US20200315657A1 - Adductor Canal Block Introducer - Google Patents

Abstract

An adductor canal block introducer for introducing a catheter and also administering an initial dose of local anesthetic. The adductor canal block introducer generally includes a cannula having an elongated body with a distal end, a proximal end, and a slot extending along the elongated body, the slot having two sides and a lower surface. It also includes a cannulated trocar positioned in the slot of the cannula, the cannulated trocar having a distal end and a proximal end, wherein the trocar includes a discharge proximate to the distal end, wherein an inlet and the discharge are in fluid communication with each other. The introducer also includes a catheter positioned in the slot, held in place by the cannulated trocar. The catheter may also be positioned by a grasper introducer that holds the catheter and also includes a discharge at its distal end through which an anesthetic can be administered.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• I hereby claim benefit underTitle35, United States Code, Section119(e) of U.S. provisional patent application Ser. No. 62/830,841 filed Apr. 8, 2019. The 62/830,841 application is currently pending. The 62/830,841 application is hereby incorporated by reference into this application.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
• Not applicable to this application.
BACKGROUNDField
• Example embodiments in general relate to an adductor canal block introducer for introducing a catheter in a position to provide local anesthetic to a target nerve or nerves.
Related Art
• Post-surgical pain is ordinarily treated by opioid analgesics and regional pain blocks (i.e. single shot blocks; long-lasting locals, and bolus or continuous drip anesthetics). Regional pain blocks are typically performed by the anesthesiologist under ultrasound guidance in the hours before (block room), in the operating suite, or after (post-op room) surgery. The bolus or continuous drip regional pain block procedure consists of passing the tip of a small diameter catheter through the skin (percutaneously) and into the vicinity of the target nerve. The proximal end of the catheter is then fastened to a pump that is maintained external to the patient's body. The pump contains a local anesthetic (i.e. lidocaine, ropivacaine, bupivacaine, etc.) and functions to bathe the target nerve (or nerves) in the anesthetic for a period of days post-surgery, and in a home care environment.
• Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field.
SUMMARY
• Bolus and continuous drip regional nerve blocks are frequently used to mitigate painful sensations following joint surgery, including following total knee arthroplasty (TKA). In this case, the catheter tip for introducing nerve blocks is placed by an anesthesiologist nearby a nerve in 1 of 3 locations: 1. Femoral nerve in the upper thigh; 2. Distal femoral nerve just proximal to the adductor canal; or 3. The Saphenous nerve within the adductor canal. Various insertion techniques (i.e. perpendicular vs. oblique approach to nerve) have been used historically to reduce catheter migration and to prolong pain management.
• Orthopedic surgeons have recently started to place catheters for regional nerve blocks in the operating room, and without ultrasound guidance. Despite the surgeon's enthusiasm and skills, it is evident that surgeons may not have the tools on-hand to reliably and safely place catheters intraoperatively. For example, some tools for catheter placement, such as pituitary rongeurs, have different head and shaft lengths, different head and shaft widths, different head angles, and different mouth sharpness, etc. Similarly, the lack of a set of standardized tools can place a significant burden on the surgical staff and administration to compile and maintain the correct set of instruments to assure safe and reliable catheter placement. Surgeons are often supplied with insufficient/incorrect instruments, causing misplaced and/or damaged catheters.
• Disclosed herein is an adductor canal block introducer (i.e., the Matthews Adductor Canal Block Introducer) that allows the surgeon to reproducibly perform these blocks in a reproducible, efficient, efficacious manner without the need for ultrasonic or electrical guidance. This can be very important for post-operative pain management and patient care in environments where anesthesia services are not available to perform these services. Using the disclosed device, the surgeon may also eliminate the additional anesthesia procedure as the catheter is placed during the surgical procedure.
• An example embodiment is directed to a nerve block introducer system, which can be used to introduce catheters and anesthetic agents in the adductor canal or elsewhere in the body of a patient. The nerve block introducer system may comprise a cannula having an elongated body with a distal end, a proximal end, and a slot extending along the elongated body, the slot having two sides and a lower surface; a cannulated trocar positioned in the slot of the cannula between the two sides, the cannulated trocar having a distal end and a proximal end, wherein the distal end of the cannulated trocar is near the distal end of the cannula, the proximal end comprising an inlet and the distal end comprising at least one discharge proximate to the distal end, wherein the inlet and the at least one discharge are in fluid communication with each other; and a catheter positioned in the slot of the cannula and held in place by the cannulated trocar, the two sides of the slot, and the lower surface of the slot, the catheter comprising a proximal end and a distal end near the distal end of the cannula.
• The distal end of the cannulated trocar may extend beyond the distal end of the cannula, and the at least one discharge may comprise a plurality of openings, and the plurality of openings may be located beyond the distal end of the cannula. Further, the plurality of openings may be located laterally on an outer surface of the cannulated trocar.
• In some embodiments, the inlet is adapted for attachment of a syringe such that the syringe can be used to introduce an anesthetic agent into the inlet.
• In some example embodiments, the cannulated trocar may be removably positioned in the slot, such that the cannulated trocar can be removed by sliding lengthwise along the slot (for example, by withdrawing it backward, away from the distal end of the cannula). Further, in some embodiments the cannulated trocar is sized and positioned such that the catheter is held in place in the slot by an interference fit.
• In some example embodiments of the nerve block introducer system, the slot may comprise a first slot portion and a second slot portion, such that the first slot portion has a larger opening between the two sides than the second slot portion, the second slot portion being positioned below the first slot portion. In such embodiments, the cannulated trocar may have a larger diameter than the catheter, and the cannulated trocar may fit in the first slot portion and hold the catheter securely in the second slot portion, for example, by an interference fit.
• Any system or components described herein may, for example, be used by inserting the distal end of the cannula into a body cavity such that the distal end of the cannula and the distal end of the catheter are positioned near a selected location in the body cavity. The method may also include attaching a fluid source to the inlet of the cannulated trocar such that the fluid source (which may be a syringe, pump, etc.) is in fluid communication with the inlet, using the fluid source to infuse an anesthetic agent into the body cavity via the at least one discharge, removing the cannulated trocar from the cannula by sliding it out of the slot and away from the body cavity, and removing the cannula from the body cavity, such that the catheter is left in the body cavity with its distal end near a nerve or multiple nerves.
• In some applications of the method, the body cavity may be an adductor canal, wherein the distal end of the catheter extends beyond the distal end of the cannula. The method may further comprise rotating the cannula rotating the cannula so that the catheter can be held in place against the femur when the cannula is removed after the cannulated trocar has been removed, so that the distal end of the catheter remains in a desired location when the cannula is removed.
• In another embodiment, the nerve block introducer system may comprise a grasper rather than a slotted cannula. The grasper may include a proximal end and a distal end. The grasper may have a pair of handles with finger loops that operate a grasping mechanism at or near a distal end of the grasper. The grasping mechanism may further comprise two grasping members, which can be used to hold a catheter in the instrument until a user places the catheter in a desired location. The grasper may include an elongated member that extends from the proximal end to near the distal end, although it may not necessarily reach the distal end.
• The elongated member may be hollow, with a cavity or channel to fluidly connect an inlet near the proximal end of member, and a discharge near the distal end of the member. The inlet may also be sized or adapted for attachment of a fluid source, such as a pump or a syringe, and may also include a standard locking mechanism to hold the syringe.
• Since the inlet is in fluid communication with the discharge (which may comprise a plurality of openings) via the channel, a syringe, or any other fluid source, may be used to force fluid, such as an anesthetic agent, through the elongated member and out through the discharge, near the distal end of the grasper.
• As discussed above, the discharge of the grasper may comprise a plurality of openings, which may be placed or located laterally around the outer surface of the elongated member, which surface may be a partial cylinder. The elongated member may be or comprise a fixed portion of the grasping member, with one grasping member near the distal end. The two grasping members may have slightly concave interior surfaces, such that they can be used to hold a catheter near the distal end without damaging it. The grasper may also have a movable grasping member that is operable by the handles.
• There has thus been outlined, rather broadly, some of the embodiments of the adductor canal block introducer in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional embodiments of the adductor canal block introducer that will be described hereinafter and that will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the adductor canal block introducer in detail, it is to be understood that the adductor canal block introducer is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The adductor canal block introducer is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
• Example embodiments will become more fully understood from the detailed description given herein below and the accompanying drawings, wherein like elements are represented by like reference characters, which are given by way of illustration only and thus are not limitative of the example embodiments herein.
• FIG. 1 is a perspective view of an introducer in accordance with an example embodiment.
• FIG. 2 is a top view of an introducer in accordance with an example embodiment.
• FIG. 3 is a side view of an introducer in accordance with an example embodiment.
• FIG. 4 is an exploded view of an introducer in accordance with an example embodiment.
• FIG. 5 is another exploded view of an introducer in accordance with an example embodiment.
• FIG. 6 is a perspective view of an assembled introducer system in accordance with an example embodiment.
• FIG. 7 is a detailed perspective view of one end of an introducer system in accordance with an example embodiment.
• FIG. 8 is an exploded perspective view of one end of an introducer system in accordance with an example embodiment.
• FIG. 9 is a perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 10 is another perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 11 is another perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 12 is another perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 13 is another perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 14 is another perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 15 is another perspective view of an introducer system in use in accordance with an example embodiment.
• FIG. 16 is another perspective view of an introducer system in use accordance with an example embodiment.
• FIG. 17 is a flow chart of steps usable with an introducer system in accordance with an example embodiment.
• FIG. 18 is a perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 19 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 20 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 21 is a flow chart of steps usable with an introducer system in accordance with another example embodiment.
• FIG. 22 is a view showing a catheter after use of an introducer system in accordance with an example embodiment.
• FIG. 23 is a view of a kit containing the components of an introducer system in accordance with an example embodiment.
• FIG. 24 is a perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 25 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 26 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 27 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 28 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 29 is another perspective view of an introducer system in use in accordance with another example embodiment.
• FIG. 30 is another perspective view of an introducer system in use in accordance with another example embodiment.
DETAILED DESCRIPTIONA. Overview.
• An example adductor canal block introducer system (or more generally, nerve block introducer system) generally comprises acannula20 having anelongated body22 with adistal end24, aproximal end26, and aslot27 extending along theelongated body22, the slot having two sides28 and alower surface29. The components referenced herein may be either reusable or disposable. Thesystem10 may also include a cannulatedtrocar30 positioned in theslot27 of thecannula20 between the two sides, the cannulatedtrocar30 having adistal end32 and aproximal end34, wherein thedistal end32 of the cannulatedtrocar30 is near thedistal end24 of thecannula20, theproximal end34 comprising aninlet36 and thedistal end32 comprising at least onedischarge38 proximate to thedistal end32, wherein theinlet36 and the at least one discharge are in fluid communication with each other, such as via a channel orcavity39. The system may also include acatheter40 positioned in theslot27 of thecannula20 and held in place by the cannulatedtrocar30, the two sides28 of theslot27, and thelower surface29 of theslot27, thecatheter40 comprising aproximal end42 and adistal end42 near thedistal end24 of thecannula20.
• Thedistal end32 of the cannulatedtrocar30 may extend beyond thedistal end24 of the cannula, and the at least onedischarge38 may comprise a plurality ofopenings33, and the plurality ofopenings33 may be located beyond thedistal end24 of thecannula20. Further, the plurality ofopenings33 may be located laterally on anouter surface37 of the cannulatedtrocar30.
• In some embodiments, theinlet36 is adapted for attachment of a fluid source, such as asyringe50, such that thesyringe50 can be used to introduce ananesthetic agent52 into theinlet36. In some example embodiments, the cannulatedtrocar30 may be removably positioned in theslot27, such that the cannulatedtrocar30 can be removed by sliding lengthwise along the slot27 (for example, by withdrawing it backward, away from the distal end of the cannula). Further, in some embodiments the cannulatedtrocar30 is sized and positioned such that thecatheter40 is held in place in theslot27 by an interference fit.
• In some example embodiments of theintroducer system10, theslot27 may comprise afirst slot portion27aand asecond slot portion27b, such that thefirst slot portion27ahas a larger opening between the twosides28athan the twosides28bof thesecond slot portion27b, thesecond slot portion27bbeing positioned below thefirst slot portion27a. In such embodiments, the cannulatedtrocar30 may have a larger diameter than thecatheter40, and the cannulatedtrocar30 may fit in thefirst slot portion27aand hold thecatheter40 securely in thesecond slot portion27b, for example, by an interference fit. The interference fit holds thecatheter40 firmly in place because the distance between the surface of the cannulatedtrocar30 and thelower surface29 of theslot27 is slightly smaller than the diameter or width of thecatheter40.
B. Cannula.
• As shown inFIGS. 1-16, one example embodiment of theintroducer system10 includes a slottedcannula20, best shown inFIGS. 1-3. The cannula and the trocar may be either reusable or disposable. The cannula generally has an elongatedbody22 with adistal end24, aproximal end26, and aslot27 extending along theelongated body22, the slot having twosides28a,28b, and alower surface29. In addition, thecannula20 may be rigid to facilitate introduction of acatheter40 into a body cavity, such as an adductor canal. The two sides28 of theslot27 may be vertical, and thelower surface29 may be rounded. The upper portion of the side edges of the cannula may be rounded as well, as also shown, and the side edges may form an angled and rounded tip at or near thedistal end24 of thecannula20. Theslot27 may be open all the way to the proximal end of thecannula20, as shown, such that thetrocar30 may be removed without obstruction by sliding it in theslot27 rearward, such that thedistal end32 of the cannulatedtrocar30 is withdrawn along the slot, from thedistal end24 toward theproximal end26 of thecannula20.
• In addition, the twosides28a,28bmay each be in multiple planes, to create multiple slot portions (i.e., portions having different widths), as will be described below. The cannula may also include ahandle21, extending at an angle away from theelongated body22, so that a surgeon can readily grasp thecannula20 by thehandle21 when preparing it for use, or using it to introduce acatheter40 into a body cavity, such as the adductor canal. For example, thehandle21 may be integrally formed with thebody22 of thecannula20, and form an angle of about 120° with thebody22, although other angles are possible. Thehandle21 may be of any suitable length, such as about 6 centimeters.
• Theelongated body22 may be of any suitable length, depending on the application. For example, thebody22 may be about 16 centimeters, which length may be used as a guide for where to position acatheter40, as will be discussed further below. As also shown, thecannula20 may include aslot27 that extends along thebody22, from theproximal end26 to thedistal end24. As mentioned, theslot27 may have two sides28 and alower surface29, with theslot27 being open at the top side of thecannula20. Theslot27 may have a single width, or it may have a larger, upper orfirst slot portion27aand a smallersecond slot portion27b, as best shown inFIGS. 3 and 8.
• The twoslot portions27aand27bmay be sized specifically to be used with the other components of theintroducer system10. Eachslot portion27a,27bmay comprise twosides28aand28b, respectively. For example, thefirst slot portion27amay be sized to accommodate and securely hold cannulatedtrocar30. Although various sizes are possible, the diameter oftrocar30 may be about 3 mm, in which case theslot27 or thefirst slot portion27amay be about 2-2/3 mm, such that the cannulatedtrocar30 fits securely within thefirst slot portion27a. Similarly, the lower orsecond slot portion27bmay be smaller, so that it holds catheter40 (e.g., a 7 FR catheter) in position, especially whentrocar30 is in place, as shown inFIGS. 7-8. However, thesecond portion27bof theslot27 need not be smaller than the diameter ofcatheter40, and if it is not, that may make for easier detachment from thecannula20 and placement of thecatheter40, as will be described further below. With the slot proportions noted above, theslot27 may have an overall depth of about 5 mm, although as noted, other dimensions are possible.
C. Cannulated Trocar.
• Theintroducer system10 also includes a cannulatedtrocar30. The cannulatedtrocar30, like the slottedcannula20, also has aproximal end34 and adistal end32, which ends correspond to the same ends of the slottedcannula20 when the system is assembled as shown inFIGS. 4-6. The cannulatedtrocar30 includes aninlet36 at or near theproximal end34, and adischarge38 at or near thedistal end32. The cannulatedtrocar30 may be in the general form of an elongated hollow tube, with a cavity orchannel39 connecting theinlet36 to thedischarge38, such that theinlet36 is in fluid communication with thedischarge38. The cannulatedtrocar30 may comprise abody35, which may be in the general form of a rigid tube having a single diameter over most of the length of the cannulatedtrocar30, as shown inFIGS. 4-6. In the example noted above, the diameter may be about 3 mm, and the diameter may be generally constant along the length of the cannulatedtrocar30, so that thetrocar30 may be smoothly and easily withdrawn by pulling it rearward out of the slottedcannula20, along and out of theslot27.
• Theinlet36 of thetrocar30 may be sized or adapted for attachment of a fluid source, such as a pump or asyringe50, and may also include a standard locking mechanism to hold thesyringe50. A syringe, such as a 10 cc syringe, may be provided in a kit having the components necessary for the procedures described herein, and may be filled with 0.5% ropivacaine, for example. Since theinlet36 is in fluid communication with the discharge38 (which may comprise a plurality of openings33) viachannel39, thesyringe50, or any other fluid source, may be used to force fluid, such as an anesthetic agent, through the cannulatedtrocar30 and out through thedischarge38, near thedistal end32 of the trocar and thedistal end24 of the slottedcannula20. Due to the relatively large diameter of the trocar30 (as compared to a catheter), it may be much easier for a surgeon to introduce a single bolus ofnerve blocking agent52 at the desired location (e.g., adductor canal), rather than only relying on the catheter to do so initially, even though the catheter may later provide for continuous introduction of medication (e.g., continuous drip) or electricity to the nerves around the knee joint including the posterior nerves of the knee joint capsule.
• To facilitate introduction of fluid through the cannulatedtrocar30, when thesystem10 is assembled (i.e., when the cannulatedtrocar30 is in position for use), thedistal end32 of the cannulatedtrocar30 may extend beyond thedistal end24 of the slottedcannula20, as best shown inFIGS. 6-8. Further, the plurality ofopenings33 may be located such that they extend beyond thedistal end24 of the slottedcannula20 when the cannulatedtrocar30 is in place for initial introduction of thecatheter40. More specifically, the plurality ofopenings33 may be placed or located laterally around the generally cylindricalouter surface37 of the cannulatedtrocar30, and the distribution may extend from thedistal end32, and back about 2 cm along theouter surface37.
• The cannulatedtrocar30 may also have aflange31 at or near itsproximal end34, which may be used by a surgeon to pull and remove it from the slottedcannula20 by sliding it out of theslot27 as described herein. The cannulatedtrocar30 may have a larger diameter than thecatheter40, and the cannulatedtrocar30 may fit in thefirst slot portion27aof thecannula20. Thus configured, thetrocar30 can hold thecatheter40 securely in thesecond slot portion27bof thecannula20, for example, by an interference fit. The interference fit holds thecatheter40 firmly in place when the trocar is in position as shown inFIG. 7 because the distance between the surface of the cannulatedtrocar30 and thelower surface29 of theslot27 is slightly smaller than the diameter or width of thecatheter40. Thus, thetrocar30, thecatheter40, or both may deform slightly, which will result in thecatheter40 being held securely in position.
D. Grasper Embodiment.
• In another embodiment, the nerveblock introducer system10 may comprise agrasper60 rather than a slotted cannula. As with the cannula, may be either reusable or disposable. Thegrasper60 may include aproximal end61 and adistal end62. As shown inFIGS. 18-20, the grasper may have a pair ofhandles64 withfinger loops66 that operate (e.g., close) a graspingmechanism67 at or near adistal end62 of thegrasper60. The graspingmechanism67 may further comprise twograsping members67a,67b, which can be used to hold acatheter40 in the instrument until a user places thecatheter40 in a desired location, such as by direct visualization. Thegrasper60 may include anelongated member68 that extends from theproximal end61 to near thedistal end62, although it may not necessarily reach the distal end.
• Theelongated member68 may be hollow, as shown in the partial sectional view ofFIG. 18, with a cavity orchannel69 to fluidly connect aninlet70 near the proximal end ofmember68, and adischarge72 near the distal end of themember68. Theinlet70 may also be sized or adapted for attachment of a fluid source, such as a pump or asyringe50, and may also include a standard locking mechanism to hold thesyringe50.
• Since theinlet70 is in fluid communication with the discharge72 (which may comprise a plurality of openings74) viachannel69, asyringe50, or any other fluid source, may be used to force fluid, such as an anesthetic agent, through theelongated member68 and out through thedischarge72, near thedistal end62 of thegrasper60. Due to the relatively large diameter or capacity of the channel69 (as compared to a catheter), it may be much easier for a surgeon to introduce a single bolus ofnerve blocking agent52 at the desired location (e.g., adductor canal), rather than only relying on the catheter to do so initially, even though thecatheter40 may later provide for continuous introduction of medication (e.g., continuous drip) or electricity to the nerves around the knee joint including the posterior nerves of the knee joint capsule.
• As discussed above, the discharge may comprise a plurality ofopenings74, which may be placed or located laterally around theouter surface76 of the elongated member, which surface76 may be a partial cylinder. As shown inFIGS. 18-20, theelongated member68 may be or comprise a fixed portion of the grasping member, with one graspingmember67anear thedistal end62. As also shown, the graspingmembers67a,67bmay have slightly concave interior surfaces, such that they can be used to hold a catheter near thedistal end62 without damaging it. Thegrasper60 may also have a movable graspingmember67athat is operable by thehandles64.
• The graspingmechanism67 may operate in a manner similar to pituitary rongeurs, such that the graspingmechanism67 generally closes when thehandles64 are moved together (as when holding a catheter), and opens when thehandles64 are moved apart. Further, the overall mechanism may have sufficient friction so that the grasper remains closed without being held closed by a user, which may facilitate catheter introduction and placement. As mentioned above, thehandles64 may includefinger loops66 to make thegrasper60 easier to position and operate when introducing a catheter in an adductor canal or other desirable location to introduce nerve block.
