US20230109771A1 - Method and apparatus for rectal anaesthesia - Google Patents

Abstract

A system and method for delivering a medicament to a target tissue site in a patient over a period of time. A catheter is configured for implantation in different target tissue sites and extends from a proximal end to a distal end and has a sidewall which defines an internal lumen. The distal end has one or more apertures either in the sidewall or at a distal end for the release of the medicament into the target tissue site; the system also comprises a medicament reservoir fluidly communicable with the internal lumen of each catheter, an adhesive member configured to adhere to the skin of the patient around the exit wound and having an opening therein to allow the catheters to pass through the adhesive member and a retaining member configured to be overlaid on the adhesive member and comprising a guide surface configured to receive a length of the two or more catheters and a plurality of retaining portions to retain the catheters against the guide surface.

Description

• The present application claims priority from AU 2018900653 filed 28 Feb. 2018. The contents of this priority application are herein incorporated in their entirety by reference.
FIELD OF THE INVENTION
• The present invention relates to a method and apparatus for the management of patient pain after a hemorrhoidectomy or similar surgery through nerve anaesthesia. More specifically, the invention relates to an implantable catheter device for the delivery of an anaesthetic to an area of tissue around a nerve of a patient following a hemorrhoidectomy or similar surgery.
BACKGROUND
• Haemorrhoids are enlarged prolapsing anal cushions which can result in bleeding, itching, and pain and which affect more than 50% of people at some point in their lives.
• The treatment for haemorrhoids includes application of topical ointments and/or suppositories, injection with sclerosants, rubber band ligation, stapled haemorrhoidopexy and in severe cases may involve surgery to physically remove the haemorrhoids. The surgical removal of haemorrhoids is known as a hemorrhoidectomy and the procedure involves the patient receiving either local or general anaesthesia. Incisions are made in the tissue around the haemorrhoid. The vessels inside the haemorrhoid are tied off to prevent bleeding, and the haemorrhoid is removed.
• Haemorrhoidectomy is considered a day case procedure, wherein the patient is typically released from hospital to return home within 24 hours of the procedure. Because of the extensive network of nerves within the anal canal, postoperative pain can be significant for the patient.
• Currently, after haemorrhoidectomy surgery, local anaesthetic is injected into the area immediately after surgery and the effect lasts for up to 24 hours. The patient is then given oral opioids/narcotics to manage pain which ensues for many weeks. Complete recovery from the procedure can vary between patients, taking between 2 weeks to 2 months.
• Severe postoperative pain not only requires opioid use, which may have unwanted risks and side effects, but may also prolong the hospital stay, and affect the comfort and wellbeing of the patient.
• It is therefore desirable to provide a method and apparatus for the controlled delivery of a medicament such as an anaesthetic to a nerve branch of a patient following a haemorrhoidectomy, or similar (other) surgery of the anal canal.
• Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.
SUMMARY
• In one aspect, the disclosure provides a system for delivering a medicament to a target tissue site in a patient over a period of time, the system comprising:
• a catheter configured for implantation in a target tissue site, the catheter extending from a proximal end to a distal end and having a sidewall which defines an internal lumen, said distal end having one or more apertures either in the sidewall or at the distal end for the release of the medicament into the target tissue site;
• a medicament reservoir fluidly communicable with the internal lumen of the catheter;
• an adhesive member configured to adhere to the skin of the patient around the exit wound and having an opening therein to allow the catheter to pass through the adhesive member; and
• a retaining member configured to be overlaid on the adhesive member and comprising a guide surface configured to receive a length of the catheter and a plurality of retaining portions to retain the catheters against the guide surface.
• In another aspect, the disclosure provides a system for delivering a medicament to a target tissue site in a patient over a period of time, the system comprising:
• two or more catheters configured for implantation in different target tissue sites, each catheter extending from a proximal end to a distal end and having a sidewall which defines an internal lumen, said distal end having one or more apertures either in the sidewall or at the distal end for the release of the medicament into the target tissue site;
• a reservoir of the medicament fluidly communicable with the internal lumen of each catheter;
• an adhesive member configured to adhere to the skin of the patient around the exit wound and having an opening therein to allow the catheters to pass through the adhesive member; and
• a retaining member configured to be overlaid on the adhesive member and comprising a substantially flat base, a guide surface configured to receive a length of the two or more catheters and a plurality of retaining portions to retain the catheters against the guide surface.
• A further aspect of the disclosure provides a method for treating pain in a patient after haemorrhoid surgery, the method including:
• providing two or more catheters, each catheter extending from a proximal end to a distal end and having a sidewall which defines an internal lumen, said distal end having one or more apertures either in the sidewall or at the distal end for the release of the medicament into a target tissue site;
• advancing the two or more catheters from an entry incision on the skin until the distal end of one catheter is positioned in a first target tissue site and the distal end of the second catheter is positioned in a second, different target tissue site;
• connecting the proximal ends of the catheters to a medicament reservoir and actuating delivery of the medicament to the first and the second target tissue sites.
• A further aspect of the disclosure provides a method for implanting a catheter to deliver medicament to a patient after haemorrhoid surgery, the method including:
• providing a catheter which extends from a proximal end to a distal end and has a sidewall which defines an internal lumen, said distal end having one or more apertures either in the sidewall or at the distal end for the release of the medicament into a target tissue site;
• connecting a distal end of the catheter to a stimulator trocar, the stimulator trocar comprising an elongate body which is made from a material having a greater rigidity than the catheter, the stimulator trocar comprising a nerve stimulator configured to stimulate nerves in a target tissue site;
• advancing the stimulator trocar and the catheter through the tissue of the patient;
• actuating the nerve stimulator at a determined frequency and adjusting the positioning of the stimulator trocar and the distal end of the catheter until a physical contraction of the external anal sphincter is observed at a frequency that correlates with the determined frequency of the nerve stimulator;
• identifying the location of the nerve stimulator and the distal end of the catheter where physical contraction of the external anal sphincter is achieved;
• disconnecting the nerve stimulator from the catheter and withdrawing the nerve stimulator through the first incision leaving the distal end of the catheter implanted in the target tissue site.
• A further aspect of the disclosure provides a method for positioning a catheter in a target tissue site to deliver a medicament to a patient after haemorrhoid surgery, the method including:
• providing a catheter which extends from a proximal end to a distal end and has a sidewall which defines an internal lumen, the distal end of the catheter having one or more apertures either in the sidewall or at the distal end for the release of the medicament to the target tissue site; making a lateral incision in the skin of the thigh of the patient and a first incision on one side of the anus;
• tunnelling a trocar from the lateral incision through the tissue and towards the first incision;
• at the first incision, connecting a tip of the trocar to the proximal end of the catheter and withdrawing the trocar towards the lateral incision until a desired length of the catheter is pulled through, and extends from, the lateral incision and the distal end of the catheter extends from the first incision;
• connecting the distal end of the catheter to a stimulator trocar, the stimulator trocar comprising an elongate body which is made from a material having a greater rigidity than the catheter, the stimulator trocar comprising a nerve stimulator configured to stimulate nerves in the target tissue site;
• advancing the stimulator trocar and the catheter through the tissue of the patient;
• actuating the nerve stimulator at a determined frequency and adjusting the positioning of the stimulator trocar and the distal end of the catheter until a physical contraction of the external anal sphincter is observed at a frequency that correlates with the determined frequency of the nerve stimulator;
• identifying the location of the nerve stimulator and the distal end of the catheter where physical contraction of the external anal sphincter is achieved;
• disconnecting the nerve stimulator from the catheter and withdrawing the nerve stimulator through the first incision leaving the distal end of the catheter implanted in the first target tissue site;
• connecting the proximal end of the catheter to a reservoir of medicament and infusing the medicament through the internal lumen of the catheter to deliver the medicament to the target tissue site.
• A second catheter may be inserted into a different target tissue site. The second catheter extends from a proximal end to a distal end and has a sidewall which defines an internal lumen, the distal end of the second catheter having one or more apertures either in the sidewall or at the distal end for the release of the medicament to the target tissue site. In this embodiment, a second incision in the skin is made on the opposite side of the anus to the first incision and a trocar is tunnelled through the tissue from the lateral incision and across the midline of the patient towards the second incision;
• at the second incision, connecting the tip of the trocar to the proximal end of the second catheter and withdrawing the trocar until a desired length of the second catheter is pulled through, and extends from, the lateral incision and the distal end of the second catheter extends from the second incision;
• connecting the distal end of the second catheter to a stimulator trocar;
• advancing the stimulator trocar and the second catheter through the tissue of the patient;
• actuating the nerve stimulator at a determined frequency and adjusting the positioning of the stimulator trocar and the distal end of the second catheter until a physical contraction of the external anal sphincter is observed at a frequency that correlates with the determined frequency of the nerve stimulator; identifying the location of the nerve stimulator and the distal end of the second catheter where physical contraction of the external anal sphincter is achieved;
• disconnecting the nerve stimulator from the second catheter and withdrawing the nerve stimulator through the first incision leaving the distal end of the second catheter implanted in the first target tissue site;
• connecting the proximal end of the second catheter to a reservoir of medicament and infusing the medicament through the internal lumen of the second catheter to deliver the medicament to the target tissue site.
• In another aspect, there is provided a method for positioning a catheter in a target tissue site to deliver a medicament to a patient after haemorrhoid surgery, the method including:
• providing a catheter which extends from a proximal end to a distal end and has a sidewall which defines an internal lumen, the distal end of the catheter having one or more apertures either in the sidewall or at the distal end for the release of the medicament to the target tissue site;
• making a lateral incision in the skin of the thigh of the patient and a first incision on one side of the anus;
• tunnelling a trocar from the first incision through the tissue and towards the lateral incision;
• at the lateral incision, connecting a tip of the trocar to the distal end of the catheter and pulling the trocar towards the first incision until a desired length of the catheter is pulled through, and extends from, the first incision and the proximal end of the catheter extends from the lateral incision;
• connecting the distal end of the catheter to a stimulator trocar, the stimulator trocar comprising an elongate body which is made from a material having a greater rigidity than the catheter, the stimulator trocar comprising a nerve stimulator configured to stimulate nerves in the target tissue site;
• advancing the stimulator trocar and the catheter through the tissue of the patient;
• actuating the nerve stimulator at a determined frequency and adjusting the positioning of the stimulator trocar and the distal end of the catheter until a physical contraction of the external anal sphincter is observed at a frequency that correlates with the determined frequency of the nerve stimulator;
• identifying the location of the nerve stimulator and the distal end of the catheter where physical contraction of the external anal sphincter is achieved;
• disconnecting the nerve stimulator from the catheter and withdrawing the nerve stimulator through the first incision leaving the distal end of the catheter implanted in the target tissue site;
• connecting the proximal end of the catheter to a reservoir of medicament and infusing the medicament through the internal lumen of the catheter to deliver the medicament to the target tissue site.
• A second catheter may be inserted into a different target tissue site. The second catheter extends from a proximal end to a distal end and has a sidewall which defines an internal lumen, the distal end of the second catheter having one or more apertures either in the sidewall or at the distal end for the release of the medicament to the target tissue site. In this embodiment, a second incision in the skin is made on the opposite side of the anus to the first incision and a trocar is tunnelled through the tissue from the second incision and across the midline of the patient towards the lateral incision;
• tunnelling a trocar from the second incision through the tissue, across the midline of the patient and towards the lateral incision;
• at the lateral incision, connecting a tip of the trocar to the distal end of the second catheter and pulling the trocar towards the second incision until a desired length of the catheter is pulled through, and extends from, the second incision and the proximal end of the second catheter extends from the lateral incision;
• connecting the distal end of the catheter to a stimulator trocar, the stimulator trocar comprising an elongate body which is made from a material having a greater rigidity than the second catheter, the stimulator trocar comprising a nerve stimulator configured to stimulate nerves in the target tissue site; advancing the stimulator trocar and the catheter through the tissue of the patient;
• actuating the nerve stimulator at a determined frequency and adjusting the positioning of the stimulator trocar and the distal end of the second catheter until a physical contraction of the external anal sphincter is observed at a frequency that correlates with the determined frequency of the nerve stimulator;
• identifying the location of the nerve stimulator and the distal end of the second catheter where physical contraction of the external anal sphincter is achieved;
• disconnecting the nerve stimulator from the distal end of second catheter and withdrawing the nerve stimulator through the second incision leaving the distal end of the second catheter implanted in the target tissue site;
• connecting the proximal end of the second catheter to a reservoir of medicament and infusing the medicament through the internal lumen of the second catheter to deliver the medicament to the target tissue site.
• In another aspect, the disclosure provides a surgical kit comprising:
• two or more catheters configured for implantation in a target tissue site of a patient, each catheter extending from a proximal end to a distal end and having a sidewall which defines an internal lumen, said distal end having one or more apertures either in the sidewall or the distal end;
• an adhesive member configured to adhere to the skin of the patient around the exit wound and having an aperture therein to allow the catheters to pass through the adhesive member;
• an open ring-shaped retaining member configured to be overlaid on the adhesive member and comprising a substantially flat base, a guide surface configured to receive a length of the two or more catheters and a plurality of retaining portions to retain the catheters against the guide surface;
