination of the foregoing. Gastric restriction or volume reduction methods promote weight loss by limiting the amount of food intake (i.e. the patient eats less), either due to physical space limitation or by inducing a feeling of early satiety in the patient. Malabsorption methods promote weight loss by limiting the uptake of nutrients (i.e. the patient digests less of what is eaten), usually by removing or bypassing a portion of the gastrointestinal (GI) tract.
Among the earliest interventional procedures directed at promoting weight loss were variations of the jejuno-ileal bypass developed in the 1950s. This surgery effectively bypasses the small intestine and is therefore a strictly malabsorption procedure, which poses serious risks. The bilopancreatic diversion procedure, which combines bypass of most of the small intestine with a partial gastrectomy, is a combined volume reduction and malabsorption procedure that was developed in effort to reduce these risks, but it too had complications and its success was limited.
Roux-en-Y gastric bypass surgery is a commonly performed bariatric procedure, especially in the US. It was originally performed as an open interventional procedure, but it is now routinely performed laparoscopically. This procedure utilizes interventional stapling and cutting devices to form a small stomach pouch, bypassing the lower part of the stomach, and creates a Roux-en-Y limb to attach the jejunum to the pouch. The Roux-en-Y procedure is predominantly a volume reduction method (the stomach pouch is typically ˜25 cc in volume), although there is a significant malabsorption component.
Despite the proven efficacy of the Roux-en-Y procedure in terms of achieving weight loss, and the recent laparoscopic improvements that have reduced the associated interventional risks, it remains a highly invasive procedure with substantial rates of morbidity. The rate of interventional mortality may be as high as 1%, and known complications include frequent pulmonary morbidity and anastomotic leaks that can be life threatening. Furthermore, the malabsorption component of the Roux-en-Y procedure can negatively affect health because of reduced vitamin uptake, and the long-term consequences of malabsorption are not yet fully understood.
A variety of other interventional procedures have also been developed involving the use of interventional stapling to bring together and fasten opposing walls of the stomach in order to reduce its volume. Most involve malabsorption to a greater or lesser extent, depending on the procedure. Examples of such procedures include the horizontal gastroplasty (HG) and vertical banded gastroplasty (VBG), as well as more recent variations such as the Magenstrasse and Mill (M&M) and laparoscopic sleeve gastrectomy (LSG) procedures that involve not only stapling, but cutting away and removal of the unused stomach portion, leaving behind a reduced volume tube or sleeve running more or less parallel to the lesser curvature between the esophagus and the pylorus. Surgically inserted artificial sleeves that longitudinally traverse the stomach may achieve similar effective volume reductions while significantly increasing malabsorption. In any case, weight loss results achieved with these procedures may sometimes approach those of the Roux-en-Y, however these procedures are not easily performed, are difficult if not impossible to reverse, and still suffer from risks of serious complications, most frequently related to failure or leakage of the staples, which can lead to dangerous infections and even death.
An alternative minimally invasive procedure recently growing in popularity involves the laparoscopic placement of an adjustable silicone ring around the upper portion of the stomach, thereby creating a small (e.g. 50-120 cc) pouch. The LAP-BAND® is one such commercially available restrictive device that, after placement, induces a feeling of early satiety in the patient. Although considerably less invasive than the Roux-en-Y procedure, and potentially reversible, significantly less weight loss has been observed with laparoscopic banding. This procedure also suffers from a variety of limitations and shortcomings. For example, because the laparoscopic band does not actually reduce the volume of the stomach, some patients report a feeling of nearly constant hunger. Additionally, long-term complications of the laparoscopic banding procedure may include tissue erosion, slippage of the band, infection, or lack of effectiveness, frequently requiring removal of the band after a period of time.
Another less invasive alternative to the above-mentioned procedures is the intragastric balloon. The intragastric balloon is an inflatable device that is deployed within the stomach, thereby displacing a known internal volume. The advantages of this method are that it is minimally invasive, involves no malabsorption component, and requires no stapling, permanent reconfiguration or removal of tissue. While the correlation between apparent stomach volume reduction and weight loss is well established by the intragastric balloon method, the weight loss achieved is typically considerably less than with Roux-en-Y. Furthermore, unless it is surgically fastened to the stomach wall, the balloon is free floating and frequent complications such as obstruction, mucosal erosion, nausea, vomiting and pain have been documented, with the result that intragastric balloons are usually removed within 6 months after initial placement.
In effort to develop even less invasive devices and procedures, more recently there has been considerable interest in various transoral (or transesophageal) endoscopic approaches for reducing stomach volume entirely from within the gastrointestinal lumen, without the need for abdominal incisions. In general, these approaches involve advancing an endoscope down the patient's esophagus and into the stomach, whereby various tools are then used to manipulate and reconfigure the stomach tissue in order to create one or more divisions or internal folds (also known as plications) within the stomach wall. To securely hold the divisions or plications so formed, some form of sutures, staples, anchors, or other similar securing means are placed transesophageally through the stomach walls, and sophisticated endoscopic tools have been developed for such purposes. Tissue approximation and fixation devices for use in endoscopic procedures are described, for example, in U.S. Patent Publications 2004/0215216, 2007/0112364, 2005/0080438. Many other types of endoscopic tissue approximation and fixation devices and fasteners are also known in the art.
While quite promising, endoscopic approaches for reducing stomach have various limitations and shortcomings. For example, they must be performed by highly skilled endoscopic surgeons and involve the use of large, complicated endoscopic devices that require specialized training to deal with the restricted access and small working space. In order to access the stomach internally, devices must be passed down the patient's esophagus, accruing a substantial risk of perforating the esophagus and injuring adjacent organs. In addition, capturing and manipulating the tissue layers and accurately applying the securing means during a transesophageal procedure is not only difficult but also hazardous, due to the significant risk of accidental injury to other organs, bleeding, etc., when piercing (intentionally or accidentally) the stomach wall. Because there is no extragastric visualization in these procedures, there is no advance warning of a developing life threatening situation that may require a rescue operation.
The stomach wall is comprised of four main tissue layers. The mucosal layer is the innermost tissue layer, adjacent a submucosal connective tissue layer. The submucosal connective tissue layer interfaces with the muscularis layer, and the serosal layer covers the exterior (extragastric) surface. Prior art gastric reduction procedures involving tissue reconfiguration from inside the stomach require the placement of sutures, staples, or anchors during surgery to hold the reconfigured tissue in place strongly enough to sustain the tensile loads imposed by normal movement of the stomach wall during ingestion and processing of food. Because the mucosal and submucosal connective tissue layers are relatively weak and prone to elastic stretching during digestion, the securing means generally penetrate the stomach wall to engage at least the muscularis layer. For this reason, the prior art securing means are generally transgastric, passing one or more times completely through the stomach wall.
Proper use and placement of fasteners that penetrate the gastric wall is challenging and concentrates significant forces over a small surface area of mucosal tissue, thereby potentially causing the suture, staple or anchor to leak or tear through the tissue, with potentially disastrous consequences. It is well known that the fasteners used in these procedures frequently migrate, dislodge or even completely disappear over time, resulting in partial or complete failure to maintain the gastrointestinal volume reduction, as well as possible complications. These are significant limitations and shortcomings of prior art bariatric procedures involving tissue reconfiguration.
Previously known interventional procedures for treating obesity through gastrointestinal volume reduction or malabsorption thus involve numerous risks, including life-threatening post-operative complications (e.g. internal bleeding, infection), and long-term problems such as diarrhea, vitamin deficiency, electrolytic imbalance, unpredictable or insufficient weight loss, and gastrointestinal reflux disease (GERD). Given the above noted shortcomings, limitations and risks of prior art procedures, it is apparent there remains a need for safe, easy-to-perform and effective interventional procedures for reducing gastric volume, as well as for devices enabling such procedures.
SUMMARY OF THE INVENTIONThe methods and devices of the present invention represent a new approach for reducing gastric volume, and thereby treating obesity and other disorders of the gastrointestinal tract, that is safe, effective, and overcomes many shortcomings and limitations of prior art procedures. In general, methods of the present invention involve reconfiguring a portion of the gastrointestinal tract (e.g., stomach wall) from the abdominal space, by contacting external tissue surfaces and drawing them toward one another to form one or more tissue invaginations, then approximating the shoulders of the extragastric tissue forming the invagination to form a tissue fold or plication and then securing the shoulders of the extragastric tissue forming the plication to maintain a permanent plication. In preferred embodiments, the extragastric tissue is approximated such that external tissue surfaces abut one another to form the tissue plication, which extends into the internal gastric space. One or more plications may be formed to effectively reduce the circumference, and thereby cross-sectional area and volume, of the gastrointestinal lumen. One of the advantages of this procedure is that the gastric volume is reduced without reducing the mucosal surface area involved in digestive absorption. In a preferred embodiment of the present invention, the portion of the gastric tissue that is reconfigured, according to the procedure described above, is the anterior surface or anterior wall of the stomach, which is readily accessible from the intra-abdominal space. In another preferred embodiment of the present invention, which may allow for even greater gastric volume reduction, the portion of the gastric tissue that is reconfigured includes both the anterior surface and posterior surface of the stomach.
