Abstract:
A fluid delivery cannula which provides an interface between an access point or port in the body of a patient and a working channel which may receive tools or instruments used during minimally invasive surgery. The cannula allows introduction of fluid(s) at the port site, or another site within the body of the patient. The fluid delivery cannula can releasably attach to a hub associated with a trocar assembly or may be integrally formed with at least a portion of the hub. In one form, an inner cannula member includes a grooved outer surface to define multiple fluid passages and a perforated outer layer is placed over the inner cannula member. Another form provides an expandable sleeve that may itself comprise a cannula through which a trocar or trocar assembly is inserted or which may take the place of the perforated outer layer of the grooved cannula.

Description:
[0001]    The present application is a continuation of PCT Serial No. PCT/US02/29356 filed on Sep. 17, 2002, now pending, which claims the priority of U.S. Provisional Patent Application Serial No. 60/325,806, filed on Sep. 28, 2001 (now abandoned) and 60/341,032, filed on Dec. 12, 2001 (now abandoned), and which is a continuation-in-part of U.S. Ser. No. 09/934,399, filed on Aug. 21, 2001 (now U.S. Pat. No. 6,695,815) which is a continuation of U.S. Ser. No. 09/511,100 filed on Feb. 23, 2000 (now U.S. Pat. No. 6,302,873). The disclosures of each of these prior related applications are hereby fully incorporated by reference herein. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention generally relates to cannulas and, more specifically, to cannulas used during minimally invasive surgery for allowing the introduction of instruments, such as laparoscopic tools, during surgical procedures.  
         BACKGROUND OF THE INVENTION  
         [0003]    Minimally invasive surgery is a popular alternative to more traditional surgery. This is due to the fact that minimally invasive surgery generally results in less pain and shorter hospital stays for the patient. Also, the cost of performing a surgical procedure through minimally invasive techniques can be substantially less than more traditional surgical approaches.  
           [0004]    Minimally invasive surgical techniques require access into the body of a patient through a small working channel of an apparatus known as a trocar-cannula complex. A relatively small access incision is made in the patient at the appropriate location on the patient to receive the trocar-cannula complex. When the trocar-cannula complex is combined with long, narrow instruments, the resulting assembly allows a surgeon to work inside the body through the small access incision or port site. This approach has resulted in the aforementioned clinical advantages and extensive health care cost savings.  
           [0005]    Traditionally, the trocar-cannula complex has been configured with three parts. The first part is the top portion and is referred to in the medical industry as the hub. The hub defines the entrance to the trocar-cannula complex and also includes various seals and air insufflation components. The second part is the trocar, which is a long, narrow blade extendable through an inner cannula to allow smooth penetration into the body of the patient through the tissue layers. The third portion is an outer cannula which is a tubular member of the complex adapted to pass into the body cavity. The outer cannula provides an interface between the patient&#39;s tissue at the access incision or port site and the trocar assembly.  
           [0006]    Minimally invasive surgery has grown in popularity in recent years and many new types of trocar-cannula products have been proposed and introduced to address different surgical needs and procedures. The various trocar-cannula complexes include reusable and disposable cannulas and trocars, as well as hybrid varieties that comprise combinations of reusable and disposable components of the trocar-cannula complexes. A complex which is a combination of reusable and disposable components is known as a resposable device. Such devices continue to improve surgical outcomes and economics.  
           [0007]    Animal studies on cancer treatments involving the performance of minimally invasive surgery point to a growing body of evidence which supports the concept of delivering an irrigant to the port site after the surgical procedure. In these studies, the irrigants were delivered by a syringe and needle and included substances such as betadine, saline and lidocaine. These studies showed that irrigating the port site with such substances immediately after the surgical procedure beneficially resulted in a lower incidence of infection or less pain, depending on the irrigant. However, the technique also resulted in increased operative time and increased exposure of the surgical staff to needle sticks. In addition, the potential for contaminants to spread to the port site during the surgery has been well documented. Irrigation performed only at the end of the surgical procedure unfortunately cannot reduce patient exposure to contaminants during the procedure.  
           [0008]    In view of the above-mentioned drawbacks in the field, there is a need for more effective delivery of fluids to an access point or port in the body of a patient before, during, and/or after the performance of minimally invasive surgery. Such delivery of fluid(s) could assist in patient treatment, such as through the delivery of cancer treatment medication or other medication, as well as reduction of port site contamination and infection, and reduction of post-operative pain. Other uses of the invention may be made in connection with delivering any desired fluid to a patient.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention generally relates to a unique fluid delivery cannula which provides an interface between an access point or port in the body of a patient and a working channel which may receive tools or instruments used during minimally invasive surgery. In accordance with one general aspect of the invention, the cannula allows introduction of fluid(s) at the port site, or another site within the body of the patient, at any time after the cannula is introduced through the access point or port site of the body. The fluids may be introduced manually, such as through a manually operated syringe coupled in fluid communication with one or more fluid passages in or on the wall of the cannula. Alternatively, the fluids may be delivered automatically through a suitable medical pump or other device.  
           [0010]    The fluids may include, for example, saline solution, lidocaine-containing fluids, betadine-containing fluids, or other substances, depending on the intended use and desired purpose. Presently, it is contemplated that such fluids will be especially beneficial to reduce post-operative pain, prevent infection and contamination at the port site and provide for many types of treatment to an affected area within the body of the patient. Another potential use is for delivering tissue adhesive to the patient.  
           [0011]    In one embodiment, the fluid delivery cannula releasably attaches to the hub. In another embodiment, the fluid delivery cannula is integrally formed with at least a portion of the hub. As one example, the fluid delivery cannula may be integrally molded with a housing portion which is configured to receive valving components and/or other insufflation components, while also allowing the trocar to pass through into the fluid delivery cannula. The hub can include a fluid inlet comprising a coupling, such as a standard luer connection, for receiving a manually operated syringe device allowing for the injection of the desired fluids. The fluid delivery cannula preferably has, in addition to a main lumen for receiving the trocar, one or more fluid passages for irrigation purposes. In the preferred embodiments, the cannula has a layered construction with multiple fluid passages contained between two layers of the cannula. The outside surface of one layer of the cannula includes grooves or recesses in fluid communication with the fluid inlet and an outer layer of the cannula includes one or more apertures or perforations communicating with the grooves for dispensing the fluid. Also in the preferred embodiment, the outside portion of the cannula, which has the fluid dispensing apertures, provides a visual target zone for the accurate delivery of the fluid to the port site. For example, this may comprise using a different color, texture, or other visually identifiable indicia at that fluid dispensing location of the cannula such that the surgeon can accurately determine where the fluid is being directed.  
           [0012]    The invention may be manufactured in many different manners while still functioning in accordance with the inventive principles. As mentioned above, the preferred form of the invention includes an inner cannula member having a grooved outer surface to define multiple fluid passages. An outer layer of biocompatible material (e.g., PTFE) is preferably heat shrunk onto the outer surface to enclose and seal the grooves to form passages. This biocompatible material includes, preferably, several apertures positioned around the circumference of the cannula and communicating with the grooves so that the fluid may be dispensed around the entire circumference of the cannula at a specific location along the length thereof. Alternatively, or in addition, fluid passages and one or more apertures may be provided only at one location about the circumference of the cannula for even more targeted delivery of the fluid.  
           [0013]    As alternative embodiments, the outer layer may be comprised of a layer which is configured similar to a condom and rolled onto the cannula and which includes the necessary aperture(s) for fluid delivery to the patient. The outer layer may be a rigid layer which is coupled to the inner cannula member in a rigid fashion or, for example, in a movable fashion such as a rotatable fashion to allow opening, closing, or size adjustment of the fluid delivery passage(s). As one additional alternative, the outer layer may be formed at least partially of a porous material which provides the necessary apertures. Such porous materials may, for example, take the form of sintered metals, filter media, paper, mesh cloth or a porous plastic.  
           [0014]    Another embodiment of the invention provides an expandable sleeve that may itself comprise a cannula through which a trocar or trocar assembly is inserted or which may take the place of the perforated outer layer of the grooved cannula discussed above. Other expandable sleeve embodiments may also be configured in accordance with this aspect of the invention as well. Such an expandable sleeve can, for example, allow trocars having different diameters to be inserted through the sleeve. Therefore, the same expandable fluid delivery sleeve may be used in connection with different sized trocars or trocar assemblies thereby reducing or eliminating the need for different sized fluid delivery cannulas or sleeves.  
           [0015]    Various objects, advantages and features of the invention will become more readily apparent to those of ordinary skill upon review of the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a perspective view showing a trocar-fluid delivery cannula complex constructed in accordance with the invention and being used during a minimally invasive surgical procedure.  
         [0017]    [0017]FIG. 2 is a cross sectional view taken generally along the longitudinal axis of the trocar-fluid delivery cannula complex of FIG. 1 for showing the irrigant flow path.  
         [0018]    [0018]FIG. 3 is an enlarged cross sectional view similar to FIG. 2, but more clearly showing the flow path for the delivery of fluid through the cannula.  
         [0019]    [0019]FIG. 4 is a cross sectional view taken along line  4 - 4  of FIG. 2.  
         [0020]    [0020]FIG. 5 is a plan view of the fluid delivery cannula with the outer layer or sheath removed for clarity.  
         [0021]    [0021]FIG. 6 is a plan view of another embodiment in which the fluid delivery cannula is integrally formed with a portion of a trocar hub.  
         [0022]    [0022]FIG. 7 is a cross sectional view taken along line  7 - 7  of FIG. 6.  
         [0023]    [0023]FIG. 8 is a longitudinal cross sectional view similar to FIG. 2, but illustrating an alternative embodiment of the invention incorporating an expandable fluid delivery sleeve.  
         [0024]    [0024]FIG. 9 is a perspective view of another alternative embodiment of an expandable fluid delivery sleeve or cannula.  
         [0025]    [0025]FIG. 10 is a cross sectional view taken along line  10 - 10  of FIG. 9.  
         [0026]    [0026]FIG. 11 is an enlarged perspective view of the distal end of another expandable fluid delivery sleeve or cannula. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]    [0027]FIG. 1 illustrates a trocar-fluid delivery cannula complex  10  constructed in accordance with one preferred embodiment of the invention. Complex  10  includes a trocar assembly  12  which may include a conventional hub assembly  14 . Representative trocar assemblies are shown and described in previous patents, such as my previous U.S. Pat. Nos. 6,063,060; 6,039,725; 5,865,817; and 5,865,809, the disclosures of which are hereby fully incorporated by reference herein. In accordance with the invention, a cannula  16  is positioned on the outside of trocar assembly  12  and includes a base portion  16   a . A syringe  18  couples to base portion  16   a  of cannula  16  through a fluid coupling, such as a standard luer connector assembly  20 . A plunger  18   a  of syringe  18  is used to manually inject a fluid into base portion  16   a  of cannula  16 . An outer layer or sheath  24 , preferably formed of PTFE (Teflon®), is secured to the outer surface of an inner tube  26  of cannula  16  and includes apertures  22 . In the preferred embodiment, sheath  24  is a tube which is heat shrunk onto inner tube  26  but it may take other forms and may be secured in other ways. As will be described below, cannula  16  includes appropriate fluid passages communicating with an inlet passage in base portion  16   a  to allow the fluid to be dispensed through apertures  22  as shown by arrows  28 . Hub assembly  14  further includes an insufflation valve  30  and a gas inlet  32  for receiving a pressurized gas, such as CO 2 .  
         [0028]    As further shown in FIGS. 2 and 3, base portion  16   a  of cannula  16  is threaded onto hub assembly  14  by threads  34 . Thus, cannula  16  may be easily coupled to and decoupled from hub assembly  14 . In the preferred embodiment, cannula  16  is disposable, however, it also may be manufactured as a reusable device intended to be sterilized between uses. Trocar assembly  12  more specifically comprises a trocar  50  received by a protective shield  52 . It will be appreciated that other instruments and tools may be inserted through the working channels formed by either irrigating cannula  16  or other tubular member(s) positioned within cannula  16 . This includes many other configurations of trocars or trocar assemblies as generally recognized in the art.  
