The invention is directed to a trocar seal adapted to form a seal around a surgical instrument, the trocar seal comprising a housing having an axis extending between a proximal end and a distal end and forming a working channel sized and configured to receive the surgical instrument; an elastomeric septum seal having a proximal face and a distal face, the septum seal being disposed in the housing and extending transverse to the axis of the housing across the working channel; portions of the septum seal defining a hole having a diameter less than or equal to the diameter of the surgical instrument so that during insertion of the instrument along the working channel the septum seal forms a seal with the instrument; and at least one structure formed integrally with or proximate to the septum seal to prevent inversion of the septum seal upon withdrawal of the surgical instrument. The septum seal or the housing may further comprise a sidewall to include the structure extending from the sidewall to the distal face of the seal to tether the seal distally. The structure may be integrally formed with the proximal face of the septum seal to reinforce the seal, or the structure may be integrally formed with the distal face of the septum seal to tether the seal distally. The structure may be an annular reinforcement or rib, and is formed so as to allow side-to-side movement or floatation of the seal. The trocar seal may further comprise a plurality of radially extending ribs formed on the proximal or distal face of the septum seal to reinforce the seal. The trocar seal may further comprise a tensile element formed on the distal face of the septum seal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to instrument seals in surgical devices and most specifically to septum seals in laparoscopic trocars.

2. Discussion of Related Art

Less invasive abdominal surgery, commonly referred to as laparoscopic surgery, is undertaken with instruments extending across the abdominal wall. In this procedure, the volume of the abdominal surgical site is increased by inflating the abdomen with a gas. In order to maintain the pressure of the gas within the abdomen while passing instruments across the abdominal wall, access devices, commonly referred to as trocars, are positioned through holes in the abdomen. These trocars are provided with seals which engage the instruments as they are passed through the trocar and into the inflated abdomen.

The seals most commonly used for this purpose are septum seals which are elastomeric and are generally planar in configuration. The septum seals are generally made of a thin material that may tend to engage the body or shaft of an inserted instrument and be drawn along with the axial motion of the instrument as the instrument is placed, used, or removed through the septum seals. These seals extend across a working channel of the trocar and form a seal with the instrument as the instrument is passed through a hole in the septum seal. When the instrument is inserted, the septum seal is pushed generally in the distal direction as it forms a seal with the instrument. When the instrument is withdrawn, the opposite effect occurs; the septum seal is pulled generally in the proximal direction causing the seal to invert. This inversion can add undesirable friction during use of the instrument and may cause the septum to bind or gather between the instrument and portions of the seal housing or floating ring or other adjacent structures when the instrument is withdrawn.

SUMMARY OF THE INVENTION

The invention is directed to a trocar seal adapted to form a seal around a surgical instrument, the trocar seal comprising a housing having an axis extending between a proximal end and a distal end and forming a working channel sized and configured to receive the surgical instrument; an elastomeric septum seal having a proximal face and a distal face, the septum seal being disposed in the housing and extending transverse to the axis of the housing across the working channel; portions of the septum seal defining a hole having a diameter less than or equal to the diameter of the surgical instrument so that during insertion of the instrument along the working channel the septum seal forms a seal with the instrument; and at least one structure formed integrally with or proximate to the septum seal to prevent inversion of the septum seal upon withdrawal of the surgical instrument. In one aspect, the septum seal may further comprise a sidewall including the structure extending from the sidewall to the distal face of the seal to tether the seal distally. In another aspect, the housing may comprise a sidewall including the structure extending from the sidewall to the distal face of the seal to tether the seal distally. In yet another aspect, the structure may be integrally formed with the proximal face of the seal to reinforce the seal, or the structure may be integrally formed with the distal face of the septum seal to tether the seal distally.

The structure may be an annular reinforcement or annular rib, and is formed so as not to prevent side-to-side movement or floatation of the seal. The trocar seal may further comprise a plurality of radially extending ribs formed on the proximal or distal face of the septum seal to reinforce the seal. The trocar seal may further comprise a tensile element formed on the distal face of the septum seal. The tensile element may be formed from surgical suture, an elastomer, a thermoplastic, or a metal wire. It is appreciated that in all of the above aspects of the invention, the structure may include any structure disposed distally of the septum seal and is placed in tension when the seal is moved proximally. Similarly, the structure may include any structure disposed proximally of the septum seal and is placed in compression when the seal is moved proximally.

In another aspect of the invention, a trocar adapted to form a seal around a surgical instrument is disclosed, the trocar comprising a cannula having an axis extending between a proximal end and a distal end; a housing disposed at the proximal end of the cannula and forming with the cannula a working channel sized and configured to receive the surgical instrument; an elastomeric septum seal having a proximal face and a distal face, the septum seal being disposed in the housing and extending transverse to the axis of the cannula across the working channel; portions of the septum seal defining a hole having a diameter less than or equal to the diameter of the surgical instrument so that during insertion of the instrument along the working channel the septum seal forms a seal with the instrument; and at least one structure formed integrally with or proximate to the septum seal to prevent inversion of the septum seal upon withdrawal of the surgical instrument.