E. Kit.
• As shown inFIG. 23, all the components needed for performing the methods and procedures described herein may conveniently be provided in akit80 containing an introducer of any embodiment disclosed herein (e.g., acannula20 andtrocar30, or alternatively, a grasper60), along with any instruments or elements needed to perform intraoperative adductor canal blocks by a surgeon through the surgical incision under direct vision or under arthroscopic guidance.
• For example, single and/or split catheters (such as a 7 FR catheter) can be included in thekit80, with single and multi-lumens to allow for placement of acatheter40 in both the adductor canal and along the posterior capsule of the knee, thus blocking multiple nerves transmitting pain sensation around the knee. These catheters can allow for continuous delivery of medication to block sensory nerve conduction (neurotmesis) in the anterior and the posterior medial and lateral compartments of the knee.
• Thekit80 may be provided in asingle peel pack81 sterile kit, or other suitable kit form. Further, in addition to the cannula, trocar, or grasper, thekit80 may include thesyringe50, such as a 10 cc syringe, and the syringe can be filled with anerve blocking agent52, such as 0.5% ropivacaine. In some cases, the kit further containsgauze82, such as 2×2 gauze, and it may also includeTegaderm84, such as 3×3 inch Tegaderm. In some cases, the kit further containssurgical glue86. The kit may also include Steri-Strips87 and anintroducer needle88 and a T-Peel sheath89, which is a proprietary device.
F. Operation.
• Surgeries around the knee can be very painful, and traditionally require parental and oral opioid analgesics to provide post-operative pain relief. Significant improvements have been made in pain management over the past decades, most significantly with the use of regional block anesthesia. Traditionally, these regional nerve blocks are placed by anesthesia services using a nerve stimulator or under ultrasonic guidance. However, these anesthesia services are not always available and when available may require a significant learning curve for the anesthesiologist to provide reproducible, efficient and efficacious nerve blocks. Efficacy of these blocks is dependent on patients' body habitus and anesthesia services willingness to perform these blocks, as well as the provider's experience, training and capabilities. Placement of nerve blocks by the surgeon under direct visualization is safer, more reliable and more efficacious.
• Surgeon-placed nerve blocks can also provide superior results as they can include more nerves, providing a broader scope of relief. As with any block technique standardized, equipment is needed to provide for a safe and reproducible procedure. Variability of current instruments produces risks of improper placement of the block and catheter which can lead to poorer efficacy, and possible injury to surrounding neurovascular structures. Because of variability of current instruments surgeons may dangerously place the catheter into the posterior space. Entering this space posterior to the adductor tendon can lead to potential damage to vital nerves and vascular structures. The adductor canal block introducer is specifically designed to provide catheter placements in a safe, reproducible and reliable fashion.
Surgical Approach:
• The catheter can be inserted during a surgical approach to the knee. The medial parapatellar procedure is performed by incising the VMO beginning medially just above the patella and extending down to the tibial tubercle, leaving a cuff of capsular tissue on the patella for repair at closure. For the mid-vastus approach, the VMO is split in-line with the muscle fibers at the superior pole of the patella and then incised distally to the tibial tubercle. The subvastus approach to TKA begins with an incision below the VMO muscle and extends to the tibial tubercle.
• 1. Exposure
• The surgeon will identify adductor tubercle of the epicondyle of the femur, and elevate the VMO with blunt retractors90 (Army/Navy) to expose its deep surface and the anterior surface of the medial intermuscular septum. The medial intermuscular septum serves as the floor for catheter placement. The adductor magnus tendon can be palpated beneath the medial intermuscular septum just cephalad to the adductor tubercle. The VMO and adductor magnus muscles form the borders of the adductor canal.
• 2. Catheter Placement
• Placement of the catheter for a continuous block is performed by inserting anintroducer needle88 and T-Peel sheath89 from the superior lateral aspect of the knee, just above the joint at the superior pole of the patella. The introducer needle and T-Peel sheath are passed under the rectus femoris tendon and into the surgical opening. Theintroducer needle88 is then removed leaving the T-Peel sheath89 in place. Thecatheter40 is then passed through the T-Peel sheath and retrieved into this potential space. The T-Peel sheath89 is peeled away and discarded. The catheter entry point is a “potential space” that is opened with blunt dissection, during VMO retraction.
• 3. Advancement of the Catheter
• After establishing the potential space with gentle digital dissection, the distal end of the catheter is grasped by the grasper or placed into the slotted cannula (seeFIGS. 9 and 24) and advanced cephalad by blunt dissection along the anterior surface of the medial intermuscular septum and deep to the VMO. The end of the catheter is placed approximately 9-10 inches cephalad to the superior patella and is located in the space created by the muscles that make up the borders of the adductor canal. Thissystem10 can also be used for placement in other parts of the body. Once the catheter is placed, theretractors90 are removed, the wound is irrigated and closed in the standard fashion of choice.
• Theintroducer system10 is used to insert acatheter40 during a standard medial parapatellar, subvastus, or midvastus approach to TKA (seeFIGS. 9-16 and 24-30). After the implant components have all been installed, the vastus medialis oblique (VMO) muscle is retracted at the level of the patella to expose the medial intermuscular septum (layers of deep fascia) that is anterior and intimate to the adductor tendon. After identifying the adductor tubercle of the epicondyle of the femur, the surgeon retracts the VMO with blunt retractors90 (Army/Navy) to expose the anterior surface of the medial intermuscular septum. The medial intermuscular septum which serves as the floor for catheter placement is readily visible and lies just anterior to the adductor tendon. The adductor longus tendon can be palpated beneath the medial intermuscular septum as it inserts onto the adductor tubercle. The VMO and adductor muscles form the muscular borders of the adductor canal.
• To use the system, opening the Introducer kit80 (if used), the surgeon lifts out theintroducer needle88 andcatheter40. After blunt digital dissection and placement ofretractors90 under the VMO, exposing the potential space that is created by the retracted muscles that make up the borders of the adductor canal, theintroducer needle88 is inserted through the skin at the superior lateral aspect of the knee, just proximal to the patella, and advanced medially just anterior to the distal femur to appear in this potential space.FIG. 9, for example, shows this positioning of the catheter.
• Thecatheter40 is retrieved from the needle sheath and then placed in the adductor canal block introducer (either the slotted cannula embodiment or the grasper embodiment) and advanced cephalad along the medial intermuscular septum, deep to the VMO, and in-line with the femoral shaft. Using the introducer, thecatheter40 is advanced cephalad until the shoulder of the introducer is stopped at, or adjacent to, the level of the superior pole of the patella. This positions thedistal end44 ofcatheter40 approximately 9-10 inches cephalad to the superior patella and within the space created by the muscles that make up the borders of the adductor canal. Cadaveric Studies have demonstrated this position to be ideal for maximum blocking of nerve conduction.
• The final, precise placement of thecatheter40 guided by the introducer (cannula20 or grasper60) positions the catheter within the medial intermuscular septum of the thigh, separating the vastusmedialisoblique (VMO) and adductor muscles that form the muscular borders of the adductor canal. When performing a cemented implant, the catheter can be placed while the cement is curing without adding additional time to the operative procedure.
• 4. Using the Slotted Cannula
• FIGS. 9-16 illustrate the use of the introducer system with a slotted cannula, and the steps for use are broadly outlined inFIG. 17. When using the slottedcannula20, acatheter40 may be first be inserted in a desired position in the lower portion ofslot27, and may have itsdistal end44 extending slightly beyond thedistal end24 of thecannula20. To hold thecatheter40 in place in the lower portion of the slot, slot27b, thetrocar30 is then slid into place in the upper portion ofslot27. As shown inFIGS. 10-11, thedistal end24 of thecannula20 is then inserted into a body cavity, such as an adductor canal, such that thedistal end44 ofcatheter40 is in a desired location for later infusion of anesthetic.
• Next, asyringe50 or other fluid source may be attached or locked toinlet36 of the cannulatedtrocar30, as shown inFIG. 12, and as stated, thesyringe50 or fluid source may contain alocal anesthetic52 of the physician's choice. Thesyringe50 may be used to administer a bolus dose of local anesthetic (FIG. 13) through the cannulatedtrocar30, and specifically, out of thedischarge38, which may comprisemultiple openings33. Once the bolus dose is administered, thetrocar30 may be removed by sliding it rearward out of thecannula20, as shown inFIG. 14. This allows thecatheter40 to be removed from thecannula20 as well, which may be accomplished by holding the catheter against the femur with a finger, as shown inFIGS. 15-16, and rotating the cannula so that the catheter can be held in place against the femur when the cannula is removed. With the catheter thus in its desired position, thecannula20 may be withdrawn from the surgical opening.
• 5. Using the Grasper
• FIGS. 24-30 illustrate the use of the introducer system with agrasper60, rather than a slotted cannula, and the steps for this use are broadly outlined inFIG. 21. The method is similar, except that thegrasper60 does not have a removable trocar, and instead includes a hollowelongated portion68 with achannel69 for carrying a local anesthetic for the bolus dose to thedischarge72, which may comprisemultiple openings74 near thedistal end62 of thegrasper60. It also uses a graspingmechanism67 to hold thedistal end44 of thecatheter40, rather than a slot, and the mechanism is operated byhandles64 withfinger loops66. When using thegrasper60, thedistal end44 of acatheter40 may be grasped in the grasping mechanism, between graspingmembers67aand67b, as best shown inFIGS. 18-20 and 24. As shown inFIGS. 24-25, thedistal end62 of thegrasper60 is then inserted into a body cavity, such as an adductor canal, such that thedistal end44 ofcatheter40 is positioned in a desired location for later infusion of anesthetic.
• Next, asyringe50 or other fluid source may be attached or locked toinlet70, as shown inFIG. 27, and thesyringe50 or fluid source may contain alocal anesthetic52 of the physician's choice. Thesyringe50 may be used to administer a bolus dose of local anesthetic (FIG. 28) through theelongated member69, and specifically, out of thedischarge72, which may comprisemultiple openings74. Once the bolus dose is administered, the surgeon may open the graspingmechanism67 usingfinger loops66 to release thecatheter40, as shown inFIG. 30, leaving it in the desired location for administering further local anesthetic. The surgeon may also hold the catheter against the femur to ensure it stays in the desired position when thegrasper60 is withdrawn, as shown inFIGS. 29-30. With the catheter thus in its desired position, thegrasper60 may be withdrawn from the surgical opening.
• After catheter placement with either device, once thecatheter40 is placed, theretractors90 are removed, and the elevated muscles are allowed to return to their anatomic location. The wound is then irrigated and closed using an appropriate surgical technique. The remaining contents of theintroducer kit80 are then retrieved from the peel pack. The catheter insertion site is sealed with thesurgical glue86 and then secured with surgical strips in a “tee pee” fashion. The external portion ofcatheter40 may be coiled into three 1 inch circles and held in position under the 2×2 gauze and clear adhesive, or using Steri-Strips87 andTegaderm84, as shown inFIG. 22. At this point, the distal end ofcatheter40 may be connected to a pump for ongoing infusion ofanesthetic52.
• Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the adductor canal block introducer, suitable methods and materials are described above. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. The adductor canal block introducer may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive. Any headings utilized within the description are for convenience only and have no legal or limiting effect.