         [0029]    More specifically referring to FIGS.  3 - 5 , irrigation fluids are introduced through luer connector  20   a  (FIG. 3) into fluid inlet  60  and groove or channel  62  formed in inner tube  26  of cannula  16 . Groove  62  communicates with an annular, circumferential groove  64  and groove  64  communicates with three separate longitudinal grooves  66  which are spaced in 120° increments about inner tube  26 . Grooves  66  respectively communicate with three partially annular grooves  68  which, in turn, each communicate with two longitudinal grooves  70 . Longitudinal grooves  70  communicate with apertures  22  in sheath  24  and apertures  22  thereby dispense the fluid at the port site  40  or, if cannula  16  is appropriately inserted and positioned, elsewhere within the patient.  
         [0030]    As mentioned above, the outer sheath  24  of the cannula  16  is preferably formed of PTFE and, more preferably, the outer sheath  24  is transparent or at least translucent. In addition, the area of sheath  24  containing apertures  22  may be formed with a distinct color, texture or other visually identifiable indicia which allows the surgeon to accurately position the apertures  22  with respect to the tissue to be infused with irrigation fluid. The various grooves in the outside surface of the inner tube  26  may be substituted with one or more passages within the walls of the inner tube  26  and may be of any suitable configuration and shape so long as the function of delivering fluid through the wall of the cannula  16  is facilitated by the configuration. The outer wall or sheath is a heat shrinkable material, such as an elastomeric material, however, this may also be substituted by other components or even eliminated, for example, if the passages and apertures are in the wall of an integrally formed cannula or if another fluid delivery structure is carried on the outer cannula. The inner tube in the preferred embodiment is preferably formed from aluminum with the various grooves in its outer surface being machined, however, it may instead be formed of other materials, such as plastic materials, and formed by other techniques such as molding. The preferred embodiment is especially advantageous in that it is simple to manufacture and the outer sheath forms a seal at the upper and lower ends of the inner tube while, at the same time, defining walls of the internal passages formed by the various grooves.  
         [0031]    [0031]FIGS. 6 and 7 illustrate a second illustrative embodiment of the invention comprising an fluid delivery cannula  100  which includes an irrigating portion  102  and a hub or housing portion  104  formed in one piece. For example, the entire structure shown in FIGS. 6 and 7 may be molded from a polymeric material, such as conventional medical grade polymers, using Mu-cell technology or other appropriate molding techniques. In FIGS. 6 and 7, the outer layer or sheath containing the one or more perforations has been removed for clarity. Housing portion  104  includes a port  106  for receiving valving and gas input components as are known in the art. A fluid input  108  is formed on cannula  100  and communicates with a passage  110  for the introduction of the necessary or desired fluids to irrigation portion  102 . A space  112  is provided for the necessary valving, sealing components, etc., typically used in trocar hubs. A lumen  114  extends along an axis  116  for receiving the trocar (not shown) and other working instruments. A system of fluid delivery passages is formed on the outside surface of irrigation portion  102  in the same illustrative pattern as discussed with respect to the first embodiment. This includes an annular groove  120  which communicates with passage  110  and delivers the fluid to three separate longitudinal passages  122  positioned at 120° increments around the outside surface of irrigation portion  102  relative to axis  116 . Grooves  122  communicate with respective partially annular grooves  124 . Again, while only two grooves  124  are shown in the drawings, a total of three grooves are formed in the outer surface of irrigation portion  102  positioned at 120° increments about axis  116 . Each partially annular groove  124  communicates with two separate longitudinal grooves  126 . Although only two grooves  126  are shown in FIG. 6, it will be appreciated that a total of six such grooves are formed in the outer surface of irrigation portion  102  in this particular embodiment. As in the first embodiment, grooves  126  communicate the fluid to perforations in the outer sheath (not shown) which then deliver the fluid to the patient. The outer sheath, as in the first embodiment, is preferably heat shrunk onto irrigation portion  102  so as to seal all of the grooves in the same manner as shown, for example, in FIGS. 2 and 3 of the first embodiment. As mentioned above, it will be appreciated that many other configurations of fluid delivery passages may be utilized in the cannula within the spirit and scope of this invention.  
