Abstract:
The present disclosure is directed to a surgical portal apparatus for use during a minimally invasive procedure. In one aspect, the apparatus includes a housing and a portal member extending distally from the housing, defining a longitudinal axis. The apparatus also has an iris seal including a plurality of leaf members, disposed within the housing. The leaf members are adapted for pivoting relative to the housing, to control the dimensioning of a passage in response to the insertion of a surgical object. The leaf members are not directly linked to each other to provide for off-axis movement of the surgical object. The apparatus further includes an actuation mechanism, including a motor and a sensor, operatively connected to the leaf members and adopted for movement upon the introduction of the surgical object.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a Continuation of U.S. Ser. No. 12/467,363, filed on May 18, 2009, which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/075,515, filed on Jun. 25, 2008, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a device, and a method of use thereof, for facilitating access to a patient&#39;s internal cavities during a surgical procedure. More particularly, the present disclosure relates to a surgical apparatus adapted for insertion into an incision in tissue, and for the sealed reception of one or more surgical objects, so as to form a substantially fluid-tight seal with both the tissue and the surgical object, or objects. 
     2. Background of the Related Art 
     Minimally invasive and laparoscopic procedures generally require that any instrumentation inserted into the body is sealed, i.e., provisions must be made to ensure that gases and/or fluids do not enter or exit the body through an endoscopic incision, such as, for example in surgical procedures where the surgical region is insufflated. For such procedures, the introduction of a tube into anatomical cavities, such as the peritoneal cavity, is usually accomplished by use of a system incorporating a trocar and cannula assembly. Since the cannula is in direct communication with the interior of the peritoneal cavity, insertion of the cannula into an opening in the patient&#39;s body to reach the inner abdominal cavity should be adapted to maintain a fluid tight interface between the abdominal cavity and the outside atmosphere. In view of the need to maintain the atmospheric integrity of the inner area of the cavity, a seal assembly for a cannula, which permits introduction of a wide range of surgical instrumentation and maintains the atmospheric integrity of the inner area of the cavity, is desirable. In this regard, there have been a number of attempts in the prior art to achieve such sealing requirements. A difficulty encountered with conventional seal assemblies, however, is the inability of accommodating the wide range of sizes of instrumentation. In addition, angulation and/or manipulation of instrumentation within the cannula often present difficulties with respect to maintaining seal integrity. 
     SUMMARY 
     Accordingly, the present disclosure provides a surgical portal apparatus with a seal assembly, which will allow a surgeon to efficaciously utilize instruments of varying diameter in a surgical procedure. This seal assembly obviates the need for multiple adapters to accommodate instruments of varying diameter by providing a seal with an adjustable opening. One embodiment is directed to a surgical portal apparatus having an iris seal for use with a surgical access device. In accordance with one aspect of the present disclosure, the surgical portal apparatus includes a housing, a portal member extending from the housing, and an iris seal disposed within the housing to limit the flow of gas through the portal apparatus. The portal member is dimensioned for positioning within tissue. The portal apparatus includes a longitudinal opening to permit passage of a surgical object through the portal apparatus. The iris seal defines a central opening and contains a plurality of leaf members adapted for movement to control the diameter of the opening. 
     Pivotal mounting of the leaf members relative to the housing allow the leaf members to move from a first relative position, having an initial diameter passage, to a second relative position, having a different diameter passage. The leaf members are movable, in response to an introduction of a surgical object, to establish a substantial sealing relationship with the surgical object. Movement is accomplished by an actuation mechanism acting upon the leaf members. The actuation mechanism includes a motor with resistive circuitry. The resistive circuitry is configured to detect the load on the motor and stops the motor when a specific load is detected. The motor releasably holds the load torque on the leaf members, in the second relative position, causing a constant seal with the surgical object. 
     The surgical portal apparatus includes a switch positioned within the housing. The engagement of the switch activates the motor, and thereby causing movement of the leaf members of the iris seal. As a result, the leaf members move from the first relative position to the second relative position. The switch may be located proximal to the iris seal and have a delay mechanism to provide a preset amount of time before actuating the iris seal. The delay allows the surgical object to enter the surgical portal apparatus before the iris seal closes upon the surgical object. 
     In another embodiment, the switch is located distal to the iris seal and adapted to be engaged by the surgical object during introduction of the surgical object within the housing. In still another embodiment, the surgical portal apparatus includes a manual switch, mounted to the housing and operatively connected to the leaf members of the iris seal. A clinician engages the manual switch to move the leaf members between the first and second relative positions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure, and together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure. 
         FIG. 1  is a right, perspective view of a trocar assembly and a seal assembly in accordance with the principles of the present disclosure; 
         FIG. 2  is a left, perspective view of a trocar assembly and a seal assembly in accordance with the principles of the present disclosure; 
         FIG. 3  is a top view of the trocar and seal assemblies in accordance with the embodiment of  FIGS. 1-2 ; 
         FIG. 4  is a side cross-sectional view of the trocar and seal assemblies in accordance with the embodiment of the present disclosure; 
         FIG. 5  is a top view of a leaf member in accordance with the present disclosure; 
         FIG. 6  is a rear, perspective view of a trocar assembly and a seal assembly in accordance with the embodiment of the present disclosure; 
         FIG. 7  is a view illustrating the trocar assembly and seal assembly accessing an internal cavity with an instrument introduced therein in accordance with the present disclosure; and 
         FIG. 8  is a flow chart illustrating one method of operation of the trocar assembly in accordance with the present disclosure. 
     
    
    
     Other features and advantages of the present disclosure will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principals of the invention. 
     DETAILED DESCRIPTION 
     The seal assembly of the present disclosure provides a substantial seal between a body cavity of a patient and the outside atmosphere, before and after insertion of an instrument through the trocar assembly. Moreover, the seal assembly of the present invention is capable of forming a gas tight seal with instruments of varying diameters, e.g., from 5 mm to 15 mm. The flexibility of the present seal assembly greatly facilitates endoscopic surgery, where a variety of instruments having differing diameters is often needed during a single surgical procedure. 
     The seal assembly maintains a fluid tight interface during the introduction and manipulation of various types of instrumentation to preserve the atmospheric integrity of a surgical procedure from gas and/or fluid leakage. Specifically, the seal assembly greatly reduces the force required for introduction and removal of the instrumentation. The fluid tight interface minimizes the entry and exit of gases and/or fluids to/from the body cavity. Examples of instrumentation adopted for insertion through a trocar and/or trocar assembly include clip appliers, graspers, dissectors, retractors, staplers, laser probes, photographic devices, endoscopes and laparoscopes, tubes, and the like. Such instruments will be collectively referred to as “surgical objects”. 
     By virtue of its features, the seal assembly starts by defining a large diameter or interval dimension and then closes to a smaller diameter. The seal is fully open in the “at rest” position and is capable of fully closing to prevent the escape of fluid when activated. The seal assembly may close around the surgical object. The ability to close around the surgical object minimizes insertion forces and decreases the probability of compromising the seal. A duck-bill seal or zero seal may be used in conjunction to aid in preventing the escape of fluid during insertion and extraction of a surgical object. 
     In the following description, as is traditional, the term “proximal” refers to the portion of the instrument closest to the operator while the term “distal” refers to the portion of the instrument remote from the operator. 
     Referring now to the drawings, in which like reference numerals identify identical or substantially similar parts throughout the several views,  FIGS. 1-2  illustrate the seal assembly  100  of the present disclosure mounted to a trocar assembly  200 . Trocar assembly  200  may be any conventional trocar suitable for the intended purpose of accessing a body cavity and permit the introduction of instruments therethrough. Trocar assembly  200  is particularly adapted for use in laparoscopic surgery, where the peritoneal cavity is insufflated with a suitable gas, e.g., CO 2 , to raise the cavity wall from the internal organs therein. Trocar assembly  200  is typically used with an obturator assembly (not shown). The obturator assembly, a sharp pointed instrument positionable within the passageway of the trocar assembly  200 , is utilized to penetrate the abdominal wall. Then the obturator is subsequently removed from the trocar assembly  200  to permit introduction of the surgical instrumentation used in the procedure. 
     With reference to  FIGS. 1-2 , trocar assembly  200  includes a trocar housing  204  mounted to an end of the sleeve  202 . Any means for mounting trocar sleeve  202  to trocar housing  204  are envisioned, including threaded arrangements, bayonet coupling, snap-fit arrangements, adhesives, etc. Additionally, trocar sleeve  202  and trocar housing  204  may be integrally formed. 
     Trocar sleeve  202  defines a longitudinal axis “a” extending along the length of sleeve  202 . Further, sleeve  202  defines an internal longitudinal passage  206  dimensioned to permit passage of surgical objects. Adjacent the distal end of trocar sleeve  202  is aperture  212 , which extends through the wall of sleeve  202 . Aperture  212  permits passage of insufflation gases through trocar sleeve  202  during the surgical procedure. 
     The diameter of sleeve  202  may vary, but, typically ranges from about 10 mm to about 15 mm for use with the seal assembly  100  of the present disclosure. Trocar housing  204  includes port opening  214  and luer fitting  216  positioned within the port opening  214 . Luer fitting  216  is adapted for connection to a supply for insufflation, and incorporates valve  218  to selectively open and close the passage of the luer fitting  216 . Sleeve  202  may be formed of stainless steel or other rigid materials such as a polymeric material or the like. Sleeve  202  may be clear or opaque. 
     With continued reference to  FIGS. 1-4 , seal assembly  100  will be discussed in detail. Seal assembly  100  may be a separate component from trocar assembly  200  and, accordingly, adapted for releasable connection to the trocar assembly  200 . Alternatively, seal assembly  100  may be incorporated as part of trocar assembly  200  forming a single unit. Seal assembly  100  includes a seal housing, generally identified as reference numeral  102 , and iris seal  104 , which is disposed within the seal housing  102 . 
     Seal housing  102  contain the sealing components of the assembly, and defines the outer valve or seal body of the seal assembly  100 . Seal housing  102  also defines central seal housing axis “b” which is preferably parallel to and coincident with the axis “a” of trocar sleeve  202 . Seal housing  102  is formed from the assembly of two housing components, namely, first housing component  106  and second housing component  108 . Housing components  106  and  108  may be assembled by any of the aforementioned connection means discussed with respect to trocar housing  204 . 
     First housing component  106  defines inner or proximal guide wall  112  and outer cylindrical wall  114 , which is disposed radially outward of the proximal guide wall  112 . Outer cylindrical wall  114  surrounds proximal guide wall  112  and extends distally. Proximal guide wall  112  defines central passage  116  and laterally confines the instrument within the seal housing  102 . As best shown in  FIG. 4 , proximal guide wall  112  defines a maximum diameter opening capable of receiving a surgical object. Proximal guide wall  112  further includes a circular seal  118 . 
     Second housing component  108  includes transverse wall  122  and cylindrical portion  124 . Transverse wall  122  includes an inner circular seal  126  about central passage  116 . Cylindrical portion  124  is dimensioned to mate with outer wall  114  of first housing component  106 . It is envisioned that outer wall  114  defines a scalloped outer surface  114   a , which provides for gripping engagement by the user. 
     Referring now to  FIGS. 3-5 , iris seal  104  is mounted between the first housing component  106  and second housing component  108 . Iris seal  104  comprises a plurality of leaf members  130 . Each leaf member  130  overlaps an adjacent leaf member  130 . As shown in  FIG. 5 , leaf member  130  has a leaf body  134 , a leading edge  140 , a pin  110 , and a hole in the leaf body  132 . 
     Leaf members  130  may be fabricated from a single suitable elastomeric material and have sufficient resiliency to form a seal about an inserted objected. Suitable materials include, but are not limited to polyurethane and copolyester. To minimize friction, the elastomeric materials may be coated with silicon, the product polytetrafluoroethylene sold under the trademark TEFLON, or the like. The leading edge  140  may be fabricated from a different material than the leaf body  134 . 
     Iris seal  104  is completely open when the seal assembly  110  is not activated. Leaf members  130  rotate from a first relative position, substantially open, to a second relative position, substantially closed. Leaf members  130  can also rotate to a second relative position forming a seal around the surgical object “i” as shown in  FIG. 6 . The amount a leaf member  130  rotates will determine the dimension of the central passage  116 . 
     The assembled components are held together by a series of screws  131 , or other positive fastening means, through circumferentially spaced holes  132 . Holes  132  extend through the iris seal  104  and the second housing component  108 . The single attachment point, of each leaf member  130 , allows pivoting about the respective fastener  131 . This pivoting allows leaf members  130  to change between first and second relative positions. A pin  110 , located radially outward from the hole  132 , attaches to an actuation mechanism to provide a force upon the leaf members  130 . The force acts in a direction out of alignment with the pivot point, causing a moment. This moment forces the leaf members  130  to rotate. 
     It is appreciated that the pin can be located elsewhere on the leaf member  130 . Further, it is appreciated that a moment applied thru hole  132  will cause the leaf members  130  to rotate about a pin  110 , and that rotation and applied force can act through two pins or two holes. Further still, the leaf members  130  may slide radially instead of rotate. 
     The actuation mechanism moves leaf members  130  between the first relative, or open position, and the second relative position to engage the surgical object and establish a sealing relation therewith, or to close the iris seal. The actuation mechanism includes a motor  134  and an associated switch  136 . The motor  134  may be any suitable miniature electric motor that is battery powered. The motor output is operatively connected to the leaf members  130  of iris seal  104  in a manner to effect pivotal movement of the leaf members  130  between the first and second relative positions. Various means of connecting the leaf members  130  and the motor  134  are envisioned and appreciated by one skilled in the art. 
     The motor is activated by switch  136 . As the inserted instrument contacts switch  136 , the triggered switch activates the motor  134 . The motor  134  then applies a force via the actuation mechanism to the leaf members  130 . As illustrated in  FIGS. 3 and 4 , the first housing member  106  is part of the actuation mechanism in this embodiment. The motor  134  acts upon the first housing member  106  to cause the housing member to rotate. Recesses in the outer wall  114  match and accept pins  110  of the leaf members  130 . As the first housing member  106  rotates, the force from the motor  134  is translated to the leaf member pins  110 . As a result, the motor  134  causes the leaf members  130  to rotate between relative positions. The iris seal closes when wall  114  rotates counterclockwise and the seal opens when the wall  114  rotates clockwise. 
     The motor  134  draws an electrical current to operate. This current can be measured by a resistive circuitry  128  associated with the motor  134 . Alternative uses of resistive circuitry to measure the load upon the motor  134  are envisioned. Once a predetermined load is detected, by the resistive circuitry  128 , the motor  134  stops in place and releasably holds the leaf members  130  in the second relative position. 
     Although a motor is disclosed as part of the actuation mechanism, it is appreciated that the actuation mechanism can be manually operated by a clinician. A clinician can activate the iris seal  104  in several ways. One way to activate the iris seal  104  is by manually rotating the scalloped outer surface  114   a . A manual lever may also be connected to a mechanism that rotates the leaf members  130 . 
     Switch  136  is located within the housing  102 , between the iris seal and the distal end. As the surgical object “i” is introduced into the center passage  116 , the switch  136 , which is operatively connected to the motor, is engaged and activates the motor  134 . The iris seal  104  then constricts around the surgical object. Thus, the leaf members  130  move from a first relative position to a second relative position around the surgical object. It is also anticipated that the switch is a sensor, capable of determining the size and location of the surgical object. The sensor may interact with a central process unit to determine the individual leaf members  130  to actuate and the degree of actuation. When the surgical object disengages the switch  136 , the iris seal  104  opens and allows the surgical object to be removed without damaging the iris seal. Once the switch is deactivated, the force required to remove the surgical object decreases. 
     It is appreciated that the switch  136  is located proximal to the iris seal  104  and includes a delay mechanism. The delay mechanism may be designed as part of the switch  136 , the motor  134 , or as a separate part of the electrical system. The delay mechanism provides a preset amount of time before actuating the iris seal. This preset amount of time allows the surgical object to be placed in the central passage  116  and positioned before iris seal  104  closes. In another alternative, the switch is manually operated by a clinician once the surgical object is in place. 
     Another envisioned configuration has the leaf members  130  interconnected, so that a force on one causes all leaf members  130  to pivot. This interconnectivity prevents the leaf members  130  from rotating independently, to form an off center seal. Thus, the center of the opening is fixed. One alternative for providing off center positioning of the surgical object is to connect, independently, each leaf member pin via spring to the actuating force. The spring allows some leaf members  130  to be biased, while allowing the other leaf members  130  to rotate a greater degree. It is appreciated that the spring force is adjusted/adjustable so that the leaf members  130  rotate enough to stop gaseous flow around the surgical object, while the clinician manipulates the surgical object within the iris seal. 
     It is further envisioned that the leaf members may be attached and activated through a series of springs and levers to allow the entire seal assembly to float within the housing assembly. A floating seal assembly could be interconnected and still provide off center movement of a surgical instrument.