US20110021881A1 - Trocar anchor - Google Patents

Abstract

Apparatus and methods for providing access to a body cavity without substantial loss of inflation gas therein. The apparatus includes an access assembly that has a tubular member having a proximal end, a distal end, an elastic portion interposed the proximal end and the distal end, and a lumen therethrough. An anchor sleeve is disposed coaxially over the tubular member and has a radially expandable region. The anchor sleeve is moveable between an axially elongated configuration and an axially shortened configuration and is biased toward the axially shortened configuration by a force exerted by the elastic portion of the tubular member. The axially shortened configuration corresponds to the anchor sleeve being in the fully deployed position. Methods for providing anchored access to a cavity within a patient are also disclosed.

Description

BACKGROUND
• 1. Technical Field
• The present disclosure relates generally to apparatus and methods for accessing the interior of the body for performing surgery, diagnostics or other medical procedures. In particular, the present disclosure relates to an access assembly having an expandable anchor to secure and seal the access assembly to the patient's body.
• 2. Discussion of Related Art
• Minimally invasive surgical procedures have recently been developed as alternatives to conventional open surgery. Minimally invasive procedures, such as laparoscopy, involve accessing the surgical area inside a patient through a plurality of ports introduced into the patient's body. This type of procedure is generally less traumatic to the body than open surgery, since these ports tend to cause less tissue damage and blood loss as compared to long incisions made for open surgery. A working space is typically created to provide space inside the surgical area for instruments to operate. For example, in laparoscopic surgery, the abdominal wall is elevated away from the organs in the body cavity. This is usually accomplished by filling the body cavity with a gas, such as carbon dioxide, raising the abdominal wall. This process, known as insufflation, is typically achieved by inserting a large-gauge needle known as a Veress needle into, for example, the intra-abdominal cavity for the introduction of gas. To perform surgical procedures in the intra-abdominal cavity, the insufflation pressure must be maintained, and the abdominal wall must remain elevated from the organs in the intra-abdominal cavity.
• Once enlarged, the cavity may be accessed by inserting a trocar and cannula assembly through the abdominal wall. The trocar is a sharp stylet used to provide an initial penetration and access opening in the abdominal wall for the cannula. The trocar is removed and the cannula remains in the body to provide access to the surgical site.
• In an alternative method known as the “open laparoscopy” method or the Hasson method, access is established to the peritoneal cavity through a small incision on the skin of the abdomen, typically through the umbilicus. A special open laparoscopic cannula is inserted. The physician uses standard laparotomy instruments and grasping forceps to laterally enlarge the initial incision and to lift/separate the fascia. This procedure eventually exposes the peritoneum and places it under tension so that it can be carefully pierced. Once accessed, the physician can pass a gloved finger into the cavity accessing the relevant anatomy and confirming safe entry. Upon securing access, the physician inserts the cannula through the incision and continues with a standard laparoscopic procedure.
• During the surgical procedure, the pressurized integrity of the peritoneal cavity or pneumoperitoneum must be maintained even though there is substantial movement of the cannula during surgery. Unfortunately, it is often difficult to maintain a proper seal between the cannula and body tissue at the initial incision point. Prior art devices have typically employed a conical shaped sealing sleeve generally constructed from a rigid material. Upon insertion into the incision, the sleeve engages the tissue along the thickness of the incision and the sleeve's conical geometry pushes or displaces outward the tissue surrounding the incision. The tissue's natural resiliency will then cause the tissue to try to return to the tissue's original position which creates a sealing force against the surface of the sealing sleeve. The sleeve is usually sutured to the skin at a depth and position where the tissue's resiliency provides sufficient compression to maintain a seal. Another device maintains the integrity of the gas seal and anchors the cannula to the body using an inflatable membrane at the distal end of the cannula. A sealing member is pushed against the exterior side of the body, capturing tissue between the sealing member and the inflatable membrane.
• It is also known to provide access for a surgeon to introduce his or her hand into the body during laparoscopic surgery. Such a hand access port should also be anchored to the patient's body, while providing a seal around the incision.
• Accordingly, a need exists for apparatus and methods for anchoring a cannula or other access member to a patient with minimum tissue trauma while still providing a positive seal.
SUMMARY
• The present disclosure is directed to apparatus and methods capable of providing a gas seal against a percutaneous opening in a patient without the use of suturing, external adhesive devices, or an inflatable anchor. The apparatus of the present disclosure generally has an expandable anchor designed to prevent withdrawal of a surgical access device such as a cannula while maintaining pneumoperitoneum in the cavity. The anchor is integrated into the device design, will not rupture, does not traumatize the body tissue against which it anchors, and automatically deploys following placement into the patient.
• In one embodiment, the apparatus of the present disclosure is an access assembly having a tubular member having a proximal end, a distal end, an elastic portion interposed the proximal end and the distal end, and a lumen therethrough. An anchor sleeve is disposed coaxially over the tubular member and has a radially expandable region. The anchor sleeve is moveable between an axially elongated configuration and an axially shortened configuration and is biased toward the axially shortened configuration by a force exerted by the elastic portion of the tubular member. The axially shortened configuration corresponds to the anchor sleeve being in the fully deployed position. Thus, an external force must be applied to the anchor sleeve to overcome the force exerted by the elastic portion of the tubular member and place the anchor sleeve in the undeployed position for entry in or exit from a percutaneous opening.
• A method of the present disclosure for providing access to a cavity in a patient includes the method step of introducing a tubular body through a percutaneous opening in the patient's dermis. A radially expandable member mounted on the tubular body is axially compressed to radially expand the member. This expansion provides a seal against the internal surface of a patient's dermis. The cavity is insufflated with a gas to provide space in the abdomen for surgical instruments. The seal created by the expandable region inhibits loss of the gas through the penetration. A proximal flange on the tubular body may be advanced to clamp against the exterior surface of the patient's dermis.
• These and other embodiments of the present disclosure, as well as its advantages and features, are described in more detail in conjunction with the text below and attached figures. Advantageously, the present disclosure provides apparatus and methods for anchoring a cannula to a patient with minimum tissue trauma while still providing a positive seal.
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 illustrates a perspective view of the access assembly in accordance with an embodiment of the present disclosure;
• FIG. 2 illustrates a perspective view of the distal end of the access assembly in the undeployed position, in accordance with the embodiment ofFIG. 1;
• FIG. 3 illustrates a perspective view of the distal end of the access assembly in the partially deployed position, in accordance with the embodiment ofFIGS. 1 and 2;
• FIG. 4 illustrates a perspective view of the access assembly in the fully deployed position, in accordance with the embodiment ofFIGS. 1-3;
• FIG. 5A is a perspective view of an access assembly in accordance with a further embodiment of the disclosure;
• FIGS. 5B-D are cross-sectional views of an access assembly penetrating the tissue of a patient in accordance with the embodiment ofFIG. 5A;
• FIGS. 6A-B are cross-sectional views of an access assembly penetrating tissue in accordance with another embodiment of the present disclosure;
• FIGS. 6C-D are side elevational views of the distal end of an access assembly in accordance with the embodiment ofFIGS. 6A-B;
• FIG. 7 is a cross-sectional view of an access assembly having a self adjusting sheath in accordance with a further embodiment of the present disclosure;
• FIG. 8 is a cross-sectional view of an access assembly with an undeployed anchor having an obturator positioned within the anchor such that the obturator stretches the elastic tubing in accordance with the embodiment ofFIG. 7; and
• FIG. 9 is a cross-sectional view of an access assembly with a deployed anchor in accordance with the embodiment ofFIGS. 7 and 8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• Methods and apparatus of the present disclosure are directed towards providing access to a body cavity for surgical procedures. Specifically, methods and apparatus of the present disclosure substantially prevent substantial loss of insufflation fluids through an incision by providing an access assembly that can form a peripheral seal against the incision and anchor the access assembly to the body, while allowing surgical instruments to access the interior of the body during minimally invasive surgical procedures.
• To reach a desired body cavity, the access assembly is inserted through a percutaneous opening in the patient's body, such as an incision through the abdominal wall. The access assembly must typically pass through the abdominal wall which includes the outer skin, a layer of fat, a layer of fascia or alternating muscle and fascia, and the peritoneum. The layers of fat and fascia may vary in thickness, depending upon the body location and whether the patient is asthenic or obese. The peritoneum is a strong, elastic membrane lining the walls of the abdominal cavity. Just below the peritoneum, lie several vital organs, such as the liver, stomach and intestines, and other sensitive tissues. This is typically the area that the access assembly is positioned to reach.
• To perform surgical procedures in this area, the abdominal wall is lifted off of the organs by inflating the area with an insufflation gas such as carbon dioxide. This provides sufficient space for surgical instruments to maneuver. To prevent loss of this gas and loss of working space, the access assembly must provide a gas-tight seal against the abdominal wall while permitting a sufficient range of motion for the instruments and minimizing damage to the portion of the abdominal wall engaged by the seal.
• Although the present disclosure is described with reference to a surgical procedure which includes a penetration of the abdominal wall, such description is made for illustrative and exemplary purposes. As those skilled in the art will appreciate, many other surgical procedures may be performed by utilizing the methods and materials described herein. Preferred embodiments of the presently disclosed access assembly, anchor and methods of using the foregoing will now be described in detail with reference to the figures, in which like reference numerals identify corresponding elements throughout the several views. As used herein, the term mesh is intended to encompass a broad range of structural configurations including, but not limited to woven and non-woven structures, fabrics, weaves, braids, knits and/or felts.
• Referring initially toFIG. 1, a perspective view of an access assembly in accordance with an embodiment of the present disclosure is illustrated. Theaccess assembly10 of the present disclosure generally comprises ahub member12 having ablunt sheath tube14 extending distally therefrom. An obturator or a trocar, slides removably into alumen16 defined by thesheath tube14.
• Thehub member12 may be fitted with a pneumostasis valve (not shown) on a proximal end for sealably receiving a surgical instrument therethrough. The pneumostasis valve may be housed insidehub member12 or otherwise attached to thehub member12 by means known to one having ordinary skill in the art. The valve may be a flap valve, a duckbill valve, or a gas-restricting device of some other design, so long as it allows entry of a surgical instrument while reducing the loss of insufflation gas during the surgical procedure. The pneumostasis valve prevents loss of gas by automatically closing access to thesheath tube14 when surgical instruments are being switched. Desirably, a second valve for sealing around the instrument is provided for minimizing the loss of insufflation gas while an instrument is inserted through the access assembly.
• Thesheath tube14 has anexpandable region24. Theexpandable region24 comprises ananchor sleeve20 disposed coaxially over the distal portion ofsheath tube14. Theanchor sleeve20 may be retained onsheath tube14 by ananchor flange22, or theanchor sleeve20 may be attached to a distal end ofsheath tube14. For example, theanchor flange22 is tightened aroundanchor sleeve20 to compress the anchor sleeve againstsheath tube14 to hold theanchor sleeve20 in place. Theanchor sleeve20 is illustrated inFIG. 1 in an undeployed position. As will be discussed in further detail below, the resting position foranchor sleeve20 is the fully deployed position. An outside force is required to maintainanchor sleeve20 in the undeployed position.
• FIG. 2 illustrates an isolated perspective view of theanchor sleeve20 in the undeployed position, in accordance with the present disclosure. Theanchor flange22 is positioned around a proximal end ofanchor sleeve20 to compress the anchor sleeve against asheath tube14 to hold theanchor sleeve20 in place. Theanchor flange22 is fitted aroundanchor sleeve20 in a manner which will allow the proximal end ofanchor sleeve20 to slide distally alongsheath tube14. In that case, theanchor sleeve20 is fixed around a circumference ofsheath tube14 at the distal end thereof. Thus,anchor sleeve20 will expand to its normally biased deployed position, as illustrated inFIGS. 3 and 4. Alternatively, the proximal end of theanchor sleeve20 may be fixed tosheath tube14 and the distal end may be slidably held tosheath tube14 by an anchor flange.
• The prior art employs a variety of mechanisms, such as using a pistol grip advancing system or some other translating mechanism, to move and expand the anchor mechanism. Theaccess assembly10 in accordance with the present disclosure is automatically biased toward the expanded (deployed) position. Thus, when there is no external force holding the access assembly in the undeployed position, theaccess assembly10 will return to the deployed position. For example, the access assembly may include a tube disposed aroundsheath tube14 and having a distal end attached to theanchor flange22. A latch at a proximal end of the assembly, holds the tube in a proximal-most position, retaining theanchor sleeve20 in the undeployed position. Upon release of the latch, theanchor sleeve20 moves to the deployed position.
• In a further embodiment, thesheath tube14 comprises a resilient and/or elastomeric material. Theanchor flange22 is attached to thesheath tube14, without being slidable in the longitudinal direction. A trocar or obturator is arranged so as to engage thesheath tube14, stretching the sheath tube in a longitudinal direction, when the trocar is inserted into thesheath tube14. As thesheath tube14 is stretched, theanchor sleeve20 is elongated in the longitudinal direction, moving theanchor sleeve20 to the undeployed position. Using the trocar, the distal end of the access assembly is then inserted into the body. Upon removal of the trocar, theanchor sleeve20 returns to the deployed position.
• The trocar,sheath tube14, or both have structure for engaging the trocar with thesheath tube14, when the trocar is inserted into thesheath tube14. The trocar may have a flange or protrusion that engages a similar protrusion in thesheath tube14. Thesheath tube14, trocar, or both may have a tapered shaped. The trocar andsheath tube14 are arranged so that the trocar stretches thesheath tube14, while permitting the cutting tip on the distal end of the trocar to protrude from the distal end of thesheath tube14.
• In a further embodiment, theanchor sleeve20 is sufficiently flexible to collapse upon insertion in an incision. Thus, upon inserting the distal end of the access assembly into the body, theanchor sleeve20 collapses. After theanchor sleeve20 reaches the body cavity, theanchor sleeve20 expands. Upon the removal of the access assembly from the body, theanchor sleeve20 collapses, allowing removal with the application of a small proximately directed force.
• FIGS. 3 and 4 illustrate progressive states of deployment ofanchor sleeve20. More specifically,FIG. 3 illustrates a perspective view of the anchor sleeve in the partially deployed position, in accordance with the present disclosure.FIG. 4 illustrates a perspective view of the anchor sleeve in the fully deployed position, in accordance with the present disclosure. As can be seen by analyzingFIGS. 2-4, as theanchor flange22 moves distally, the anchor expands to form a peripheral seal between theaccess assembly10 and a percutaneous opening in the abdominal wall. Theanchor sleeve20 comprises a flexible and/or elastic material and may comprise polymeric sheet materials, braided, woven, knitted and non-woven materials, and combinations thereof. The materials desirably comprise medical grade materials.
• In a specific aspect of the present disclosure, theexpandable region24 is a non-distensible imperforate cylindrical surface preferably constructed from an elastomeric sheet covering a plurality of polymeric strands. Exemplary materials for the mesh material include braided polymer strands such as medical grade metals, PET, polypropylene, polyethylene, and the like. Exemplary materials for the elastomeric sheet include latex, silicone, thermoplastic elastomers (such as C-Flex, commercially available from Consolidated Polymer Technology), and the like. The braided material is braided in the shape of a cylinder, or otherwise formed into a cylindrical geometry, and, as mentioned, is translatably disposed oversheath tube14.
• Thesheath tube14 can be constructed from a variety of materials including stainless steel, composite filament wound polymer, or extruded polymer tubing (such as Nylon 11 or Ultem, commercially available from General Electric), and other materials known in the art. These materials have sufficient strength so that thesheath tube14 will not collapse when inserted into the abdomen. Although specific dimensions vary depending on the surgical procedure, thesheath tube14 typically has an outer diameter from about 4 mm to 20 mm and a length between about 5 cm and 15 cm.
• Referring now toFIGS. 5A-5D, another embodiment of anaccess assembly50 is disclosed.Access assembly50 includes asheath tube54 andanchor sleeve52. Thesheath tube54 is preferably configured to be self adjusting along its length. For example,sheath tube54 may be of a telescoping design or it may be formed of an elastic material which will allow the sheath tube to stretch and contract in the longitudinal direction.
• A short tip section ofsheath tube54 is illustrated inFIG. 5A. Prior to making the percutaneous opening in the patient, theanchor sleeve52, which is made of a flexible and/or elastic material and may comprise the materials discussed above foranchor sleeve20, is disposed on the patient's body and thesheath tube54 extends proximally from theanchor sleeve52. Once the percutaneous opening has been made, thesheath tube54 is at least partially inserted into the opening.
• Anexpandable region56 ofanchor sleeve52 is preferably formed of an elastic membrane layer and a plurality of polymeric strands, such as the braided polymer strands ofanchor sleeve20. In a specific aspect of the present disclosure, theexpandable region56 is a non-distensible imperforate cylindrical surface preferably constructed from an elastomeric sheet covering the braided material. Exemplary materials for the braided material include polymer strands such as medical grade metals, PET, polypropylene, polyethylene, and the like. Exemplary materials for the elastomeric sheet include latex, silicone, thermoplastic elastomers (such as C-Flex, commercially available from Consolidated Polymer Technology), and the like. The braided material is braided in the shape of a cylinder or otherwise formed into a cylindrical shape and disposed over thesheath tube54.
• The anchor sleeve initially has the shape of a circular sheet. Anouter member53 is desirably attached to anchorsleeve52 and is preferably formed of a relatively rigid material, as compared to theanchor sleeve52, so as to hold theanchor sleeve52 on the outer surface of the body. Theouter member53 may comprise anannular member60 of at least semi-rigid material to assist in maintaining a circular configuration foranchor sleeve52.
• In use, and with continued reference toFIGS. 5A-D, theaccess assembly50 is placed on the patient's body, as illustrated inFIG. 5B. In order to access the abdominal cavity, for example, atrocar device62 is inserted into a proximal end ofsheath tube54. As discussed above, at rest, theaccess assembly50 is in the fully deployed position, as illustrated inFIGS. 5A and 5B.Trocar device62 is arranged such that, when it is inserted into a proximal end of the lumen defined bysheath tube54, the trocar device engages the distal end of thesheath tube54, thereby stretching thesheath tube54 to a point where theanchor sleeve52 collapses to a cylindrical shape with a diameter approximating the diameter of thetrocar device62. Thetrocar device62 extends beyond the distal end ofanchor sleeve52 to form an opening in the skin of the patient. As illustrated inFIGS. 5C and 5D, a point or cutting edge oftrocar device62 extends beyond the distal end of thesheath tube54 andanchor sleeve52, so that thetrocar device62 penetrates the patient's skin and can advance into the underlying tissue of the abdominal wall. Once an opening is formed in theabdominal wall58,trocar device62 is removed fromsheath tube54. When the force of thetrocar device62, thesheath tube54, which is holdinganchor sleeve52 in the undeployed position, retracts andanchor sleeve52 returns to its deployed position. The opening in the abdominal wall holds the proximal end of theanchor sleeve52, while allowing theanchor sleeve52 to bulge outwardly at the distal end of the access assembly. Accordingly, in the deployed position,anchor sleeve52 extends radially and exerts a force upon an inner surface of the patient'sabdominal wall58, thereby forming a seal which will prevent insufflation gas from escaping around the outer circumference ofsheath tube54.
• To facilitate insertion of the access assembly into a pre-existing percutaneous opening, a surgical instrument such as, preferably, a blunt obturator (not shown), is inserted into thesheath tube54. A blunt obturator is preferred for the reason that it will tend to minimize the trauma to the location of the insertion of the access assembly through the percutaneous opening. As discussed above, at rest, theaccess assembly50 is in the fully deployed position. Accordingly, a surgical instrument having a suitable diameter must be inserted into a proximal end of the lumen defined bysheath tube54. Having a suitable diameter will permit the obturator to engage the distal end ofanchor sleeve52, thereby stretching the anchor sleeve to a point where theanchor sleeve52 collapses to a cylindrical shape approximating the diameter of the blunt obturator. At this point, theaccess assembly50 may be inserted through the percutaneous hole formed in the abdomen of the patient. Finally, the obturator is removed from theaccess assembly50 and theanchor sleeve52 will return to the fully deployed position, in response to the force of thesheath tube54, thereby forming a peripheral seal against the inner surface ofdermis58 to prevent the loss of insufflation gas.
• After theaccess assembly50 is secured and peripherally sealed around the opening in the patient, the blunt obturator is completely removed from thesheath tube54 so that surgical instruments (not shown) can be inserted into the lumen ofsheath tube54 to access the body cavity below.
• In removing theaccess assembly50 from the body, the anchor sleeve may be collapsible so that a small proximally-directed force can pull theaccess assembly50 out of the incision. Alternatively or additionally, a trocar or blunt obturator may be used to stretch thesheath tube54 and collapse the anchor sleeve.
• FIGS. 6A-D are side views of a trocar anchor penetrating the dermis layer of a patient in accordance with another embodiment of the present disclosure. This embodiment utilizes a step system to penetrate the dermis of the patient to allow theaccess assembly70 to be inserted into the percutaneous opening. As theaccess assembly70 is placed adjacent thedermis78 of a patient, as illustrated inFIG. 6A, atailpiece80 of theaccess assembly70 is inserted into thedermis78 of the patient. The insertion of thetailpiece80 into thedermis78 provides stability to the remainder of the access assembly while also providing a pilot hole for the final percutaneous opening. Thus, the formation of the percutaneous opening and the insertion of an access assembly is achieved by a stepped approach.
• Once thetailpiece80 has been inserted into thedermis78, in order to form a percutaneous opening large enough to accommodate a surgical instrument, atrocar device82 is inserted into a proximal end ofsheath tube74. As discussed above, at rest, theaccess assembly70 is in the fully deployed position. Accordingly,trocar device82 has a suitable diameter such that, when it is inserted into a proximal end of the lumen defined bysheath tube74, the trocar device engages the distal end ofanchor sleeve72, thereby stretching theanchor sleeve72 to a point where theanchor sleeve72 collapses to its smallest diameter. Thetrocar device82 then continues down through the pilot hole formed bytailpiece80 to form an opening in thedermis78 of the patient. As best illustrated inFIGS. 6C and 6D, once an opening is formed in thedermis78,trocar device82 is removed fromsheath tube74. When the force of thetrocar device82, which is holdinganchor sleeve72 in the undeployed position, as illustrated inFIG. 6C, is removed,anchor sleeve72 returns to its biased, deployed position, as illustrated inFIG. 6D. In the deployed position,anchor sleeve72 exerts a force upon an inner surface ofdermis78, thereby forming a seal which will prevent insufflation gas from escaping around the outer circumference ofsheath tube74.
• Referring now toFIG. 7, a side view of atrocar access assembly90 having a self-adjusting sheath tube in accordance with another embodiment of the present disclosure is illustrated. Thetrocar access assembly90 includes aanchor sleeve92; ananchor base94 which extends proximally fromanchor sleeve92; and ananchor flange96 to prevent the access assembly from falling into the cavity of the patient. Theanchor sleeve92 is configured and dimensioned to form a peripheral seal around the percutaneous opening formed in the patient's body as it presses against the inner surface of the dermis of the patient. Similar to the embodiments described above,anchor sleeve92 is predisposed to the deployed position by the self-adjustingsheath tube98. An external force is required to alter the dimensions ofanchor sleeve92 such thatanchor sleeve92 is capable of being inserted into a percutaneous opening having a diameter which is less than the diameter ofanchor sleeve92 in the fully deployed position.Anchor flange96 rests on an outer surface of the dermis of the patient around the periphery of the percutaneous opening.
• A self-adjustingsheath tube98 is disposed withintrocar access assembly90. Self-adjustingsheath tube98 includes atip portion100, anelastic tubing portion102, and aflange portion104.Tip portion100 forms the distal end of the self-adjusting sheath tube.Tip portion100 is preferably formed of plastic. Theelastic tubing portion102 is connected at a distal end to the proximal end of thetip portion100.Elastic tubing portion102 forms the middle portion of the self-adjustingsheath tube98.Flange portion104 is connected to a proximal end ofelastic tubing portion102.
• The distal end ofanchor sleeve92 is connected to a distal end oftip portion100. Therefore, with reference toFIGS. 7 and 8, to insert theanchor sleeve92 through a percutaneous opening in thedermis112 of a patient, anobturator110 or other instrument is inserted into the lumen defined by self-adjustingsheath tube98. Theobturator110 is dimensioned such that it engages the distal end oftip portion100. Upon further distal translation of theobturator110,elastic tubing portion102 elongates as a result of the force exerted by the obturator ontip portion100. Astip portion100 moves in the distal direction,anchor sleeve92 is forced into the undeployed position, thereby forcinganchor sleeve92 to have a smaller cross-section.
• Once thetrocar access assembly90 is in position within the percutaneous opening formed in thedermis112 of the patient, as illustrated inFIG. 8,obturator110 is removed from thetrocar access assembly90 thereby allowing theelastic tubing portion102 to return to its normal position.FIG. 9 illustrates thetrocar access assembly90 with theanchor sleeve92 in the fully deployed position. Accordingly, in the deployed position,anchor sleeve92 exerts a force upon an inner surface ofdermis112, thereby forming a seal which prevents insufflation gas from escaping around the outer circumference ofsheath tube98.Anchor flange96 rests on an outer surface ofdermis112, to prevent the access assembly from falling into the cavity of the patient.
• It will be understood that various modifications may be made to the embodiments disclosed herein. For example, although the above embodiments are described with reference to a surgical procedure implicating the abdomen, it is contemplated that the disclosure is not limited to such an application and may be applied to various medical instruments. Therefore, the above description should not be construed as limiting, but merely as exemplary of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims.

Claims (8)

1-11. (canceled)

12. A method for providing anchored access to a cavity within a patient, said method comprising the steps of:

providing a tubular member having an anchor sleeve disposed coaxially over the tubular member, said anchor sleeve having a radially expandable region, wherein the anchor sleeve is moveable between an axially elongated configuration and an axially shortened configuration and is biased toward the axially shortened configuration by a force exerted by an elastic portion of the tubular member;

elongating the anchor sleeve in an axial direction to reduce an outside diameter of the sleeve;

inserting the tubular member and anchor sleeve into a percutaneous opening in a patient; and

returning the anchor sleeve to its biased axially shortened configuration, thereby forming a seal against an inside surface of the dermis of a patient around the percutaneous opening.

13. The method as recited inclaim 12 further comprising the step of inserting an obturator into a lumen defined by the tubular member in a distal direction to elongate the elastic portion of the tubular member and the anchor sleeve.

14. The method as recited inclaim 13 wherein the obturator engages a distal end portion of the tubular member.

15. The method as recited inclaim 13 further comprising the step of removing said obturator from the lumen after inserting the tubular member through the percutaneous opening.

16. The method as recited inclaim 12 further comprising the step of insufflating the cavity with a gas, wherein the seal inhibits loss of the gas through the percutaneous opening.

17. The method as recited inclaim 12 further comprising the step of axially advancing a flange on a proximal end of said tubular member to clamp against an exterior surface of the dermis of the patient.

18-24. (canceled)

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