         [0032]    In FIG. 8, like reference numerals refer to like elements of structure between the two embodiments. In the alternative trocar-cannula complex  150  of FIG. 8, the outer sleeve or layer  24  (not shown) which was affixed to the grooved cannula  26  has been removed and replaced by an expandable sleeve  152 . Expandable sleeve  152  may be a layered construction including a mesh layer  154  and an outer elastomeric layer  156 . Layer  156  is uniformly perforated about its entire periphery, such as in a circumferential zone  158  as shown in FIG. 8, so that at least some of the perforations  160  line up with the longitudinal grooves  70  of the cannula  26 . Thus, fluid is delivered through input  20   a  and into grooves  66 ,  68 ,  70  as described previously with respect to the first embodiment and this fluid is transferred through the expandable inner mesh layer  154  and expandable outer elastomeric layer  156  containing perforations  160 . It will be appreciated that many other forms than the layered mesh construction shown may be used in place of the expandable sleeve  152  shown in FIG. 8. FIG. 8 illustrates the use of the expandable sleeve  152  in connection with a 10 mm trocar assembly, however, in accordance with this aspect of the invention, the expandable fluid delivery sleeve  152  may alternatively be used with other trocars having larger or smaller diameters. A rigid handle portion  162  is provided at the proximal end of sleeve  152  to allow application and removal of sleeve  152  to and from trocar  12 . In order to seal the distal end of the expandable sleeve, a seal  164  may be provided distally of the mesh layer  154  as generally illustrated in FIG. 8. Alternatively, this seal  164  may be eliminated and the mesh layer  154  could then allow additional fluid to be delivered from the distal end of the sleeve  152 .  
         [0033]    [0033]FIGS. 9 and 10 illustrate another embodiment of an expandable fluid delivery sleeve  200  which does not need the separate cannula  26  (FIG. 8) for fluid delivery as in the embodiment of FIG. 8. Instead, this sleeve  200  is formed in a manner allowing fluid delivery to take place via an input  202  and sleeve  200  alone. Sleeve  200  is formed of a layered construction including an outer perforated layer  204 , an intermediate mesh layer  206 , and an inner layer  208 . Each layer  204 ,  206 ,  208  is expandable such that sleeve  200  may be used effectively on trocars having different diameters. The intermediate mesh layer  206  allows fluid to travel through the interstices therein from an appropriate fluid passageway extending through input  202  and an upper handle portion  210 . Alternatively, other types of fluid passages may be utilized. A trocar (not shown) is inserted through the bore  212  at the proximal end such that it extends through the distal end  214  of the expandable sleeve  200 . Perforations  216  are preferably formed in a desired zone  218  of sleeve  200  generally as described with respect to the previous embodiments. This zone  218  may be formed of a different color or in any other manner which indicates the positioning of the perforations to the doctor during the surgical procedure. Although not shown in FIGS. 9 and 10, this sleeve  200  may also have a seal at the distal end  214  to prevent fluid from leaking out the distal end  214 .  
         [0034]    As exemplified in FIG. 11, a distal end  230  of the expandable sleeves may be formed so as to allow fluid delivery to take place directly at the distal end. This aspect is shown in FIG. 11 schematically by indicating that the intermediate mesh layer  206  extends slightly beyond the other layers or is otherwise unsealed and, therefore, the fluid pathway through the mesh material  206  remains unblocked at the distal end  230 . This general aspect of fluid delivery from the distal end  230  may be used alone or in conjunction with fluid delivery from surface perforations as previously described.  
         [0035]    Many different types of irrigation fluids may be introduced through the fluid delivery cannulas of this invention. These include, but are not limited to, saline solutions, lidocaine-containing fluids, betadine-containing fluids, cancer treatment fluids, or any other fluid necessary or desired for a particular medical procedure. In addition, fluids other than irrigation fluids or treatment fluids may be delivered through the cannulas of this invention. As one additional example, bioadhesives may be delivered to an incision site or any other necessary tissue repair site to provide for quicker and more effective administration of the adhesive to the desired site. Many different types of trocars and cannulas may be utilized within the scope of this invention. These trocars and cannulas may be inserted through a port site of a patient together in one operation or separately, for example, by using a needle introducer for an expandable cannula and subsequently introducing the trocar.  
         [0036]    While the present invention has been illustrated by a description of a preferred embodiment and while this embodiment has been described in some detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features of the invention may be used alone or in numerous combinations depending on the needs and preferences of the user. This has been a description of the present invention, along with the preferred methods of practicing the present invention as currently known. However, the invention itself should only be defined by the appended claims, wherein I claim: