Abstract:
A surgical portal assembly includes a portal member adapted for positioning within tissue. The portal member defines a central longitudinal axis and has a longitudinal passageway for permitting passage of a surgical object. In addition, the portal member includes a seal mount. A seal member is mounted within the seal mount of the portal member. Further, the seal member has inner surface portions defining a passage for receiving the surgical object. Aside from the seal member, the surgical portal assembly contains a plurality of seal magnets mounted to the seal member. The seal magnets are arranged with respect to the passage of the seal member whereby respective poles of the seal magnets generate an attractive force to draw the inner surface portions of the seal member about the surgical object to facilitate establishing a substantial sealing relation therewith.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/075,856, filed on Jun. 26, 2008, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to surgical devices and, more particularly, to surgical seal assemblies for use with a surgical access device during minimally invasive surgical procedures. 
         [0004]    2. Description of the Related Art 
         [0005]    Minimally invasive surgical procedures, including both endoscopic and laparoscopic procedures, permit surgery to be performed on organs, tissues and vessels far removed from an opening within the tissue. Laparoscopic and endoscopic procedures generally require that any instrumentation inserted into the body be sealed, i.e. provisions must be made to ensure that gases do not enter or exit the body through the incision as, for example, in surgical procedures in which the surgical region is insufflated. These procedures typically employ surgical instruments which are introduced into the body through a cannula. The cannula has a seal assembly associated therewith. The seal assembly provides a substantially fluid tight seal about the instrument to preserve the integrity of the established pneumoperitoneum. 
         [0006]    Minimally invasive procedures have several advantages over traditional open surgery, including less patient trauma, reduced recovery time, reduced potential for infection, etc. However, despite its recent success and overall acceptance as a preferred surgical technique, minimally invasive surgery, such as laparoscopy, has several disadvantages. In particular, the maintenance of the seal about the surgical instrument has proved to be difficult in certain procedures, e.g., in procedures requiring extensive manipulation of the long narrow endoscopic instruments within a remote site. In addition, the force needed to insert the surgical instrument requires great effort by the user to overcome the seal&#39;s retention force. 
       SUMMARY 
       [0007]    The presently disclosed surgical portal assembly includes a portal member adapted for positioning within tissue. The portal member defines a central longitudinal axis and has a longitudinal passageway for permitting passage of a surgical object. In addition, the portal member includes a seal mount. A seal member is mounted within the seal mount of the portal member. Further, the seal member has inner surface portions defining a passage for receiving the surgical object. Aside from the seal member, the surgical portal assembly contains a plurality of seal magnets mounted to the seal member. The seal magnets are arranged with respect to the passage of the seal member whereby respective poles of the seal magnets generate an attractive force to draw the inner surface portions of the seal member about the surgical object to facilitate establishing a substantial sealing relation therewith. 
         [0008]    An embodiment of the surgical portal assembly additionally includes a plurality of mount magnets associated with the seal mount. The mount magnets are arranged to generate a repulsive force with respect to the seal magnets to repel the seal magnets thereby biasing the inner portions of the seal member toward the central longitudinal axis and about the surgical object. 
         [0009]    A further embodiment of the surgical portal assembly incorporates first and second seal magnets mounted to the seal member. The first and second seal magnets have inner poles disposed adjacent the passage of the seal member. The inner poles of the first and second seal magnets are oppositely charged whereby attractive forces between the inner poles draw the inner surface portions of the seal member about the surgical object to facilitate establishing a substantial sealing relation therewith. 
         [0010]    Another embodiment of the surgical portal assembly includes first and second mount magnets mounted to the seal mount and disposed radially outward relative to the central longitudinal axis. The first and second mount magnets are arranged whereby respective poles thereof are oppositely charged with respect to corresponding outer poles of the first and second seal magnets to bias the first and second seal magnets toward the central longitudinal axis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Embodiments of the present disclosure are described hereinbelow with reference to the drawings, wherein: 
           [0012]      FIG. 1  is a perspective front view of a surgical portal assembly and a cannula assembly in accordance with the principles of the present disclosure; 
           [0013]      FIG. 2  is a perspective rear view of the surgical portal assembly and a cannula assembly of  FIG. 1 ; 
           [0014]      FIG. 3  is a perspective exploded view of the surgical portal assembly and the cannula assembly of  FIG. 1 ; 
           [0015]      FIG. 4  is a side cross-sectional view of the surgical portal assembly of  FIG. 1 ; 
           [0016]      FIG. 5  is a side cross-sectional view of the surgical portal assembly of  FIG. 1  with electromagnets; and 
           [0017]      FIG. 6  is perspective view illustrating the surgical portal assembly and a cannula assembly of  FIG. 1  accessing an internal cavity with a surgical instrument inserted therethrough. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0018]    The present disclosure will now describe in detail embodiments of a surgical portal assembly with reference to the drawings in which like reference numerals designate identical or substantially similar parts in each view. As used herein, “clinician” refers to a doctor, nurse or other care provider and may include support personnel. Throughout the description, the term “proximal” will refer to the portion of the assembly closest to the clinician, whereas the term “distal” will refer to the portion of the assembly farthest from the clinician. 
