P/00/01I Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: Single use cholangiogram forceps and method The following statement is a full description of this invention, Including the best method of performing it known to us: 2 SINGLE USE CHOLANGIOGRAM FORCEPS AND METHOD Field of the invention The invention relates to cholangiogram forceps. Background of the invention 5 The cholangiogram forceps is an instrument used during laparoscopic (keyhole surgery) cholecystectomy (gall bladder removal) to facilitate the insertion of a catheter into the cystic duct for the purpose of injecting contrast material for X-ray investigation (intraoperative cholangiography) of the biliary tract for bile duct stones or surgical injury and other pathology. Double action jaws, lockable at the handle end of the instrument 10 allow for clamping of the cystic duct around the catheter to prevent reflux of contrast material injected into the biliary tree for imaging. Known forceps are manufactured in high grade stainless steel and are cleaned and sterilised between uses. These forceps include a pivotally mounted jaws mounted at an end of an elongate shaft. 15 At the other end, there is a pair of scissor-like handles mounted approximately at right angles to the shaft that are relatively moveable to open and close the jaws. The shaft typically has an outer diameter (OD) of about 5 mm. The shaft is hollow and carries a smaller, approximately 2.5 mm OD, tube and an actuating rod which operably connects the handles to the jaws. The smaller tube functions to carry a flexible catheter. 20 In use, the jaws are initially in a closed position for insertion through an access port placed through an incision in a patient's abdomen. Using known laparoscopic techniques, an incision is made in the cystic duct. A flexible catheter is fed in through the smaller inner tube until it extends past the jaws at the end of the forceps. The flexible catheter is inserted into the incision in the cystic duct and the jaws positioned 25 about the cystic duct below the incision. By operating the handles of the forceps the jaws are closed about the cystic duct, thereby clamping the cystic duct about the catheter. This prevents reflux of contrast material during injection of the contrast material (via the flexible catheter) into the biliary tree.
3 Cholangiogram forceps are difficult to clean. The intricate components are fragile and the narrow spaces within the shaft and about the actuating rod and the smaller tube are difficult to access and clean. These difficulties in cleaning the cholangiogram forceps have been formally recognised. The Therapeutic Goods Administration (an Australian 5 government body) document "Reducing Public Health Risks Associated with Reusable Medical Devices, May 2004" identified cholangiogram forceps as "difficult to clean". Some hospital sterilisation departments have refused to sterilise cholangiogram forceps forcing other less desirable surgical techniques to be used. Similar problems exist in respect of other laparoscopic instruments. In response to this 10 problem, the majority of laparoscopic instruments are provided in two styles: 1. Dismantlable - Those able to be dismantled into two or more components for accessing the internal surfaces for optimal cleaning of bioburden and, importantly, visual inspection prior to reassembly and sterilisation in the hospital setting. 15 2. Flushable - This type is not able to be dismantled as above but is fitted with a flushing port to allow high pressure irrigation of the internals of the instrument and subsequent air drying and sterilisation. This type of instrument is less expensive and therefore favoured in some markets These conventional approaches to overcoming or minimising cleaning and sterilisation 20 difficulties of laparoscopic equipment have been applied to cholangiogram forceps with only limited success. Option 1, the dismantlable construction, has been unsuccessful due to the fragile nature of the smaller componentry. Option 2 has been applied, but with only limited success. In some known cholangiogram forceps a flushing port is provided on the side of the handles providing a means for fluidly connecting to the 25 passage within the shaft so that it can be flushed clean. The addition of a flushing port improves the cleanability of the instrument but is not the ideal solution. It is an incremental improvement but is still unsatisfactory. It is an object of an embodiment of the present invention to provide improved cholangiogram forceps.
