Patent Application
20240033463
The present invention relates to devices and methods for use in the management of patient pain through nerve anaesthesia. More specifically, the invention relates to an delivery device for an implantable catheter system for the delivery of anaesthetic to an area of tissue around a nerve of a patient following a haemorrhoidectomy or similar surgery.
Haemorrhoids are enlarged, prolapsing anal cushions, which can result in bleeding, itching and pain and can affect more than 50% of people at some point in their lives.
In severe cases, treatment may involve surgery to physically remove the haemorrhoids, a procedure known as a haemorrhoidectomy. Under local or general anaesthesia, incisions are made in the tissue of a patient around the haemorrhoid. The vessels inside the haemorrhoid are tied off to prevent bleeding, and the haemorrhoid is removed.
Haemorrhoidectomy is generally considered a day procedure, with the patient typically released from hospital to return home within 24 hours. However, due to 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 with the effect lasting for up to 24 hours. The patient is then given oral opioids/narcotics to manage pain which may persist for many weeks. Complete recovery from the procedure can vary between patients, from 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 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.
According to one aspect of the present disclosure, there is provided a nerve stimulating trocar assembly for insertion into tissue of a patient comprising: an elongate trocar body extending from a proximal end to a distal end, the trocar body having an elongate open channel which extends along a length of the trocar body; a nerve stimulator having a shaft extending from a proximal end to a distal end, and at least one electrode at or adjacent to the distal end of the shaft; wherein the open channel of the trocar body is configured to receive both a catheter tube and the shaft of the nerve stimulator such that the catheter is releasably secured between the trocar body and the nerve stimulator in an assembled configuration.
In some embodiments, the electrode may partially extend beyond the distal end of the trocar body. In such embodiments, the electrode may also act as a tissue separator during insertion of the trocar. For example, a distal tip of the electrode may have a curved or wedge-shaped profile. Further, a width, height or diameter of the electrode may be smaller than a width, height or diameter of the trocar body, such that the electrode encounters less initial resistance to passing through the tissue. The electrode may have a substantially rounded or curved distal tip. The electrode tip may be devoid of sharp or bevelled edges, for example. The non-sharp shape of the distal end of electrode tip and the distal end of the trocar body may allow the electrode and trocar of the nerve stimulation assembly to pass through tissue without causing damage to anatomical structures, such as the pudendal nerves. This may be in contrast to conventional insertion of infusion catheters using a sharp trocar which could cut or otherwise damage anatomical structures, such as nerves, during insertion.
The channel may have a substantially U-shaped cross section.
The assembly may further comprise a locking mechanism for releasably locking the nerve stimulator to the trocar body in the assembled configuration. The locking mechanism may be provided at or adjacent to the distal end of the trocar body.
In further embodiments, the locking mechanism comprises a notched region in a distal wall of the trocar body and a transversely extending locking bar of the electrode. The transversely extending locking bar of the nerve stimulator may be received in the notched region.
When in an assembled configuration, the locking bar of the nerve stimulator is typically held in a tight engagement with the distal wall. The notched region of the distal wall may include a stop surface to prevent the locking bar advancing towards the distal end of the trocar body when in the assembled configuration. The tight engagement of the locking bar with the distal wall and the stop surface together prevent any substantial longitudinal movement of the nerve stimulator shaft relative to the trocar body in the assembled configuration.
The tight engagement of the locking bar with the distal wall may be released by pulling the nerve stimulator shaft in a direction away from the distal end of the trocar body, wherein the force applied to the nerve stimulator shaft is sufficient to cause the locking bar to release its engagement with the distal wall.
The notched region of the distal wall may include a ramped surface proximal to the stop surface. When a force is applied to the nerve stimulator shaft in a direction away from the distal end of the trocar body, the locking bar typically releases from its tight engagement and rides up the ramped surface such that the nerve stimulator may be withdrawn entirely from the trocar body.
In the assembled configuration, the nerve stimulator overlies the catheter and substantially locks the catheter within the channel of the trocar body. A distal end of the catheter may be positioned set back proximally from the distal end of the trocar body.
The assembly may further comprise a handle at a proximal region of the nerve stimulating trocar assembly. Typically, the assembly is made of two separate components including a base and a slider. The base may be connected to the proximal end of the trocar body. In one embodiment, the base is integral with the trocar body to form a single unit. The base may include an elongate channel extending longitudinally along its length. The channel of the base is typically aligned with the open channel of the trocar body. Further, the channel of the base of the handle is typically in fluid communication with the open channel such that together they may both receive a length of a catheter therein.
The base and the slider may be slidably connected to each other in the assembled configuration. Where the base in integral with the trocar body and therefore fixed relatively to the trocar body, the slider may slide longitudinally relative to the base. In the assembled configuration, the slider and the base may be in relatively locking engagement to each other to prevent sliding of the slider. However, the engagement between the two parts may be released to allow the side to move relative to the base.
The slider may be comprised of a pair of shells, which may mate to form a housed configuration. The slider may be connected to the proximal end of the nerve stimulator shaft. The slider may be configured to receive the nerve stimulator shaft in the housed configuration. One or more shells of the slider may include a notched region, configured to engage a locking bar of the nerve stimulator shaft, thereby to inhibit relative longitudinal movement between the nerve stimulator shaft and the slider when the nerve stimulator shaft is received in the slider in the housed configuration. In this embodiment, sliding of the slider relative to the base in a direction away from the distal end of the trocar body will apply a force on the nerve stimulator shaft. A sufficient force will release the transverse locking bar of the electrode from its tight engagement with the distal wall of the trocar body and up the ramped surface to allow withdrawal the nerve stimulator from the trocar body. In use, this allows a surgeon to fully withdraw the nerve stimulator once the trocar body is in a desired location within the tissue of a patient.
The slider may include a housing having a passage extending from a proximal end opening to a distal end opening. A proximal length of the nerve stimulator shaft may be received through the distal end opening. The proximal end opening of the slider may receive an electrical lead for electrical connection with the proximal end of the nerve stimulator shaft. The electrical lead may be connected to an energy source to deliver energy to the electrode of the nerve stimulator.
According to another aspect of the present disclosure, there is provided a trocar assembly having: an elongate trocar shaft extending from a proximal end to a distal, tissue separating end and including an adapter at the proximal end to connect the trocar shaft to a catheter; a handle configured to house a length of the trocar shaft adjacent to its proximal end in a housed configuration and to disengage from the trocar shaft in a release configuration; wherein in the housed configuration, the handle includes an access port for connection of the adapter with the catheter.
In some embodiments, the trocar assembly may further comprise a catheter connector configured to connect to the adapter. In some embodiments, the catheter connector comprises a male connecting portion. The adapter typically comprises a receiving portion to receive the male connecting portion. The catheter connector may also include a female connecting portion at an opposite end to the male connecting portion. The female connecting portion may be configured to receive an end of the catheter.
In some embodiment, the catheter connector may include two male connecting portions and two female connecting portions. In such embodiments, the adapter may include two receiving portions to receive the two male connecting portions of the connector.
In other embodiments, a proximal portion of the trocar shaft may include an adapter configured to receive the ends of one or more catheter tubes. For example, the proximal portion of the trocar shaft may define one or more bores, apertures or slits configured to receive the ends of the one or more catheter tubes. The proximal portion of the trocar shaft may be configured to be crimped, thereby to secure the one or more catheter tubes within the adapter.
For example, in some embodiments, the proximal portion of the trocar shaft may include one or more walls defining a central bore, or lumen. The bore or lumen may be configured to receive the ends of one or more catheter tubes. The walls of the proximal region of the trocar shaft may be configured to be crimped, compressing the catheter ends within the bore thereby to secure the catheter tubes to the trocar shaft.
In other embodiments, a proximal region of the trocar shaft may define one or more apertures configured to receive the end of one or more catheter tubes therethrough (in the manner of threading a needle, for example). In some embodiments, the proximal region of the trocar shaft may define a transverse aperture having a widened portion and a narrowed portion. The trocar shaft may be configured to be crimped at the proximal end, adjacent the aperture, thereby to secure the ends of one or more catheter tubes therein.
In alternative embodiments, the trocar shaft may include two or more tines at a proximal end of the shaft. The tines may define a slit therebetween, adapted for receiving one or more catheter tubes. One or more of the tines may be adapted to be crimped (by bending the tines towards each other, for example) to secure the ends of the one or more catheter tubes in the slit. One or more of the tines may include one or more notches for more securely gripping the one or more catheter tubes.
In some embodiments, one or more surfaces of the trocar shaft may be roughened for more securely gripping the one or more catheter tubes.
The handle may be configured to house a length of the trocar shaft adjacent to its proximal end in the housed configuration and to disengage from the trocar shaft in the release configuration. In the housed configuration, the handle may include an access port for connection of the adapter with a catheters.
The handle of the assembly may be configured to facilitate easier insertion of the trocar shaft through the tissue of the patient. Once the distal tip of the trocar shaft has passed through an exit incision, the handle may be removed, by causing it to move to its release configuration. This allows the trocar shaft and attached catheter tube to be drawn through the tissue of the patient.
The handle may comprise two components, mateable with each another to form the housed configuration. In some embodiments, the handle is comprised of a pair of shells. The handle may comprise a snap-fit connection system for fastening the shells together in the housed configuration. In some embodiments, one of the shells comprises one or more projections receivable in corresponding recesses in the other shell portion to prevent relative movement between the shell portions in the housed configuration.
The handle may further comprise a release mechanism to release the one or more projections from their corresponding recesses. The release mechanism may be in the form of a button which may be depressed to release the shells from their housed engagement.
The handle further comprises interior ribs configured to engage corresponding notches on a proximal portion of the trocar shaft to prevent relative axial movement of the handle and the trocar shaft when in the housed configuration.
In some embodiments, the handle may be configured to crimp a portion of the trocar shaft. For example, the handle may comprise one or more interior projections or surfaces configured to impinge on and deform a region of the trocar shaft as the shells are mated to crimp the region of the shaft.
According to another aspect of the present disclosure, 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:
The first trocar typically includes a removable handle which is removed from the trocar after the step of tunnelling the first trocar from the first incision through the tissue and through the lateral incision.
According to another aspect of the present disclosure, there is provided a method for positioning first and second catheters in respective first and second target tissue sites to deliver a medicament to a patient after haemorrhoid surgery, the method including:
The first trocar again typically includes a removable handle which is removed from the trocar after the step of tunnelling the first trocar from the first incision through the tissue across the midline of the patient and through the second incision. The second trocar may also include a removable handle which is removed after the step of tunnelling the second trocar from the second incision through the tissue and through the lateral incision.
In another embodiment, rather than a connecting both catheters to the second trocar, one catheter may be connected to the second trocar and the other to a third trocar, each of which may pull the respective catheter through the lateral incision.
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 or anaesthetic agent. The analgesic or anaesthetic agent 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 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.
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 therethrough and out of the distal end through the lumen.
In a further aspect, there is provided a surgical kit comprising:
The surgical kit may further comprise 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.
The surgical kit may further comprise 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 a 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.
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.
By way of example only, embodiments are now described with reference to the accompanying drawings, in which:
A wearable apparatus according to one embodiment of the present disclosure is illustrated as 10 in
In other embodiments, as discussed in more detail below, each of the catheters may exit the body on the same side and connect to a single housing unit.
In the depicted embodiments, both proximal ends 30a, 30b of catheters 13a, 13b, respectively, are in fluid connection with pump 12 such that the pump 12 pumps a medicament into both catheters 13a, 13b. The proximal end of the two catheters 13a and 13b may be connected either directly or indirectly to pump 12. The medicament may be pumped in unison, delivering medicament to both catheters 13a and 13b at substantially the same time. Alternatively, the pump may alternate between delivery of medicament to catheter 13a and catheter 13b at different time periods.
Pump 12 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 of belt 11 to sit adjacent the small of the back of a wearer, or at the side of the belt. Pump 12 may draw medicament from a single reservoir or it may draw from multiple reservoirs.
In the embodiment shown in
The distal end 312 of the trocar assembly 300 includes a tissue separator 330. An enlarged view of tissue separator 330 is shown in
An adapter 320 is provided at the proximal end for connecting the trocar shaft 310 to a catheter. In some embodiments, trocar assembly 300 further comprises a catheter connector 340 configured to connect to the adapter 320. One example of a catheter connector 340 is shown in
The distal end 412 of the trocar assembly 400 includes a tissue separator 430, as shown in
An adapter 420 is provided at the proximal end 411 for connecting the trocar shaft 410 to one or more catheters. In some embodiments, trocar assembly 400 further comprises a catheter connector 440 configured to connect to the adapter 420. One example of a catheter connector 440 is shown in
The catheter connector 440 shown in
Each of the trocar assemblies 300, 400 further includes a handle 350, 450.
In the illustrated embodiment, the handle 450 is comprised of a pair of shells 451a, 451b which mate together via a snap-fit connection system to form a housed configuration. Shell 451a comprises projections 452a, 452b which are receivable in corresponding recesses of shell 451b to align the shell members and fasten the shells to each other and to prevent relative movement between the shell portions in the housed configuration. Projections 452b comprise resilient arm members having shoulder portions 453 which latch in corresponding recesses in shell 451b to fasten the shells 451a, 451b to each other in housed engagement.
The handle further comprises a release mechanism 454 to release the shoulder portions 453 of the resilient arm members 452 from their corresponding recesses, thereby to release the two shells from their housed engagement. In the illustrated embodiment, the release mechanism 454 is a button, which may be depressed to release the shells 451a, 451b. When depressed, the button pushes against sloped surfaced of the resilient arm members 452, causing them to deform out of latching engagement with the recesses, releasing the shells 451a, 451b from their engagement. In the embodiment of
In the housed configuration, the handle 450 houses a length of the trocar shaft 410 adjacent to its proximal end 411 (e.g. as shown in
The handle 450 of the assembly may be configured to facilitate easier insertion of the trocar shaft 410 through the tissue of the patient. Once the distal tip 412 of the trocar shaft 410 has passed through an exit incision, the handle 450 may be removed, by causing it to move to its release configuration. This allows the trocar shaft 410 and attached catheter tube (or tubes) to be drawn through the tissue of the patient.
The handle 450 further comprises interior ribs 455 configured to engage corresponding notches on a proximal portion of the trocar shaft 410 to prevent relative axial movement of the handle 450 and the trocar shaft 410 when in the housed configuration.
An adapter in the form of a bore 1320 is provided for connecting the trocar shaft 1310 to a catheter. The bore 1320 is defined by a peripheral wall 1315 at the proximal end 1311 of the trocar shaft 1310 and is configured to receive one or more catheter tubes therein. The wall 1315 is configured to be crimped, thereby to secure the one more catheter tubes within the bore 1320.
An alternative embodiment of a trocar shaft 1510 is shown in
Another embodiment of a trocar shaft 1610 is shown in
Each of the trocar shafts 1410, 1310, 1510 is receivable in a respective handle 1450, 1350, 1550 as shown in
Handle 1350 is comprised of a pair of shells 1351a, 1351b (as shown in
Handle 1450 is similarly comprised of paired top shell 1451a and base shell 1451b, as shown in
Similarly, handle 1550 is comprised of paired top and base shells 1551a, 1551b. (as shown in
The nerve stimulator 550 has a shaft 560 extending from a proximal end 561 to a distal end 562, and at least one electrode 570 at or adjacent to the distal end 562 of the shaft 560.
The elongate trocar body 510 extends from a proximal end 511 to a distal end 512. As shown in
As shown in
The nerve stimulating trocar assembly 500 further comprises a locking mechanism 530 adjacent the distal end 512 of the trocar body 510 for releasably locking the nerve stimulator 550 to the trocar body 510 in the assembled configuration. The locking mechanism 530 is shown in detail in
When the trocar body 510 and nerve stimulator 550 are in an assembled configuration (for example, as shown in
The tight engagement of the locking bar 580 with the distal wall 513 may be released by pulling the nerve stimulator shaft 560 in a direction away from the distal end 512 of the trocar body 510. The notched region 531 of the distal wall 513 includes a ramped surface 533 proximal to the stop surface 532. When sufficient force is applied to the nerve stimulator shaft 560 in a direction away from the distal end 512 of the trocar body 510, the locking bar 580 typically releases from its tight engagement with the distal wall 513 and rides up the ramped surface 533 such that the nerve stimulator 550 may be withdrawn entirely from the trocar body 510.
The assembly may further comprise a handle 590 at a proximal region of the nerve stimulating trocar assembly. Typically, the assembly is made of two separate components including a base 591 and a slider 592. The base 591 is connected to the proximal end 511 of the trocar body 510. In the illustrated embodiment, the base 591 is integral with the trocar body 510 to form a single unit. The base 591 includes an elongate channel extending longitudinally along its length. The channel of the base 591 is typically aligned with the open channel 520 of the trocar body. Further, the channel of the base of the handle is typically in fluid communication with the open channel such that together they may both receive a length of a catheter therein.
The base 591 and the slider 592 are longitudinally slidably connected to each other in the assembled configuration. In the assembled configuration, the slider 592 and the base 591 may be in relatively locking engagement to each other to prevent sliding of the slider 592. However, the engagement between the two parts may be released to allow the slider 592 to move relative to the base 591.