These and other features of the invention will become more apparent with a discussion of the various embodiments in reference to the associated drawings.

DESCRIPTION OF THE INVENTION

A feature of the present invention is to prevent the septum portion of a trocar seal from inverting during withdrawal of instruments such as laparoscopic clip appliers or laparoscopic graspers. The septum seal normally includes an access hole which is smaller than the diameter of the utilized instrument to affect a seal around the instrument shaft and prevent loss of pneumoperitoneum during laparoscopic procedures. Frictional forces between the instrument shaft and the opening of the septum seal are therefore present and predispose the septum seal to invert during withdrawal of laparoscopic instruments.

Inversion of the septum seal during instrument withdrawal can result in binding of the instrument between the proximal opening of the seal housing, the septum seal, and the shaft of the instrument. This occurs as a result of the septum seal first being pulled into the proximal opening of the seal housing and then being compressed between the instrument shaft and the proximal opening of the seal housing. The present invention includes features which inhibit or prevent inversion of the septum seal during withdrawal of laparoscopic instruments and therefore the present invention eliminates the risk of an instrument binding within the trocar seal during withdrawal.

Another feature of the present invention is that by preventing the inversion of the septum seal, the surface area of the septum which is in contact with the outer diameter of the instrument shaft is limited to the circumference of the opening of the septum seal multiplied by the thickness of the septum seal at the opening. This translates into a reduction of frictional forces between the septum seal and the utilized instrument, which is highly desirable during laparoscopic procedures. If the septum seal is allowed to invert, then the surface area of the septum which is in contact with the instrument is significantly increased, as compared to the present invention, resulting in very high frictional forces which can lead to operative complications at a critical point when the laparoscopic surgeon must quickly and smoothly remove and replace instruments through the trocar. By reducing the frictional forces or instrument drag, the present invention facilitates rapid and smooth instrument exchanges during laparoscopic procedures.

The present invention also facilitates smooth and accurate positioning of instruments such as laparoscopic clip appliers within the peritoneal cavity due to the fact that inversion of the septum seal is prevented. In prior art devices in which the septum seal can invert, axial movement of clip appliers can result in a stutter-step motion which occurs as the septum seal toggles between a non-inverted state and an inverted state. This in turn can cause many difficulties, for example, in positioning of the clip applier jaws over a vessel, delaying placement of the clip or even in misplacing of the clip itself. By eliminating the inversion of the septum seal during instrument positioning within the peritoneal cavity, the present invention facilitates rapid, smooth, and accurate positioning of laparoscopic instruments at the operative site.

The present invention includes novel features which can inhibit the inversion of the septum seal. These features serve generally to either tether the septum seal on its distal side or reinforce the septum seal on its proximal side.

Referring toFIG. 1, there is shown an axial cross-section view of a trocar seal100adapted to form a seal around a surgical instrument. The trocar seal comprises a housing10having an axis12extending between a proximal end14and a distal end16and forming a working channel18sized and configured to receive the surgical instrument, and an elastomeric septum seal20having a proximal face and a distal face, the septum seal20being disposed in the housing10and extending transverse to the axis12of the housing across the working channel18. It is appreciated that portions of the septum seal20define a hole22having a diameter less than or equal to the diameter of the surgical instrument so that during insertion of the instrument along the working channel18the septum seal forms a seal with the instrument. In this aspect, the seal20further includes a plurality of gussets24incorporated onto the distal face of the seal20to prevent inversion as the surgical instrument is withdrawn from the trocar seal100. It is appreciated that the trocar seal100typically includes a zero closure valve30such a double-duckbill valve. Both of the septum seal20and the zero closure valve30function to form seals across the working channel18, the septum seal20forms its seal in the presence of the surgical instrument while the zero closure valve30forms its seal in the absence of the instrument.

In one aspect, the septum seal20may further comprise a sidewall including the gussets24extending from the sidewall to the distal face of the septum seal20and serving to tether the seal distally and thus preventing inversion. The gussets24are configured such that side-to-side movement or floatation of the septum seal20is not compromised. The gussets24may or may not be integral to the septum seal20. Alternatively, the gussets24may be incorporated onto the proximal face of the septum seal20.