         [0019]    With reference to  FIGS. 1-4 , a surgical portal assembly  100  is operatively attached to an access assembly  200 , such as a cannula or trocar assembly. Access assembly  200  defines passageway therethrough and is particularly adapted for use in laparoscopic surgery where the peritoneal cavity is insufflated with a suitable gas, such as carbon dioxide, to separate the cavity walls from the internal organs. During a conventional laparoscope surgery, the clinician inserts an obturator assembly (not shown) through the passageway of access assembly  200 . The obturator assembly may have a blunt, non-bladed, or sharp pointed distal end. Typically, the clinician uses the obturator assembly to penetrate the abdominal wall or introduce the access assembly  200  through the abdominal wall. The clinician subsequently removes the obturator from the access assembly  200  to clear passage for surgical instrumentation. The surgical instrumentation is then inserted through the access assembly  200  to conduct the appropriate surgical procedure. 
         [0020]    Access assembly  200  includes a cannula sleeve  202  and a cannula housing  204 . Cannula sleeve  202  defines a longitudinal axis “a” extending along the length of cannula sleeve  202  and contains an internal longitudinal passage  206  adapted to allow passage of surgical instrumentation. Cannula sleeve  202  may be constructed of a translucent or opaque material. Moreover, cannula sleeve  202 , or any portion thereof, may be formed of stainless steel or any other suitable rigid material such as polymer or the like. The outer diameter of cannula sleeve  202  may vary to accommodate different surgical instruments. For example, the outer diameter of cannula sleeve may range from about 4.5 mm to about 15 mm. Irrespective of its size, cannula sleeve  202  is configured to be operatively coupled to surgical portal assembly  100  through cannula housing  204 . 
         [0021]    As shown in  FIG. 3 , cannula sleeve  202  is operatively secured to cannula housing  204  by any suitable means. In embodiment shown in  FIG. 3 , cannula housing  204  includes a housing flange  207  and a main housing  208 . The housing flange  207  is attached to a proximal end of cannula sleeve  202 . A bayonet coupling  209 , or any other suitable connecting apparatus or mechanism, couples housing flange  207  to main housing  208 . Specifically, bayonet coupling  209  includes radially spaced tongues  210  positioned around an external surface of housing flange  207  and corresponding recesses  212  radially spread around an internal surface of main housing  208 . Tongues  210  are configured for reception within recesses  212 . To attach housing flange  207  to main housing  208 , a clinician has to position tongues  210  inside recesses  212  and rotate either housing flange  207  or main housing  208  to lock bayonet coupling  209 . 
         [0022]    With further reference to  FIG. 3 , cannula housing  204  contains a first seal member  216 , such as a duckbill valve, zero closure valve, a multiple or single slit valve, a trumpet valve, a flapper valve or the like. First seal member  216  closes in the absence of a surgical instrument, in response to the pressurized environment of the insufflation gases present in the abdominal cavity, or when a combination of the mentioned conditions takes place. Conversely, when a surgical instrument is introduced through the first seal member  216 , first seal member  216  expands and allows passage of the surgical instrument therethrough. 
         [0023]    Referring to  FIGS. 3 and 4 , cannula housing  204  is releasably connected to a surgical port assembly  100 . Surgical port assembly  100  includes a seal housing  102  defining a central seal housing axis “b” that is substantially parallel to the longitudinal axis “a” extending along the length of cannula sleeve  202 . (See  FIG. 2 ). The central housing axis “b” may even coincide with the longitudinal axis “a.” Seal housing  102  further includes first, second, and third interconnected housing components  106 ,  108 ,  110 . First, second, and third housing components  106 ,  108 ,  110  may be assembled together using suitable technique. Altogether, cannula housing  204  defines an internal passageway  114  to allow insertion of surgical instruments therethrough. 
         [0024]    First housing component  106  includes a second seal member  104  mounted thereon. Second seal member  104  is made of a pliable material, such as polyisoprene, natural rubber, soft urethane, silicone, or the like. In addition, seal member  146  defines a slit or aperture  112  positioned in an inner portion thereof for permitting passage of a surgical instrument therethrough. During use, second seal member  104  forms a seal about a surgical instrument inserted through the slit  112 . When a surgical instrument is inserted through slit  112 , second seal member  104  conforms to the shape of the inserted surgical instrument and forms a seal about the surgical instrument. Upon removal of the surgical instrument, slit  112  returns to its closed position and inhibits fluid transfer between internal passageway  114  and the exterior of cannula housing  204 . 
