Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1998-12-10
2001-05-08
Kennedy, Sharon (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
Reexamination Certificate
active
06228058
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates broadly to body cavity piercing devices used in surgery to provide access to internal cavities through small puncture sites rather than large incisions. More particularly, the present invention is directed to such a body cavity piercing device, known as a trocar, having a multi-portion obturator, or multiple obturator portions.
A standard trocar is typically a pointed rod, usually formed from metal, which is designed to be contained within a blunt-tipped sleeve known as a cannula. The tip of the trocar is typically needle-like with a beveled piercing tip having sharp edges.
A tissue puncture is manually conducted with the combination trocar and cannula, and then the trocar is removed from the cannula The cannula is left in place to provide an access conduit to the internal body cavity. According to one of two typical trocar designs, a retractable sleeve is positioned around the trocar, with the sleeve being biased such that it slides back on contact with the outer walls of the body cavity covering to expose the tip of the trocar during insertion, but is advanced forwardly to cover the sharp point of the trocar once the internal cavity has been breached.
Another style of trocar is similar in design to a Verress needle, which consists of a sharp tubular needle with an internal blunt obturator provided with a passageway for fluid, the internal obturator being spring biased so that it is forced into the body of the needle during piercing or puncture. Throughout the present application, the terms piercing and puncturing are used interchangeably. The tubular needle itself pierces the tissue, while the obturator blocks the interior of the needle to prevent tissue from entering into the needle. This type of trocar, which is also used in combination with a cannula, has a sharp tubular member or sleeve containing a retractable obturator, with the obturator being spring biased so that the tissue will push it some small distance into the sleeve during the puncture or piercing event. When the tip of the trocar reaches the internal cavity, which is usually inflated with a gas in a procedure known as insufflation, to provide an enlarged cavity, the biasing spring pushes the obturator forward past the sharp tip of the sleeve to prevent accidental puncturing or cutting of internal organs.
It is sometimes difficult for a surgeon to ascertain when the internal cavity wall has been breached by the trocar. Typically, the only indication provided by a standard trocar is a reduction in the amount of resistance felt by the surgeon, with a vibration or sound caused by the forward movement of the spring biased sleeve or obturator once the trocar has entered the internal cavity. Various devices have been developed to provide a more positive indication of when the cavity wall has been breached. These devices typically utilize visual or audible signals.
Other problems with conventional trocar assemblies include the capture of tissue intermediate the obturator and the piercing sleeve wall when the obturator is retracted or pushed back by the body cavity wall. Since the tip is beveled, the initial piercing and cutting is performed by the forwardmost extent of the blade formed on the beveled edge of the sleeve. Once the initial opening is formed, further insertion of the trocar generally forms an aperture in the body cavity wall absent any meaningful cutting action from the remainder of the beveled edge of the trocar sleeve. Therefore, the cut at the trailing edge of the beveled tip may not be as smoothly formed as the initial cut and retraction of the obturator can capture tissue intermediate the obturator and the sleeve.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a sleeve trocar which reduces the capture and withdrawal of tissue during obturator retraction.
It is another object to the present invention to provide such a trocar that provides an audible signal responsive to gas release when entry into the body cavity has occurred.
It is another object to the present intention to provide such a trocar that improves the speed at which the obturator projects ahead of the tip upon breach of the body cavity wall.
To those ends, a sleeve trocar for piercing tissue to provide a conduit to an internal body cavity insufflated by gas includes a sleeve member having a generally tubular wall member defining a bore therethrough, and a cutting edge. The trocar also includes an obturator assembly telescopically disposed within the sleeve member, the obturator assembly including at least one moveable obturator portion having a generally blunt tip. The at least one moveable obturator portion is moveable between a first position wherein the generally blunt tip projects beyond the wall member and a second position wherein the generally blunt tip is disposed interiorly of at least a portion of the cutting edge. The obturator assembly further includes at least one stationary obturator portion having a face member, the at least one stationary obturator portion being fixed relative to the sleeve member with the face member projecting beyond a portion of the wall member. An assembly for biasing the at least one moveable obturator portion into the first position is also included. It is preferred that the sleeve member include a cutting edge with a sharp piercing tip formed thereon and the moveable obturator portion projects beyond the piercing tip in the first position.
Preferably, the at least one stationary obturator portion includes a plug member fixedly disposed within the sleeve member with the face member being formed on one end of the plug member and projecting beyond an end portion of the wall member. The face member preferably includes a smoothly contoured surface for smooth separation of tissue during piercing for enhanced ease of entry of the trocar into the body cavity.
The trocar preferably further includes a penetration indication assembly including a penetration indicator operatively associated with the sleeve member and at least one passageway formed in the obturator assembly in fluid communication with the penetration indicator to allow gas to flow from a pierced body cavity through the at least one passageway to actuate the penetration indicator. It is preferred that the penetration indicator produce an audible signal responsive to gas from the body cavity passing therethrough to thereby indicate that a body cavity wall has been breached.
It is further preferred that the trocar include a handle formed on one end of the sleeve member and having a bore extending therethrough to form the penetration indicator, the bore being in fluid communication with the at least one passageway and configured to produce an audible signal responsive to gas from the body cavity passing therethrough thereby indicating that a body cavity wall has been breached.
Preferably, the penetration indication assembly includes a plurality of passageways formed about a periphery of the at least one moveable obturator portion to form peripheral passageways, the peripheral passageway being formed by a combination of the tubular wall of the sleeve member and walls formed in the periphery of the at least one moveable obturator portion. A plurality of passageways may also be formed about a periphery of the at least one stationary obturator portion to form peripheral passageways with the peripheral passageways being formed by a combination of the tubular wall of the sleeve member and walls formed in the periphery of the at least one stationary obturator portion. Further, a plurality of passageways may be formed about respective peripheries of the at least one moveable obturator portion and the at least one stationary obturator portion to form peripheral passageways, the peripheral passageways being formed by a combination of the tubular wall of the sleeve member and walls formed in the respective peripheries of the at least one moveable obturator portion and the at least one stationary obturator portion.
The plurality of passageways may also be forme
Dennis William G.
Prosek Michael E.
Core Dynamics, Inc.
Kennedy Sharon
Lam Ann Y.
McGuireWoods LLP
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