Abstract:
An endoscopic assembly, utilizing a braided mesh material as an expandable sheath, is disclosed. The mesh sheath is adapted to receive an endoscope for viewing the interior of a body cavity or lumen and one or more channels for performing medical procedures within the patient. The mesh sheath expands laterally as it is compressed longitudinally, which allows it to come into contact with the interior of the body cavity. By doing so, it can anchor the assembly, take samples from the body cavity, or dilate a stricture in the body cavity. Additional dilation procedures can be performed by removing the endoscope and inserting other instruments without removing the entire assembly from the patient. The body cavity can be hermetically sealed to reduce the risk of contamination of the endoscope and channels.

Description:
This is a continuation of application Ser. No. 09/130,784, filed Aug. 7, 1998, now U.S. Pat. No. 5,916,145 all of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     A. Field of the Invention 
     The present invention relates to surgical assemblies, and more particularly, to assemblies for enclosing surgical scopes in flexible sheaths. 
     B. Description of the Prior Art 
     A variety of surgical scopes are used in medical procedures within a patient&#39;s body. For example, endoscopes are used for viewing the interior of a body cavity or a hollow organ. They are often categorized by the part of the body they are used to examine, such as the esophagus, stomach, colon, and blood vessels. Endoscopes have been combined with complementary devices into endoscopic assemblies to perform various functions within a patient&#39;s body more efficiently. A sheath is often used to enclose the endoscope with these other devices into a unitary endoscopic assembly. 
     In addition to a sheath, the endoscopic assembly may include multiple channels or passages, sometimes referred to as working channels, that allow several functions to be performed at the distal end of the assembly. The endoscope and working channels are often disposed within the sheath, with the working channels arranged around the perimeter of the endoscope. The endoscope itself does not necessarily have working channels, but may contain a visual imaging device, illumination devices, and control wires that bend the distal end of the endoscope and any working channels attached to it. Various functions can be performed with, endoscopic assemblies having channels, including providing air, water and suction, or the taking of biopsies when the appropriate instruments are introduced through the channels of the endoscopic assembly. Accessories such as those used when taking a specimen typically have an elongated flexible shaft and jaws or other cutting instruments operatively connected to the shaft&#39;s distal end. 
     Sheaths may serve several additional purposes in a surgical assembly, including enclosing endoscopic assemblies. For example, the endoscope, as well as any working channels, need to remain together, in a single unit, when in the patient to allow for easy movement through the interior of a patient. Sheaths can be used to hold the assembly together within the body, with the endoscope and any working channels disposed within the sheath. In addition, sheaths are used to protect the assembly from contamination that can occur during an endoscopic procedure wherein the assembly contacts body tissues and fluids within the patient. Proper cleaning and sterilization of the assembly is very laborious and costly, which reduces the cost effectiveness of performing the endoscopic procedures. In response to the contamination problem, disposable endoscopic sheaths have been developed. The disposable sheaths fit over the endoscope and completely isolate it from the contaminating environment. The distal ends of the working channels are left open to allow for the passage of air, water, suction or endoscopic accessories through the channels to the patient. 
     Existing assemblies with sheaths, some containing multiple channels, can allow more than one task to be performed at the same time. For example, the sheath can reduce contamination while the channels are used to perform a biopsy. However, additional tasks cannot be completed without first removing the endoscope from the patient and then inserting another instrument or instruments to perform the additional task. For example, to dilate a passageway, an endoscope may be used to view the area to be dilated, but then the endoscope would have to be removed and another instrument such as a balloon catheter would need to be inserted to carry out the dilation procedure. Such processes increase the likelihood of contamination, the time required to complete a procedure and the cost due to the need to purchase separate instruments for each procedure. Accordingly, there is a need for an endoscopic assembly that can carry out multiple tasks without requiring the removal of instruments from the body. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a surgical assembly that provides improved capability to perform other functions while the assembly remains in the patient. The present invention accomplishes this result by increasing the capabilities and functionality of a sheath used to enclose an endoscope and/or other surgical devices being placed internally in a patient. 
     Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. 
     To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention, in one embodiment, comprises a sheath for enclosing a surgical scope, the sheath comprising an elongated flexible tube adapted to coaxially surround a surgical scope; one or more elongated passages aligned axially within the tube; the elongated tube being adapted for axial extension or contraction to either lengthen or shorten the length of the tube while respectively diminishing or enlarging the radial dimensions thereof. 
     In another embodiment, the present invention provides a surgical assembly comprising an elongated flexible outer tube; a scope coaxially disposed within the elongated tube; one or more elongated passages aligned axially within the outer tube; the elongated outer tube being adapted for axial extension to lengthen or retraction to shorten the length of the tube while respectively diminishing or enlarging the radial dimensions thereof. The assembly may also include channels running alongside the endoscope that are open on each end to allow for medical instruments to be used at the distal end of the assembly within the patient. A distal housing may also be disposed at a distal end of the assembly, the housing having a suction chamber and an endoscope entry chamber. The mesh sheath may be hermetically sealed to reduce contamination of the assembly and channels. 
     The present invention also provides a method of using a surgical assembly having an elongated flexible outer tube, the outer tube being adapted for axial extension to lengthen or retraction to shorten the length of the tube while respectively diminishing or enlarging the radial dimensions thereof, comprising the steps of placing an endoscope having a distal end within an elongated flexible tube; inserting the tube, with the endoscope disposed within it, into a body cavity of a patient for viewing the interior of the body cavity; and using the endoscope to view through a window in a distal housing disposed at the distal end of the assembly. Another method of using the assembly includes using the channels within the assembly to perform procedures within the body cavity of the patient. Additional methods expand the diameter of the mesh sheath by dilating the sheath with cylindrical rods in place of the endoscope, with a dilation balloon, or by compressing the sheath longitudinally to cause the sheath to expand laterally. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the present invention with the sheath partially cut away. 
     FIG. 1A is a cross section of a side view of the present invention. 
     FIG. 1B is a detail of the distal end of the present invention. 
     FIG. 2 is a perspective view of the present invention with the sheath partially cut away. 
     FIG. 2A is a side view of the present invention with the sheath in a first position. 
     FIG. 2B is a side view of the present invention with the sheath in a second position. 
     FIG. 2C is a side view of the present invention with the sheath in a third position. 
     FIG. 3 is a perspective view of the present invention with a distal portion of the sheath expanded. 
     FIG. 3A is a cross section of a side of the present invention with a distal portion of the sheath expanded. 
     FIG. 4 is a perspective view of the present invention with a distal portion of the sheath expanded. 
     FIG. 5 is a perspective view of the present invention with a distal portion of the sheath expanded and working channels that can be used for stabilizing the tamponade. 
     FIG. 6 is a perspective view of the present invention with a distal portion of the sheath expanded that can be used for stabilizing, retrieval, or tamponade. 
     FIG. 7 is a perspective view of the present invention with a distal portion of the sheath expanded that can be used for stabilizing, retrieval, or tamponade. 
     FIG. 8 is a perspective view of the present invention with a distal portion of the sheath expanded that can be used for stabilizing, retrieval, or tamponade. 
     FIG. 9 is a perspective view of the present invention being used with a bougie or dilator and with a portion of the sheath cut away. 
     FIG. 10 is a perspective view of the present invention with a distal portion of the sheath expanded and with a device on the proximal end for inflating the distal portion of the sheath. 
     FIG. 11 is a side view of the present invention with a forceps, snare, sclerotherapy needle and suction adaptor (endoscope not shown). 
     FIG. 12 is a side view of the mesh sheath in its compressed state with its diameter expanded. 
     FIG. 13 is a side view of the mesh sheath in its relaxed state. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     A preferred embodiment of the invention utilizes a mesh material. The mesh material used in accordance with the invention expands in diameter laterally as it is compressed longitudinally and contracts in diameter as it is kept in tension longitudinally or allowed to return to its relaxed state. Mesh materials useful in the invention, for example, are manufactured by Bentley Harris and distributed by Schaal™. The mesh is typically made of polyester in a cylindrical braided configuration. The mesh is formed by overlapping strands of flexible or semi-rigid material, cross-woven over and under each other in generally clockwise and counterclockwise directions. The mesh is such that a counterclockwise strand is able to slidably and intersectingly move with respect to a generally clockwise strand. The maximum diameter of the expanded mesh is dependent upon the extended length and the pitch of the mesh tube. 
     The biocompatibility of the mesh material makes it suitable for use in diagnostic and therapeutic applications. The mesh can be shaped and set to a configuration as described above. Alternatively, in the case of a plastic mesh, the mesh can be set in a desired configuration by dipping it into hot water at a temperature of 100 degrees C. for a period of 10 minutes. The capabilities of the material render it particularly well suited for the objects of the present invention. It is to be understood, however, that other flexible mesh materials having the requisite characteristics are also suitable in the invention. Depending on the application, the mesh could be made of stainless steel, nylon, polyurethane, urethanes or any other biocompatible material. For tamponade, the mesh should be a relatively soft material. For tissue gathering, the mesh should be stiffer. 