The methods of the present invention may be carried out using open interventional procedures, which are useful, for example, to penetrate the abdominal space and obtain access to difficult or remote regions of the abdomen and gastrointestinal tract, such as the stomach. Alternatively, however, abdominal access to the gastrointestinal tract (e.g., stomach) is provided using conventional laparoscopic procedures that involve relatively minimal penetration of the abdominal space. Minimally invasive non-laparoscopic methods may also be used (i.e. wherein access to the abdominal cavity is achieved without establishing a pneumoperitoneum via insufflation) to access the external surface(s) of the gastrointestinal tract. Numerous methods for accessing the internal abdominal space, and for monitoring intra-abdominal interventions (e.g., imaging and visualizing the intra-abdominal space and intervention) are known and may be used in conjunction with methods of the present invention.
According to one embodiment of the present invention, a method for reducing gastric volume comprises obtaining access to an external surface of the gastrointestinal tract (e.g. stomach); invaginating and approximating the wall of the gastrointestinal tract from its external surface to create at least one plication therein; and fastening surfaces of the approximated gastrointestinal wall to one another to secure the plication(s). According to another embodiment, a method for reducing gastric volume comprises obtaining access to an external surface of the gastrointestinal tract (e.g., stomach); invaginating and approximating the wall of the gastrointestinal tract from its external surface by drawing external surfaces of the gastrointestinal tract toward one another to form a plication extending into the interior space of the gastrointestinal tract; and fastening the approximated surfaces of the gastrointestinal wall to one another to secure the plication(s). This methodology provides a significant reduction in the internal volume of the gastrointestinal tract (e.g., stomach) without reducing the interior wall surface available for digestion and nutrient absorption.
The exterior serosal layer and adjacent muscularis layers of the gastrointestinal tract have relatively more strength than the submucosal and mucosal layers. In certain embodiments of methods of the present invention wherein external surfaces of the gastrointestinal wall are approximated to form a plication projecting into the internal space of the gastrointestinal tract, fastening of the approximated portions of the gastrointestinal wall is accomplished by penetrating fewer than all of the layers of the gastric wall. In preferred embodiments, fastening of the approximated portions of the gastric wall is accomplished by penetrating at least the thin, tough serosal layer covering the exterior of the gastrointestinal lumen and, optionally, the serosal and muscularis layers, without penetrating the submucosal and mucosal layers of the gastric wall. In these embodiments, the intragastric space is not breached during the procedure, and the mucosal layer of the gastrointestinal tract remains intact. This is advantageous not only because it simplifies the procedure, but also because it avoids a variety of known complications arising from prior art procedures that may result when transgastric methods are employed that puncture, damage or otherwise compromise the mucosa during the intervention. Thus, according to another embodiment, a method for reducing gastric volume comprises obtaining access to an external surface of the gastrointestinal tract (e.g. stomach); invaginating and approximating the wall of the gastrointestinal tract from its external surface to form a plication extending into the interior space of the gastrointestinal tract; and fastening approximated surfaces of the gastrointestinal wall to one another without penetrating all layers of the gastric wall to secure the plication(s). In one embodiment, the surfaces of the gastrointestinal wall are fastened to one another using fasteners that penetrate at least the serosal layer, and preferably the serosal and muscularis layers of portions of the gastrointestinal wall forming the plication.
Additional embodiments of methods of the present invention, disclosed in detail below, incorporate additional features for the purpose of improving the safety and effectiveness and/or reducing the complexity and cost of the procedure. For example, in one embodiment of methods of the present invention, immediately prior to, or contemporaneously with the above mentioned invaginating and approximating steps, serosal tissue on surfaces of the gastrointestinal wall that adjoin to form the plication is treated to promote bonding or adhesion of adjoining tissue layers within the plication. In one embodiment, bonding of adjoining tissue layers within the plication is accomplished by disrupting the serosal tissue and promoting a healing response therein. In one preferred embodiment, a serosal tissue treatment that involves serosal tissue disruption and/or promotion of the formation of a serosal-to-serosal bond is provided over substantially the gastrointestinal surface area involved in forming the one or more tissue folds.
It is known that serosal tissue is capable forming strong adhesions to itself, or adjacent tissues, following inadvertent disruption of or damage to the serosal tissue that occurs during surgery. Typically, such adhesions are considered an undesirable and sometimes dangerous complication of abdominal surgery, and avoiding inadvertent damage to the serosa to minimize the formation of adhesions is an important goal during abdominal interventions. In contrast, in methods of the present invention, serosal tissue disruption and formation of the consequent adhesions may be optionally and intentionally promoted on targeted surface areas of the gastrointestinal lumen. When combined with the invaginating and approximating methods of the present invention, it has unexpectedly been discovered that serosal adhesions can be used beneficially for the purpose of providing a supplementary or even primary securing means for the gastrointestinal reconfiguration. According to the present invention therefore, serosal tissue on surfaces of the gastrointestinal wall that form the plication may be treated to disrupt the serosal tissue and promote a healing response for the purpose of selectively promoting the formation of a serosa-to-serosa bond across the approximated tissue boundary within the gastrointestinal plication.
A strong serosa-to-serosa bond is typically formed after a relatively brief period of time (e.g. approximately 7 days after surgery). Once formed, this serosa-to-serosa bond is sufficiently strong to substantially resist the separation forces generated by the stomach during ingestion and digestion, and ensures the long-term integrity of the plication. The formation of a strong serosa-to-serosa bond in the gastric plication of the present invention significantly improves the durability and lifespan of the plication, and consequently of the gastric reduction, and offers a significant improvement compared to the (solely) mechanical fastening methods used in tissue approximation and plication in the prior art. Thus, in the present invention, the fasteners used during the intervention to initially secure the tissue fold serve as the sole structural support for securing the plication only during the brief healing phase following surgery. Following its formation, the serosa-to-serosa bond may provide the primary structural support for securing the plication, and the fasteners initially placed to secure the plication may be removed, absorbed or, more typically, left in place within the patient to provide additional support for the plication.
In contrast to Roux-en-Y or other gastrectomy procedures involving stapling, it should be pointed out that the method of the present invention does not require cutting, transection, anastomosis, or removal of any gastrointestinal tissues from the body. It is therefore possible that the gastric reduction accomplished during this procedure is interventionally reversible. For example, if at a later date the surgeon/patient elects to reverse the gastric reduction, it is possible to substantially restore the original gastrointestinal configuration using a simple and safe procedure wherein the plication is substantially eliminated by removal of any remaining implanted securing means, followed by dissection of the serosa-to-serosa bond along the original line of tissue approximation, and subsequent localized treatment to prevent further formation of adhesions during post-operative healing.
A variety of novel devices, tools and systems are provided herein that enable a medical professional to engage and approximate soft body tissues during an interventional procedure, more safely and conveniently than possible using the prior art instruments. These inventive devices, tools and systems are useful for, among a variety of other possible interventional purposes, performing gastric reduction procedures by invaginating and approximating the wall of the gastrointestinal tract from its external surface to create at least one plication therein; and fastening surfaces of the approximated gastrointestinal wall to one another to secure the plication(s).
Gastric reduction methods of the present invention are performed in the abdominal cavity and involve contacting and manipulating the gastrointestinal tract from its external surface. The methods are typically accomplished using minimally invasive laparoscopic techniques, and the devices and systems of the present invention are therefore generally intended to be used in connection with laparoscopic techniques. However, any technique that provides access to the intra-abdominal space and, particularly, the exterior surface of the gastrointestinal tract may be used, including natural orifice transluminal endoscopic surgery (NOTES) techniques and other minimally invasive non-laparoscopic techniques. For example, smaller diameter, flexible embodiments of the tissue approximation and fastening devices described in detail below can be deployed through a flexible endoscope that may be inserted into the patient's gastrointestinal tract orally, anally or vaginally, after which access to the intra-abdominal space and, particularly, the exterior surface of the gastrointestinal tract may be obtained transluminally. Such flexible, endoscopic tissue approximation and fastening devices are considered within the scope of the present invention.
In one embodiment, a specialized device is provided for carrying out the tissue invagination and approximation steps; another device may optionally be provided for disrupting and/or promoting the bonding of serosal tissue, and yet another device may be provided for securing the tissue plication(s). A device for invaginating and approximating gastric tissue of the present invention preferably comprises a tool having an actuation mechanism (generally on or in proximity to a handle) manipulable by an operator, at least one extendible member, and at least two tissue engagement mechanisms. Tissue engagement mechanisms are generally provided at or in proximity to the distal end(s) of the device or extendible member(s), but may be provided at other locations. In one embodiment, the approximation device comprises at least one tissue engagement mechanism provided in association with a device shaft that is inserted at the site of the intervention, and another tissue engagement mechanism provided in association with an extendible member. In this embodiment, tissue is approximated by engaging tissue at two spaced apart locations using the tissue engagement mechanisms and then moving the extendible member and the device shaft relative to one another to approximate the engaged tissue.
According to another embodiment, the approximation device of the present invention comprises at least one tissue engagement mechanism provided in association with each of at least two extendible members. The extendible members are adjustable by the operator between an insertion (collapsed, pre-deployed) condition, in which they may be inserted into the abdominal space, and an expanded (extended, deployed) condition, in which the associated tissue engagement mechanisms are separated and positioned to engage two portions of tissue spaced apart from one another. The extendible member(s) are also adjustable by the operator, by means of an actuation mechanism, following engagement of the two portions of tissue to draw together, or approximate, the two portions of tissue engaged by the tissue engagement mechanisms. The tissue engagement mechanisms are furthermore manipulable to release engaged tissue, and the extendible members are manipulable to reposition the members in a low profile, collapsed condition for withdrawal of the device from the abdominal space. Thus, in operation, the distal portion of the tissue invagination and approximation device is positioned in the abdominal space; a control feature is actuated by the operator to adjust the extendible members from a low-profile, collapsed condition to a desired extended condition; and the tissue engagement mechanisms are positioned to engage the exterior surface of spaced-apart portions of the gastrointestinal tract (e.g., stomach); a control feature is actuated by the operator to draw the tissue engagement mechanisms together and approximate the two engaged portions of tissue; the engagement mechanisms are disengaged from the tissue; and after repeating the above steps any desired number of times, the extendible members are collapsed and the device is withdrawn from the abdominal cavity.
In one embodiment, the device for invaginating and approximating gastrointestinal tissue has a selection feature that allows the medical professional to select the degree of separation of the extendible members in the expanded condition, and thereby select and control placement of the tissue engagement mechanisms and the overall size of the one or more tissue folds to provide a desired degree of gastric reduction. In another embodiment, a variety of interchangeable tools may be provided, allowing the operator to select approximation tools providing the desired placement of tissue engagement mechanisms and, consequently, the overall size of the tissue fold(s).
Another tissue invagination and approximation device of the present invention comprises a tool having at least two extendible members adjustable between a collapsed insertion condition and an extended operating condition, and additionally comprising at least one tissue invagination structure arranged and adjustable along an axis to contact and invaginate tissue located generally at a midline between the tissue portions engaged by the tissue engagement mechanisms. The tissue invagination structure is preferably axially adjustable between a withdrawn insertion condition in which it does not extend substantially beyond the terminal ends of the extendible members and an invaginating, projected condition, in which the tissue invagination structure projects toward the midline of the tissue surface engaged by the tissue engagement mechanisms. In one embodiment, the axial movement of the tissue invagination structure may be coordinated with the extension of the tissue engagement mechanisms such that, following engagement of two spaced apart portions of tissue, the tissue invagination structure is extended to contact and invaginate tissue as the approximation members are drawn together to approximate the two spaced apart tissue portions. A selection feature may allow the medical professional to select the degree of extension of the invagination structure, thereby controlling the overall size of the tissue invagination and plication, and providing a desired degree of gastric reduction.
In yet another embodiment, a serosal treatment device may be provided and used separately from or in coordination with the tissue approximation and invagination device. A serosal tissue treatment device, in one embodiment, is adapted to disrupt serosal tissue lying between spaced apart tissue surfaces engaged by the approximating members to promote healing and formation of a serosal-to-serosal bond between serosal tissue surfaces contacting one another in the plication formed during the tissue approximation. The serosal treatment device may utilize one or more mechanical structures, such as a discontinuous or a non-smooth surface structure, to disrupt serosal tissue and thereby promote serosal tissue adhesion. Additionally or alternatively, the serosal treatment device may be operated to facilitate application or administration of an agent that promotes serosal tissue disruption and/or healing in serosal-to-serosal bonds, or to administer a tissue bonding agent that promotes serosal-to-serosal tissue bonds. The serosal treatment device may incorporate an alternative modality for serosal tissue treatment, e.g., by application of heat, RF radiation, ultrasound, electromagnetic radiation, or other types of radiating energy. In one embodiment, the serosal tissue treatment device may be integrated with the approximating members and/or the tissue invagination structure, as described more fully below.
A separate tissue securing or fastening device may be provided for fastening the two adjacent portions of approximated tissue to one another to secure the plication. Suitable devices, such as suturing, stapling and other types of mechanical tissue fastening devices are well known in the art. The tissue fastening device, in one embodiment, is a multi-fire device that is capable of administering multiple fasteners, in multiple positions along a line of approximated tissue, without requiring removal from the abdominal space. Various types of fasteners and fastening devices may be used, as described more fully below.
In another embodiment, an integrated device may be provided for carrying out the tissue invagination and approximation steps, and for optionally treating serosal tissue in the invaginated tissue, while a separate device may be provided for securing the tissue plication. This beneficially eliminates the need for at least one laparoscopic incision and trocar during the procedure. In yet another embodiment, a single multi-functional device is provided that comprises tools capable of invaginating and approximating tissue, optionally treating the serosal tissue to promote a healing response, and for securing the tissue fold to produce the plication. In this embodiment, a single minimally invasive laparoscopic device is provided, thereby minimizing the number of trocars needed to complete the procedure. For example, assuming one access port is needed for the video camera and one is needed for a grasper, liver/organ manipulator, dissector, or other tissue manipulation device, the procedure may be completed using only 3 trocars. In another embodiment, the single integrated minimally invasive laparoscopic device may be optionally configured having one or more extra service channels through which the camera and other tissue manipulation devices may be inserted, thereby allowing the entire gastric reduction intervention to be completed using only a single access port. In comparison, 5 or more laparoscopic incisions are commonly needed for the Roux-en-Y procedure. Using a multifunctional tool of the present invention, the gastric reduction procedure is less invasive, requires less time to complete and therefore reduces the risks attendant any intervention, speeds patient recovery, and reduces the overall cost of treatment.
Other embodiments of medical devices of the present invention further incorporate novel tool configurations detailed below, that enable and simplify the steps of securing the one or more tissue folds created in order to produce the one or more plications in the wall of the gastrointestinal tract. In one embodiment, means are provided for delivering individual tissue anchors comprising a securing assembly. In yet another embodiment, individual tissue anchors are reconfigured from a first state (e.g. a configuration used for delivery) to a second state (e.g. a deployed configuration). In yet another embodiment, the deployed securing assembly is configured to penetrate only the serosal and muscularis tissue layers, without penetrating completely through the wall of the gastrointestinal tract.
According to the brief summary provided above, it is apparent that methods and devices of the present invention offer several advantages over the prior art. For example, because the one or more gastric tissue plications produced may achieve substantial therapeutic gastric reductions, it is possible to obtain weight loss results comparable to prior art procedures using an interventional alternative that may be performed using minimally invasive laparoscopic or non-laparoscopic abdominal access procedures, while at the same time avoiding a variety of complications associated with malabsorption, the long-term presence of restrictive devices within the body, leakage or failure at transgastric anastomosis or anchoring sites, permanent restructuring of the gastrointestinal tract, and the like. Gastric reduction procedures of the present invention are therefore simpler, easier to perform, and safer that prior art interventional methods. In addition, the methods of the present invention, which may optionally be performed substantially or entirely extragastrically, may be carried out by conventionally skilled laparoscopic surgeons, requiring minimal specialized training to achieve substantial gastric volume reduction and effective weight loss results, while significantly reducing the risk of injury or damage to neighboring organs and other complications. This is a significant advantage compared to prior art transesophageal endoluminal interventional methods.
While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments are shown and explained, it is to be understood that persons skilled in the art may modify the embodiments herein described while achieving the same methods, functions and results. Accordingly, the descriptions that follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope.
FIG. 1A-1B2 schematically illustrates an interventional method according to one embodiment of the present invention, wherein FIGS. 1A-1A3 shows the pre-procedure tissue configuration; and FIGS. 1B-1B2 shows the post procedure tissue configuration.
FIGS. 2A-2E2 schematically illustrate an exemplary interventional gastric reduction method according to one embodiment of the present invention.
Methods of the present invention provide effective reduction of the functional volume of the gastrointestinal tract (e.g., stomach) using an extragastric gastroplasty procedure. In this procedure, a portion of the gastrointestinal tract is reconfigured by invaginating and approximating tissue to form one or more tissue folds, and then securing the one or more tissue folds in order to produce one or more plications. While the following detailed descriptions refer in general to reducing the functional volume of the gastrointestinal tract, the stomach in particular, it should be recognized that the invaginaton, approximation and securing methods of the present invention may be used on other body tissues and for other interventional purposes, within the scope of the present invention.
Gastric reduction procedures of the present invention generally access the gastrointestinal tract via the abdominal cavity. This is most typically accomplished using conventional laparoscopic techniques wherein the patient is anesthestetized, one or more small incisions are made through the abdominal wall, and a pneumoperitoneum is established by insufflation, thereby allowing the insertion of imaging devices and one or more interventional instruments through laparoscopic ports, also known as trocars. Alternatively, methods of the present invention may also be carried out when access to the abdominal cavity and gastrointestinal tract is obtained using even less invasive, non-laparoscopic techniques. A variety of such non-laparoscopic techniques may be utilized within the scope of the present invention, typically involving grasping and lifting, or otherwise retracting the abdominal wall to create sufficient working space within the abdominal cavity, without the need for insufflation. Alternatively, the methods and devices of the present invention may also be adapted for flexible endoscopic use, allowing access to the abdominal cavity and external surface of the gastrointestinal tract to be obtained by first entering the body through a natural orifice (e.g. esophagus, anus or vagina), then penetrating through the wall of an anatomical lumen into the abdominal cavity.