• a tunnelling trocar configured for attachment to the proximal ends of the catheters;
• a stimulator trocar comprising an elongate body which is made from a material having a greater rigidity than the two or more catheters, the stimulator trocar comprising a nerve stimulator configured to stimulate nerves in a target tissue site;
• a pump and a medicament reservoir;
• a sheet for application to the patient's skin around the surgical site, the sheet having an adhesive surface for adhering to the skin of the patient and a series of frangible regions for removal of parts of the sheet.
• A retainer for securing one or more catheters at an exit wound site of a patient, the retainer comprising a retainer body having a lower, skin facing surface and an opposed guide surface configured to receive one or more catheters, the retainer further comprising a plurality of clips to secure a length of the one or more catheters to the retainer.
• The guide surface may be curved and terminate in an outer rim. The clips may be formed integrally with the retainer body or may be a separate structure which clip onto the body.
• The retainer may engage with a housing. The housing may comprise a circular base having an outer facing surface and a substantially flat inner surface. An outer rim may extend from the circular base and terminate in a peripheral lip. The peripheral lip is configured to attach to the rim of the retainer body to secure the two parts together. A plurality of arms may extend inwardly and upwardly from an inner edge of the circular base. The arms may terminate in a central body. The central body may comprise a substantially solid circular structure.
• In another aspect, there is provided a trocar comprising an elongate, substantially solid body extending from a proximal end to a distal end, the distal end of the trocar having a tissue separating tip and a hook feature to capture part of another medical instrument.
• In a further aspect, the disclosure provides an implantable catheter for the delivery of a medicament to a target tissue site, the catheter extending from a proximal end to an open distal end and having a sidewall which defines an internal lumen, said catheter having one or more apertures in the sidewall adjacent to the distal end, the apertures forming a fluid flow path from the internal lumen to an exterior of the catheter, the catheter further comprising a trocar receiving opening positioned proximal to the open distal end and sized to receive part of a trocar.
• In a further aspect, the disclosure provides an implantable catheter for the delivery of a medicament to a target tissue site, the catheter extending from a proximal end to an open distal end and having a sidewall which defines an internal lumen, said catheter having one or more apertures either in the sidewall adjacent to the distal end or at the distal end, the apertures forming a fluid flow path from the internal lumen to an exterior of the catheter, the catheter further comprising a trocar receiving opening positioned at the proximal end, the opening sized to receive part of a trocar.
• In another aspect, the disclosure provides a nerve stimulating trocar comprising an elongate, substantially solid body having a proximal region, a distal region terminating in a tip and an intermediate region between the proximal and distal regions, the nerve stimulating trocar further including a nerve stimulating electrode connectable to an energy source and extending distally along a length of the nerve stimulating trocar, terminating at a stimulation region beyond, at or proximal to the tip, wherein the proximal region has an inner curved surface to conform with the outer surface of a substantially cylindrical medical instrument, the intermediate region forming a bend in the trocar body such that a main axis of the proximal region is substantially parallel to a main axis of the distal region.
• A further aspect discloses a wearable apparatus for delivery of a medicament to a patient, the apparatus comprising:
• a belt attachable to the patient;
• a channel extending within or along a surface of the belt;
• a catheter fluidly connected to the channel and extending from the belt, the catheter having a sidewall which defines an internal lumen and wherein further, the sidewall of the catheter includes one or more openings which define a fluid flow path from the internal lumen to the outside of the catheter or the distal end includes an aperture to define a fluid flow path from the internal lumen to the outside of the catheter;
• a pump;
• wherein the medicament is held in the channel and the pump is configured to pump the medicament from the channel and into the internal lumen of the catheter.
• The target tissue site may comprise tissue adjacent to the anal and/or rectal branches of the pudendal nerves although any site adjacent to nerve of interest is envisaged. The first target tissue site may comprise tissue around the left pudendal nerve and the second target tissue site may comprise tissue around the right pudendal nerve or vice versa.
• The medicament to be delivered may be an analgesic. The analgesic may include but is not limited to bupivacaine, lidocaine, ropivacaine, opioid analgesics such as buprenorphine, hydromorphone, ketobemidone, levomethadyl, levorphanol, mepiridine, methadone, morphine, nalbuphine, opium, oxycodone, pentazocine, phenoperi-dine, butorphanol, dextromoramide, dezocine, dextropropoxyphene, diamorphine, fentanyl, alfentanil, sufentanil, hydrocodone, piritramide, dextropropoxyphene, remifentanil, sufentanil, tilidine, tramadol, codeine, dihydrocodeine, meptazinol, dezocine, eptazocine, flupirtine or a combination thereof.
• Typically the analgesic is ropivacaine . The ropivacaine may be delivered in solution with a concentration of 0.25%, or 0.5% or 0.75% or 1.0%. The ropivacaine may be in a concentration of between 0.25 to 0.5% or 0.5% to 1.0%. In some embodiments, the concentration of ropivacaine may exceed 0.75%.
• The analgesic may be delivered at a dose of 20 mls per day (24 hours). Alternatively, the analgesic may be delivered at a dose of 1 ml or 5 ml or 10 mls or 15 mls or 25 mls or 30 mls per day. The dose may, in some embodiments exceed 30 mls per day including 40 mls, 50 mls, 60 mls, 70 mls, 80 mls, 90 mls or 100 mls per day. In some embodiments, the dose may exceed 100 mls per day.
• The analgesic may be delivered to the patient continuously over the time period. Alternatively, it may be delivered in dosage intervals within the time period. The dosage intervals may occur every 1, 5, 10, 20, 30, 40 or 50 minutes. Further, the dosage intervals may occur hourly, every 2 hours, every 3 hours, every 4 hours, every 5 hours, every 6 hours, every 7 hours, every 8 hours, every 9 hours, every 10 hours, every 11 hours or every 12 hours.
• The dosage intervals may range of from 30 secs up to 6 hours. The dosage intervals may be 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours of 6 hours. In some cases, the dosage intervals may be longer than 6 hours. For example the dosage interval may be 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours. Further, the dosage intervals may exceed 12 hours and may be from 12 hours to 23 hours.
• The time period may range from 1 day to 3 months. For example, the time period may be 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 2 months or 3 months.
• The analgesic may be delivered in an initial burst followed by continuous delivery thereafter or alternatively followed by dosage intervals.
• The initial burst may enable a larger initial dose to be delivered over an initial period of time to achieve an immediate pain relief for the patient. The initial burst may deliver a percentage of the daily dose. For example, the initial burst may deliver 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the daily dose. The regimen may be such that such an initial burst occurs daily, or every second, third, fourth, fifth or sixth day during the time period. Further, an initial burst may occur once every week, every 2 weeks, every three weeks
• Alternatively, an initial burst may only occur once, for example, on the first day of treatment.
• In a preferred embodiment, the catheters are relatively flexible. However, the catheters may have sufficient rigidity so as to permit passage through the body to the target tissue site.
• The catheters may be made from one or more biodegradable polymers including but not limited to: polylactic acid, polyglycolic acid, poly(L-lactide), poly(D,L-lactide), polyglycolic acid, poly(L-lactide-co-D,L-lactide), poly(L-lactide-co-glycolide), poly(D, L-lactide-co-glycolide), poly(glycolide-co-trimethylene carbonate), poly(D,L-lactide-co-caprolactone), poly(glycolide-co-caprolactone), polycaprolactone, polycaprolactone co-butylacrylate, polyhydroxybutyrate, poly(phosphazene), poly(phosphate ester), poly(amino acid), polydepsipeptide, maleic anhydride copolymer, polyiminocarbonates, poly[(97.5% dimethyl-trimethylene carbonate)-co-(2.5% trimethylene carbonate)], poly(orthoesters), tyrosine-derived polyarylate; polyethylene oxide, polyoxaester, polydioxanone, polypropylene fumarate, poly(ethyl glutamate-co-glutamic acid), poly(tert-butyloxy-carbonylmethyl glutamate).
• In some embodiments, the catheters may be made from one or more non-biodegradable materials including, but not limited to, various cellulose derivatives (carboxymethyl cellulose, cellulose acetate, cellulose acetate propionate, ethyl cellulose, hydroxypropyl methyl cellulose, and alkyl celluloses), silicon and silicon based polymers (such as polydimethylsiloxane), polyethylene-co-(vinyl-acetate), poloxamer, polyvinylpyrrolidone, poloxamer, polyvinylpyrrolidone, poloxamine, polypropylene, polyamide, polyacetal, polyester, poly ethyl-ene-chlorotrifluoroethylene, polytetrafluoroethylene (PTFE or “Teflon™”), styrene butadiene rubber, polyethylene, polypropylene, polyphenylene oxide-polystyrene, polychloro-p-xylene, polymethylpentene, polysulfone, non-degradable ethylene-vinyl acetate, and other related bio-stable polymers.
• The catheters may have a lubricious outer coating to aid in delivery towards the target tissue site. The catheter coating may also comprise one or more drugs selected from the group consisting of antimicrobial agents, anti-inflammatory agents, anti-scarring agents, anti-fibrotic agents and leukotriene inhibitors.
• The overall shape of the catheters may comprise an elongated tube. The catheters may be of the same diameter relative to each other or different diameters relative to each other. In one embodiment the catheters may have a diameter in the range of 2 mm to 10 mm. Specifically, the catheters have a diameter of approximately 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.
• The one or more apertures may be positioned at or adjacent to the distal end of the catheters. The catheters may comprise a single aperture at or adjacent the distal end. Alternatively the catheters may include a plurality of apertures at or adjacent the distal end. The plurality of apertures may be positioned around the circumference of the catheters.
• The apertures may be evenly spaced relative to each other or unevenly spaced. Further, the apertures may be arranged in ring-like arrangements around the circumference of the catheters. The apertures may extend a length of the catheter from the distal end. Alternatively, the apertures may be positioned along one side of a catheter. In such an embodiment, the catheter may be oriented during use such that the apertures are adjacent and facing the nerve or nerve branch.
• The apertures of a catheter may be arranged in a number of configurations in addition to the ring like arrangement described above. For example, the apertures may be arranged in a helical or partially helical arrangement along a length of the catheter.
• Different catheters may have the same configuration of apertures or may differ relative to each other.
• The sidewalls of the catheters may define substantially circular apertures although any suitable shape or size of aperture is also envisaged. The sizes of the apertures may vary along the length of the catheter or the apertures may be uniform in size.
• An aperture may be formed in a distal end of the catheter. In one embodiment, the internal lumen may be open ended to allow fluid to flow therthrough and out of the distal end through the lumen.
• In embodiments where a stimulator trocar is not used, a catheter may comprise a nerve stimulator. The catheter nerve stimulator may comprise one or more electrodes positioned in or on the sidewall of the catheter. The one or more electrodes may be positioned adjacent to the distal end of the catheter. The one or more electrodes may be connected to an energy source by an insulated electrode lead. The electrode lead may be embedded in the sidewall of the catheter and extend the full or a partial length of the catheter. Alternatively, the electrode lead may extend through the internal lumen of the catheter. The electrode lead may be of sufficient stiffness to stiffen the catheter to assist in its delivery to a target tissue site.
• A catheter may contain one or more flow restrictors, located within the lumen of the catheters. The one or more flow restrictors may control the fluid flow rate through the catheter from the proximal end toward the distal end.
• A catheter may exit the exit wound of the patient and be fluidly connected to the reservoir. Multiple catheters may be connected to the reservoir by a suitable connector such as a Y-connector or other multi-limbed connectors in the case of more than two catheters.
• Where a common conduit connects to the reservoir, one or more flow restrictors may be provided in at least one of the catheters as a means to control the flow of medicament through the catheter such that the flow rate of medicament in one catheter may differ from the flow rate of medicament in another catheter.
• The proximal end of a catheter may be sealable such as to maintain a sterile and enclosed internal environment of the catheter when not fluidly connected to the reservoir.
• In a further embodiment of the wearable apparatus described above, the belt may be made a suitably flexible material to encircle a user's body adjacent to the user's skin. Because the belt may, in part, be in contact with the skin of a user, it is desirable that the belt is made of a suitably biocompatible material. Typically the belt is attached around the waist region of a user.
• The belt may house one or a number of channels which may either extend through the belt or along a surface of the belt. The channel may include a reservoir channel configured to store a volume of a medicament in liquid form. The reservoir channel may be connected to the pump which, when actuated, draws liquid medicament from the reservoir channel. The channel may also include a delivery channel. The delivery channel may also be connected to the pump. The pump may pump the liquid medicament drawn from the reservoir channel into the delivery channel.
• The catheter may be in fluid connection with the delivery channel. The catheter may extend from a connection with the delivery catheter at an access region of the belt. The access region may be at or adjacent to an inner, skin facing surface of the belt.
• The belt may include two reservoir channels separated by the pump. Further, the belt may include two delivery channels also separated by the pump. In this embodiment, the pump may draw a medicament from a first reservoir channel and pump this medicament into a first delivery channel. The first delivery channel may be fluidly connected to a first catheter. The pump may also draw a medicament from a second reservoir channel whereupon it pumps this medicament into a second delivery channel. The second delivery channel may be fluidly connected to a second catheter.
• The apparatus may further include a housing unit. The housing unit may at least partially surround the belt at or near the access region. The housing unit may include a base. The base may be substantially planar or, alternatively the base may have a slight curvature. The base may be configured for positioning on or adjacent to the user's skin at the access region. The base may also include an aperture which is sized to allow part of the catheter to pass therethrough. The base may further include at least one flange member extending from an edge which defines the aperture. The at least one flange member may be configured to engage or grip a sidewall of part of a catheter which extends through the aperture. The flange member may comprise an inwardly extending skirt around the entire edge defining the aperture. The flange member may be made from a flexible, biocompatible material.
• The housing unit may further include an outer protective surface which is spaced from the base by sidewalls. The outer protective surface may cover an outer surface of the belt. The outer protective surface may be made from a relatively harder material than the base.
• The base of the housing unit may include an adhesive layer to secure the base to the skin of a patient. The adhesive of the adhesive layer may be made from a suitably biocompatible material.
• The catheter typically extends from a proximal end connected to the delivery channel to a distal end which is implanted in the body of the patient. However, the catheter may connect directly to the pump. In this embodiment, the catheter may be received in a channel which is formed on a surface of the belt. Typically the channel is formed on an inner surface of the belt. The catheter may be press-fit into the channel.
• It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
• Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
EXAMPLES
• A 60year-old female having previously had rubber banding of haemorrhoids presented with prolapsing large grade3 haemorrhoids and spontaneous bleeding through clothing. Rubber banding had not controlled the symptoms. A haemorrhoidectomy was scheduled. Two catheters as described herein were implanted into the patient with their distal ends positioned adjacent to the branches of the pudendal nerves on either side of the anus and the surgical removal of the haemorrhoids was carried out. Bilateral infusion of ropivacaine through the catheters was commenced at 2 ml/hr 0.2%. Pain was reported by the patient as 2-4 out of 10 and the patient was observed as very comfortable post operatively. Pain was experienced with each daily bowel action eg 4-8 out of 10, 5-6 out of 10. Oral opioids after bowel actions were introduced.
• A 40 year-old male presented with haemorrhoids which were bleeding. Rubber banding treatment had previously been conducted. The haemorrhoids enlarged over the years and he presented with grade4 haemorrhoids not suitable for any treatment other than haemorrhoidectomy. He deferred the operation until a pain device was available. A haemorrhoidectomy was scheduled. Two catheters as described herein were implanted into the patient with their distal ends positioned adjacent to the branches of the pudendal nerves on either side of the anus. The surgical removal of the haemorrhoids was carried out. Bilateral infusion of ropivacaine through the catheters at 2 ml/hr with 0.2% was commenced and top-up bolus injections after defecation with 10 ml 0.75% ropivacaine each side on days 1, 3 and 5. The patient reported very low-grade pain only, other than the first bowel action. Oral opioids were used once only, after the first bowel action. The catheters were removed on day 7 after surgery.
• A 53 year-old female presented with longstanding haemorrhoids, treated by banding several times. The patient had been advised against a haemorrhoidectomy because of pain. She presented with large grade 3 haemorrhoids causing discomfort and itching. A haemorrhoidectomy was scheduled and during the surgery two catheters as described herein were implanted into the patient with their distal ends positioned adjacent to the branches of the pudendal nerves on either side of the anus. The surgical removal of the haemorrhoids was carried out. Bilateral infusion of ropivacaine through the catheters at 2 ml/hr with 0.2%. The patient reported very low levels of pain at 1-2 out of 10 and used only one opioid in first 48 hrs. On day 4 post surgery pain was reported as 8 out of 10 after bowel action. Opioids were used on that day. The catheters were removed on day 6 and the patient required twice daily long-acting opioids subsequently for two weeks.
DESCRIPTION OF DRAWINGS
• By way of example only, embodiments are now described with reference to the accompanying drawings, in which:
• FIG.1A and1B show perspective views of a wearable apparatus for delivery of a medicament device according to an embodiment of the present disclosure;
• FIG.2A,2B, and2C shows front, top, and side views, respectively, of the wearable apparatus ofFIG.1A and1B;
• FIG.3 shows a perspective view of a catheter of the wearable apparatus ofFIG.1A and1B;
• FIG.4 shows a view of a distal end of the catheter ofFIG.3;
• FIG.5 shows a view of a distal end of the catheter of a wearable apparatus according to another embodiment of the present disclosure where the catheter includes a trocar;
• FIG.6 shows a perspective view depicting a cross sectional cut away of the belt of the wearable apparatus ofFIG.1A and1B;
• FIG.7 shows a perspective view depicting a cross sectional cut away of the belt of a further embodiment of the wearable apparatus ofFIG.1A and1B; and
• FIG.8 shows a top cross-sectional view of part of the wearable apparatus ofFIG.1A and1B.
• FIGS.9ato9hshow the steps of one exemplary embodiment of a method of implanting two infusions catheters in a patient;
• FIG.10 is a side view of a trocar used in the method shown inFIGS.9ato9h;
• FIG.11ais a side view of a hook feature of the trocar ofFIG.10;
• FIG.11bis a perspective view of the hook feature of the trocar ofFIG.10;
• FIG.12ais a side view showing the engagement of the hook feature of the trocar ofFIG.10 engaging with a catheter of the present disclosure;
• FIG.12bis a cross-sectional view ofFIG.12a;
• FIG.12cis a perspective view ofFIG.12a;
• FIG.13ais a top plan view of an embodiment of a catheter of the present disclosure;
• FIG.13bis a perspective view of the catheter ofFIG.13a;
• FIG.14ais a top plan view of a further embodiment of a catheter of the present disclosure;
• FIG.14bis a perspective view of the catheter ofFIG.14a;
• FIG.15ais a top plan view of an embodiment of another catheter of the present disclosure;
• FIG.15bis a perspective view of the catheter ofFIG.15a;
• FIG.16ais a top plan view of a further embodiment of a catheter of the present disclosure;
• FIG.16bis a perspective view of the catheter ofFIG.16a;
• FIG.17 is a side view of a nerve stimulating trocar;
• FIG.18ais a partial side view of part of the nerve stimulating trocar ofFIG.17;
• FIG.18cis a perspective view of part of the nerve stimulating electrode ofFIG.17;
• FIG.19ais a side view of an embodiment of a nerve stimulating trocar inserted into part of a catheter of the present disclosure;
• FIG.19bis a cross-sectional view of the embodiment shown inFIG.19a;
• FIG.19cis a cross-sectional view through X-X ofFIG.19b;
• FIG.19dis a perspective view of the embodiment shown inFIG.19a;
• FIG.20ais a side sectional view of an embodiment of a nerve stimulating trocar;
• FIG.20bis a side perspective view of the embodiment shown inFIG.20a;
• FIG.21ais a side sectional view of another embodiment of a nerve stimulating trocar;
• FIG.21ba side perspective view of the embodiment shown inFIG.21a;
• FIG.22ais a perspective view of the parts making up a retainer in one embodiment;
• FIG.22bdepicts the retainer with a cover over the parts;
• FIG.23ais a cross sectional view of the retainer and catheters of the present disclosure;
• FIG.23bis a cross sectional view of the retainer wherein the catheters wherein the catheters comprise balloons;
• FIG.24ais a perspective view of the various parts of a casing of the present invention;
• FIG.24bshows the casing ofFIG.24a, held in a pouch on a patient's body;
• FIG.24cis a sectional view of the casing; and
• FIG.25 illustrates the various part of a kit according to the present disclosure.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
• A wearable apparatus according to an exemplary embodiment of the present disclosure is illustrated generally as10 in the accompanying drawings. Thewearable apparatus10 includes abelt11, pump12,catheters13a,13b,andhousing units14a,14b.As discussed in more detail below, thebelt11 is attachable to a patient around their waist andcatheters13a,13bare configured to be implanted in the patient withdistal ends31aand31bat or adjacent to a right and left pudendal nerve respectively to deliver pain relief medicament directly to the nerves.
• Catheter13aextends from aproximal end30ato adistal end31aand has asidewall32awhich defines an internal lumen34a.Apertures35aprovide a fluid flow path from the internal lumen34ato the outside ofcatheter13a.Catheter13bextends from aproximal end30bto adistal end31band has a sidewall32bwhich defines an internal lumen34b.Apertures35bprovide a fluid flow path from the internal lumen34bto the outside ofcatheter13b.
• In the depicted embodiments, both proximal ends30a,30bofcatheters13a,13b,respectively, are in fluid connection withpump12 such that thepump12 pumps a medicament into bothcatheters13a,13b.The medicament may be pumped in unison, delivering medicament to bothcatheters13aand13bat substantially the same time. Alternatively, the pump may alternate between delivery of medicament tocatheter13aandcatheter13bat different time periods.
• FIG.3 depicts a view of one of thecatheters13a.The same features may equally apply tocatheter13b.Catheter13aextends fromproximal end30atodistal end31a.Adjacentdistal end31a,the catheter sidewall has a plurality of apertures as described above for the delivery of a medicament. A coiledregion60aofcatheter13aextends fromproximal end30a.Coiled region60ais configured such that it is positioned beneath the skin of the patient when thecatheter13ais implanted. The coiled structure acts as a strain relief and prevents pulling or tugging at the wound site which could open the wound and cause discomfort for the patient and an increased risk of infection. Typically, the coiledregion60aextends a length of thecatheter13asuch that it sits in the fatty layer beneath the skin of the patient.Catheter13balso has a coiledregion60bas depicted in, for example, inFIGS.1A and2B.
• Coiled regions60aand60bmay include a shape memory material such that when inserted in the body, said regions adopt the coiled configuration.
• Thedistal end31bofcatheter13bis shown in more detail inFIG.4. The same features are to be understood to also apply tocatheter13aandcatheter13bhas been selected purely for illustrative purposes. In thisembodiment catheter13bcomprises adistally extending electrode40. Theelectrode40 is connected proximally to an electrical source (not shown). Theelectrode40 is used during surgery to achieve accurate positioning ofcatheters13aand13badjacent to respective pudendal nerves. By stimulating the tissue adjacent the nerve with the electrode, the surgeon may view twitching of the muscles adjacent to the anus thus establishing that the distal ends of thecatheters13aor13bare properly positioned.
• Referring toFIG.5, in another embodiment of the present disclosure, adelivery trocar50 may substantially surroundcatheter13b.Trocar50 is of sufficient rigidity to guide thecatheter13bthrough the tissue to a desired nerve site. Thetrocar50 in this embodiment includes anelectrode51 at its distal end. Similarly,catheter13amay also be guided by atrocar50. Once guided bytrocar50 to the desired site in the patient's body, the trocar is withdrawn to leave thecatheter13aor13bin situ.
• Once thecatheters13aand13bare positioned and the distal ends31aand3 lb respectively are adjacent to the desired nerve tissue, the proximal end of the twocatheters13aand13bmay be connected either directly or indirectly to pump12. In this regard,FIG.6 shows an embodiment whereincatheter13ais aligned with atrench70 on an inner surface ofbelt11. The catheter is typically press fit into thetrench70 which runs along a length of the inner surface ofbelt11 and terminatesadjacent pump12 to allowcatheter13ato be directly connected to pump12.
• In a further embodiment, thecatheters13a,13bdo not connect directly withpump12 but instead are connected torespective delivery channels80a,80bwhich extend internally withinbelt11.
• In the embodiment shown inFIG.7, the proximal ends30aofcatheter13aand30bofcatheter13bextend from a wound site on the skin of a patient and intorespective housings14aand14b.As shown more clearly inFIG.8,proximal end30aofcatheter13aconnects with adelivery channel80awithinhousing14a.Although not shown,delivery channel80aextends through the belt and connects withpump12. Similarly,proximal end30bofcatheter13bconnects with adelivery channel80bwithinhousing14b.Delivery channel80bextends through thebelt11 on an opposite side of the belt and connects withpump12.
• Pump12 may be positioned either at the front of the belt such that it sits adjacent to the navel region of a wearer or at the rear ofbelt11 to sit adjacent the small of the back of a wearer.Pump12 may draw medicament from a single reservoir or it may draw from multiple reservoirs. InFIGS.6 and7, twoseparate reservoirs90aand90bare depicted. InFIG.6catheters13aand13bextend along atrench70 on a surface ofbelt12 and connect directly to thepump12.Pump12 draws medicament fromreservoir90aand pumps this medicament tocatheter13a.Pump12 also draws medicament held inreservoir90band pumps this medicament intocatheter13b.
• In the embodiment depicted inFIG.7, pump12 draws medicament fromreservoir90aand pumps this medicament intodelivery channel80afor delivery tocatheter13a.Pump12 also draws medicament fromreservoir90band pumps this medicament intodelivery channel80bfor delivery tocatheter13b.
• Housing14ahas a base95aand an outer surface96a.Base95amay include an adhesive surface to secure the housing over the wound site of a patient. The housing has a height sufficient to allow part of the proximal region ofcatheters13a,13bto turn at an angle and connect with a delivery channel without the risk of the catheters kinking.Housing14bmay have the same features ashousing14a.
• Turning to the exemplary method shown inFIGS.9ato9h, the drawings depict a patient in position for an operation to surgically remove their haemorrhoids. The patient is typically placed on the operating table under general anaesthetic with muscle relaxation in the depicted modified lithotomy position. The perineum, pelvic area and thighs are prepared in a sterile field using a solution of iodine and alcohol. An iodine-impregnatedadhesive mat500 is placed vertically from the pubis to cover the vagina/scrotum and the anal region. This area is kept sealed until thecatheters100 and200 are implanted in the desired position. Theadhesive mat500 comprises a firstfrangible region501 with serrations in the mat allowing a small area of the mat (here shown as a square but could be any shape) to be torn off, for access to the skin beneath. The surgeon makes a stab incision A at this region and then removes a similarly shapedfrangible region502 ofmat500 and makes a second stab incision B at this region. A lateral stab incision is made at point C.
• Trocar300 comprises anelongate body301 extending fromhandle302 to tip303. Thetip303 may be shaped to separate tissue in the patient. Thetrocar300 may also have ahook feature304adjacent tip303.
• Catheter100 extends from aproximal end101 to adistal end102 and has asidewall103 which defines aninternal lumen104. One ormore apertures105 are formed in the sidewall adjacentdistal end102 to allow for fluid in the internal lumen to pass into the surrounding tissue.Distal end102 may be further modified to have atrocar receiving opening106. Theapertures105 may be positioned proximal to thetrocar receiving opening106 and theinternal lumen104 may terminate proximal to thetrocar receiving opening106 to prevent medicament flowing at an uncontrolled flow rate out of thelarger opening106 rather than through theapertures105. In an alternative embodiment, the proximal end ofcatheter100 has the trocar receiving opening with the apertures positioned at thedistal end102.
• Trocar300 is typically between 30 cm and 40 cm in length and may also have a surrounding sheath (not shown in the drawings). Thetrocar300 is passed subcutaneously from incision A to incision C as shown inFIG.9a. At incision C thehook feature304 is hooked into a receivingaperture106 atdistal end102 ofcatheter100 and the trocar withdrawn back subcutaneously to incision A untildistal end102 ofcatheter100 is drawn through incision B. A length ofcatheter100 atdistal end102 extends through incision A and a length ofcatheter100 adjacentproximal end101 extends through incision C as depicted inFIG.9b.
• Catheter200 extends from aproximal end201 to adistal end202 and has asidewall203 which defines aninternal lumen204. One ormore apertures205 are formed in the sidewall adjacentdistal end202 to allow for fluid in the internal lumen to pass out and into the surrounding tissue.Distal end202 may be further modified to have atrocar receiving opening206. Theapertures205 may be positioned proximal to the trocar receiving opening and theinternal lumen204 may terminate proximal to thetrocar receiving opening206 to prevent medicament flowing at an uncontrolled flow rate out of thelarger opening206 rather than through theapertures205.
• Trocar300 is passed subcutaneously from incision B to incision C as shown inFIG.9c. This step requires passing thetrocar300 through the thicker central midline tissue to create a path forcatheter200. At incision C thehook feature304 of the trocar is hooked into receivingaperture206 ofcatheter200 and thetrocar300 withdrawn back subcutaneously to incision B untilcatheter200 is drawn through incision B. A length ofcatheter200 atdistal end202 extends through incision A and a length ofcatheter200 adjacentproximal end201 extends through incision C as can be seen inFIG.9d.
• Anerve stimulating trocar400 comprises an elongatesolid body401 having aproximal region402, adistal region403 terminating in atip404. Thenerve stimulating trocar400 further includes anintermediate region405 between the proximal402 anddistal regions403.
• Nerve stimulating trocar400 acts to both deliver a stimulation to a nerve in the patient and also to provide a relatively rigid structure to deliver thecatheters100 or200 to the desired location in the body. Thenerve stimulating trocar400 can have one or morenerve stimulating electrodes410 at, or proximal totip404. Alternatively, theelectrode410 may extend beyondtip404 as shown in, for example,FIGS.19aand19b.
• The nerve stimulating assembly may comprise an electricallyconductive lead411 that is substantially embedded in the trocar and extends along a length of thetrocar400.Electrode lead411 connects to an energy source (not shown). Theelectrode410 in this embodiment is formed wherelead411 extends beyondtip404 oftrocar400.
• In an alternative embodiment, as shown inFIG.20a, theelectrode lead411 is insulated withnon-conductive insulator430 and extends along an external surface oftrocar400. Theelectrode410 comprises a non-insulated part of thelead411.
• Nerve stimulating trocar400 is configured to align with an outer surface ofcatheter100 or200 and as such typically has an innercurved surface420 as shown inFIG.19c.
• Intermediate region405 oftrocar400 forms a bend inbody401 such that a main axis of theproximal region402 is offset and substantially parallel to a main axis of thedistal region403.
• Tip404 oftrocar400 is inserted into opening106 ofcatheter100 or opening206 ofcatheter200 such that it extends beyonddistal ends102 or202 respectively.Distal region403 sits recessed within theopenings106 or206.
• Referring toFIG.9e, once thedistal region403 is in position withinopening106,trocar400 andcatheter100 are passed through incision A and angled to pass deeply into the tissue until at a region where the target nerve branches e.g. the pudendal nerve branches are located.
• In another exemplary embodiment shown inFIGS.14a,14b,16aand16b, thecatheters100 and200 include an electricallyconductive lead111 and211 that is either embedded in the sidewall of the catheters or passes through theinternal lumina104/105.Electrode lead111 connects to an energy source (not shown) and theelectrode110 in this embodiment is formed wherelead111 extends beyonddistal end102 ofcatheter100. Similarly,electrode lead211 connects to an energy source (not shown) and theelectrode210 in this embodiment is formed wherelead211 extends beyonddistal end202 ofcatheter200.
• In the embodiments where theelectrodes100 and200 have an electrode, they may still be used with a modified trocar similar to thenerve stimulating trocar400 but without theelectrode410 andelectrical lead411.
• The energy source is then activated. In one embodiment, the energy source is an electrical energy source which delivers an electrical stimulus toelectrode410. The electrical stimulus is typically between 3-5 mAmp and at a frequency of between 0.5-1.0 Hz. The surgeon watches for contraction of the external sphincter of the anus at a cycle rate as set. The surgeon may move thetrocar400 andcatheter100 until this contraction is observed. This indicates to the surgeon that the one ormore electrodes410 are adjacent to the branches of the pudendal nerve and that thedistal end102 of the catheter is thus in a position to infuse medicament fromapertures105 to the branches of the pudendal nerve.
• The next step is to disengagetrocar400 fromcatheter100, careful not to dislodgedistal end102 from its position adjacent to the pudendal nerve branches.Trocar400 is withdrawn from the patient through incision A.
• The process is repeated through incisionB using trocar400 andcatheter200 as also shown inFIG.9e.
• The proximal ends101 and201 ofcatheters100 and200 are then pulled in the direction shown by the arrows inFIG.9fto pull the excess of each catheter at incisions A and B subcutaneously. Again, the catheters are not pulled such as to cause any dislodgement of the positioning of the distal ends102 and202 adjacent to the branches of the pudendal nerves.
• The surgeon removes a portion of theadhesive mat500 by tearing alongfrangible line503. The incisions A and B are then sealed.
• The lengths of catheter that exit incision C are retained byretainer600.Retainer600 has several parts including anadhesive film610 which adheres to the skin over incisionC. Adhesive film610 has a central aperture, slit or flap to allow the passage ofcatheters100 and200 from incision C therethrough.
• Retainer600 further includes aretainer body620 which comprises a partially circular structure having a relativelyplanar base surface621 configured to sit on theadhesive film610 and anopposed guide surface622 to receive a length of thefirst catheter100 and/or thesecond catheter200. Theguide surface622 may be curved and terminate in anouter rim623. A series ofclips630 retain thecatheters100 and/or200 to theguide surface622. Theclips630 may be formed integrally with theretainer body620 or may be a separate structure which clip onto theretainer body620. Theclips630 includejaw members631 which together form a tunnel through which one or more of thecatheters100 or200 may pass. Theclips630 may be made from a resiliently flexible material and the jaw members may be moveable between an open configuration to allow the catheter to be laid along theguide surface622 and a closed configuration to form the tunnel to secure the catehters100 and200. Thejaw members631 may be biased to adopt the closed configuration.
• Retainer600 further includeshousing650.Housing650 comprises a substantiallycircular base651 having an outer facingsurface652 and a substantially flatinner surface653. Anouter rim657 extends peripherally fromcircular base651 and terminates in alip660.Lip660 attaches to part ofrim623 ofretainer body620 to secure the two parts together. A plurality ofarms654 extend centrally from aninner edge655 ofcircular base651.Arms654 terminate in acentral body656.Central body656 is configured to sit directly over incision C where thecatheters100/200 exit the patient's body to provide extra protection from any external forces to this area.
• Retainer600 also includes acover660 configured to clip onto thehousing650.
• Retainer600 both protects the wound of the patient and prevents strain oncatheters100/200 which could cause them to be pulled out of the incision C.
• Theretainer body620 is a split ring structure as shown and therefore it can be oriented such as to direct thecatheters100 and/or200 in a desired direction as they exit theretainer body620. The proximal ends101 and201 of the catheters are ultimately connected to amedicament reservoir700 which can be carried in apouch800 or like device anywhere on the patient's body. The patient may choose their preference for the location ofpouch800 prior to surgery and theretainer body620 oriented accordingly such that thecatheters100 and/or200 are directed towards thepouch800.
• Before connecting thecatheters100/200 to amedicament reservoir700,balloon members190 and290 may be threaded over proximal ends101 and201 ofrespective catheters100 and200 and inserted though incision C to a location just beneath the skin as shown inFIG.23b. Theballoon members190 and290 are typically inserted into the skin in a deflated configuration and once in position they are inflated using a flexible inflation tube (not shown). Theballoons190 and290 act to secure thecatheters100/200 and prevent dislodgement.
• Casing710 houses medicamentreservoir700 and pump750. Themedicament reservoir700 is connected to separate pumpingmembers750aand750bofpump750 by twotubes701 and702. In the example shown,pump members750aand750bare peristaltic pumps but other pump means are envisaged. In the depicted embodiment,tube701 is fed through and extends from pumpingmember750a.Likewise,tube702 is fed through and extends from pumpingmember750b.
• The twotubes701 and702 extend through an opening in710 and are connectable to the proximal ends ofcatheters100 and200 respectively.
• Havingseparate pumping members750aand750bfor each catheter has the advantage of a greater control on flow to each target tissue site.Catheter200 is longer than catheter100 (because it travels further in the body) so requires a different pumping programme to ensure that the same amount, and at the same rate, of medicament is delivered to the nerve branches relative tocatheter100.
• Aprotective plate770 covers thepump750 and themedicament reservoir700 and the power supply such asbatteries790. Casing710 also has aremovable lid780 which may be readily opened to allow replacement of themedicament reservoir700 as needed.
• Turning to the method step depicted inFIG.9g, oncecatheters100 and200 are implanted adjacent to respective pudendal nerve branches, the surgeon can then remove the part of themat500 which seals the anus by tearingfrangible line504.
• The haemorrhoids may then be surgically removed. Once surgery has been completed, pump750 is actuated and the medicament is drawn from themedicament reservoir700 through thecatheters100 and200 to the branches of the pudendal nerves on either side of the anus.
• FIG.25 shows the parts of the system in akit900 which includes the various parts of the system disclosed herein to allow the placement ofcatheters100 and200 adjacent to respective pudendal nerve branches to deliver medicament to a patient and alleviate pain after the surgical removal of haemorrhoids.Kit900 comprises twocatheters100 and200,retainer600, twotrocars300 and twotrocars400,mat500 andcasing710housing medicament reservoir700 and pump750.