     Referring first to FIGS. 1,  1 A and  1 B, which illustrate one embodiment of the present invention, the surgical assembly, in this case an endoscopic assembly  10 , is shown with a proximal end  12  and distal end  14 . An endoscope  16  is shown within an elongated flexible tube in the configuration of a mesh sheath  18 . The mesh sheath  18  has a distal end  20  attached to a proximal end  24  of a distal housing  26 . The mesh sheath  18  in FIGS. 1 and 1A is in a compressed state, with its diameter larger than the diameter of the endoscope  16 . 
     The distal housing  26  includes a suction chamber  28  on its distal end  30  and a tapered endoscope entry chamber  32  on its proximal end  24 . Between the endoscope entry chamber  32  and the suction chamber  28  is a clear window  36  through which a person using the endoscope  16  can view a desired area of the patient. A mesh sheath mating surface  38  is provided on the proximal end  24  of the distal housing  26 , the mating surface  38  having a slightly smaller diameter than the rest of the distal housing  26 . One or more lumens  40  may be provided in the distal housing  26  to accommodate one or more working channels  42 , the lumen  40  passing through the distal housing  26  between the tapered endoscope entry chamber  32  and the suction chamber  28 . The channel  42  runs the length of the assembly  10  alongside the endoscope  16 . The channel  42  terminates at the distal end  14  of the assembly at the channel port  34 . The channel  42  and lumen  40  could accommodate medical instruments, supply air and water, or provide suction. 
     In most cases the mesh sheath  18  is introduced into the body in a collapsed form over a endoscope  16 , and is converted into its expanded configuration inside the body by the use of a channel and/or pull wire (both indicated by  42 ). The channel and/or pull wire  42  is held at the proximal end  12  of the assembly  10 , while the sheath  18  is pushed toward the distal end  14  to form the expanded configuration. A channel (tube) has a lumen through it, whereas a pull wire does not. A pull wire is used when there is no need for a lumen, thus reducing the profile of the assembly  10 , or to add strength to the channel tubing. The pull wire  42  is attached to the distal housing and runs the length of the device similar to channel  42 . The channel and/or pull wire  42  are needed to expand or convert the sheath  18  into its expanded configurations, especially when the distal end  14  of the assembly  10  is in the body. The sheath  18  is expanded by holding the channel and/or pull wire  42  at its proximal end  60  (FIG. 3) and pushing the sheath  18  toward its distal end  20  to expand its diameter and converting it to its expanded configuration. To collapse the expanded diameter, the sheath  18  is pulled toward proximal end  60 . 
     FIGS. 2,  2 A and  2 B show the assembly  10  with the mesh sheath  18  in its relaxed state, with its diameter just greater than the diameter of the endoscope  16  (not shown) and any channels  42  (not shown) within it. The mesh sheath  18  may be pulled in tension from its proximal end by pulling on the mesh itself or using a means attached to the proximal end to do so. In one preferred embodiment, elastic bands  44  are attached to a proximal end  22  of the mesh sheath  18  to enable one to pull the mesh sheath into tension. When the mesh sheath  18  is in tension, or when the diameter of the endoscope  16  and channels  42  within it are greater than the diameter of the sheath  18  in its relaxed state, the sheath  18  exerts a radial compression force on the endoscope  16  and any channels  42  within it. The amount of force applied by the sheath  18  and the diameter at which it begins applying the force can be varied by selecting sheaths  18  of various types, sizes, and rigidities. The rate at which the sheath  18  expands as compressed can also be controlled and monitored while the assembly  10  is in the patient. 
     FIGS. 2A,  2 B and  2 C also show a connector  45  attached to the channel  42 . The connector  46  can then be attached to other devices that nay supply air, water, suction or instruments. In FIG. 2C, the mesh sheath  18  is shown in a compressed (diameter expanded), as opposed to the relaxed state shown in FIGS. 2A and 2B. 
     FIGS. 3,  3 A,  4  (without endoscope) and  5  (with additional channels) show another embodiment of the present invention. In this embodiment, only the distal end  20  of the sheath  18  is able to expand. The sheath  18  comprises two portions, a distal portion  50  and a proximal portion  52 . The distal portion  50  is coated by an elastic rubber or plastic material  54 , so that it is gas- and liquid-impervious, yet still allows the mesh strands  56  (FIG. 1A) to move within the mesh sheath  18  when compressed or when relaxed. Alternatively, the distal portion  50  of the sheath  18  can be without a coating to allow gas and liquids to pass while the distal portion  50  of the sheath  18  is expanded. The proximal portion  52  of the sheath  18  is not able to expand or contract as it is compressed. Instead, the proximal portion  52  of the sheath  18  transmits the compressive force to the distal portion  50  of the sheath  18 , causing it to expand. A flexible tube may be used for this purpose and attached to the distal portion  50  of the sheath  18 . Alternatively, the proximal portion  52  of the sheath  18  may be a continuation of the distal portion  50  of the mesh sheath  18 , but coated with a plastic material that prevents the proximal portion  52  of the sheath  18  from expanding laterally. If a coated mesh is to be used for the proximal portion  52  of the sheath  18 , it should be sized large enough so that the endoscope  16  and channel  42  can pass easily through the sheath  18 . 
     FIGS. 3-5 illustrate an alternative embodiment which can be used in accordance with a method whereby the distal portion  50  of the sheath  18  is expanded while the proximal portion  52  of the sheath  18  maintains the same diameter. For example, in one method, the channel  42  is held at its proximal end  60  external to the human body, while the proximal portion  52  of the sheath  18  is pushed toward the distal portion  50  of the sheath  18 . The proximal portion  52  of the sheath  18  transfers the force to compress and shorten the distal portion  50  of the sheath  18  in length and expanding its outer and inner diameters laterally. This function can serve several purposes. For example, the expanded distal portion  50  of the sheath  18  can be used to anchor or stabilize the endoscope  16  in the gastrointestinal tract, to occlude the distal end  14  of the endoscopic assembly  10  from the proximal end  12  of the endoscopic assembly  10  or to tamponade a bleeding lesion. FIG. 5 shows the expanded sheath  18  configuration that can be used for used for stabilizing the tamponade. The surface of the expanded distal portion  50  of the sheath  18  would cover and apply pressure against the tract wall to tamponade any bleeder. This configuration could also anchor the assembly  10  within the tract. The expanded diameter of the sheath  18  against the tract wall would prevent the assembly  10  from migrating in the tract. 
     FIGS. 6,  7  and  8  show the assembly  10  in different configurations that could be used for retrieval. FIG. 6 shows the expanded sheath  18  open distal to a battery in the gastrointestinal tract. The battery is retrieved by pulling the entire expanded assembly  10  proximal and out of the body. In this configuration the expanded sheath  18  is also preventing the passage of fluid from one side of the expanded sheath  18  to the other. The configuration of the invention shown in FIG. 7 could be used similar to that of FIG. 6 for retrieval or can be used as a dilator to be pushed distally to open strictures in a tract. In this configuration, the assembly  10  is expanded proximal to the stricture, which avoids dilating the entire proximal tract. The taper towards the distal end  20  of the mesh sheath  18  is pushed into the stricture to be dilated. The configuration of the invention shown in FIG. 8 is in its expanded state, scraping the walls of the gastrointestinal tract, collecting cell or tissue samples as the assembly  10  is pulled proximal. The samples are shown to fall into the center catch area of the expanded sheath  18  for retrieval. 
     In each embodiment of the present invention, the endoscope  16  is removable and can be exchanged for an instrument such as a balloon catheter (not shown) to dilate a stricture underneath the distal end  20  of the sheath  18 . When a balloon catheter is used, the mesh sheath  18  does not need to be compressed to expand its diameter, but the sheath  18  does need to be capable of expanding with the balloon. Thus, if a coating is applied to the sheath  18 , it should not limit the ability of the sheath  18  to expand. 
     FIG. 9 illustrates an alternative embodiment which can be used in accordance with a method utilizing bougie dilation. In this method, the endoscope  16  and sheath  18  in the figure are introduced into the gastrointestinal tract. The endoscope  16  is removed. Then, the sheath  18  is re-expanded by holding the channel  42  at its proximal end  60  and pushing the sheath  18  toward its distal end  20  to expand its diameter. At the stricture, the sheath  18  only expands to the limits the stricture imposes on it. A small bougie or dilator  70  is introduced to dilate the stricture, while the sheath  18  acts as a protective shield and guide for the bougie  70  to follow. The bougie  70  is inserted past the stricture allowing the diameter of the bougie  70  to force the stricture to expand to the diameter of the shaft of the bougie  70 . This procedure can be repeated with successively larger diameters of each bougie  70 , until the diameter of the stricture reaches a desired value. 
     FIG. 10 shows another embodiment of the present invention. The device is similar to the device of FIG. 3 in that the distal portion  50  of the sheath  18  can expand, while the proximal portion  52  of the sheath  18  cannot. Instead of pushing the proximal portion  52  of the sheath  18  to expand the diameter of the distal portion  50 , a proximal fitting  80  is used to seal around the endoscope  16  and channel  42  to enable the inflation of the distal portion  50  of the sheath  18  to a higher pressure for the purpose of dilation of strictures. The proximal fitting  80  includes an inflation port  82  and a medical hub  84 . 
     Another embodiment of the present invention is depicted in FIGS. 11-13. Referring to FIG. 11, the assembly  10  includes the mesh sheath  18  shown with several instruments (collectively 90) within channels  42 . In this embodiment, by way of example, the instruments  90  included are a forceps  92 , a sclerotherapy needle  94 , a snare  96  and a distal housing  26  having a suction chamber  28 . The channels  42  and the mesh sheath  18  are attached to the distal housing  26 . The sheath  18  assembly  10  can be set up for a certain procedure. For a mucosectomy, for example, the mesh sheath  18  would be equipped with a minimum of a snare  96 , suction, and a sclerotherapy needle  94 . 
     FIGS. 12 and 13 illustrate expansion of the mesh sheath  18  in diameter as it is compressed (FIG. 12) and contraction in diameter as it is in tension or allowed to return to its relaxed state (FIG.  13 ). The handles  98  of the instruments  90  are operated by the physician external to the patient and external to the sheath  18  to facilitate the maneuverability of the handles. 
     The channels  42  include additional working channels  42  for the endoscope  16 . The additional channels  42  (FIG. 5) could be used for suction, infusion, or to provide access for instruments  90  such as a forceps  92 , sclerotherapy needle  94 , snare  96  or cautery devices (not shown) to be used in conjunction with each other rather than on an individual basis. The present invention could be provided without instruments  90  or with instruments  90 . 
     The endoscope  16  and the channels  42  or both may be hermetically sealed within the mesh sheath  18 . In one embodiment, the mesh sheath  18  itself is sealed with a urethane or similar expandable complex in such a way that it is impervious to water and air but retains its ability to expand and contract, as discussed above. In another embodiment, the mesh sheath  18  is an open mesh, but the endoscope  16  is enclosed in a baggy condom, tube or similar device (not shown) to ensure contaminants do not reach the endoscope  16 . If a baggy condom or tube is used, the end should be clear so that the endoscope  16  can view the interior of the patient. The baggy condom will allow the endoscope  16  to be easily slipped into the condom, yet will conform to the outside of the endoscope  16  when the mesh sheath  18  closes around it. 
     Although the endoscope may be free of contaminants, the channels  42  can become, contaminated by coming into contact with body tissues and fluids during a procedure. The mesh sheath  18  provides some protection from the elements, especially if coated with an impervious material. If the channels  42  become contaminated with each use, the channels  42  can be made from a less resistant, less expensive material so that they can be disposed of after each use along with the mesh sheath  18 . 
     Additionally, the mesh sheath  18  provides a flexible and durable outer layer that can be coated to create a gas- and liquid-impervious membrane if desired. The ability of the mesh  18  to expand laterally when compressed axially allows for easy insertion and removal of the endoscope  16  and working channels  42  within the sheath  18 . It also provides an easy way to expand the diameter of the distal end  14 , or any other area, of the endoscopic assembly  10 . This ability to expand and retract is important for carrying out the functions mentioned above, namely dilation, anchoring and sampling. It also allows the endoscope  16  to be inserted, removed or exchanged both external and internal to the patient with diminished risk of contamination. 
     Another advantage of the present invention is that a lesion or disease can be treated with a single placement of the endoscope  16  instead of additional exchanges. Exchange includes removing the endoscope  16  from the patient, exchanging instruments  90 , reintroducing the endoscope  16 , and locating and repositioning at the desired site. An example of one procedure may include one instrument holding and stretching a lesion while the another instrument cuts it. The suction chamber  28  is also designed according to the present invention where it can hold on to lesions while other instruments  90  perform other operations. In addition, different combinations of instruments  90  can be exchanged in the channels  42  without removing the endoscope  16  from the patient. The examples are purely exemplary of the present invention. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the method of using the endoscopic assembly of the present invention and in construction of this assembly without departing from the scope or spirit of the invention. 
     Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.