Once abdominal access has been obtained, the medical professional employs one or more cameras or other imaging devices, along with a variety of tools known in the art, to manipulate the internal organs and/or tissues to expose the region of the gastrointestinal tract of interest. In preferred embodiments of the present invention, at least the anterior portion of the stomach is exposed sufficiently to allow for its reconfiguration. This may require dissection and/or removal of at least a portion of the omentum, and it may require lifting and/or partial retraction of the liver, both of which are relatively simple interventional steps that are well known in the art. The subsequent reconfiguration and gastric reduction may then be performed, preferably using the devices and systems of the present invention, which are described in detail below.
In a preferred embodiment of the present invention, a single fold and plication is produced in the above described manner and location, as illustrated in
In
In
After the tissue has been approximated to create the tissue fold 180 as described above, and tissue shoulders 195 have been brought together into proximity of one another, a tissue fastener 185 is then applied at that location to secure the plication 190, as shown in
The tissue engagement, approximation and fastening steps are repeated any number of times as is necessary to completely form and secure the one or more tissue plications. In the example provided herein, the final result is shown schematically in
For convenience, the procedure may progress sequentially in one direction along the length of the intended fold, as illustrated in
At each of one or more locations along the length of the intended fold, the tissue is invaginated, approximated and secured with one or more tissue fasteners before moving to the next location. In one embodiment, a device may be provided that allows simultaneous or sequential placement of multiple tissue fasteners while the invaginating and approximating tool is placed and held at one location. Alternatively, in another embodiment, a device may be provided that allows placement of a single tissue fastener along a substantial length, or even along the complete length, of the tissue fold, while the invaginating and approximating tool is held at one location.
According to one embodiment of the present invention, prior to securing the approximated tissue to produce the one or more plications, at least a portion of the surface area of the serosal tissue enfolded by the one or more plications is selectively treated to promote serosal-to-serosal tissue bonding. There is a considerable body of clinical knowledge regarding the mechanisms of abdominal adhesion formation, and a variety of methods known to those skilled in the art may be used to selectively treat the serosal tissue surfaces to promote tissue adhesion of the serosal tissue layers adjoining one another inside the tissue fold forming the plication. Examples of such tissue treatments include but are not limited to mechanical disruption methods (e.g. abrasion), energy deposition methods (e.g. RF, ultrasonic, electromagnetic, and the like), methods involving treatment using liquids (e.g. chemicals, pharmaceuticals, adhesives, etc.) and methods involving treatment using solids (e.g. powders, films, etc.). Regardless of the tissue treatment method used, an important aspect of this embodiment is that serosal tissue bonding or adhesion is promoted over a sufficiently large interfacial surface area across the approximated tissue boundary within the plication to achieve a strong and durable serosa-to-serosa bond post-operatively.
In yet another embodiment of the present invention, additional tissue fasteners may also be optionally applied while the tissues are being approximated to aid in forming, stabilizing and/or providing additional strength to the resulting tissue plication, as well as to further promote the formation of a strong serosa-to-serosa bond inside the plication. For example, as illustrated in the enlarged cross sectional view X-X shown in
In yet another embodiment of the present invention, more than one tissue plication may be produced according to the previously described methods. For a variety of reasons, it may be advantageous in some cases to produce two or more plications. These advantages may include, for example, allowing a greater range of effective volume reductions in the stomach to be achieved, allowing smaller laparoscopic devices to be used, allowing the surgeon more flexibility in positioning of the plications relative to the stomach or surrounding organs, for reducing the maximum forces generated on the individual securing means, and so on.
Interventional Devices and Systems
Interventional devices for performing methods of the present invention are described herein that, taken together, comprise systems of the present invention. The devices and systems of the present invention provide the ability to carry out the above described volume reduction procedures in a safe, efficient and minimally invasive manner, which is difficult or impossible to accomplish using prior art devices. It will be appreciated that while the devices and systems of the present invention are described below with respect to their use in gastric reduction methods of the present invention, they have utility and may be used for general approximation and fastening of other types of soft body tissues and in other types of interventional procedures as well.
In general, at least one handheld interventional instrument is provided having one or more integrated tool assembly(ies) adapted for placement at an interventional site, such as within the abdominal cavity, in combination with one or more actuator(s) positioned remotely from the tool assembly and providing operator control of the tool assembly(ies) during an intervention. The tool assembly is preferably capable of engaging tissue at two or more separate locations, and then invaginating and approximating tissue to effectively create a tissue fold between the tissue engagement locations. In one embodiment, the tool assembly comprises at least two tissue engagement mechanisms (e.g. clamps, grippers, forceps, jaws, hooks, barbs, vacuum ports or the like, or combinations of these mechanisms) positioned at or in proximity to the distal end of an elongate shaft of a laparoscopic device. The tissue engagement mechanisms may be positionable by means of a remote actuator, or they may be mounted on supporting members that may be positionable to engage desired tissue sites. Using this device, the laparoscopic shaft is positioned within the abdominal cavity, and the distal end of the shaft is positioned at a first desired tissue engagement site, where a tissue engagement mechanism is engaged with the tissue. The operator then repositions the shaft by moving it to a second location, dragging the first engaged tissue location toward the second, and thereby approximating the first and second tissue locations. The approximated tissues may then be fastened to one another to secure the plication using fasteners applied with an independent device or an integrated assembly of the tissue approximation device.
In another embodiment, a first tissue engagement mechanism may be positioned at the distal end of the elongate shaft of a laparoscopic device, while a second tissue engagement mechanism may be positioned at the distal end of an extendible member that can be manipulated by an operator to move away from the axis of the device shaft to position the second tissue engagement mechanism at a second location, remote from the distal end of the device. The extendible member may be substantially rigid, or it may be flexible, or it may have both substantially rigid and flexible portions, and it may either be deployable from inside the elongate shaft of the laparoscopic device, or attached near the distal end of the shaft by mechanical means. In one embodiment, a proximal end of an extendible member is attached near the distal end of the elongate shaft using a pivot connection, a hinge connection, a flexible connection, or the like, that allows the extendible member to be operatively and selectively actuated to move its distal, operating end (comprising a tissue engagement member) away from the axis of the laparoscopic device to engage tissue. In operation, the distal end of the shaft of the laparoscopic device is first positioned at a desired tissue surface and the tissue is engaged at a first site. The extendible member and its associated tissue engagement mechanism is then deployed, extending away from the axis of the shaft to independently engage tissue at a second location. The extendible arm and its associated tissue engagement mechanism is then retracted, under control of the operator, and the second engaged tissue location is drawn in toward the axis of the shaft and thereby approximated adjacent the first engaged tissue site. An invaginated tissue fold projecting away from the distal end of the device and into the gastrointestinal space is created as the two tissue sites are drawn together and approximated.
In other embodiments, described in detail below, two or more such extendible members are provided on an interventional device, each extendible member having at least one tissue engagement mechanism, generally (but not necessarily) positioned at its distal end, such that the engagement of tissue at multiple separate locations can be accomplished without requiring the shaft of the laparoscopic device itself to contact the tissue surface. The extendible members may be actuated and positioned separately and independently of one another, or they may be actuated and positioned simultaneously and in coordination with one another. Operation of this type of device involves deploying each of the extendible members and their associated tissue engagement mechanisms, independently or in coordination, to contact the tissue engagement mechanisms at two locations on the tissue, then approximating the engaged tissue to form an invaginated tissue fold by moving at least one of the extendible members toward the other and, in some embodiments, by moving multiple extendible members toward a central location, thereby approximating the engaged tissue substantially near the distal end of the device (or along a longitudinal axis extending therefrom).
Another embodiment that provides an alternative to using two or more extendible members to engage tissue involves the use of tethers. In this case, the distal end of the shaft of a laparoscopic instrument may be positioned to sequentially engage tissue at each of two or more locations using releasable tissue engagement mechanisms mounted on retrievable tethers, wherein each tissue engagement mechanism, after being engaged in tissue, is released from the end of the shaft of the laparoscopic instrument, yet remains connected to the instrument by a tether (e.g. a suture, wire, or the like). This allows the instrument to be moved freely between each desired tissue engagement location to deploy two or more tissue engagement mechanisms at different tissue sites. Subsequently, the tethers may be selectively retrieved, or retracted back toward the shaft of the device to draw the engaged tissue sites toward one another, thereby approximating the tissue sites. Alternatively a cinching member through which the flexible tethers pass may be slid distally down the length of tethers, causing the engaged tissue locations to move toward each other, thereby approximating tissue. Retrieval of the tether(s) and/or operation of the cinching member(s) is under the control of an operator using associated actuation mechanisms.
It will be appreciated that methods and systems of the present invention may be used in connection with other diagnostic and therapeutic methods and devices. Methods of the present invention may thus be used, for example, in connection with conventional diagnostic and therapeutic methods and may involve the administration of diagnostic or therapeutic agents, agents for visualizing the interventional site, and the like. Similarly, device components of the present invention may be used in connection with various procedures and agents that are known in the art. Certain device components that are intended for introduction to the interventional site, such as tissue engagement mechanisms, probes, extendible members, fasteners, and the like may be administered in association with various types of diagnostic or therapeutic agents, or may be coated or impregnated with such materials. Suitable agents may include clotting agents, healing agents, hydrophobic and/or hydrophilic materials, agents promoting lubricity, and the like.
The degree of extension of the extendible members, and the spacing 521 between distal ends 524 of extendible members 520 may be governed by the degree of deployment out of shaft 502. In some embodiments, both the degree of extension of distal ends 524 from the shaft 504, indicated as longitudinal spacing 519, and the distance between extended distal ends 524 are selectably controllable by the operator to facilitate tissue engagement at desired locations, and to facilitate the creation of a tissue plication of the desired dimensions, thereby producing the desired gastric volume reduction.
Tissue approximating device 500 illustrated in
Illustrative operation of a tissue approximation device 500 illustrated in
In another embodiment, extendible members 520 are designed to be released from the collapsed state to the expanded state in a self-actuating manner, automatically achieving the desired tissue engagement configuration when extended out of working channel 504 beyond the end of elongate tubular member 502. Such self-actuating motions can be achieved by various methods known in the art. For example, in one preferred embodiment of the present invention, extendible members 520 are produced from a highly elastic material (e.g. spring steel, hardened stainless steel, a shape change material such as a superelastic NiTi alloy, superelastic polymer, or the like) and are formed during manufacturing into the desired final deployed shape by mechanical and/or thermomechanical processing means known in the art. Extendible members 520 are then biased (i.e. mechanical potential energy is stored, similar to a pre-loaded spring) by elastically deforming and loading them into working channel 504 to thereby provide the device in its collapsed state. As extendible members 520 are then pushed out of working channel 504 during deployment, the stored energy is released and extendible members 520 automatically return to the pre-determined shape desired for subsequent tissue engagement when brought into contact with the tissue surface. It will be appreciated that different assemblies of extendible members having different dimensions, different curvatures, different elastic properties, and the like may be provided for use in a tissue approximating device of the present invention and an operator may select an appropriate extendible member assembly having the desired dimensions and extension properties and install the desired assembly in the working channel prior to an intervention.
In yet other embodiments, deployment of extendible members 520 from the collapsed state to the expanded state may be accomplished, by means of an actuating mechanism, by any combination of manual pushing to cause expansion and self-actuating expansion mechanisms. Factors that may be adjusted to optimize the above described reconfiguration and deployment motions include, for example, the cross sectional shape, curvatures, mechanical properties, length, etc. of extendible members 520. It should also be obvious to those skilled in the art that, within the scope of the present invention, other mechanical actuation mechanisms of providing the desired reconfiguration and deployment to adjust the extendible members from the collapsed state to the expanded state may also be used. Such actuating mechanisms may comprise, for example, springs, levers, cams, gears, linkages, and the like may be used.
Distal ends 524 of extendible members 520 each incorporate one or more tissue engagement means configured to allow targeted tissue surface 535 to be selectively and controllably engaged by the device when actuated by the operator. Various tissue engagement mechanisms are known in the art may be employed to provide secure and robust tissue engagement having sufficient strength, for example, to allow the tissue to be subsequently pulled or otherwise manipulated without disengaging, slipping or tearing. Tissue engagement mechanisms that may be used include, for example, hooks, barbs, grippers, teeth, clamps, jaws, clips, t-tags, and the like. According to one embodiment of the present invention, as shown in
While more complicated mechanical tissue engagement means may be employed in accordance with the present invention (e.g. hinged jaws, mechanical clamps, forceps, grippers, vacuum actuated mechanisms, and the like) there are several advantages to the embodiment described above, and similarly designed self-actuating embodiments. One advantage, for example, is that it is a simple, single component design having low production cost. Additionally, successful operation of this device is not particularly dependent upon operator technique (i.e. no sophisticated hand motions or unusual device manipulations are required), successful operation instead being more dependent upon device design factors that control, for example, the directions and magnitudes of the forces generated by extendible members 520 during the pushing and pulling motions involved in deployment and/or retraction of the device. Examples of design factors that may be optimized in the self-actuating design embodiments of the present invention include the shape, physical dimensions, geometrical angles, surface finish, and the like, of extendible members 520, distal ends 524, tissue hooks 526, and sharpened points 528, as well as their materials of manufacture and mechanical properties.
In one embodiment, extendible members 520 have a non-circular, generally flattened cross section to effectively increase the lateral (i.e. out of plane) stiffness when extendible members 520 are extended. Examples of suitable non-circular cross sectional shapes include square cross sections, rectangular cross sections, triangular cross sections, arcuate cross sections, hemispherical cross sections, oblong or flattened cross-sections, and combinations of the foregoing. The cross sectional shape, physical dimensions, mechanical properties, and so on, of extendible members 520 may be designed having variations along their length to provide improved deployment, tissue engagement or retraction characteristics.
In another embodiment, extendible members 520 have a pre-determined shape when in the expanded state that includes at least two bends having radii of curvature in substantially opposing directions. Such a shape, as illustrated in
After tissue has been securely engaged by approximating tool assembly 508, as described above, the operator actuates device 500 to initiate the tissue invagination and approximation step, wherein the desired tissue fold is formed by bringing serosal tissue surfaces between the engaged tissue sites in contact with each other, so that the mucosal tissue surface 540 forms a plication extending into the gastrointestinal lumen.
The retraction of extendible members 520 causes tissue engagement locations 530 to be gradually pulled inward toward longitudinal axis 518. In one device embodiment that incorporates a pushing member, the operator may selectively and independently actuate pushing member 522 from within handle assembly 506 (i.e. using slider 512) as the tissue engagement locations are drawn toward one another. The pushing member is extended distally along longitudinal axis 518 to contact and push against the tissue, e.g. with pushing force 532, at a location between tissue engagement points 530. This promotes tissue invagination in the desired manner while the engaged tissue is approximated, as shown in
The combination of extendible members and a pushing member in devices of the present invention, enabling the combined action of pulling tissue engagement points 530 toward one another via retraction of extendible members 520 while simultaneously having the user selectable option to push against the tissue between tissue engagement points 530 with pushing member 522 promotes creation of a uniform and consistent tissue fold, as shown in
In other embodiments of the present invention, additional user selectable controls may be optionally provided within handle assembly 506. For example, controls may be optionally provided to allow the surgeon to adjust the span 521 of extendible members 520 when in the expanded state, and the distal extension distance 505 and pushing force 532 of pushing member 522. Independent, operator controlled actuation mechanisms may be provided for each of the more than one extendible member 520, and the actuation mechanisms may control the speed and force that may be used to retract extendible members 520, as well as other operating parameters. It should also be recognized that the actuation means described above are exemplary, and that other actuation and control mechanisms that are known to those skilled in the art may be used and are considered within the scope of the present invention. For example, actuation may be accomplished manually by one or more various means known in the art (e.g. triggers, levers, buttons, knobs, or the like) or by one or more various powered means known in the art (e.g. AC or DC electric motors, compressed gas, vacuum, or the like), or by any combination of the foregoing.
As described previously, according to one embodiment of the present invention, it is desirable to selectively and therapeutically treat the serosal tissue layer to promote bonding or adhesion of the serosal layers that abut one another within the plication. This may be accomplished using device 500 in various ways. For example, in one embodiment illustrated in Figures SC-SF, the distal tip and/or lateral surfaces of pushing member 522 may be used to mechanically disturb and disrupt the thin layer of mesothelial cells that form the outermost covering of the serosa. Since the layer of mesothelial cells covering the serosa is quite thin and fragile, it is easily disrupted, and pushing member 522 may be scraped, dragged or otherwise frictionally moved across the surface of the tissue to produce the desired disruption. To further aid in disrupting the serosal tissue surface and promote tissue adhesion, pushing member 522 may be modified, for example, by incorporating roughening features 523, illustrated as protuberances in Figures SC-SF. As will be obvious to those skilled in the art, a wide variety of such roughening features and arrangements may be used to accomplish the desired serosal treatment, for example, ridges, bumps, bristles, teeth, scales, serrations, and the like may be used.
The optional serosal treatment described above may be carried out before the tissue fold is formed, after the tissue fold is formed but prior to the securing means is applied, after the tissue fold is formed and the securing means is applied, or any combination of the foregoing. For example, prior to actuating extendible members 520 to engage tissue, the distal end of pushing member 522 may be moved across substantially the identified area of serosal tissue to be included within the tissue fold in a sweeping or painting type of motion. Alternatively, the lateral surfaces of pushing member 522 contact and slide across the opposing serosal tissue surfaces of the tissue fold when pushing member 522 is retracted from within the tissue fold (as is evident in
In another serosal treatment embodiment, ports may be provided near the distal tip of shaft 502 and/or along pushing member 522 such that, when the shaft and/or pushing member lumen is connected to a supply of source material (e.g., a liquid reservoir located within or attached to the proximal handle assembly 506), the device provides controlled dispensing of a chemical or therapeutic agent (e.g. liquid, gas, solid powder, solid film, or combinations thereof) onto the tissue surface that promotes tissue bonding and adhesion. Alternatively, the distal tip of shaft 502 and/or pushing member 522 may optionally incorporate an energy deposition mechanism capable of delivering energy to the target tissue. Exemplary energy deposition mechanisms include, for example, components capable of RF cauterizing, electro-cauterizing, ultrasonic vibration, and the like.