Referring toFIG. 2, there is shown an axial cross-section view of a trocar seal100b, wherein elements of structures similar to those previously discussed are designated by the same reference numeral followed by the lower case letter “b”, the trocar seal100bbeing adapted to form a seal around a surgical instrument. The trocar seal100bcomprises a housing10bhaving an axis12bextending between a proximal end14band a distal end16band forming a working channel18bsized and configured to receive the surgical instrument, and an elastomeric septum seal20bhaving a proximal face and a distal face, the septum seal20bbeing disposed in the housing10band extending transverse to the axis12bof the housing across the working channel18b. It is appreciated that portions of the septum seal20bdefine a hole22bhaving a diameter less than or equal to the diameter of the surgical instrument so that during insertion of the instrument along the working channel18bthe septum seal forms a seal with the instrument. In this aspect, the seal20bfurther includes an annular reinforcement26incorporated onto the distal face of the seal20bto prevent inversion as the surgical instrument is withdrawn from the trocar seal100b. In particular, the annular reinforcement26serves to tether the distal face of the septum seal20bdownward and thus prevents inversion. The annular reinforcement26is configured so that side-to-side movement or floatation of the septum seal20bis not compromised. The annular reinforcement26may or may not be integral to the septum seal20b. Alternatively, the annular reinforcement26may be incorporated onto the proximal face of the septum seal20b.

Referring toFIG. 3, there is shown an axial cross-section view of a trocar seal100c, wherein elements of structures similar to those previously discussed are designated by the same reference numeral followed by the lower case letter “c”, the trocar seal100cbeing adapted to form a seal around a surgical instrument. The trocar seal100ccomprises a housing10chaving an axis12cextending between a proximal end14cand a distal end16cand forming a working channel18csized and configured to receive the surgical instrument, and an elastomeric septum seal20chaving a proximal face and a distal face, the septum seal20cbeing disposed in the housing10cand extending transverse to the axis12cof the housing across the working channel18c. With this aspect, the seal20cfurther includes an annular rib28incorporated onto the distal face of the seal20cto prevent inversion as the surgical instrument is withdrawn from the trocar seal100c. The annular rib28serves to reinforce the face of the septum seal20cand thus prevents inversion. The annular rib28is configured so that side-to-side movement or floatation of the septum seal20cis not compromised. The annular rib28may or may not be integral to the septum seal20c. Alternatively, the annular rib28may be incorporated onto the proximal face of the septum seal20c.

Referring toFIG. 4, there is shown an axial cross-section view of a trocar seal100d, wherein elements of structures similar to those previously discussed are designated by the same reference numeral followed by the lower case letter “d”, that is adapted to form a seal around a surgical instrument. The trocar seal100dcomprises a housing10dhaving an axis12dextending between a proximal end14dand a distal end16dand forming a working channel18dsized and configured to receive the surgical instrument, and an elastomeric septum seal20dhaving a proximal face and a distal face, the septum seal20dbeing disposed in the housing10dand extending transverse to the axis12dof the housing across the working channel18d. In this aspect, the seal20dfurther includes a plurality of radially extending ribs32incorporated onto the distal face of the seal20dto prevent inversion as the surgical instrument is withdrawn from the trocar seal100d. The radially extending ribs32serve to reinforce the face of the septum seal20dand thus prevent inversion. The ribs32are configured so that side-to-side movement or floatation of the septum seal20dis not compromised. The radially extending ribs32may or may not be integral to the septum seal20d. Alternatively, the radially extending ribs32may be incorporated onto the proximal face of the septum seal20d.

In yet another aspect of the invention as illustrated inFIG. 5, there is shown an axial cross-section view of a trocar seal100e, wherein elements of structures similar to those previously discussed are designated by the same reference numeral followed by the lower case letter “e”, that is adapted to form a seal around a surgical instrument. The trocar seal100ecomprises a housing10ehaving an axis12eextending between a proximal end14eand a distal end16eand forming a working channel18esized and configured to receive the surgical instrument, and an elastomeric septum seal20ehaving a proximal face and a distal face, the septum seal20ebeing disposed in the housing10eand extending transverse to the axis12eof the housing across the working channel18e. In this aspect, the seal20efurther includes a plurality of tensile elements or tethers34incorporated onto the distal face of the seal20eto prevent inversion as the surgical instrument is withdrawn from the trocar seal100e. The tensile elements34serve to reinforce the face of the septum seal20eand thus prevent inversion. The tensile elements34may be configured from surgical suture and may be integral to the septum seal20e. In another aspect, the septum seal20emay further comprise a sidewall including the tensile elements34extending from the sidewall to the distal face of the septum seal20eand serving to tether the distal face of the seal downward and thus preventing inversion.

The invention further contemplates any structure, whether or not it is attached to the septum valve, which will inhibit movement of the valve in the proximal direction upon withdrawal of an instrument. This might include any structure disposed on the distal side of the septum valve which would be placed in tension if the valve tended to move proximally. It would also include any structure disposed on the proximal side of the valve which would typically be placed in compression if the valve were to move in the proximal direction.

It will be understood that many other modifications can be made to the various disclosed embodiments without departing from the spirit and scope of the invention. For these reasons, the above description should not be construed as limiting the invention, but should be interpreted as merely exemplary of preferred embodiments.