An apparatus may serve as a surgical portal for the reception of surgical instruments for use in laparoscopic or similar surgery. The apparatus may include inner and outer tubular elongate members adapted for a longitudinal translation relative to one another to effect a length adjustment of the apparatus. An interface between the two elongate members includes a helical thread providing a mechanism for the translation of the elongate members, and indentations in one of the members provides a locking mechanism for affixing the length.

BACKGROUND

1. Technical Field

The present disclosure relates generally to an apparatus for permitting the introduction of a surgical instrument into a patient's body cavity in a laparoscopic or similar surgery. In particular, the disclosure relates to a telescoping cannula assembly configured for longitudinal extension and retraction to effect a length adjustment.

2. Background of Related Art

A relatively small incision is required for minimally invasive surgical procedures such as laparoscopic, arthroscopic, and endoscopic procedures as compared with conventional open procedures. Small incisions are preferred because they are inherently less traumatic to the body tissue and subject internal organs to a minimum of exposure to contaminants in the outside atmosphere. Thus, small incisions enable shorter hospital stays and faster recoveries with less pain and scarring than is common with the larger incisions required for conventional surgery.

Minimally invasive surgery is possible due in part to the availability of instruments designed specifically for this purpose. A cannula, for example, is an elongated tube that may be inserted through the small incision made in a body cavity wall of a patient to provide a working conduit between an internal body cavity adjacent an operative site and the environment exterior to the patient. The body cavity is often inflated with an insufflation gas such as carbon dioxide to separate the body cavity wall from vital organs and to provide some space where a distal end of the cannula can safely protrude into the patient below the body cavity wall.

The length of a cannula is generally selected to span a range of anatomies and consequently a portion of the cannula assembly which remains on the outside of the patient may extend above the body cavity wall to a greater extent than otherwise desired. The cannula assembly may need to extend into deeper regions of the body cavity, e.g., the abdominal cavity, to access remote underlying organs therein. Furthermore, because several instruments of various lengths might be required for a surgical procedure, an instrument may protrude above the cannula assembly to a greater extent than otherwise desired. Accordingly, a need exists for a cannula assembly which facilitates the introduction of surgical instruments to a surgical site, while allowing a longitudinal retraction or extension to effect an adjustment in length.

SUMMARY

The present disclosure describes a surgical portal apparatus which permits a length adjustment to accommodate a range of body cavity wall thicknesses. The apparatus comprises a tubular elongate inner member adapted and sized appropriately for the introduction of a surgical instrument. The elongate inner member has a proximal end, a distal end and a length therebetween, with a portion of the length radially surrounded by a tubular elongate outer member. A length adjustment structure provides an adjustment interface between the elongate inner member and the elongate outer member. The length adjustment structure includes a generally helical thread on at least one of the elongate members and feature on the other for engaging the thread. A length fixation structure includes inter-engaging components for selectively and non-permanently securing a longitudinal position of the elongate inner member within the elongate outer member.

The inter-engaging components may include a series of indentations arranged in a generally helical pattern corresponding to the generally helical thread. The series of indentations may be disposed on an interior surface of the generally helical thread. The surgical portal apparatus may include a housing at or near the proximal end containing a seal apparatus capable of sealing the apparatus before, during and after the introduction of a surgical instrument. The housing may include a connection for introducing an insufflation gas into the body cavity. The elongate outer member may be positioned distally of the elongate inner member.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The attached figures illustrate exemplary embodiments of the present disclosure and are referenced to describe the embodiments depicted therein. Hereinafter, the disclosure will be described in detail by explaining the figures wherein like reference numerals represent like parts throughout the several views.

The present disclosure contemplates the introduction into a person's body of all types of surgical instruments including clip appliers, graspers, dissectors, retractors, staplers, laser fibers, photographic devices, endoscopes and laparoscopes, tubes, and the like. All such objects are referred to herein generally as “instruments.” In the drawings and in the description that follows, the term “proximal,” as is traditional, will refer to the direction toward the operator or a relative position on the surgical device or instrument that is closer to the operator, while the term “distal” will refer to the direction away from the operator or relative position of the instrument that is further from the operator.

Referring initially toFIG. 1, a surgical portal apparatus is generally depicted as telescoping cannula assembly10. Telescoping cannula assembly10includes an elongate outer member14, an elongate inner member18and a housing22. Elongate outer member14is positioned through the skin26and within a layer of body tissue28. Skin26and body tissue28together define a body cavity wall30with a thickness “t.” A distal end34of the elongate outer member14protrudes into an interior body cavity of a patient, and housing22remains in an exterior environment. A proximal end38of elongate inner member18may be rigidly coupled to housing22such that there is no relative motion therebetween, and a distal end40(FIG. 2) of inner member18is telescopically arranged within elongate outer member14. Using a length adjustment structure as described in greater detail below, the overall length “L” of telescoping cannula assembly10may be adjusted by retracting or extending elongate inner member18, for example to accommodate a variance in the thickness “t” of body cavity wall30.

Referring now toFIG. 2, telescoping cannula assembly10is depicted in partial cross section. Housing22includes an insufflation gas valve44and internal seal system46, which may be capable of permitting the passage of an instrument while preventing insufflation gasses from escaping through a proximal end of telescoping cannula assembly10before, during and after introduction of the instrument. Internal seal system46may take any form including the form described in U.S. Pat. No. 5,603,702 to Smith et al., filed Aug. 8, 1994, the entire contents of which are hereby incorporated by reference.

Elongate inner member18includes a longitudinal bore50defining a passageway adapted for the introduction of an instrument. The distal end40and a substantial portion of elongate inner member18are radially surrounded by elongate outer member14. A length adjustment structure defines the degree to which elongate inner member18is nested within elongate outer member14and therefore, the overall length L of telescoping cannula assembly10.

The length adjustment structure may include a female thread52(shown in phantom) disposed on an outer surface58of elongate inner member18. A corresponding male protrusion60or rib is disposed on an interior surface62of elongate outer member14and extends into thread52. Male protrusion60may take the form of a full male thread. Alternatively, male protrusion60may comprise one or more narrow tabs appropriately positioned to guide the relative motion of elongate outer member14along thread52. As seen best inFIG. 3A, thread52includes several interior surfaces64for engaging male protrusion60. Thread52may exhibit a course pitch allowing for large adjustments to be made quickly requiring only a few rotations of either the inner or outer elongate member18,14. The overall length of cannula assembly may be adjusted by corresponding rotational movement of inner member18and outer member14.

As seen inFIG. 3B, a length fixation structure may comprise a series of indentations66on the exterior surface58of elongate inner member18. Indentations66may be discrete, incrementally spaced notches or serrations arranged along the length of elongate inner member18. Male rib68may extend into an indentation66to non-permanently arrest the relative motion of elongate inner and outer members14,18. When sufficient force is applied to either the elongate inner or outer member14,18in an axial direction, male rib68may be temporarily displaced to move over ridges70between indentations66. In this way, male rib68can act as a pawl engaging a ratchet formed from the series of indentations66and ridges70to non-permanently fix the overall length “L” of cannula assembly10. Male rib68may be formed from a flexible material, ball plunger, or other suitable arrangement. Indentations66and male rib68may encircle elongate inner member or any part thereof.

Referring now toFIG. 3C, a length adjustment interface is described that incorporates a length adjustment structure and a length fixation structure. A helical thread72wraps around elongate inner member18. Helical thread72is equipped with a series of internal spaced ridges or detents74and indentations (not visible) between ridges74arranged along a helical path corresponding to an inner surface78of thread72. Male protrusion80is equipped with male rib or pawl88configured to interface with the indentations between ridges74in, e.g., a pawl detent arrangement or in the manner described in connection with the embodiment ofFIG. 3B. Male protrusion80may alternatively be adapted to engage the indentations between ridges74directly.

The positioning of the indentations may take various forms. For example, the indentations may be positioned in a helical path on the outside surface58of elongate inner member18rather than on an inside surface78of thread72. In this case a male rib88on the inside surface62of elongate outer member may engage the indentations to secure the relative positions of elongate members14,18. Also, rather than resembling closely spaced serrations, the indentations may comprise a limited number of strategically placed detents to accommodate the use of standard sized instruments or to accommodate the most typical tissue thicknesses.

In use, the overall length “L” of telescoping cannula10may be adjusted by rotating elongate inner member18along thread72until elongate inner member18reaches a satisfactory longitudinal position within elongate outer member14. The engagement of male rib88with an indentation may provide a tactile queue that such a position has been achieved. The engagement of male rib88is sufficiently robust to prevent any unintended longitudinal migration of elongate inner member18under the weight of housing22and other forces associated with introducing and manipulating a surgical instrument.

In drawing figures and the corresponding descriptions above, the male features of the adjustment interface have been associated with the elongate outer member14and the female components have been associated with the elongate inner member18. However, this convention made for clarity may be reversed and these features may be associated with either elongate member18,14. Also, the elongate inner member has been described as fixedly attached to the housing22and the elongate outer member movable relative to the housing and elongate inner member. This convention may also be reversed such that the elongate outer member is fixedly attached to the housing and the elongate inner member is movable within the elongate outer member14.

Although the foregoing disclosure has been described in some detail by way of illustration and example, for purposes of clarity or understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims.