Background of the Invention
This invention relates generally to the field of surgical instruments and methods. More particularly, it relates to an apparatus and method for suture ligation of blood vessels and other bodily ducts, using a laparoscopic access site.
Laparoscopy has become increasingly popular as a technique of minimally invasive surgery because of its significant advantages over conventional surgical techniques: reduced surgical trauma and scarring, substantially less pain and discomfort, significantly decreased risks of infection, and shortened recuperation times (and thus shorter, less expensive hospital stays). Thus, laparoscopy has been used in such procedures as cholecystectomy, hysterectomy, bowel resection, and hernia repair.
In laparoscopy, all of the steps of a surgical procedure (such as dissection, cutting, suturing, and ligating) are performed by means of elongated instruments that are inserted into the abdominal cavity via trocars that, in turn, are inserted through small, "minimally invasive" incisions or punctures.
One of the more difficult surgical skills to acquire is that of laparoscopic knot-tying or ligation of vessels and tissue pedicles and the like. Ligation of such structures during laparoscopy requires the passing of sutures and the tying of knots remotely, using elongated forceps, under videoscopic observation. Several devices have come into use to facilitate laparoscopic ligation, but these have either required the use of clips that may be prone to dislodgement, or the use of preformed suture loops that necessitate the cutting of the vessel prior to tightening the knot, so that the loop may be placed around a free end of the vessel, (which may be disadvantageous in some procedures). Furthermore, some prior art devices may require the surgeon to learn complicated new knots, or they may require additional access sites to complete or tighten the knot.
While there have been a number of suture-tying or ligation devices developed in the prior art, none of these is particularly well-suited to laparoscopic procedures.
For example, Soviet Union Patent No. 549,146 discloses a device for applying ligatures to a blood vessel or the like, comprising an elongate, hollow body having a conical head, and a hook extending from the body so that its terminus is spaced from and opposed to the head. The hook has a grooved aperture near its terminus. A length of ligature is wrapped around the body near the head in one or more loops, and includes a segment that is carried in the groove across the aperture. A retractable rod is carried in the body, the rod having a finger at one end that is insertable through the head and into the aperture. In use, the hook is guided under the vessel to be ligated, and the rod is inserted through the aperture so that the finger grasps the ligature. The rod is then retracted into the head, pulling the ligature with it. The loops of the ligature are then manually slid off the head and over the portion of the ligature pulled toward the head by the rod, and then manually tightened to form a knot around the vessel. This need for the surgeon to reach into the surgical sight with his or her fingers to manipulate and tighten the ligature loops manually thus necessitates an enlarged surgical opening, thereby making a device of this type unsuitable for minimally invasive surgery, such as laparoscopy.
U.S. Pat. No. 5,059,201--Asnis discloses a tool that can be used for ligating a vessel during a laparoscopic procedure. The device includes an elongate outer tube with a bracket on the end. The outer tube carries an axially-movable inner tube, which, in turn, contains an axially-movable shaft with a notch on its end. One end of a suture is clamped to the handle end of the device and is threaded across the bracket. The bracket is placed under a vessel, and the inner tube is extended to capture the vessel. The shaft is then extended through a hole in the bracket to capture the suture in the notch of the shaft. The shaft and the inner tube are then withdrawn into the outer tube to draw the suture around the vessel. A slip knot can then be formed around the vessel, but the knot must be tightened with a separate implement comprising a shaft with a ring at one end. In other words, the Asnis device lacks self-contained means for manipulating and tightening the knot, requiring a separate tool for this task.
U.S. Pat. No. 2,455,833--Trombetta and U.S. Pat. No. 3,985,138--Jarvik disclose ligating devices having clamping jaws for grasping a vessel to be ligated while a suture is tied around the vessel. While these devices (and especially the Jarvik device) may be adapted for use through a trocar, both devices require severing and clamping of the vessel prior to the application of the ligatures, and thus may be disadvantageous where clamping is sought to be avoided or minimized.
Other devices for applying ligatures are disclosed in U.S. Pat. No. 1,400,653--Barbour; U.S. Pat. No. 1,545,682--Nelson; U.S. Pat. No. 3,040,747--Wood; and British Patent No. 479,719--Webb et al. The devices are typically forceps-like implements that are not adapted for insertion and use through a trocar, and that may require clamping of the vessel and/or manual manipulation and tightening of the ligature knot.
Thus, there has been an as-yet unfulfilled need for a ligature tying device that is suitable for use through a trocar for laparoscopic procedures, that includes self-contained means for manipulating and tightening the ligature knot through the trocar without the need for manual manipulation and tightening, and that do not require clamping of the vessel. Furthermore, it would be advantageous to provide such a device that is also simple to manufacture and to use, and that does not require the use of new, complex suture knots. It would be further advantageous to provide a device of this nature that can be made in a disposable or single use embodiment.
Summary of the Invention
Broadly, the present invention is a suture ligation device, comprising an elongate outer tube having a patient, or distal end and an operator, or proximal end. Extending distally from the patient end of the outer tube are first means for (1) grasping and isolating a vessel or duct, and (2) holding the tag end of a suture. The outer tube carries within it axially movable second means for releasably holding a plurality of loops of the suture. The second means, in turn, carries within it axially movable, spring-biased third means, for capturing the tag end of the suture from the first means, and for drawing the tag end of the suture through loops released by the second means so as to form and tighten a ligating knot around the vessel.
In a preferred embodiment of the invention, the outer tube has an open patient end, and the first means comprises an arcuate finger having a tip that is spaced from and opposed to the open patient end of the outer tube, the tip being configured so as to hold a portion of the length of a suture, near its tag end, in opposition to the open patient end of the outer tube. The second means comprises an inner tube or mandrel that is axially movable within the outer tube, and that has a distal end protruding from the open patient end of the outer tube. Wrapped around the distal end of the inner tube are several loops formed in the standing part of the suture, the tag end of which is held by the finger. The third means comprises a spring-loaded push rod disposed within the inner tube, the distal end of the push rod having a hook that is extensible from the inner tube for grasping the tag end of the suture from the finger. The spring bias of the rod is such as to urge the rod proximally, that is, away from the finger and toward the operator.
To perform a ligation, the patient end of the outer tube is passed down a trocar to the surgical site. The outer tube is manipulated so that the finger isolates the vessel or duct, and captures the vessel or duct in the arcuate bend of the finger, between the tip of the finger and the open patient end of the outer tube. The push rod is moved distally, against the bias of its spring, until the hook at its distal end emerges from the distal or patient end of the inner tube and captures the tag end of the suture from the finger. The push rod is then released, and its spring bias causes it to move proximally, looping the tag end of the suture over the captured vessel or duct, and into the inner tube, thereby passing the tag end of the suture through the loops carried on the distal end of the inner tube.
The inner tube is now pulled proximally through the outer tube, dropping the loops off of its distal end, and onto the tag end of the suture, thereby forming a loose knot. The knot is then tightened on the tag end of the suture as the tag end is pulled through the loops by the continued proximal movement of the push rod, the engagement of the suture against the distal side of the finger providing the required counter-tension. As the tightening tension increases, the finger flexes, thereby releasing the suture, which then forms a loop that tightens around the vessel or duct. Continued pulling of the tag end by the push rod causes the knot to lodge in a notch in the patient end of the outer tube, whereby further proximal movement of the knot is halted. Continued tension applied to the tag end by the push rod brings the vessel or duct up against the knot and constricts the suture around the vessel or duct until ligation is completed. The suture is finally cut above the knot by rotating the device to bring the tag end and the standing part of the suture into contact with a cutting blade built into the distal end of the outer tube. The finger is then disengaged from the vessel or duct, and the ligation device is withdrawn from the trocar.
As will be better appreciated from the detailed description that follows, the present invention offers several advantages over prior art ligation devices. First, it is especially well-suited to laparoscopic surgery, by virtue of its ability to be inserted into a trocar, and by its ability to tighten the ligature knot without the use of either a separate implement or the surgeon's manual manipulation of the suture. Second, the device can be supplied with the suture pre-loaded, and it does not require the surgeon to learn new or complex ligature knots. In addition, a ligature device in accordance with the present invention can be inexpensively manufactured, and thus is adapted for disposable, single-use embodiments. Furthermore, use of the present invention does not require clamping of the vessel or duct prior to ligation. Moreover, facility in using the present invention may be easily acquired, especially as a result of its automatic knot-tightening capability.
These and other advantages of the present invention will be made apparent in the detailed description that follows.
Brief Description of the Drawings
FIG. 1 is a perspective view of a laparoscopic ligation device in accordance with a preferred embodiment of the present invention;
FIG. 2 is a plan view of the distal portion device, taken along line 2--2 of FIG. 1;
FIG. 3 is a plan view of the proximal portion of the device, taken along line 3--3 of FIG. 1;
FIG. 4 is an axial cross-sectional view, taken along line 4--4 of FIG. 1;
FIG. 5 is an enlarged, detailed, fragmentary view of the portion of the device enclosed within the broken outline 5 in FIG. 4;
FIG. 6 is a fragmentary, axial, cross-sectional view of the distal portion of the device, showing the suture loops wrapped around the inner tube;
FIG. 7 is a fragmentary elevational view of the distal portion of the device, loaded with a length of suture, prior to performing a ligation;
FIG. 8 is a fragmentary top plan view of the distal portion of the device, loaded with a length of suture, prior to performing a ligation;
FIG. 9 is an axial cross-sectional view of a laparoscopic trocar inserted into a patient's abdomen via a laparoscopy incision;
FIG. 10 is a view similar to that of FIG. 9, but showing the device of FIG. 1, in elevation, disposed within the trocar of FIG. 9;
FIG. 11 is a top plan view of the distal portion of the device, prior to engagement with a vessel to be ligated;
FIG. 12 is an elevational view of the distal portion of the device, showing the step of engaging a vessel to be ligated;
FIG. 13 is an elevational view of the distal portion of the device, showing the step of extending a spring-loaded plunger, disposed within the inner tube of the device, toward and beyond the vessel engaging finger, prior to capturing the tag end of the suture;
FIG. 14 is a top plan view of the distal portion of the device, showing the same step as shown in FIG. 13;
FIG. 15 is an elevational view of the distal portion of the device, showing the step of capturing the tag end of the suture in a hook on the distal end of the plunger;
FIG. 16 is a cross-sectional view of the distal portion of the device, showing the step of drawing the tag end of the suture through the suture loops carried on the outside of the inner tube;
FIG. 17 is an elevational view of the distal end of the device, showing a further progression of the step shown in FIG. 16;
FIG. 18 is an elevational view of the distal end of the device, showing the step of withdrawing the inner tube to drop the suture loops onto the tag end of the suture to form a knot;
FIGS. 19, 20, and 21 are elevational views of the distal end of the device, showing the progression of the step of tightening the knot onto the tag end of the suture, FIG. 21 further showing the suture being released from the finger to form a loop around the vessel;
FIG. 22 is an elevational view of the distal portion of the device, showing the tightening of the loop around the vessel, the suture having been released from the finger;
FIG. 23 is an elevational view of the distal portion of the device, showing the knot having reached its proximal limit of travel, having become seated in a notch in the distal end of the outer tube;
FIGS. 24 and 25 are top plan views of the distal portion of the device, showing the progression of the step of constricting the vessel by tightening the loop around it;
FIG. 26 is a top plan view, similar to that of FIGS. 24 and 25, showing the vessel having been ligated by the complete tightening of the loop around it, and showing the step of cutting the suture to free the ligation device prior to its withdrawal from the trocar;
FIG. 27 is a perspective view of a laparoscopic ligation device in accordance with an alternative embodiment of the invention;
FIG. 28 is a fragmentary top plan view of the proximal portion of the device of FIG. 27, taken along line 28--28 of FIG. 27;
FIG. 29 is an axial cross-sectional view, taken along line 29--29 of FIG. 27; and
FIG. 30 is an enlarged, detailed, fragmentary view of the portion of the device enclosed within the broken outline 30 in FIG. 29.
Detailed Description of the Invention
Referring first to FIGS. 1-8 of the drawings, a laparoscopic ligation device 10, in accordance with a preferred embodiment of the invention, is shown. The device 10 comprises an elongate outer tube 12, having a distal or patient end 14 and a proximal or operator portion 16. The distal end 14 of the outer tube 12 is provided with an acutely-angled notch 17, the purpose of which will be described below. The proximal portion 16 of the outer tube 12 is fixed in a tubular sleeve 18 having an enlarged diameter proximal end 19 that abuts against the distal end of a hollow, cylindrical handle member 20. The handle member 20 and the sleeve 18 are detachably joined together by means such as a heat stake 21, as best shown in FIGS. 3 and 5. The interior of the handle 20 defines an axial internal chamber 22.
An elongate inner tube 23 or mandrel is disposed within the outer tube 12 for axial movement therein. The inner tube 23 has a distal or patient end 24 that normally protrudes through, and extends distally from, the open distal end of the outer tube 12. The inner tube 23 extends from its distal end 24, through the proximal portion 16 of the outer tube 12 (which resides in the sleeve 18), to a proximal end 26 that is fixed to the distal end of the handle member 20.
Attached to the outer tube 12 near its distal end 14, and extending distally therefrom, is a curved finger 28. The finger 28 has an arcuate bend 29, and a substantially vertical portion that terminates in a tip 30 that is spaced from, and opposed to, the open distal end 14 of the outer tube 12. A suture access aperture 32 is provided near the tip 30 of the finger 28. As best shown in FIGS. 12 and 13, a lateral suture retention groove 34 is formed in the finger tip 30, on either side of the aperture 32, the grooves 34 being located on the proximal side of the finger tip 30, that is, on the side facing the open distal end of the inner tube 23.
An elongate push rod 36 is disposed longitudinally within the inner tube 23 for axial movement therein between first (proximal) and second (distal) axial positions. The push rod 36 has a distal portion provided with suture grasping means, such as a hook 38, and a proximal portion 40 that extends through the axial internal chamber 22 of the handle member 20. A piston or plunger 42 is disposed within the chamber 22, and has a distal end 44 residing within the chamber 22, and a proximal end formed as a manual grip or knob 46 that protrudes from the open proximal end of the chamber 22. The plunger 42 is disposed within the chamber 22 for axial movement therein between first (proximal) and second (distal) axial positions, respectively corresponding to the first and second positions of the push rod 36.
Biasing means, such as a coil spring 48, are disposed within the chamber 22 so as to engage against the distal end 44 of the plunger 42 and a distal interior wall surface 50 of the chamber 22. The spring 48 biases the plunger 42, and therefore also the push rod 36, proximally, that is, toward their respective first positions.
Extending radially from the external surface of the plunger 42 is a pin 52 that rides in a longitudinal slot 54 formed in the adjacent wall surface of the handle member 20. The engagement of the pin 52 in the slot 54 prevents the rotation of the plunger 42 relative to the handle member 20, while the proximal and distal ends of the slot 54 define the proximal and distal limits of travel, respectively, of the plunger 42.
The operation of the ligation device 10 is illustrated in FIGS. 6 through 26.
Referring first to FIGS. 6, 7, and 8, the ligation device 10 is loaded with a length of suture 56, by wrapping at least one loop 58 (and preferably several loops as shown) of the suture 56 around the distal portion of the inner tube 23, with the inner tube in its first (distal) position, that is, extending distally from the open distal end 14 of the outer tube 12. The loops 58 are formed in the standing part of the suture 56, leaving a free or tag end 60 that is wrapped around the tip 30 of the finger 28, so as to be seated in the lateral grooves 34. (See FIGS. 12 and 13.) So positioned, the tag end 60 extends laterally across the aperture 32 in the finger tip 30. The tag end 60 is advantageously terminated by a simple knot 61 (such as an over-hand knot) to provide a better grasp by the hook 38. The end of the suture 56 opposite the tag end 60 may be held in a notch 62 formed at the juncture between the finger 28 and the outer tube 12.
The ligation device 10, loaded with the suture 56 as described above, is now ready for insertion into a laparoscopic surgical site, as illustrated in FIGS. 9 and 10. The site is typically formed as a small incision, or more accurately, a puncture, through a patient's skin and abdominal wall (indicated generally by the numeral 64 in the drawings), through which a trocar 66 is inserted to provide access to the tissue or organ (not shown) upon which the surgical procedure is performed.
The trocar 66 is a well-known surgical implement, and it is not a part of the subject invention. Briefly described, the trocar 66 comprises a tubular collar 68 having a neck 70 that seals against the skin around the surgical opening. Seated within the neck 70 is one end of a tubular conduit 72, the other end of which opens proximate the tissue or organ upon which the surgical procedure is performed. The outer end of the collar 68 is provided with an annular seat 74 defining a central access orifice 76. The orifice 76 is sealed on its inner side by a hinged cover 78.
As shown in FIG. 10, when a tissue or organ is to be ligated during, or at the conclusion of, the surgical procedure, the ligation device 10, loaded with the suture 56, is inserted into the trocar 66, so that the finger 28 is near the tissue or organ to be ligated. The insertion of the ligation device 10 involves pushing the ligation device against the cover 78 so that the cover 78 pivots on its hinge (not shown), thereby opening the access orifice 76. The outside diameter of the sleeve 18 and the diameter of the orifice 76 are preferably sized so that a seal is formed between the sleeve and the periphery of the orifice 76. As is standard in laparoscopic surgery, visualization of the insertion (and subsequent manipulation) of the ligation device is through a conventional videoscopic implement (not shown), inserted through a separate trocar (not shown), installed in an adjacent laparoscopic puncture site.
The steps in the method of using the ligation device are illustrated in FIGS. 11 through 26. As shown in the figures, the device 10 is used to ligate a blood vessel 80, but the device can be used, in a similar sequence of steps, to ligate a wide variety of tissues and organs.
The device is first positioned with the finger 28 adjacent the vessel 80 (FIG. 11), and is then manipulated first to isolate the vessel 80 with the finger tip 30, and then to seat the vessel 80 in the bend 29 of the finger 28 (FIG. 12). As shown in FIGS. 13 and 14, the push rod 36 is then extended from its first or proximal position to its second or distal position, by the surgeon pushing the plunger 42 distally, so that the push rod 36 passes over the vessel 80, with its hook 38 passing through and past the suture access aperture 32 in the finger tip 30. The plunger 42 is then released, allowing the push rod 36 to be pulled back to its first or proximal position by the spring 48. On its return back through the suture access aperture 32, the hook 38 snags the tag end 60 of the suture 56 (FIG. 15), and pulls the tag end 60 out of the retention grooves 34, proximally over the vessel 80, and into the distal or patient end 24 of the inner tube 23 (FIG. 16). The knot 61 helps keep the tag end 60 from slipping out of the hook 38 while being pulled in the proximal direction. The proximal motion of the hook 38 thus creates a suture loop 82 around the vessel 80, while also pulling the tag end 60 of the suture through the suture loops 58 wrapped around the outside of the inner tube 23 (FIG. 17).
The next step, as shown in FIG. 18, is for the inner tube 23 to be drawn proximally into the outer tube 12, thereby causing the suture loops 58 to be dropped over the tag end 60 of the suture 56, thereby forming a loose knot 84. This is done by twisting the handle member 20 with respect to the sleeve 18, thereby breaking the heat stake connection 21 between the two, and then pulling the handle member proximally away from the sleeve 18.
The process of tightening the knot 84, and drawing the knot 84 and the vessel 80 together, is shown in FIGS. 19 through 22. This tightening and drawing process is accomplished by the continued proximal movement of the push rod 36, under the biasing force of the spring 48. Tension for tightening the knot is provided by the engagement of the suture loop 82 with the finger 28. In FIG. 19, the knot 84 is still relatively loose and widely separated from the vessel 80. The suture loop 82 encompasses both the finger 28 and the vessel 80. FIG. 20 shows the knot having been drawn tighter and closer to the vessel 80 by the proximal movement of the push rod 36. Continued tightening of the knot 84, by the further proximal movement of the push rod 36, is shown in FIG. 21, which also shows the finger tip 30 beginning to flex toward the distal end 14 of the outer tube 12, as a result of the tension applied by the proximally-moving push rod 36 to the suture loop 82. The flexing of the finger tip 30 finally results in the suture loop 82 being released, as shown in FIG. 22, allowing the suture loop 82 to begin to close around the vessel 80, as the knot 84 continues to be tightened and drawn closer to the vessel.
FIGS. 23 and 24 show the knot 84 at its limit of travel in the proximate direction, having been drawn up into the notch 17 at the distal end 14 of the outer tube 12. While the proximal movement of the knot 84 is stopped in the notch 17, the tag end 60 of the suture is still pulled proximally (that is, away from the knot 84) by the continued proximal movement of the push rod 36, thereby further tightening the knot. Moreover, the continued pulling of the tag end 60 through the knot 84 causes the loop 82 to tighten around the vessel 80, until, as shown in FIG. 25, the vessel is completely ligated.
Finally, the ends of the suture on either side of the knot 84 are cut off, so that the ligation device 10 can be removed from the completely ligated vessel 80. This can be accomplished by passing a cutting tool (such as a scalpel or scissors) down into the trocar. Preferably, however, this is accomplished, as shown in FIG. 26, by providing a cutting blade 86 in the distal end 14 of the outer tube 12, near the juncture between the outer tube 12 and the hook 28. The cutting blade is employed by manipulating the ligation device so as to free the suture 56 from the notch 62 at the juncture between the finger 28 and the outer tube 12, and so as to free the knot 84 from the notch 17 at the distal end 14 of the outer tube 12. The device is then axially rotated to bring the cutting blade 86 to bear against the tag end 60 and the opposite end of the suture 56, thereby to sever these ends from the knot.
FIGS. 27 through 30 illustrate another ligation device 110, in accordance with an alternative embodiment of the invention. The ligation device 110 includes an elongate outer tube 112 having a distal end 114, a central, main portion 116, and a proximal portion 118. The distal end 114 of the outer tube 112 is provided with an acutely-angled, knot-tightening notch 120. The proximal portion 118 is detachably joined to the main portion 116 by means such as a heat stake 122.
An elongate inner tube or mandrel 124 is disposed within the outer tube 112 for axial movement therein. The inner tube 124 has a distal end 126 that normally protrudes through, and extends distally from, the open distal end 114 of the outer tube 112. The inner tube 124 extends from its distal end 126, through the main portion 116 of the outer tube 112, to a proximal end 128 that is fixed within the proximal portion 118 of the outer tube 112.
Attached to the outer tube 112 near its distal end 114, and extending distally therefrom, is a finger 130, having an arcuate bend 131, and a substantially vertical portion 132 terminating in a tip 133 that is spaced from the open distal end 114 of the outer tube 112. The finger tip 133 is slightly offset from axial alignment with the outer tube 112, for reasons to be made clear below. A lateral suture retention groove 134 is formed in the finger tip 133, on the side facing the distal ends of the inner and outer tubes. A vertically-oriented, suture-holding clip 136 is attached to the distal side of the substantially vertical finger portion 132, that is, on the side opposite the groove 134. The suture-holding clip 136 is located so as to hold a length of suture 138 against the distal side of the finger portion 132, with the tag end of the suture 138 seated in the groove 134. A suture-holding notch 139 is formed at the juncture between the finger 130 and the outer tube 112.
An elongate posh rod 140 is disposed longitudinally within the inner tube 124 for axial movement therein between a first, proximal position, and a second, distal position. The push rod 140 has a distal end provided with suture grasping means, such as a hook 142, and a proximal portion that extends proximally out of the proximal portion 118 of the outer tube 112, terminating in a button 144. Biasing means, such as a coiled wire spring 146, are connected between the button 144 and the proximal portion 118 of the outer tube 112, biasing the push rod 140 toward its first, proximal position.
Disposed on the push rod 140 proximally of the hook 142 is a first protuberance forming a first stop element 148. A second protuberance, forming a second stop element 150, is disposed on the interior surface of the inner tube 124. The first stop element 148 abuts against the second stop element 150 to limit the travel of the push rod 140 in the proximal direction under the force of the spring 146, thereby defining the first position of the push rod.
The method of using the alternative embodiment ligation device 110 is very similar to the method of using the preferred embodiment device 10. The device 110 is loaded with a length of suture 138 by wrapping several turns of the standing part of the suture around the distal end of the inner tube 124. The suture is then passed around the distal side of the vertical finger portion 132, held in place by the clip 136, the tag end of the suture being seated in the groove 134 in the finger tip 133. The opposite end of the suture 138 is held in the notch 139 at the juncture between the finger 130 and the outer tube 112.
The device 110 is then directed to the tissue or organ to be ligated through a trocar, as described above. The tissue or organ (e.g., a blood vessel) is isolated by the finger tip 133 and seated in the finger bend 131, as previously described. The push rod is pushed distally, to its second position, by manual pressure applied to the button 144, until its hook 142 extends past the finger tip 133, the tip being axially offset, as mentioned above. When the pressure on the button is relieved, the push rod begins its return, under the force of the spring 146, to its first, proximal position, and the tag end of the suture is captured by the hook 142 as it passes by the finger tip 133 on its return travel.
The tag end of the suture is carried into the inner tube 124, as with the previously-described embodiment, and the turns of the suture are dropped onto the tag end by the surgeon manually pulling the inner tube proximally with respect to the outer tube by first radially twisting the outer tube proximal portion 118 with respect to the main portion 116 to break the heat stake 120, and then by pulling the proximal portion 118 proximally away from the main portion. Since the inner tube 124 is fixed to the proximal portion 118 of the outer tube, the movement of the outer tube proximal portion 118 away from the outer tube main portion 116 causes the inner tube 124 to be withdrawn into the outer tube 112, thereby dropping the suture turns onto the tag end of the suture to form a loose knot, as previously described.
As with the previously-described embodiment, the knot and the vessel are drawn together, and the knot is tightened, by the movement of the hook 142 toward its proximal (first) position, carrying the tag end of the suture with it. The tension applied by the hook 142 to the suture causes the suture to be released from the clip 136 on the finger 130, thereby forming a loop around the vessel, which loop is tightened by the movement of the hook 142. Finally, the knot is drawn up into the notch 120 for final tightening, the ligation of the vessel being then completed, as described above. With this alternative embodiment, it is contemplated that the final step of cutting off the knot would be accomplished by a separate implement, although a cutting blade (not shown) can be provided in the outer tube, as in the previously-described embodiment.
From the foregoing description, it can be seen that the present invention offers several distinct advantages over prior art devices of this general nature. First, it is easily appreciated that the invention is especially well-adapted for laparoscopic surgery performed through a trocar. Second, the invention allows the surgeon to (1) engage and isolate the tissue or organ to be ligated, (2) wrap the suture around the tissue or organ, (3) form a ligating knot, (4) tighten the ligature and the knot so as to ligate the tissue or organ, and (5) cut the knot off of the suture, all with a single implement. Furthermore, all of these steps are performed without the need for any manual manipulation of the suture; nor is there any need to clamp the tissue or organ. Moreover, since the device forms, ties, and tightens the knot automatically, there is no need for the surgeon to learn any new or complex knots. Consequently, facility in using the present invention is easily acquired. Furthermore, the invention can be inexpensively manufactured, lending itself to disposable, single use embodiments, such as those described above.
While two specific embodiments of the invention have been described above, it will be appreciated that a number of variations and modifications will suggest themselves to those skilled in the pertinent arts. For example, if a reusable device is desired, the heat stake juncture between the handle member 20 and the sleeve 18 in the first embodiment described above can be replaced with a pin and socket assembly, or a threaded fitting between the two members. It may also be desirable to provide different sizes and configurations for the tissue-engaging finger, depending upon the type of tissue or organ to be ligated. To this end, it may be desirable to have a finger that is removably attached to the outer tube, so that the finger can be replaced. In addition, the specific means employed to hold the suture onto the finger may be varied to suit different application or the individual preferences of the surgeon. For example, The offset finger and clip used in the second embodiment described above can be used in the first embodiment, while the apertured finger tip used in the first embodiment can be employed in the second. Still other types of suture holding means may be employed without departing from the scope of the invention. Likewise, a wide variety of means can be employed for biasing the push rod toward its proximal position. These modifications and variations, and others that may suggest themselves, are considered to be within the spirit and scope of the present invention, as defined in the claims that follow.