System and method for morcellation of tissue

A device for selectively grasping and cutting tissue includes an outer tube having a longitudinal axis and an open proximal end and an open distal end; also an inner tube within the outer tube, the inner tube having a longitudinal axis and an open distal end and an open proximal end; as well as a cup-shaped cutting member mounted to the distal end of the outer tube, the cutting member being larger in diameter than the diameter of the outer tube, the cutting member including one or more cutting surfaces around the lip of the cup-shaped cutting member, the one or more cutting surfaces facing in a distal direction; also, a cylindrical cup-shaped cutting member mounted to the distal end of the inner tube; the cutting member including one or more cutting surfaces mounted around the lip of the cylindrical cup-shaped cutting member facing in a proximal direction; and, the inner tube is of a diameter to be slidably movable within the outer tube; whereby moving the inner tube alternately in distal and proximal directions along the longitudinal axis causes the one or more cutting surfaces of the inner tube to approach and distance themselves from the one or more cutting surfaces of the outer tube, and, whereby tissue situated between the inner tube and the outer tube is grasped and cut.

BACKGROUND OF THE PRESENT INVENTION

In certain laparoscopic or endoscopic surgeries, such as the laser enucleation of the prostate, hysterectomy or other procedures, there is a need to extract masses of tissue from a surgical site to outside of the body through a channel formed in an endoscope. That channel is generally known as and will be referred to herein as a working channel.

A morcellation device is one type of instrument frequently used to cut masses of tissue into smaller pieces and to then to extract these smaller pieces through a channel within the morcellator. The morcellator may have (and usually does have) a number of channels whose various uses or functions are described herein.

In the prior art, rotational morcellators, such as disclosed in U.S. Pat. No. 8,998,887 or linear morcellators, such as disclosed in U.S. Pat. No. 8,945,021 are known. One common feature of these morcellation devices is the application of negative pressure through a channel of the morcellator. The negative pressure induced pulls a tissue mass toward an opening located in the distal tip of the morcellator. The negative pressure further assures mechanical contact between the tissue mass and one or more moving blades located in the opening. Rotational or linear blades move inside a working channel of the morcellator and cut the tissue mass into smaller pieces which can then be suctioned out of the body through a channel in the morcellator.

Different tools may be inserted through the endoscope and into a surgical site, such as graspers, suturing devices, lasers, knifes etc. The endoscope itself is inserted into the body through a natural orifice or through an incision site. In a laser enucleation procedure, for example, an ureteroscope is inserted through the urethra into the bladder. A waveguide is then inserted through the scope into the bladder and up to the prostate in order to deliver the laser radiation to cut pieces of the prostate, in the case, for example, of benign prostate hyperplasia. Masses of prostate tissue then fall into the bladder and these masses need to be removed from the patient's body through a working channel of the endoscope. These tissue masses, however, may be too large to fit and move through the working channel of the endoscope unless cut into smaller pieces. Therefore, a morcellation device may then be applied to first cut the tissue mass in the bladder and only then to use a suction channel to extract them from the patient.

The level of vacuum in the working channel of the morcellator, among other parameters, controls the efficacy of the morcellator for pulling tissue masses floating in the bladder into its opening and the level of mechanical contact a tissue mass establishes with the morcellator's moving blades. However, there is a practical limit to the vacuum level which can be created inside the bladder. As a result, often the suction or vacuum forces designed to pull tissue masses toward the opening in the morcellator shaft are insufficient and, further, there may be insufficient mechanical coupling during morcellation between a tissue mass and the moving blades. As a result, expensive time is wasted chasing tissue masses which become separated from the morcellator during the cutting process.

A variety of solutions are suggested in the prior art for dealing with these problems. One set of possible solutions is the implementation of different blade designs and geometries, such as disclosed in US Patent application 2008039880, which discloses a round blade with grooves which are designed to better hold the tissue and keep it in place. Serrated blades along or across a morcellator's opening are disclosed in US Patent application 2015305765, WO16018457, U.S. Pat. No. 9,433,437, or in US patent application no. 2016235469 to provide an improved cutting mechanism.

Also known in the prior art are baskets and snares mechanisms, such as disclosed, for example, in U.S. Pat. No. 8,435,237 or US Patent application no. 2016045214, which are designed to be inserted in a folded position through an endoscope or a morcellator into a surgical site and to collect tissue debris in an extended position distally to the surgical instrument. Snaring and wire-cutting loops are also known and are disclosed, for example, in US Patent application no. 20122289971. The foregoing US patent application discloses an extendable loop wire which is designed to hold a tissue mass in the vicinity of a surgical grasper. Yet, an improved mechanism to collect, hold and cut tissue masses effectively within a surgical site is still desired and needed. It is one aspect of the present invention to provide a morcellation system with improved efficiency to remedy the above shortcomings of the prior art devices.

SUMMARY OF THE PRESENT INVENTION

In an aspect, a device for selectively grasping and cutting tissue includes an outer tube having a longitudinal axis and an open proximal end and an open distal end; also an inner tube within the outer tube, the inner tube having a longitudinal axis and an open distal end and an open proximal end; as well as a cup-shaped cutting member mounted to the distal end of the outer tube, the cutting member being larger in diameter than the diameter of the outer tube, the cutting member including one or more cutting surfaces around the lip of the cup-shaped cutting member, the one or more cutting surfaces facing in a distal direction; also, a cylindrical cup-shaped cutting member mounted to the distal end of the inner tube; the cutting member including one or more cutting surfaces mounted around the lip of the cylindrical cup-shaped cutting member facing in a proximal direction; and, the inner tube is of a diameter to be slidably movable within the outer tube; whereby moving the inner tube alternately in distal and proximal directions along the longitudinal axis causes the one or more cutting surfaces of the inner tube to approach and distance themselves from the one or more cutting surfaces of the outer tube, and, whereby tissue situated between the inner tube and the outer tube is grasped and cut.

In another aspect, the cutting surfaces on one or both of the inner and outer tubes are either straight or serrated. The device further may include an endoscopic tube having a distal end and a proximal end, the endoscopic tube having a working channel having a diameter greater than that of the outer tube, whereby the proximal end of the working channel of the endoscopic tube accepts the distal end of the outer tube and the distal end of the outer tube accepts the proximal end of the inner tube through the distal end of the working channel.

In a further aspect, the cup-shaped cutting members of the outer and the inner tubes may have a diameter no greater than that of the endoscopic tube, whereby the overall profile of the endoscopic and cup-shaped members present an overall diameter no greater than that of the endoscopic tube. Also, the inner tube just proximal of the cup-shaped cutting member may include a cutout cavity along the longitudinal axis of the inner tube, further including a second cutting surface facing in a proximal direction within the cutout to grasp and cut tissue with the cutout. Further, the second cutting surface may be one of straight or serrated.

In yet another aspect, the outer tube just distal of the cup-shaped cutting member may include a cutout along the longitudinal axis of the inner tube, further comprising a grasping device which grasps and holds tissue during cutting by moving the inner tube in a proximal direction along its longitudinal axis. Further, the grasping device may include a one or pair of wires which engage and hold tissue portion prior to and during cutting by the one or more cutting surfaces on the inner and outer tubes. Also, the grasping device may include a looped wire that grasps and holds a tissue portion prior to and during cutting by the one or more cutting surfaces on the inner and outer tubes. A vacuum device which pulls tissue into the inner tube cavity may be provided.

In an aspect, a method of grasping and cutting tissue includes the steps of: providing an outer tube having a longitudinal axis and an open proximal end and an open distal end; providing an inner tube within the outer tube, the inner tube having a longitudinal axis and an open distal end and an open proximal end; providing a cup-shaped cutting member mounted to the distal end of the outer tube, the cutting member being larger in diameter than the diameter of the outer tube, the cutting member including one or more cutting surfaces around the lip of the cup-shaped cutting member, the one or more cutting surfaces facing in a distal direction; further, providing a cylindrical cup-shaped cutting member mounted to the distal end of the inner tube; the cutting member including one or more cutting surfaces mounted around the lip of the cylindrical cup-shaped cutting member facing in a proximal direction. The inner tube may be of a diameter to be slidably movable within the outer tube; the method further includes the step of moving the inner tube alternately in distal and proximal directions along the longitudinal axis, the moving causing the one or more cutting surfaces of the inner tube to approach and distance themselves from the one or more cutting surfaces of the outer tube; whereby tissue situated between the inner tube and the outer tube is grasped and cut. The method may further include the step of employing a vacuum device to pull tissue into the inner tube cavity.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

A working channel diameter in a laparoscope, endoscope or any other surgical scope such as for example, uretroscope, cystoscope or naphroscope, is, as a practical matter, limited in size due to, for example, the need for it to be inserted into body orifices or target tissue dimensions. Further, at any given time, additional other instruments may be required to be inserted through the instrument's channel or channels simultaneously. Therefore, surgical instruments which are designed to be inserted through such working channels are very limited in size and shape. The working channel of the scope is designed to be used with different instruments for performing surgical procedures. At different stages of the procedure, different instruments are inserted into the surgical site. In case of a multiple incision procedure, more than one working channel may be available for the physician and multiple tools may be used together. Some surgical instruments are designed to be inserted in a reduced folded form into the channel and allowed to expand once they reach the distal tip of the scope. This requires specific solutions to transform the shape of these instruments from a folded position to an unfolded position. This transformation may be “spontaneous”, for example, by using shape memory materials or by a control mechanism which allows the control of an instrument located in the distal tip of the scope from its proximal site by a physician.

Other channels present in the scope may contain other devices which are purposed to provide illumination, visualization and irrigation or other fluid supply. These devices are crucial to maintain an appropriate surgical environment in order that the physician be able to effectively perform the surgery. The room within the scope that the above-mentioned parallel channels occupy within the scope further increase the problem of having sufficient space within the scope. Usually, these parallel channels and the instruments which occupy these channels, are characterized by a round cross section. As a result there are “dead zones” in the scope located in the space(s) in between the round cross sectional channels which are not used. It is one aspect of the present invention to provide a solid cutting instrument which is not a flexible or foldable and yet wider and bigger than available cross section of the scope working channel.

Referring now toFIGS. 1A through 1D, those figures illustrate the general structure of a nephroscope10, which has a first illumination channel11a, a second optional illumination channel11b, and a visualization channel12. A morcellator14is positioned in the working channel of the scope. As can be seen best in theFIG. 1D, due to the round nature of these channels, dead spaces13aand13bare located between these channels. Dead spaces13a,13baround and between channels11a,11band12may be used as inlet ports for the provision of, for example, an irrigation fluid. Dead spaces around the working channel15for the morcellator, shown as two channels14aand14b, are usually not in use. The working channel of the endoscope however, is limited to a diameter16and is large enough only to insert the shaft141of the morcellator, as may be seen inFIGS. 1A and 1B. The distal tip of the shaft141comprises an external ring142which is configured to hold and cut tissue mass and an external blade143which is configured to hold and cut a tissue mass. These structures have larger diameters than the diameter of the working scope15and therefore cannot be inserted through the working channel of scope in a rigid form. However, as can be seen inFIGS. 1A and 1B, the diameter of scope10is larger than that of the shaft141. Moreover, the diameter17of scope10dictates the size of an incision required should the scope not be inserted through a natural orifice in the body. Therefore, according to this aspect of the invention, there is provided a modular morcellator which consists of an elongated shaft member141, as can be seen inFIG. 2and a handpiece21. Shaft member141is configured to be inserted into a working channel of a scope from its distal end rather than its proximal end and before the scope is inserted into the body through a trocar. Proximal end2001of shaft member141extends out of the proximal end of scope10and is configured to be connected to handpiece21.

Referring now again toFIGS. 1A and 1B, the distal tip of a morcellator14which consists of elements142and143has a larger diameter than the diameter16of the working channel15of scope10and may be approximately the same diameter as that of scope10. According to this aspect of the invention, solid and rigid tissue holders and cutting blades located at a distal end of a morcellator, having a larger diameter than the diameter of the working channel of a scope10may be used. Dead zones13a,13b,14aand14bor channels11,12or13will no longer consume expensive real estate available for the distal tip of shaft141of the morcellator14.

FIG. 3shows a reverse assembly of a morcellator shaft member30into scope10as described above. As shown inFIG. 4, morcellator40may be used externally and in conjunction with an outer sheath which includes channels11a,11band12ofFIG. 1D.FIG. 1Dshows a cross-section view100of endoscope200. Irrigation channels13a,13bmake use of dead spaces located between illumination channels11aand11band visualization channel12. However, dead areas14a,14blocated around the endoscope working channel15are not utilized. Any surgical instrument which is designed to pass through working channel15cannot have a diameter larger than the diameter16of working channel15. However, endoscope200diameter17is much bigger. A surgical instrument having a similar diameter to diameter17will not increase the cross sectional foot print of the scope, but it cannot be delivered into the surgical site through working channel15due its smaller diameter16. It is one aspect of the present invention to provide a modular morcellator and a reverse assembly method having a morcellator tip14which is larger than diameter16.

FIG. 5shows one exemplary configuration of distal shaft member50. As can be seen inFIG. 5B, an external shaft tube54is configured to accommodate internal shaft member55in a slidable configuration. A first external cavity is defined by external blades51and52and a second internal cavity is defined by internal blades530and531, best seen inFIG. 5A. Blades510,520,530and531are configured to hold and cut tissue masses. Such blade members may be plain and/or serrated. As can be seen inFIG. 6A, external and internal blades71and72respectively, are rigidly connected to inner shaft70and are configured to move with it along the X axis73. Addition external and internal blades61and62respectively, are rigidly connected to outer shaft60and are configured to move with it along the X axis1301. It is the relative movement of inner shaft70and outer shaft60which hold and cut the tissue both in the external cavity600and internal cavity610.FIG. 6Bshows the closed configuration of cavities600and610. A negative pressure pump is configured to create negative pressure within the inner cavity610in order to pull and hold tissue masses into the blades area.

According to another aspect of the embodiments described inFIGS. 1-6, the external cavity which is defined by the proximal blade51and distal blade52shown inFIG. 5, reduces the impulsion force a tissue mass experiences due to the flow of irrigating fluid delivered by irrigation outlet ports. This impulsion force works on the tissue mass in an opposite direction to that required in order to get effective morcellation because it tends to push a tissue mass away from the morcellation cavity. Dealing with this problem often consumes valuable time during the procedure. Blade51, by reason of it having a diameter which is larger than that the diameter of the working channel of the endoscope, masks or shields at least some of the direct impulse fluid force created by the fluid inlet ports13a,13bof the irrigation system which is applied to a tissue mass. It should be mentioned that according to an aspect of the invention, a wideangle camera may be used to view the surgical site so that external blade51will not block the field of view of visualization system utilized channel12.

During a morcellation procedure, the morcellator is configured to extend out of the distal end of the endoscope so that distal tip of shaft member141does not block the field of view of channel12.

Referring now toFIGS. 7A, 7B and 7C, shown are three blade embodiments, and including serrated teeth71, sharp teeth72and rounded teeth73respectively. As can be seen in these three non-limiting examples, each of the blades inFIGS. 7A, 7B, and 7Cworks against a planar or straight opposite blade170. It should be mentioned that according to this aspect of the invention, the opposite blade may not necessarily be planar or straight and can also be any of the geometries described inFIG. 7. Referring now toFIGS. 8A, 8B, 8C and 8Dshown are experimental results of different blade geometries and different blade pairings and different cavity sizes.

Referring now toFIG. 9-15shown are different grasping solutions for tissue masses. These are designed to hold a tissue mass during morcellation and to create a positive force to push a tissue mass against the moving blades. This mechanical manipulation is in addition to the negative pressure pulling force applied on a tissue mass by the vacuum discussed above.

FIG. 9illustrates a pair of flexible wires90made of a memory shape material, such as nitinol, which are connected to inner tube91and are configured to move with it along the X axis. During morcellation, inner tube91slides linearly inside outer tube93along X axis. This movement opens and closes cavity94. During a closing movement, as wires90hit edge92of outer tube93they tend to bend inside outer tube93and therefore to create a positive force against a tissue mass which is trapped between wires90.

FIG. 10shows another version of a similar solution to that inFIG. 9in which wires1000are only connected to inner tube101in one side and are configured to grasp a tissue mass on its collapsible free edges102.

FIG. 11illustrates another version of a similar collapsing shaped memory wire which is connected as a loop structure1111to inner tube111.

FIG. 12illustrates an external tube120which is located along outer tube121and is configured to accommodate a slidable shaped memory wire123. In its folded position, wire123runs around and adjacent morcellator tip122. In its unfolded position, wire123which is made of a memory shaped material, is configured to create a loop127having a scorpion-tail shape, which is configured to hold and push tissue mass124into and against cavity125. Wire123may be handled manually or automatically from the handpiece. The ability to control and manipulate from the handpiece wire123, or any other grasping and tissue pushing element disclosed herein, improves the ability to hold and push tissue masses having different sizes and geometry.FIG. 15shows another design.

FIG. 13illustrates another version of a collapsible element made of a memory shaped material which is configured to create a positive pressure on a tissue mass. According to this embodiment, a leaf spring130is attached to inner tube131. Leaf spring130is configured to hold a tissue mass132and push it toward cavity133. While inner tube131moves in outer tube134, leaf spring130hits edge135of outer tube134and further pushes tissue mass132toward cavity133and the morcellator blades assembly.

FIG. 14illustrates yet another embodiment of the present invention in which the inner tube has an extension to manually grasp a tissue segment (augmented by suction) and bring it back towards the cutting edge as shown, after which the segment is enclosed within the inner tube recess and removed from the body as in previous embodiments.

FIG. 15Aillustrates a series of further embodiments of grasping and cutting implements.

FIG. 15Billustrates a further embodiment of a tissue grasping device mounted on the distal portion of the device.

FIG. 15Cillustrates further details of the distal portion of the device of the present invention.