         [0025]    With further reference to  FIG. 4 , cannula housing  204  further includes first and second magnets  302 ,  304  mounted on the first housing component  106  in a diametrical opposed relation. Each of first and second magnets  302 ,  304  is arranged so that an inner pole is positioned closer to slit  112  and an outer pole is positioned farther from slit  112 . The inner poles of first and second magnets  302 ,  304  have opposite charges and are configured to interact electromagnetically with the outer poles of third and fourth magnets  306 ,  308 . 
         [0026]    Second seal member  104  has third and fourth magnets  306 ,  308  imbedded therein. Each of third and fourth magnets  304 ,  308  is arranged such an inner pole is closer to the slit  112  and an outer pole is farther from the slit  112 . The outer poles of third and fourth magnets  306 ,  308  have opposite charges. Furthermore, the inner pole of first magnet  302  and the outer pole of third magnet  306  have like charges, as seen in  FIG. 4 . Consequently, the electromagnetic field induced by first and third magnets  302 ,  306  causes a repulsion force between the inner pole of first magnet  302  and the outer pole of third magnet  306 . Since first magnet  302  is fixed to first housing component  106  and third magnet  306  is imbedded to pliable second seal member  104 , the repulsion force caused by the electromagnetic field causes third magnet  306  to move toward slit  112 . Given that third magnet  306  is embedded in second seal member  104 , the portion of second seal member  104  surrounding third magnet  306  moves toward slit  112  and aids in the formation of a seal. Similarly, the inner pole of second magnet  304  and the outer pole of fourth magnet  308  have like charges. Thus, the electromagnetic filed induced by second and fourth magnets  304 ,  308  causes a repulsion force between the inner pole of second magnet  304  and the outer pole of fourth magnet  308 . Because second magnet  304  is fixed to first housing component  106  and fourth magnet  308  is imbedded to pliable second seal member  104 , the repulsion forced caused by the electromagnetic filed causes fourth magnet  308  to move toward slit  112 . Since fourth magnet  308  is imbedded in second seal member  104 , the portion of second seal member  104  surrounding fourth magnet  308  moves toward slit  112  and aids in the formation of a seal. 
         [0027]    Moreover, the inner poles of third and fourth magnets  306 ,  308  have opposite charges and thus attract each other. The attraction force between the inner poles of third and fourth magnets  306 ,  308  causes the portions of second seal member  104  surrounding third and fourth magnets  306 ,  308  to move toward slit  112 , thereby aiding the formation of a seal. 
         [0028]    As shown in  FIG. 5 , cannula housing  204  may include first and second electromagnets  303 ,  305  instead of first and second magnets  302 ,  304 . Like first and second magnets  302 ,  304 , first and second electromagnets  303 ,  305  are secured to first housing component  106  and are arranged so that their electromagnetic fields induce repulsive forces that repel or move third and fourth magnets  306 ,  308  toward slit  112 , thus assist the formation of a seal around slit  112 . The repulsive force of first and second electromagnetic  303 ,  305 , however, may be controlled by electronic circuitry  310 . Hence, first and second electromagnets, which may be formed by one or more coils, are disposed in electrical connection with electronic circuitry  310 . Electronic circuitry  310  is operatively connected to a power source  320  and is adapted to control the repulsive force produce by first and second electromagnets  303 ,  305 . Power source  320  supplies electronic circuitry  310  and first and second electromagnets  303 ,  305  the power necessary to function properly. 
         [0029]    During operation, the clinician initially introduces access assembly  200  into an insufflated abdominal cavity, as shown in  FIG. 6 . Then, the clinician inserts a surgical instrument “i” into surgical port assembly  100  and advances surgical instrument “i” through passage  114  of seal housing  102 . As surgical instrument “i” passes through slit  112 , the attractive and repulsive forces generated by first, second, third, and fourth magnets  302 ,  304 ,  306 ,  308  draw portions of second seal member  104  toward slit  112  and surgical instrument “i” and consequently facilitate the formation of a seal between surgical instrument “i” and second seal member  104 . As a result, second seal member  104  engages surgical instrument “i” in a substantial sealing relation. The clinician thereafter further advances surgical instrument “i” toward the body cavity through cannula sleeve  202 . Once the surgical instrument reaches the desired surgical site, the clinician may commence the appropriate surgical procedure. 
         [0030]    In the case of the embodiment shown in  FIG. 5 , the clinician may control the repulsive forces of the first and second electromagnets  303 ,  305  with electronic circuitry  310  before, during, or after inserting surgical instrument “i” through slit  112 . To regulate these repulsive forces, the clinician controls the power output by power source  320 . An increase in the power supplied to the electronic circuitry  310  increases the repulsive forces generated by first and second electromagnets  303 ,  305 , causing portions of second seal member  104  to move further toward slit  112 . Conversely, a decrease in the power supplied to electronic circuitry  310  decreases the repulsive forces generated by first and second electromagnets  303 ,  305 , thereby diminishing the advancement of portions of second seal member  104  toward slit  112 . 
         [0031]    It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.