Claims (24)

1. A system for delivering a medicament to a target tissue site in a patient over a period of time, the system comprising:

a catheter configured for implantation in a target tissue site, the catheter extending from a proximal end to a distal end and having a sidewall which defines an internal lumen, said distal end having one or more apertures in the sidewall for the release of the medicament into the target tissue site;

a medicament reservoir fluidly communicable with the internal lumen of the catheter;

an adhesive member configured to adhere to the skin of the patient around the exit wound and having an opening therein to allow the catheter to pass through the adhesive member; and

a retaining member configured to be overlaid on the adhesive member and comprising a guide surface configured to receive a length of the catheter and a plurality of retaining portions to retain the catheters against the guide surface.

2. The system ofclaim 1 wherein the catheter comprises two or more catheters.

3. The system ofclaim 2, wherein the two or more catheters have a trocar receiving opening in the sidewall at the distal end, the proximal end or both the distal and proximal ends.

4. The system ofclaim 1, further comprising a trocar, said trocar having an elongate solid body which extends from a proximal end to a distal end, the trocar having a hook feature at or adjacent to either the proximal or distal end.

5. The system ofclaim 3, further comprising a nerve stimulating trocar.

6. The system ofclaim 5, wherein the nerve stimulating trocar comprises an elongate body having a proximal region, a distal region having a distal tip and an intermediate region between the proximal and distal regions.

7. The system ofclaim 6, wherein the nerve stimulating trocar comprises one or more electrodes.

8. The system ofclaim 7, wherein the one or more electrodes are at the distal tip of the nerve stimulating trocar.

9. The system ofclaim 6, wherein the intermediate region of the nerve stimulating trocar forms a bend such that a main axis of the proximal region is offset and substantially parallel to a main axis of the distal region.

10. The system ofclaim 9, wherein the proximal region of the nerve stimulating catheter is configured to extend along an outer surface of the two or more catheters and the intermediate region passes through the trocar receiving opening such that the distal region is housed within the internal lumen of the two or more catheters and the distal tip extends from the distal end of the two or more catheters.

11. The system ofclaim 1, wherein the retaining member is a partially circular structure having a relatively planar base surface and wherein the guide surface is opposed to the planar base and is a curved surface which terminates in an outer rim.

12. The system ofclaim 11, wherein the retaining member includes one or more clips to retain the catheter against the guide surface.

13. The system ofclaim 12, wherein the clips comprise a pair of opposed jaw members which together form a tunnel therethrough.

14. The system ofclaim 13, wherein the jaw members are made from a resiliently flexible material and are biased in a closed configuration such as to form the tunnel therethrough.

15. The system ofclaim 1, further comprising a retainer housing comprising a substantially circular base having an outer facing surface and a substantially flat inner surface and an outer rim which extends peripherally from circular base and terminates in a lip.

16. The system ofclaim 15, wherein the retainer housing further comprises a plurality of arms which extend centrally from an inner edge of the circular base and which terminate in a central body.

17. The system ofclaim 1, wherein the catheter includes a balloon having an internal passage to thread over an end of the catheter such that the balloon slides over the catheter to a desired location.

18. The system ofclaim 1, further comprising a pump, wherein the pump comprises two separate pumping members each connected to the medicament reservoir and to respective catheters.

19. The system ofclaim 18, further comprising a power source to power the pump and a control unit to control the rate of flow of the medicament from the medicament reservoir to the two or more catheters.

20. The system ofclaim 19, wherein the control unit is pre-programmed to deliver a pre-determined regimen of medicament over a period of time.

21. The system ofclaim 20, wherein the pre-determined regimen includes different pre-programmed intervals.

22. The system ofclaim 21 including a bolus interval wherein during the bolus interval, an increased amount of medicament is delivered to the patient compared to one or more of the other pre-programmed intervals.

23-34. (canceled)

35. A surgical kit comprising:

two or more catheters configured for implantation in a target tissue site of a patient, each catheter extending from a proximal end to a distal end and having a sidewall which defines an internal lumen, said distal end having one or more apertures in the sidewall;

an adhesive member configured to adhere to the skin of the patient around the exit wound and having an aperture therein to allow the catheters to pass through the adhesive member;

an open ring-shaped retaining member configured to be overlaid on the adhesive member and comprising a substantially flat base, a guide surface configured to receive a length of the two or more catheters and a plurality of retaining portions to retain the catheters against the guide surface;

a tunnelling trocar configured for attachment to the proximal ends of the catheters;

a stimulator trocar comprising an elongate body which is made from a material having a greater rigidity than the two or more catheters, the stimulator trocar comprising a nerve stimulator configured to stimulate nerves in a target tissue site;

a pump and a medicament reservoir;

a sheet for application to the patient's skin around the surgical site, the sheet having an adhesive surface for adhering to the skin of the patient and a series of frangible regions for removal of parts of the sheet.

Images