Claims (22)

What is claimed is:

1. A nerve block introducer system, comprising:

a cannula having an elongated body with a distal end, a proximal end, and a slot extending along the elongated body, the slot having two sides and a lower surface;

a cannulated trocar positioned in the slot of the cannula between the two sides, the cannulated trocar having a distal end and a proximal end, wherein the distal end of the cannulated trocar is near the distal end of the cannula, the proximal end comprising an inlet and the distal end comprising at least one discharge proximate to the distal end, wherein the inlet and the at least one discharge are in fluid communication with each other; and

a catheter positioned in the slot of the cannula and held in place by the cannulated trocar, the two sides of the slot, and the lower surface of the slot, the catheter comprising a proximal end and a distal end near the distal end of the cannula.

2. The nerve block introducer system ofclaim 1, wherein the inlet is adapted for attachment of a syringe such that the syringe can be used to introduce an anesthetic agent into the inlet.

3. The nerve block introducer system ofclaim 1, wherein the at least one discharge comprises a plurality of openings.

4. The nerve block introducer system ofclaim 3, wherein the plurality of openings are located laterally on an outer surface of the cannulated trocar.

5. The nerve block introducer system ofclaim 1, wherein the cannulated trocar is removably positioned in the slot, such that the cannulated trocar can be removed by sliding lengthwise along the slot.