An alternative embodiment of a nerve stimulator 550′ including a shaft 560′ and a slider 592′ is shown in
As shown in
The slider 592 includes a housing 593 having a passage extending from a proximal end opening 594 to a distal end opening 595. A proximal length 561 of the nerve stimulator shaft may be received through the distal end 594 opening. The proximal end opening of the slider may receive an electrical lead 565 for electrical connection with the proximal end 561 of the nerve stimulator shaft. The electrical lead 565 may be connected to an energy source to deliver energy to the electrode 570 of the nerve stimulator 550.
In some embodiments, the slider 592 is provided with a distal grip portion 596 engageable by a user's finger to enable force to be exerted on the assembly in a distal direction, e.g., during insertion of the nerve stimulating trocar assembly 500 through tissue of a patient.
Turning to the method shown in
An iodine-impregnated adhesive mat 600 is placed vertically from the pubis to cover the vagina/scrotum and the anal region. This area is kept sealed until catheters 100 and 200 are implanted in the desired position. The adhesive mat 600 comprises first and second frangible regions 601, 602 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 the first frangible region and then removes the second frangible region 602 of mat 600 and makes a second stab incision B at this region, on the other side of the anus to stab incision B. A lateral stab incision C is made at the lateral thigh.
A proximal end of catheter 100 is attached to trocar 300. Trocar 300 is tunnelled from incision A to incision B, through the patient's tissue across the midline of the patient as shown in
The proximal end 201 of the catheter 200 is attached to trocar 400. Additionally, the proximal end 102 of catheter 100 is connected to trocar 400. Trocar 400 is then passed from incision B to incision C, as shown in
As shown in
The energy source is then activated. In one embodiment, the energy source is an electrical energy source which delivers an electrical stimulus to electrode 570 of nerve stimulating trocar assembly 500. 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 corresponding to the applied electrical stimulus. The surgeon may move the trocar 500 and catheter 100 until this contraction is observed. This contraction indicates to the surgeon that the electrode 570 of nerve stimulating trocar assembly 500 is adjacent to the branches of the pudendal nerve and that the distal end 102 of the catheter 100 is thus in a position to infuse medicament from apertures 105 to the branches of the pudendal nerve.
The nerve stimulator 550 may then be separated from the nerve stimulating trocar assembly 500 by sliding the slider 592 of the handle 590 in a proximal direction. This applies tension on the nerve stimulator shaft 560, causing the locking bar 580 to disengage from the notched region 531 in the trocar body 510. The nerve stimulator 550 may then be withdrawn from the trocar body 510, and fully withdrawn from incision A. Withdrawal of the nerve stimulator 550 releases catheter 100 from the trocar body 510. Trocar body may then be withdrawn through incision A, careful not to dislodge distal end 102 from its position adjacent to the pudendal nerve branches.
This nerve stimulation process is then repeated with catheter 200 through incision B, as also shown in
The proximal ends 101 and 201 of catheters 100 and 200 are then pulled in the direction shown by the arrows in
The surgeon then removes a portion of the adhesive mat 600 by tearing along frangible line 503. The incisions A and B are then sealed.
The lengths of catheter that exit incision C may be retained by retainer 700, as shown in
Retainer 700 includes a retainer body 720 which comprises a partially circular structure having a relatively planar base surface 721 configured to sit on the skin (or on an adhesive film applied over incision C) and an opposed guide surface 722 to receive a length of the first catheter 100 and/or the second catheter 200. The guide surface 722 may be curved and terminate in an inner rim 723a and an outer rim 723b. A series of clips 730 retain the catheters 100 and/or 200 to the guide surface 722. The clips 730 may be formed integrally with the retainer body 720 or may be a separate structure attachable onto the retainer body 720. In the illustrated embodiments, the clips 730 include hinged portions 731 and a fastening mechanism comprising resiliently deformable projections 732 at one end of the clip 730 which latch in an aperture 733 at an opposite end of the clip 730. The hinged portions 731 may be made from a flexible material such that the clips are moveable between an open configuration in which the catheters may be laid along the guide surface 722 and a closed configuration in which clips 730 are folded around the catheters 100, 200 and the projections 732 latched in the apertures 733 to secure the catheters 100 and 200.
In the illustrated embodiment, the retainer 700 includes two clips 730a, 730b. The catheters may be positioned in a desired location in the retainer 700 before securing with the clips 730.
The proximal ends 101 and 201 of the catheters are ultimately connected to a medicament reservoir 800 which can be carried in a pouch 900 (e.g., as shown in
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020904358 | Nov 2020 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2021/051294 | 11/3/2021 | WO |
