reference will now be made in detail to one or more embodiments of the invention , examples of the invention , examples of which are illustrated in the drawings . each example and embodiment is provided by way of explanation of the invention , and is not meant as a limitation of the invention . for example , features illustrated or described as part of one embodiment may be used with another embodiment to yield still a further embodiment . it is intended that the invention include these and other modifications and variations as coming within the scope and spirit of the invention . the anatomy view of fig1 is provided for an appreciation and understanding of a tap block procedure . the anterior abdominal wall ( including the skin , muscles , parietal peritoneum ) is innervated by the anterior rami of the lower thoracic nerves and the first lumbar nerve . terminal branches of these somatic nerves run through the lateral abdominal wall within a plane between the internal oblique and transverse abdominis muscles . this intermuscular plane is referred to as the transversus abdominis plane ( tap ). referring to fig1 , a tap procedure is performed at the triangle of petit , which is the area bounded posteriorly by the latissimus dorsi , anteriorly by the external oblique muscle , and inferiorly ( base of the triangle ) by the iliac crest . fig2 is an ultrasound image of the external oblique ( eo ), internal oblique ( io ), and transversus abdominis ( ta ) muscle layers . the procedure involves insertion of a needle from a direction transverse to the planes depicted in fig2 through the eo , io , and into the tap plane . this plane has been shown to provide good postoperative analgesia for a variety of procedures . fig3 a through 3h depict various items and components that may be used by a practitioner to practice the tap procedure described herein . it should be appreciated that the particular articles depicted in the figures and described herein are not limiting factors on practice of the present method , but are devices that have proven to be useful and preferred . fig3 a depicts an embodiment of a needle 24 for use in the procedure , as discussed in greater detail below . the needle 24 may include a handle at the proximal ( away from the patient ) and a piercing tip at the distal end region 28 . the needle 24 is particularly configured for delivery of a fluid through an injection site . a useful embodiment of a needle 24 is a weiss epidural needle . in particular , the needle 24 may be a weiss epidural needle supplied by becton dickinson ( bd ) having fixed wings 26 and a modified tuohy point . the needle may be a five - inch , 18 gauge needle and is identified by the bd product number 405190 . it should be appreciated , however , that other types of suitable epidural needles may also be utilized . fig3 b depicts an extension set 40 for configuration with the proximal end of the needle 24 . in a simple embodiment , the extension set 40 may be an extension tube 42 having any desired length , for example a thirty - inch extension tube . the extension set 40 may include any manner of additional components , such as a 90 - degree adapter 44 that mates with the proximal end of the needle 24 , with the tube 42 extending from the adapter 44 at a 90 - degree angle relative to the axis of the needle 24 . an embodiment of such an adapter is provided in a product commercially available from braun and identified as the “ contiplex tuohy continuous nerve bblock set ” ( product reference number 331691 ). a 30 - inch extension set is available from hospira ( product reference number 3229 - 03 ). fig3 c depicts an embodiment of a sheath 14 having a handle 16 at a proximal end thereof . an extension 18 extends perpendicularly from the handle 16 and terminates at a distal ( towards the patient ) end 22 . the sheath 14 has a size and length such that the needle 24 extends through the sheath 14 with the distal end region 28 of the needle 24 extending distally from the end 22 of the sheath 14 when the components are configured together and inserted into the tap region of the patient . the sheath 14 may be a generally semi - rigid or flexible member that has at least some ability to conform within the tap region , particularly within the confines of the liquid pool generated in the tap . a particularly useful sheath 14 is available from iflo as a component of the 2 . 5 inch soaker catheter ( product reference number pm 010 ). the extension 18 of the sheath 14 is generally composed of a semi - rigid or flexible material , such as plastic , elastomeric , and the like . such materials are , however , inherently non - echogenic . in this regard , it may be desired to render the extension portion 18 of the sheath 14 echogenic by , for example , forming the extension 18 with one or more echogenic elements integrated with the extension 18 . these elements may be , for example , a metallic thread affixed to the outer surface of the extension portion 18 or embedded within the extension portion 18 . metallic flakes may be adhered or attached to the external surface of the extension portion 18 , or impregnated within the extension portion 18 . in a particularly unique embodiment , the extension portion 18 of the sheath 14 may be rendered echogenic by simply perforating the extension portion 18 with a series of holes or other openings along the axial length thereof . these holes or openings essentially expose the needle 24 to ultrasonic imaging . thus , portions or sections of the needle disposed within the extension portion 18 are visible in an ultrasonic imaging process , thereby essentially rendering the sheath echogenic . referring to fig3 c , perforations 20 are depicted along the axial length of the extension portion 18 of the sheath 14 . fig3 d represents any manner of suitable catheter site dressing , which may be one or more tegaderm ™ products from 3m . fig3 f depicts any manner of suitable syringe 46 that connects with the proximal end of the extension set 40 to deliver a local anesthetic or saline / anesthetic mixture through the extension set 40 and needle 24 . fig3 e depicts any number of vials 48 of local anesthetic , saline , or any other liquid that may be desired in performance of the tap procedure . fig3 g is meant to depict any manner of drape 52 that is uniquely configured for performance of the tap procedure . for example , the drape 52 may have any manner of fenestration located within the drape 52 for access to the tap procedure site . a suitable drape is provided by arrow as a clear 24 × 36 inch fenestrated drape with a four - inch fenestration ( with adhesive ). fig3 g depicts a continuous flow catheter 30 that is eventually deployed within the tap region to provide a relatively continuous flow of a local anesthetic from a reservoir 36 , through tubing 32 , and eventually out through a delivery end 34 . a suitable continuous flow catheter 30 is provided by iflo as the 2 . 5 inch soaker catheter ( product reference number pm010 ). fig4 is meant to depict a kit 56 that includes any manner of suitable container 58 in which is provided any combination of the components depicted in fig3 a through 3h . the container 58 may be , for example , a suitable tray having a removable sealed covering in which the articles are contained . it should be appreciated that the kit 56 need not contain all of the articles depicted in fig3 a through 3h . for example , an embodiment of the kit 56 may include the container 58 with a fluid delivery needle 24 , extension set 40 , sheath 14 , and a continuous flow catheter 30 , as discussed above . other embodiments of a kit 56 may include additional items , such as the local anesthetic 48 ( fig3 ), syringe 46 ( fig3 f ), as well as any combination of drape 52 ( fig3 g ), catheter site dressing 50 ( fig3 d ), and so forth . the invention encompasses a kit 56 with any combination of the items of fig3 a through 3h . fig5 a through 8b depict various procedural steps of a tap block procedure in accordance with aspects of the invention . fig5 a depicts the abdominal region 10 of a patient that has been prepped for the tap procedure . any manner of suitable ultrasonic probe 12 is first used to identify and mark the external oblique ( eo ), internal oblique ( io ), and transversus abdominis ( ta ). the epidural needle 24 has been inserted into the sheath 14 such that the distal end region of the needle 24 extends beyond the distal end of the sheath 14 ( as depicted in fig5 a ). while ultrasonically imaging the procedure site , the needle 24 and sheath 14 are advanced into the tap and a liquid pool 54 ( fig5 a ) is created in the tap by injecting a local anesthetic or saline / anesthetic combination through the needle 24 via a syringe and extension set 42 , as discussed above . fig5 b depicts formation of the liquid pool 54 in the tap . it can be appreciated from fig5 b that the distal end of the needle 24 is echogenic , and thus clearly distinguishable in an ultrasonic imaging procedure . the extension portion 18 of the sheath 14 has , in this particular embodiment , a series of perforations such that sections of the needle 24 within the extension section 18 are also visible in the ultrasonic imaging procedure . thus , placement of the sheath 14 is also verified by referencing the position of the needle 24 . fig6 a and 6b depict a subsequent step wherein the needle 24 is removed from sheath 14 while maintaining the extension portion 18 of the sheath 14 within the liquid pool 54 , as depicted by the arrows in fig6 a . the ultrasonic probe 12 may be useful for providing an image of removal of the needle 14 . if the sheath 14 includes echogenic material , as discussed above , an ultrasonic imaging technique may also be used to verify that the sheath 14 is properly placed within the tap , particularly within the liquid pool 54 . with this step , it may also be desired to extend the sheath 14 further into the liquid pool 54 , as depicted by the arrow in fig6 a , until a slight resistance is felt by the practitioner on the extension section 18 . fig7 a and 7b depict insertion of the catheter 30 through the sheath 14 . in particular , the delivery end 34 of the catheter 30 is inserted through the sheath and resides within the extension portion 18 of the sheath 14 within the pool 54 . during this procedure , back flow of the liquid from the pool 54 through the catheter 30 may be experienced , which is an indication of proper placement of the sheath 14 within the liquid pool 54 . referring to fig8 a and 8b , once the delivery end 34 of the catheter has been positioned within the pool 54 , the sheath 14 is withdrawn from the tap by being slid proximally over the catheter tubing 42 while maintaining the delivery end 34 of the catheter stationary within the liquid pool 54 . the catheter site may then be dressed with any suitable dressing , such as the dressing 50 depicted in fig3 b . a reservoir of a local anesthetic is connected to the proximal end of the tubing 32 and configured for delivering a controlled flow rate of the local anesthetic over a prolonged defined time period . the catheter 30 , including the reservoir 36 , tubing 32 , and the delivery end 34 , may be configured as a single integral unit , or independent components that are subsequently connected together . while the present invention has been described in connection with certain preferred embodiments it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments . on the contrary , it is intended for the subject matter of the invention to include all alternatives , modifications and equivalents as can be included within the spirit and scope of the following claims .
a kit is provided for performing an ultrasound - guided transversus abdominis plane procedure . the kit includes a container having a fluid delivery needle with a length and gauge for penetration into a patient &# 39 ; s tap . an extension set is included having a distal end that mates with the fluid delivery needle . a sheath is included having a size and length such that the needle slides into sheath and extends distally beyond a distal end of the sheath . a tap catheter is included having a size and length so as to slide through the sheath . the tap catheter has a reservoir with a defined fill volume and flow rate for delivery of a local anesthetic through said catheter .