According to the present invention, once the tissue has been approximated and the desired tissue fold has been created as described above, fasteners are then applied to secure the plication. This is most conveniently accomplished while approximating tool assembly 508 is held in place by the operator to maintain the tissue in a stable, folded configuration. In one embodiment, a separate interventional instrument may be introduced through a separate trocar, and its distal tip may be positioned immediately adjacent approximating tool assembly 508. This instrument is then actuated to apply a fastener directly into and across the shoulders of the approximated tissue forming the tissue fold, thereby securing the plication. In this embodiment illustrated in
Accordingly, the laparoscopic interventional stapler shown in
In another embodiment of the present invention, the tissue approximating and fastening functions described above requiring the use of two separately operable handheld interventional instruments are combined into a single multi-functional device having one or more integrated tools capable of invaginating and approximating tissue to create a tissue fold, as well as one or more integrated tools for applying fasteners to secure the plication. By combining these functions conveniently in a single handheld device, the overall procedure is simplified, and it can be performed without requiring extensive operator training Furthermore, the need for one laparoscopic access port is eliminated, which provides a significant advantage.
A close up cross sectional view of the distal end of device 700 is shown in
Device 708 additionally incorporates pushing member 722, which is operatively connected to slider 712, such that when slider 712 is pushed from its proximal (fully retracted) position, the distal end of pushing member 720 moves along longitudinal axis 718, thereby extending out of working channel 704 a user selectable distance 705 beyond the end of elongate tubular member 702. The pushing member facilitates invagination and folding of the tissue between the engaged portions and may, additionally, function to disrupt the serosal tissue surface, or facilitate application of a tissue bonding promoter, as described above. Operation of the pushing member may be independent of, or coordinated with, extension and retraction of the extendible members and tissue engagement mechanisms.
The steps of deploying device 700, engaging tissue, and invaginating and approximating tissue to create a tissue fold are substantially similar to what was previously described with reference to
As illustrated in
Actuating tube 822 is inserted into the proximal end of outer tube 820 and terminates at its distal end at a location proximally from the distal end of outer tube 820. In this manner actuating tube 822 is capable of sliding longitudinally within outer tube 820 from its proximal most (i.e. pre-deployed) position to a distal most (i.e. deployed) position. The outer diameter of actuating tube 822 is slightly less than the inner diameter of outer tube 820 such that a small gap exists between the tubular walls. This substantially eliminates sliding friction between actuating tube 822 and outer tube 820, except at a small area of intimate frictional contact established between the tubes (described below). Inner tube 824 fits within actuating tube 822 and is also fixedly connected to outer tube 820 near the distal end of device 800, as described below. Located inside inner tube 824 is working channel 826 within which proximal gasket 827 is mounted. As will be described later, the purpose of proximal gasket 827 is to support and frictionally hold in position a complementary medical device that may optionally be inserted within working channel 826 of inner tube 824 during operation of device 800, as will be described later.
Tube assembly 815 therefore consists of a concentric tube configuration where actuating tube 522 is slidably positioned between the walls of outer tube 820 and inner tube 824, which are fixedly connected to one another at their distal ends. Outer tube 520, actuating tube 822 and inner tube 824 are all manufactured from suitable biocompatible materials, typically polymers and/or metals, that are known to those skilled in the art for common usage in either re-usable or single patient use medical devices. The tubes are 30 typically substantially rigid, although they may be provided with a designed degree of elastic flexibility, or they may optionally incorporate articulation means (e.g. using mechanical methods well known in the art) along their length, which can prove useful in certain surgical situations.
Fixedly connected to the proximal end of outer tube 820 is distal grip 828, and fixedly connected to the proximal end of actuating tube 822 is proximal grip 830. When proximal grip 830 is moved toward distal grip 828 by the operator, actuating tube 822 slides distally between the walls of outer tube 820 and inner tube 824. Likewise, when proximal grip 830 is moved away from distal grip 828, actuating tube 822 slides proximally between the walls of outer tube 820 and inner tube 824. Distal grip 828 and proximal grip 830 can have the same or different shape, and are designed based on ergonomic considerations to allow easy gripping and secure holding by the hand of the operator, typically with the forefingers positioned on distal grip 828 and thumb positioned on proximal grip 830.
It should be recognized by those skilled in the art that various other types of grips may be used according to the present invention to allow the operator to affect the same type of relative sliding motion between actuating tube 822 and outer tube 820. For example, knobs, rings, grooves, levers, handles, and the like may be used. Distal grip 828 and proximal grip 830 may be produced from any polymeric or metallic material commonly known in the art for usage in either re-usable or single patient use medical devices. In other embodiments that will be obvious to those skilled in the art (not shown), one or both grips may be replaced by other means for engaging outer tube 820 and actuating tube 822, wherein said engagement means may be operatively connected to an alternative actuation mechanism (e.g. trigger, lever, pi votable handle, scissors grip, or the like) that may optionally be positioned farther away from the proximal end of tube assembly 815. In this manner, when said alternative actuation mechanism is operated by the user, substantially the same type of longitudinal sliding motion between actuation tube 822 and outer tube 820 is effected. Said alternative actuation mechanisms may be operated by user hand power, or they may be powered partially or entirely using an external power source such as an AC or DC electromagnetic motor, compressed gas, ultrasonic motor, or the like.
Located between distal grip 828 and proximal grip 830, and positioned outside actuating tube 822 is spring 832. Spring 832 is held in place by, and pushes against, distal grip 828 at recess 834, and also pushes in the opposite direction against the distal most surface 835 of proximal grip 830. Spring 832 is designed to operatively maintain a specified biasing force along longitudinal axis 825 that acts to push actuating tube 822 toward its proximal most position relative to the position of outer tube 820 when the device is in the pre-deployed configuration. When spring 832 is in its maximum allowable expanded state (i.e. device 800 is in the pre-deployed configuration), flange 836 located at the proximal end of deployment tube 824 comes into contact with the bottom of recess 838 located on the proximal side of proximal grip 830, thereby limiting the extent of proximal motion of actuating tube 822.
Moveable arms 818 can be made from any substantially flexible material and can be produced having a wide variety of shapes. Preferably moveable arms 818 have a noncircular cross section in order to minimize space requirements in the pre-deployment configuration, while also providing sufficient lateral rigidity (i.e. significant resistance to undesirable out of plane bending and rotation when in the deployed configuration). In device 800, moveable arms 818 have a rectangular cross section as shown, however it should be obvious to those skilled in the art that other cross sectional shapes can be used to provide the same functionality, for example, square cross sections, triangular cross sections, arcuate cross sections, hemispherical cross sections, and combinations of the foregoing may be used. The cross sectional shape, physical dimensions, mechanical properties, and so on, of moveable arms 818 may also be designed having variations along their length in order to provide improved deployment, tissue engagement or refraction characteristics.
Each of said moveable arms 818 is configured at its distal end with arm tip 842, wherein each said arm tip 842 includes one or more elements whose working function is to controllably and selectively grasp, grab, grip, pierce, hold or otherwise engage tissue. In the example shown, arm tips 842 incorporate sharpened tissue hooks 844. A variety of other configurations and mechanisms are possible within the scope of the present invention for engaging tissue at the distal end of moveable arms 818. For example, teeth, barbs, jaws, graspers, forceps, clamps and the like may be used, the choice of which may depend upon the nature of the tissue to be engaged, desired depth of penetration, and so on. In the predeployed configuration (
Inner tube 824 has working channel 826 therewithin that provides a means for inserting and holding in position a variety of interchangeable and complementary tools (e.g. a device for manipulating or treating tissue, a device for applying fasteners, etc.) that, along with device 800, further comprise the systems of the present invention. Working channel 826 is designed to accept any instrument having a diameter that is smaller and within a specified size range. In the embodiment shown, for example, working channel 826 is designed to accept an instrument having a diameter from approximately 3.5 mm to 5.5 mm. Located inside working channel 826 are one or more retaining means capable of holding the inserted instrument in a desired longitudinal position, preferably allowing said position to be adjusted by the user prior to or during use. In the example shown, the retaining means is provided as an proximal gasket 827 (
Also located inside working channel 826 are optional alignment means that may engage with optional alignment features provided on the outside of an inserted instrument, to ensure a desired alignment of the inserted instrument is maintained relative to the orientation of device 800. In the example shown, alignment groove 860 located within the inside wall of inner tube 824 is configured to slidably engage with a suitably designed male feature (e.g. a protruding tab, nipple, pin, or the like) that may optionally be included on the exterior of the shaft of the medical device to be inserted. This allows for keyed insertion and longitudinal sliding to take place, but prevents undesirable rotation of the inserted device inside working channel 826 once inserted. This system feature may be important in a variety of situations, for example, a fastener applicator inserted into working channel 826 may need to be aligned in a specific orientation relative to the position of moveable arms 818 in order to properly secure the created tissue fold and produce a plication, according to the methods of the present invention. When it is desirable for the surgeon to change the overall orientation of the instrument relative to the target tissue, tube assembly 815 may be configured to rotate to any user selectable orientation relative to handle assembly 805; in such a configuration, the inserted instrument rotates along with tube assembly 815 thereby maintaining proper functional alignment of the instruments regardless of the user's hand position.
At the distal end of device 800 is end cap 850 which matingly connects to the inner wall of outer tube 820 and the outer wall of inner tube 824, thereby serving to fixedly connect these components together. End cap 850 further incorporates means for supporting, guiding and maintaining proper alignment of moveable arms 818 during actuated sliding, corresponding to the desired alignment between actuating tube 822 and outer tube 820. In the example shown, end cap 850 is produced from molded polymeric material and includes longitudinal slots 852 substantially matching the rectangular cross section of moveable arms 818 and through which moveable arms 818 are inserted during assembly.
Fixedly or removeably connected to end cap 850 is optional tissue configuration element 855 that is intended to guide, position and shape tissue that is approximated during use of device 800 as moveable arms 818 are retracted and the engaged tissue is drawn close to the distal end of tube assembly 815. In its simplest form, optional tissue configuration element 855 is provided as a pair of arms extending distally from end cap 850, defining a U-shape or V-shape (the example provided in
As described previously, device 800 is actuated by moving proximal grip 830 toward distal grip 828, thereby compressing spring 832. This causes actuating tube 822 to slide distally between outer tube 820 and inner tube 824, and moveable arms 818 thereby extend beyond the distal end of tube assembly 815, as shown in
In the deployed configuration, each of moveable arms 818 are reconfigured such that arm tips 842 are separatively spaced and positioned on opposite sides of longitudinal axis 825. Both the longitudinal positioning 862 and spacing 864 of arm tips 842 are selectably controlled by the user to facilitate the desired subsequent tissue engagement, up to the limit of full deployment when proximal grip 830 has been pushed together against distal grip 828 to compress spring 832 to the maximum allowable amount. Devices of the present invention may be designed to approximate tissue over a variety of size ranges, where longitudinal positioning 862 and spacing 864 are primary design factors that can be adjusted based on the intended medical mission. For use according to the methods of the present invention, it has been found that longitudinal positioning 862 is preferably between 0.5 cm and 20 cm, more preferably between 1 cm and 15 cm, and most preferably between 2 cm and 12 cm. Similarly, spacing 864 is preferably between 1 cm and 30 cm, more preferably between 1.5 cm and 20 cm, and most preferably between 2 cm and 15 cm.
During deployment of device 800, moveable arms 818 are designed to be reconfigured from a collapsed state to an expanded state to prepare the device for subsequent tissue engagement steps. In one preferred embodiment, moveable arms 818 are designed to be reconfigured from the collapsed state to the expanded state in a self-actuating manner, automatically achieving the desired tissue engagement configuration when extended out of tube assembly 815. Such self-actuating motions can be achieved by various methods known in the art. For example, in one preferred embodiment of the present invention, moveable arms 818 are produced from a highly elastic material (e.g. spring steel, hardened stainless steel, superelastic NiTi alloy, superelastic polymer, or the like) and are formed during manufacturing into the desired final deployed shape by mechanical and/or thermomechanical processing means known in the art. Moveable arms 818 are then spring biased (i.e. mechanical potential energy is stored, similar to a pre-loaded spring) by elastically deforming and loading them into tube assembly 815 to thereby provide the device in its pre-deployed state. As moveable arms 818 are then pushed out of tube assembly 815 during deployment, the stored energy is released and moveable arms 818 automatically return to the predetermined shape, being the shape of the deployed state (
The operation of device 800 will now be explained in greater detail with reference to the steps used in performing the procedure of the present invention, illustrated in
After tissue is engaged by tissue hooks 844 on arm tips 842, proximal grip 830 is subsequently released and the elastic energy stored in compressed spring 832 produces a longitudinal force 1220 that retracts actuating tube 822 and connected moveable arms 818 proximally toward the original (pre-deployed) configuration. Depending on the spring force available (which may be fixed by the design of device 800 and/or may be adjustable by the user) relative to the required forces for approximating the tissue, proximal grip 830 is moved proximally relative to distal grip 828 using an assisting hand force provided by the user, if desired or necessary. As retraction of moveable arms 818 back into tube assembly 815 begins, tissue engagement locations 1210 and 1215 are gradually pulled inward toward longitudinal axis 825, as illustrated in
Also shown in
As illustrated in
According to one embodiment of the present invention, it is optionally desirable to selectively and therapeutically treat the serosal tissue layer to promote a healing response across the approximated serosal tissue surfaces within the produced plication. In one embodiment, the optional serosal treatment may be carried out before the tissue is approximated to form the tissue fold, as a separate tissue surface preparation step. For example, an independent surgical instrument designed for treating the serosa to promote a healing response may be introduced into the abdominal cavity through the same trocar used for device 800, or through a different trocar.
In another embodiment of the present invention the optional serosal treatment is carried out during creation of invaginated tissue fold 1225 by mechanically disturbing and disrupting the thin layer of mesothelial cells that form the outermost covering of the serosa. Since the layer of mesothelial cells covering the serosa is quite thin and fragile, it is easily disrupted, e.g. when an instrument is scraped, dragged or otherwise frictionally moved across the surface of the tissue. Consequently, the desired optional serosal treatment may be accomplished with the assistance of device 800 in various ways. For example, with device 800 in the pre-deployed configuration, the distal end of tube assembly 815 itself may be used to mechanically abrade the serosa. Alternatively, the distal tip and/or lateral surfaces of optional pushing member 1222 may similarly be used. To further aid in ensuring adequate serosal treatment occurs, optional pushing member 1222 may further be optionally configured with various means for treating the serosa. In one embodiment, as illustrated in
According to the methods of the present invention, once the desired invaginated tissue fold projecting into the gastrointestinal cavity has been created as described above, securing means are then applied in order to produce a plication. While a variety of prior art fasteners and fastener applicators could conceivably be used for this purpose, various limitations and shortcomings have been encountered. In general, prior art surgical methods involving either cutting of the gastrointestinal lumen or the creation of gastrointestinal tissue folds rely upon the placement of surgical staples or other fasteners through the stomach wall. This necessarily involves the fastener penetrating at least the mucosal and muscularis tissue layers. Unfortunately, the mucosal and muscularis tissue layers are known to be relatively weak and unreliable for securely holding fasteners, and the placement of fasteners through these tissue layers often results in complications or lack of long-term durability. For example, prior art fasteners may produce chronic tissue irritation or result in tearing of tissue near the fastener penetration sites, may undergo post-surgical migration or dislodging, and may fail to heal and/or result in life threatening leakage at transgastric penetrations.
The tissue retaining fasteners of the present invention overcome the above stated problems. These fasteners are designed to be placed extragastrically into gastrointestinal tissue folds created using the tissue approximating devices of the present invention. In some embodiments placement of the tissue retaining fasteners may involve complete penetration through the stomach wall, whereas in other preferred embodiments the fasteners do not involve complete trans gastric penetration. In either case, the tissue retaining fasteners of the present invention are preferably designed to engage and securely hold the thin, tough serosal layer covering the exterior of the gastrointestinal lumen. In this manner, these inventive tissue retaining fasteners thereby provide substantially improved strength, reliability and durability to the plication produced, while avoiding the serious risks associated with transecting the stomach wall, compressing the muscularis tissue layers, or excessively compromising the internal mucosal layer. According to the methods of the present invention, optional treatment of the serosal tissue to promote a healing response results in the formation of a strong serosa-to-serosa bond across the approximated tissue boundary within the plication, providing additional long-term structural support to the extragastrically placed fasteners. As such, the tissue retaining fasteners of the present invention may optionally be produced from a bioabsorbable or dissolvable material designed to disappear after the strong serosa-to-serosa bond has formed, further minimizing the risks associated with long-term fastener implants.
The tissue retaining fasteners of the present invention are designed to accurately penetrate, engage and securely hold invaginated tissue folds created by approximating devices of the present invention, thereby producing strong and durable plications. Minimally invasive fastener applicators of the present invention (described below) are provided that are designed to deliver and deploy these tissue retaining fasteners by operating in conjunction with the approximating devices of the present invention. The approximating devices, fasteners and fastener applicators of the present invention, taken together, comprise systems of the present invention.
According to one embodiment of the present invention, a tissue retaining fastener is shown in
Positioned on at least one tissue contacting surface of each tissue penetrating projection 1310 is one or more tissue retention features, e.g. barb 1320 in
The width of fastener 1300 is established by the width 1330 of cross member 1305. It is desirable that width 1330 be as small as possible in order to minimize the size of the required fastener deployment device and to leave behind the minimum amount of material implanted within the body, while at the same time ensuring the fastener is able to span across the approximated tissue boundary within the created tissue fold to reliably penetrate and engage tissue on opposing sides of said tissue fold. As shown in
In contrast to prior art tissue fasteners, it has rather unexpectedly been found for the case of the extra gastric tissue fasteners of the present invention that improved holding force and performance is achieved when the tissue penetrating projections are made as short as practicable. This is because it is most desirable to provide for complete penetration through the serosal layer and into the underlying muscularis layer, but otherwise not penetrate substantially deeper into the underlying muscularis tissue than necessary as this can reduce the retaining strength of the fastener, lead to inadvertent mucosal penetration, or result in undesirable tissue damage during or after surgery.
Other novel embodiments of the fasteners of the present invention are also illustrated in
As illustrated in
Yet other embodiments of fasteners of the present invention are shown in
As illustrated in
The fastener applicator of the present invention may be designed to deploy one fastener (single fire instrument) or more than one fastener (multi-fire instrument) into tissue by propelling the fasteners out of the distal end of tube assembly 1904 and into target tissue at a predetermined speed and force. In a preferred embodiment, fastener applicator 1900 is a multi-fire device intended for single patient use, and is provided pre-loaded with a plurality of fasteners stored within tube assembly 1904. The speeds and forces at which fasteners are propelled into tissue may be significantly greater than what is typically achieved using prior art fastener deployment mechanisms (e.g. hand powered deformable staples, helical or threaded fasteners, tacks pushed directly into tissue, etc.). In this manner, the fastener applicators of the present invention provide more consistent and controlled fastener deployment and also overcome high tissue insertion forces to ensure complete fastener penetration and engagement within the target tissue. Propelling of fasteners is accomplished in fastener applicator 1900 using a unique spring loaded, impact driver-type mechanism described below.
A detailed cross section of handle assembly 1902 in the pre-fired position is shown in
According to one embodiment of the present invention, in this example a multi-fire device, distal fastener deployment assembly 1906 is shown in the pre-fired position in
The details of operation of distal fastener deployment assembly 1906 during a single firing sequence is illustrated in
In
In other embodiments, described in detail below, the tissue approximating devices of the present invention may optionally incorporate operable means for articulating (i.e. rotating, deflecting or otherwise selectively moving and/or re-positioning) the distal end of 10 the device relative to the position of the elongate tubular assembly. This functionality improves the surgeon's ability to quickly and efficiently engage and approximate the target tissue regardless of the angle of approach (which is dictated by the positioning of the laparoscopic access port or trocar), and thereby not only speeds the procedure but may allow the procedure to be performed using fewer trocars. In certain preferred embodiments, sufficient articulation functionality is provided in the device such that by appropriately placing a single trocar through the abdominal wall the entire method of the present invention can be completed.
One embodiment of an articulating device is shown in
Arm tips 2330 and 2332, each having tissue engagement means 2334 and 2336, respectively, are then placed in proper deployed position for engaging tissue, as described previously. After tissue is engaged, the user again operatively actuates the handle assembly, thereby retracting moveable arm assembly 2320 back into distal tube 2328 (
Other embodiments incorporating operable means for articulating the distal end of the device are illustrated in
According to another embodiment of the present invention, tissue retaining fastener 2600 is shown in the deployed configuration in
In the pre-deployed configuration, fastener 2600 is held within a suitable fastener applicator (described below) in the shape illustrated in
For minimally invasive applications, fastener 2600 preferably has a relatively small width 2635 such that it can be held within the smallest possible fastener applicator. Width 2635 is therefore preferably less than about 12 mm, more preferably less than about 8 mm and most preferably less than about 5 mm. The length 2640 of tissue penetrating members 2610 limits the final size of the loop formed by the deployed fastener. Length 2640 is preferably between 5 and 50 mm, more preferably between 8 and 30 mm, and most preferably between 10 and 20 mm. An unique aspect of this self-expanding and self-actuating fastener design is that the size of the loop 2622 in the final deployed configuration (
During the use of a fastener such as fastener 1600 for the purpose of extragastrically producing a plication by securing invaginated tissue folds created by approximating stomach tissue, according to the methods of the present invention, it is possible to place the fastener in either configuration shown in
An alternative and preferred fastener configuration possible with fasteners of the present invention is shown in
Detailed close up distal end views showing two different embodiments for deploying fasteners 1600 into approximated tissue are shown in
An alternative embodiment for distal tube assembly 2925 is shown in
Although the tissue approximation devices, tissue fasteners and fastener applicator devices comprising the systems of the present invention are illustrated above (e.g.
The use of the above described devices and systems for carrying out the surgical procedure of the present invention will now be described in greater detail.
An alternative embodiment of a fastener of the present invention is illustrated in
As shown in
Claims
1. A method for manipulating tissue, comprising: accessing an external surface of a wall of the gastrointestinal tract; engaging at least two tissue sites spaced apart from one another on the external surface of the wall of the gastrointestinal tract, thereby providing at least two engaged tissue sites; manipulating each of the at least two engaged tissue sites to form a tissue shoulder at each engaged tissue site; approximating the tissue shoulders toward one another and moving the tissue shoulders in proximity to one another to form a tissue fold extending into an internal gastric space; and securing the tissue shoulders to one another by applying a tissue fastener, thereby securing the tissue fold.
2. The method according to claim 1 wherein the tissue fastener is selected from the group consisting of sutures, staples, screws, tacks, clips, hooks, clamps and t-tags.
3. The method according to claim 1, wherein the steps of engaging, manipulating, approximating and securing are repeated a plurality of times to extend a dimension of the tissue fold, wherein the dimension is selected from the group consisting of a length dimension and a depth dimension.
4. The method of claim 1, wherein an interior surface of the wall of the gastrointestinal tract is not contacted or penetrated during the steps of engaging, manipulating, approximating and securing tissue.
5. A device for engaging, approximating and fastening tissue comprising: tool assembly adapted for insertion into a body cavity and having at least two extendible members adjustable between a pre-deployed, insertion condition and a deployed extended condition, each of the extendible members comprising at least one associated tissue engagement mechanism for securely engaging tissue; an actuating mechanism adapted for reversibly positioning at least one of the two tissue engagement mechanisms spaced apart from another tissue engagement mechanism; an integrated tool configured to deploy a plurality of tissue retaining fasteners sequentially for fastening engaged and approximated tissue; and a plurality of tissue retaining fasteners retained in the device.
6. The device according to claim 5, additionally comprising a cartridge loaded with the plurality of fasteners and a mechanism for feeding fasteners from the cartridge to the integrated tool.
7. The device according to claim 5, additionally comprising a proximal handle assembly, wherein the actuating mechanism adapted is located on the handle assembly, and the handle assembly additionally comprises a fastener deployment actuating mechanism adapted to deploy the tissue retaining fasteners.
8. The device according to claim 5, wherein the actuating mechanism is adapted for reversibly positioning at least two tissue engagement mechanisms.
9. The device according to claim 5, wherein the tissue engagement mechanisms are selected from the group consisting of hooks, barbs, grippers, teeth, clamps, jaws, clips, and t-tags.
10. The device of claim 5, additionally incorporating a selection feature allowing user-selection of a distance of separation between the tissue engagement mechanisms when the extendible members are in the deployed extended condition.
11. The device of claim 5, additionally comprising a mechanism for releasably holding the at least two extendible members in the pre-deployed, insertion condition.
12. A device of claim 5, wherein at least one extendible member is configured to provide user control of directions and magnitudes of forces generated on the tissue during deployment and/or retraction of the device.
13. A device according to claim 5, wherein the extendible members are substantially rigid, or are flexible, or have both substantially rigid and flexible portions.
14. A device of claim 5, wherein the tissue retaining fasteners are deformable staples, and the integrated tool comprises a mechanism for feeding, forming and releasing the staples.
15. A method for forming and securing a fold in tissue comprising: accessing a tissue surface with a device for engaging, approximating and fastening tissue; engaging at least two spaced apart tissue sites on the tissue surface; manipulating the at least two spaced apart tissue sites to form tissue shoulders at each of the spaced apart tissue sites; approximating the tissue shoulders to form an invaginated tissue fold extending away from the distal end of the device; and fastening tissue in proximity to the approximated tissue shoulders to secure the tissue fold.
16. A method of claim 15, wherein approximating the tissue shoulders is accomplished through a combination of motions selected from the group consisting of pushing motions, pulling motions, twisting motions and shearing motions.
17. A method of claim 15, additionally comprising treating the tissue surface to promote bonding between the approximated tissue shoulders.
18. A method of claim 15, wherein approximating the tissue shoulders to form the invaginated tissue fold extending away from the distal end of the device involves a combination of pulling the tissue shoulders toward the distal end of the device while simultaneously pushing the tissue surface between the tissue shoulders away from the distal end of the device.
19. A method of claim 15, wherein the tissue surface is an external surface of the wall of the stomach, and the tissue fold reduces the volume of the stomach by at least 20%.
20. A method of claim 15, wherein the depth of the tissue fold is increased by repeating the recited operational steps on the tissue surface in order to approximate and secure a second set of tissue shoulders over the top of the previously secured tissue fold.
Type: Application
Filed: Mar 13, 2015
Publication Date: Jul 2, 2015
Inventors: Peter S. HARRIS (Pacific Beach, WA), Barry Hal RABIN (Idaho Falls, ID)
Application Number: 14/658,094
