The present invention generally relates to extraction devices capable of capturing and releasing hard objects, and particularly for surgically moving, manipulating and extracting biological material and man-made material from the human body, such as required in ureteroscopic and renal stone extraction procedures.
Various instruments are known in the art for surgically removing stones, calculi and other hard materials from the body. An example is an extraction instrument disclosed in U.S. Pat. No. 5,281,230 to Heidmueller as comprising a pair of bowls that are pivoted toward and away from each other by engaging their proximal ends with a sheath. Other types of extraction instruments make use of multiple wires that are flexed to grasp an object. For example, U.S. Pat. No. 5,944,728 to Bates discloses an instrument having arcuate wires with rectangular, round, D-shaped, or V-shaped cross-sections. The wires form a basket when a plunger associated with the instrument is in a distal position, allowing the legs to radially collapse toward each other. To expand the legs, the plunger must be actuated into engagement with the legs, forcing the legs radially apart from each other. As such, surgically moving, manipulating and extracting material from a body cavity is complicated by the requirement to additionally operate the plunger to expand and contract the legs.
Another example of an extraction instrument is disclosed in U.S. Pat. No. 6,203,552 to Bagley et al. As with Bates, the instrument taught by Bagley et al. has arcuate legs that form a collapsible basket when actuated with respect to a sheath. Each leg has a wedge-shaped cross-sectional shape, so that together they fill the cross-sectional area of the sheath. Contrary to Bates, the instrument disclosed by Bagley et al. does not require a separate plunger to expand (dilate) and collapse the basket.
U.S. Pat. No. 6,500,182 to Foster and U.S. Patent Application Publication No. 2002/00668954 to Foster disclose other extraction instruments configured to be actuated without the assistance of a plunger. Each instrument taught by Foster has resilient grasping members (legs) that form a basket or forceps when extended from a sheath, and which collapse toward each other when the sheath is advanced over the legs (or the legs are retracted into the sheath). According to Foster, the legs are formed by cutting or forming slots in an elongated cylindrical member, such as a cannula. If formed from a cannula, the legs are said to have semicircular cross-sectional shape. The edges of the legs are said to be spaced apart when in the compact (collapsed) position, a condition which appears to be inherent because each adjacent pair of legs is separated by the slot formed during the cutting/forming operation that defined the legs. As such, it appears the legs cannot be fully collapsed with the sheath, since the sheath cannot have an inner diameter smaller than the cannula from which the legs were defined and which must also be accommodated within the sheath.
There is an ongoing effort to devise surgical extraction instruments with greater grasping capabilities to more easily capture biological material during a variety of medical procedures.
The present invention provides extraction devices adapted to grasp, hold and move a variety of biological materials.
According to one aspect of the invention, such an extraction device has a sheath with an interior passage and legs slidably received within the passage of the sheath. The legs are adapted to move outwardly away from each other when deployed from the sheath to establish a deployed position, and to move inwardly toward each other to collapse within the sheath and define a stowed position. Each leg has a transverse cross-sectional shape defined by a first surface that is concave and an oppositely-disposed second surface that is convex. The legs have adjacent distal ends that define a grasping and holding feature when the legs are moved between their deployed and stowed positions. Each distal end has an arcuate portion that extends along an arc of greater than 90 degrees, and each distal end defines a distal surface that is substantially parallel to the longitudinal axis of the corresponding leg thereof when the legs are in the stowed position. The concave inward surface of each leg and the distal surface cooperate to define at least two points adapted for grasping when the legs are retracted into the sheath.
Other aspects and advantages of this invention will be better appreciated from the following detailed description.
With reference to
The extraction devices are each depicted as comprising a sheath, legs that project from a passage within the sheath, and a laser fiber that also projects from the sheath passage. As known in the art, the legs are adapted to capture and hold stones and other biological materials, and the laser fiber can be employed to fragment the biological material. Alternatively or in addition, the sheath passage may be sized to accommodate an irrigation or injection lumen. The legs are shown as being deployed from the sheath as a result of their distal portions protruding from the sheath passage. The embodiments of
The distal portions of the legs are represented in
A key feature of the present invention is that the distal end of each leg is arcuate, following an arc of greater than 90 degrees, for example, between about 135 and 180 degrees. Furthermore, the distal end of each leg defines a distal surface that is substantially flat and parallel to the longitudinal axis of its corresponding leg when the leg is in its stowed position. Finally, the concave inward surface of each leg (the surface facing the other legs of the device) defines a pair of points with the corresponding distal surface of its leg. While two points are shown, it is foreseeable that the distal surface or the cross-section of the legs could be modified to create more than two points. The multi-point configuration at the distal ends of the legs defines what may be referred to as a claw, which promotes the ability of the devices to grasp and hold a variety of biological materials. As evident from
For comparison,
The multi-point configuration of the legs shown in
The arcuate shape of the distal ends of the legs is also beneficial when the device is configured or otherwise used as a simple grasper/extraction device, in which case “lasing” of a stone (calculi) or other biological material is not necessary. In this scenario, the superior grasping effect of the multi-point claws enhances the ability of the device to grasp and extract biological material through an existing body orifice. The elastically deformable legs enable their distal ends to also release a biological material by advancing the sheath over the legs, enabling a user to release a biological material (for example, a stone/calculi) that is too large to pass out of the body through a natural orifice.
Another feature of the legs is that their concave inner surfaces cooperate to define a central channel, through which the laser fiber (for example, a diameter of 145 micrometers or more) can be passed to disintegrate calculi, blood clots, kidney stones, bladder stones, biliary tract stones, gall stones, and other solid human or animal calculi. The devices enable a user to lase or break up stones (calculi) or other biological material into multiple pieces and immediately use the distal ends as forceps to grasp, manipulate and remove the individual pieces without inserting another device, until the patient is stone-free. The legs are preferably sufficiently resilient so that they are able to securely grasp biological material, without the need for a basket to fully enclose the material. This aspect provides another safety feature by eliminating a basket tip that could be inadvertently cut off by the laser and left in the body during the lasing process.
As evident from
The devices represented in
While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, appropriate materials could be substituted for those noted. Accordingly, the scope of the invention is to be limited only by the following claims.
This application claims the benefit of U.S. Provisional Application No. 61/348,377, filed May 26, 2010, the contents of which are incorporated herein by reference. In addition, this application is related to U.S. Pat. No. 6,416,519, dated Jul. 9, 2002. The contents of this patent are also incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
61348377 | May 2010 | US |