6. The nerve block introducer system ofclaim 1, wherein the cannulated trocar is sized and positioned such that the catheter is held in place in the slot by an interference fit.

7. A method of using the system ofclaim 1, comprising:

inserting the distal end of the cannula into a body cavity;

attaching a fluid source to the inlet of the cannulated trocar such that the fluid source is in fluid communication with the inlet;

using the fluid source to infuse an anesthetic agent into the body cavity via the at least one discharge;

removing the cannulated trocar from the cannula by sliding it out of the slot and away from the body cavity; and

removing the cannula from the body cavity, such that the catheter is left in the body cavity with its distal end near a nerve.

8. The method ofclaim 7, wherein the body cavity is an adductor canal and wherein the distal end of the catheter extends beyond the distal end of the cannula, the method further comprising rotating the cannula so that the catheter can be held in place against the femur when the cannula is removed.

9. The method ofclaim 7, wherein the fluid source is a syringe.

10. The method ofclaim 7, wherein the cannula is inserted into the body cavity such that the distal end of the cannula and the distal end of the catheter are positioned near a selected location in the body cavity.

11. The method ofclaim 7, wherein the at least one discharge comprises a plurality of openings.

12. The method ofclaim 11, wherein the distal end and the plurality of openings of the cannulated trocar are located beyond the distal end of the cannula when the cannulated trocar is in an initial position.

13. The method ofclaim 11, wherein the plurality of openings are located laterally on an outer surface of the cannulated trocar.

14. The nerve block introducer system ofclaim 1, wherein the distal end of the cannulated trocar extends beyond the distal end of the cannula.

15. The nerve block introducer system ofclaim 14, wherein the cannulated trocar is removably positioned in the slot, such that the cannulated trocar can be removed by sliding lengthwise along the slot.

16. The nerve block introducer system ofclaim 14, wherein the at least one discharge comprises a plurality of openings, and wherein the plurality of openings are located beyond the distal end of the cannula.

17. The nerve block introducer system ofclaim 16, wherein the plurality of openings are located laterally on an outer surface of the cannulated trocar.

18. The nerve block introducer system ofclaim 1, wherein the slot comprises a first slot portion and a second slot portion, such that the first slot portion has a larger opening between the two sides than the second slot portion, the second slot portion being positioned below the first slot portion, wherein the cannulated trocar has a larger diameter than the catheter, and wherein the cannulated trocar fits in the first slot portion and holds the catheter securely in the second slot portion.

19. The nerve block introducer system ofclaim 18, wherein the cannulated trocar is sized and positioned such that the catheter is held in place in the second slot portion by an interference fit.

20. A nerve block introducer system, comprising:

a cannula having an elongated body with a distal end, a proximal end, and a slot extending along the elongated body, the slot having two sides and a lower surface, wherein the slot comprises a first slot portion and a second slot portion, such that the first slot portion has a larger opening between the two sides than the second slot portion, the second slot portion being positioned below the first slot portion;

a cannulated trocar removably positioned in the first slot portion of the cannula between the two sides such that the cannulated trocar can be removed by sliding lengthwise along the slot, the cannulated trocar having a distal end and a proximal end, wherein the distal end of the cannulated trocar is near the distal end of the cannula and extends beyond it, the proximal end comprising an inlet and the distal end comprising a plurality of openings proximate to the distal end and located laterally on an outer surface of the cannulated trocar beyond the distal end of the cannula, wherein the inlet and the a plurality of openings are in fluid communication with each other, and wherein the inlet is adapted for attachment of a syringe such that the syringe can be used to introduce an anesthetic agent into the inlet and out through the plurality of openings; and

a catheter positioned in the second slot portion of the cannula and held in place by an interference fit with the cannulated trocar, and by the two sides and the lower surface of the slot, the catheter comprising a proximal end and a distal end near the distal end of the cannula.

21. A kit for use in performing a nerve block procedure, the kit comprising:

a catheter having a proximal end and a distal end, the catheter usable to provide local anesthetic to a target nerve;

a nerve block introducer comprising an inlet and a discharge in fluid communication with each other, the introducer usable for positioning the distal end of the catheter near the target nerve;

an introducer needle;

a syringe containing a nerve blocking agent, the syringe adapted for attachment to the inlet;

a surgical glue; and

a plurality of surgical strips.

22. A method of administering a local anesthetic during a surgical procedure, comprising:

using a nerve block introducer to hold a catheter, the nerve block introducer having a proximal end comprising an inlet and a distal end comprising at least one discharge, the inlet and the at least one discharge being in fluid communication with each other;

advancing the distal end of the nerve block introducer into a body cavity such that a distal end of the catheter is near a target nerve;

attaching a fluid source to the inlet such that the fluid source is in fluid communication with the inlet;

using the fluid source to infuse an anesthetic agent into the body cavity via the at least one discharge;

releasing the catheter from the nerve block introducer such that the distal end of the catheter remains positioned near the target nerve; and

withdrawing the nerve block introducer from the body cavity.

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