4 Summary of the invention The Applicant has realised that by providing single use cholangiogram forceps, the difficulties of cleaning and sterilisation can be avoided. Moreover, the Applicant has developed a range of structural improvements to provide cost effective single use 5 cholangiogram forceps. Accordingly, there is provided a single use cholangiogram forceps. There is also provided a sealed and sterilised package containing the forceps. This advantageously allows the forceps manufacturer to produce and sterilise the forceps using their own specialised facilities and eliminates the need for hospitals to be able to sterilise the 10 forceps. There is also provided a method of supplying cholangiogram forceps including the steps of sterilising the forceps, sealing the forceps in such a package, and supplying the package to end users (such as hospitals). Advantageously, the cholangiogram forceps have a handle assembly manufactured from plastic and most preferably made from injection moulded plastic. Advantageously, 15 an off-the-shelf handle could be used. Preferably the forceps, and most preferably the handle, bear indicia (such as the internationally accepted numeral 2 within a circle and slash) communicating that the forceps are disposable and should not be cleaned. The indicia could be etched into the shaft, for example on the shaft adjacent the handle. Advantageously, the forceps, and most preferably the handle assembly, may include an 20 obvious difficult to clean formation, such as a blind hole, which serves to highlight the fact that the forceps are disposable and should not be cleaned. Advantageously, off-the shelf handles configured for electrosurgical devices, and most preferably handles intended for scissors or dissection instruments of various tip configuration are used. The cavity for an electrical connection (when used for an electrosurgical device) is an 25 obvious difficult to sterilise formation in this context. Advantageously, the jaws may be formed by metal injection moulding. Advantageously, the shaft need not be polished. An end of the shaft can have an external thread which is preferably integral with a sleeve which is fixed, for example by laser welding, to the shaft. The thread advantageously allows the shaft and the handle 5 to be threadingly connected. The handle might have a corresponding thread, which could be machined into the handle or could be a moulded feature. The handle assembly advantageously may include a locking mechanism for locking the handles, and thus the jaws, relative to each other. The forceps can include an elongated 5 ratchet member extending from one handle member and being engageable with a pawl fixed relative to the other handle member, the ratchet member being formed from a sheet metal blank. Advantageously, the ratchet member may include a button portion formed by deforming a neck portion on the blank. By laser cutting the blank, tooling costs can be minimised. 10 Alternatively each handle may be a unitary member, and the locking system may include one or more complementary engagement features as part of each handle, wherein the complementary engagement features are engageable to hold the handles at selected relative disposition. The complementary engagement features could be, for example, a matched set of teeth on each handle, or a pawl on one handle cooperable 15 with a ratchet formation on the other handle. The complementary engagement features may be disengageable by relative lateral movement of the handle. Similar locking arrangements have previously been applied to artery forceps. Various embodiments of the single use cholangiogram forceps have: relatively moveable handles (e.g. a fixed handle and a moving handle); 20 a pair of jaws for engaging a biliary duct; actuating means operably connecting the handles and the jaws to enable operating of the jaws by the handles; and a hollow elongate shaft extending from the handles to the jaws and carrying the actuating means. 25 Various embodiments may include one or more of the following features: the shaft being unpolished; 6 . the shaft being threadingly engaged with the fixed handle; . the jaws being formed by metal injection moulding; . at least one obvious difficult to clean formation for communicating that the forceps are not for reprocessing/reuse; 5 . the handles being formed of plastic; . the handles having a ratchet member formed from a sheet metal blank. Most preferably the ratchet member is integrally formed and includes a button portion. The invention also provides a cholangiogram forceps including, a handle assembly including relatively movable handles; 10 a shaft extending forwardly from the handle assembly to a jaw mechanism, the jaw mechanism including a first jaw member and a second jaw member; and an actuating means directly linking the handle assembly to the jaw mechanism and arranged to move longitudinally relative to the shaft in response to relative movement of the handles and thereby move the first jaw member between an open and 15 a closed position in response to the relative movement of the handles. There is also provided a cholangiogram forceps including, a handle assembly including relatively movable handles, a shaft extending forwardly from the handle assembly to a jaw mechanism, an actuating means extending from the handle assembly to the jaw mechanism 20 and arranged to move longitudinally relative to the shaft in response to relative movement of the handles, the jaw mechanism including: 7 a first jaw member pivotally connected at a first pivot to one of the shaft or the actuating rod, a second jaw member, a first slot inclined relative to the actuating rod, 5 a first engagement projection portion slidably received within the first slot wherein upon longitudinal movement of the actuating rod relative to the shaft the first engagement projection portion slides relatively along the first slot to rotate the first jaw member about the pivot. The actuating means is preferably an actuating rod. 10 Preferably the first pivot is fixed relative to the shaft, and is most preferably a pin passing through an aperture in the first jaw member. Advantageously the first slot may be formed in a portion of the first jaw member rearward of the pivot. The first engagement projection portion is preferably fixed relative to the actuating rod. Of course there are a range of other possibilities. By way of example, the first jaw 15 member may be pivotally connected to the actuating rod, and the first engagement projection portion fixed relative the shaft and slidable along a inclined slot formed in the first jaw member. Optionally the jaw mechanism may be configured so that upon longitudinal movement of the actuating rod relative to the shaft a second engagement projection portion slides 20 relatively along a second slot to rotate the second jaw member about a second pivot. In a preferred form the second pivot is aligned with the first pivot, for example the second pivot may be formed by the pin extending through an aperture in the second jaw member. Advantageously the second slot may be formed in a portion of the second jaw member rearward of the second pivot. The second engagement projection portion is 25 preferably fixed relative to the actuating rod.
8 The first engagement projection portion may be coaxially aligned with the second engagement projection portion, for example each may be a pin or stub projecting from a respective side of the actuating rod. In another aspect of the invention, there is a provided a method of indicating that a 5 disposable medical device is not for reuse including the steps of providing an obvious difficult to clean formation. Difficult to access cavities (such as blind holes) and heavily textured surfaces (such as a waffle pattern gripping surface) are examples of obvious difficult to clean formations. The various aspects of the invention are complementary and each may incorporate the 10 features of the other aspects. Brief description of the drawings The figures 1 to 6 illustrate cholangiogram forceps according to an embodiment of the invention. Figure 1 is a perspective view; 15 Figure 2 is a side view; Figure 3 is a top view; Figure 4 if a side view of an end portion; Figure 5 is a cutaway top view of the end portion; and Figure 6 is a cross section view of the shaft. 20 Figures 7 to 9 show components of the jaw mechanism of a cholangiogram forceps according to an alternative embodiment of the invention. Figure 7 is a side view of the jaw components; Figure 8 is a top view of the jaw components; and 9 Figure 9 is a top view of the jaw components in the open condition. Detailed description of the embodiments Forceps 10 include a shaft 30 extending from a handle assembly 20 to a jaw mechanism 40. The handle assembly 20 includes handles 20A and 20B which are 5 operable to open and close jaws 40A and 40B. As indicated in Figures 4, 5 and 6, the shaft 30 is a hollow elongate body containing smaller hollow shaft 60 and actuating rod 70. As illustrated in Figure 5, the jaw mechanism 40 includes jaw members 40A and 40B which are pivotally connected at pivot 90. Pivot 90 is fixed relative to the shaft 30. Jaw 10 members 40A and 40B are in turn pivotally connected to linkages 80A and 80B at pivotal connections 91A and 91B respectively. Linkages 80A and 80B are in turn pivotally connected to each other and to the actuating rod 70 at pivotal connection 92. Thus when the actuating rod 70 is moved axially jaws 40A and 40B are opened and closed in scissor-like fashion. 15 The jaw members 40A and 40B in plan view have a curved shape for gripping a biliary duct. The inner surfaces 41A and 41B of the jaw members 40A and 40B are textured to better grip the biliary duct. As illustrated in Figure 4, jaw members 40A and 40B have an oval shaped opening 50 passing horizontally therethrough. This assists with sealing the biliary duct portions about a catheter. 20 Figures 7 to 9 show components of an alternative embodiment of the jaw mechanism 40'. The jaw mechanism 40' includes jaw members 40A' and 40B' which are pivotally connected at pivot 90'. Pivot 90' is fixed relative to the shaft 30 (not shown in figures 7 to 9). As described below, the jaw members 40A' and 40B' are connected to the actuating rod 70' by a pin and slot arrangement so that upon advancement of the 25 actuating rod 70' the jaws are moved to the open position. Also as described below, the handle assembly 20 is connected to the actuating rod to advance the actuating rod 70'. Relative movement of the handles 20A and 20B thereby opens and closes the jaws 40A' and 40B'.
10 The jaw members 40A' and 40B' are similar to the jaw members 40A and 40B of the previous embodiment excepting that a rear portion of each jaw member is enlarged to accommodate a slot 91A', 91B'. As in the previously described embodiment, the jaw members 40A', 40B' are pivotally connected to the shaft 30 (not shown in figures 7 to 9) 5 by a pin 90'. The pin 90' is engaged with the shaft 30 (e.g. using a thread or solder etc) and passes through an aperture within each of the jaw members 40A' 40B', the apertures being dimensioned for the jaw members 40A', 40B' to pivot about the pin 90. As best shown in Figure 8 the slot 91A is inclined relative to the longitudinal axis of the actuating rod 70'. A short pin 92' projects from the opposed upper and lower surfaces of 10 the rod 70' and is slidably received within the slot 91A'. As best illustrated in Figure 9, as the rod 70' is advanced (ie moves forward) the pin 92' and pivot 90' are moved relatively closer. The pin 92' is driven to slide along the inclined slots 91A' and 91B' thereby driving the jaws towards the open position. As best shown in Figure 7 the actuating rod 70' of this embodiment includes a relatively 15 flat thin end portion which is received between the jaw members 40A' and 40B'. The jaw members 40A' 40B' each include a stepped profile so that when assembled the jaw members slidingly contact each other about the pivot 90' and define a space rear of the pivot 90' for receiving the actuating rod 70'. The pin 92' projects symmetrically from the opposed upper and lower surfaces of the actuating rod 70' to define two short 20 engagement portions for co-operating with the slots 91A' and 91B'. The advantage of this alternative embodiment over the previous embodiment is a reduction in complexity. By connecting the rod 70' directly to the jaw members 40A', 40B' linkages 80A and 80B are eliminated and three pivotal connections (91A, 91B and 92) are replaced with two sliding interactions (formed by 91A', 92' and 91B', 92' 25 respectively). This arrangement allows the actuating rod and the jaw members 40A', 40B' to be loosely held together and inserted into the forward end of the shaft then secured in place by the single pin 90'. The jaw members 40A and 40B (or 40A' and 40B') are formed by metal injection moulding. Metal injection moulding typically involves combining fine metal powders with 30 plastic binders which allow the metal to be injected into a mould using standard plastic 11 injection moulding machines. After the part is moulded and before the binders are removed, the part is referred to as a "green part". The next step is to remove the binders with solvents and thermal processes. The resultant metal part is sintered at temperatures great enough to bind the particles but not melt the metal. 5 The shaft 30 is made of surgical grade stainless steel and is not polished. In reusable instruments, the shaft is polished to facilitate cleaning. As cleaning is not required, the cost of polishing can be avoided. Toward the forward end of shaft 30 are arranged cut-outs 31. Cut outs 31 are positioned on each side of the shaft 30 and have a horizontal U-shaped profile with an open end 10 opening forwardly and a curved closed rearward end. The cut-outs 31 provide clearance for the jaws 40A, 40B and linkages 80A, 80B. Cut-outs 31 define portion 32 of the shaft 30. Portion 32 is a lower portion of the wall of shaft 30 and forms a forwardly extending tongue for carrying the pivot 90. The shaft 30 is threadingly engaged with the handle assembly 20. A rearward end 15 portion of the shaft 30 is fitted with an externally threaded sleeve (not shown). The sleeve is sized to fit over the outer diameter of shaft 30 and is laser welded to the shaft 30. Fixed handle 20A has a corresponding female thread (not shown) for receiving the external thread on the shaft 30. The forceps 10 are assembled by screwing the shaft 30 into handle 20A so that the handle 20A is fixed relative to the shaft 30. Advantageously, 20 the threaded sleeve is about 10mm long which is slightly longer than the corresponding female thread within the handle 20A such that a small portion, about 1mm or so, of the male thread is exposed. This exposed portion of the male thread is an obvious difficult to clean formation. Such obvious difficult to clean formations advantageously draw the attention of hospital cleaning staff which serve to minimise the risk of the forceps being 25 reused (see the discussion below). The forward handle 20A is threadingly engaged with and fixed relative to shaft 30. Handle 20A is pivotally connected to handle 20B at pivot 130. Handle 20B is free to pivot about pivot 130. The actuating rod 70 has a ball (now shown) soldered onto its rearward end. The actuating rod 70 is angled downwards slightly to allow engagement 12 with a metal lined socket (not shown) in an upper portion of the moveable plastic handle 20B. The metal lined socket is optional: the ball may simply engage the plastic in a recess of the injection moulded handle 20B. The recess is located in an upper portion of handle 20B above pivot 130. In this way, when a surgeon moves handle 20B relative to 5 20A, the actuating rod 70 is moved axially along shaft 30. Of course a range of engagement features are possible, for example the actuating rod 70 may include a perpendicular bent end portion or a 'T' piece for engaging the handle 20B. A ratchet member 160 extends between the handles 20A, 20B to allow the handles 0 20A, 20B to be selectively locked at a range of discrete positions. This allows a surgeon to clamp the jaws 40A, 40B about a biliary duct so that the tool is fixed in position thus freeing the surgeon's hands for other activities. The ratchet member 160 of this embodiment is made from a single blank of material. The blank is laser cut which avoids the costs of tooling. The blank is roughly "L" shaped. 5 At the outer end of the longer arm of the "L shape the blank has a neck portion 110, (i.e. a relatively thin portion) that is twisted and bent over to form button portion 100 for the surgeon to press. The other arm of the blank in use forms an upwardly extending portion of the ratchet member 160. The upwardly extending portion is received within an upwardly extending slot that is formed within the moving handle portion 20B and opens 20 into a V-shaped space defined between handles 20A and 20B. The ratchet member 160 is pivotally connected to the moving handle portion 20B by a pin (not shown) which extends transversally through the moving handle portion 20B proximal with the junction of the two arms of the blank. A tang 120 of spring steel is fixed to the moving handle 20B and extends downwardly to overlie an end portion of the upwardly extending 25 portion of the ratchet member 160. The arrangement is such that when a button portion 100 is depressed the ratchet 160 rotates downwardly (i.e. with reference to Figure 2 in a anticlockwise direction) about the pin so as to deflect the tang 120 against bias. The ratchet member 160 includes upward facing teeth (not shown) engageable with a sharp downward facing edge (not shown) on handle 20A which functions as a pawl. The 30 arrangement is such that tang 120 biases the ratchet member 160 into engagement 13 with the pawl. The sharp downward facing edge is formed by a small planar piece of metal punched transversely into the fixed handle portion 20A. To disengage the ratchet and pawl, the surgeon presses button portion 100 to lower the ratchet member away from the pawl. 5 As illustrated in Figures 2 and 6, a smaller hollow shaft 60 is carried within the shaft 30. The smaller hollow shaft 60 projects from the rearward end of the forceps 10 and functions to carry a flexible catheter the full length of the shaft 30 so that the catheter can project past the jaw mechanism 40 for insertion into the cystic duct. As shown in Figure 2, the rearward end of smaller hollow shaft 60 has a ball portion 140 for receipt 0 within a flexible cap for sealing around the flexible catheter. In this embodiment, the handle assembly 20 is an off the shelf component manufactured for an electrosurgical laparoscopic instrument. The handles 20A, 20B are injection moulded plastic and are therefore a relatively inexpensive. Another advantage of using this off-the-shelf component is the blind hole 150. When used for an 5 electrosurgical application, the blind hole 150 would carry an electrode. The blind hole 150 is formed by a through hole formed in the handles 20 for threadingly receiving an electrode (when used for an electrosurgical application) being blocked by shaft 30 when the forceps 10 are assembled. In order to minimise the chance of an electrosurgical supply being erroneously connected to the forceps 10 the through hole can be 'drilled 0 out' to remove the thread. As an electrode is not required for the cholangiogram forceps 10, the blind hole 150 serves no purpose during use. However, after use it serves an important function: blind hole 150 is very difficult to clean such that if a hospital cleaning/sterilising department inadvertently picks up this device, attention will be drawn to this feature and careful !5 consideration given to the forceps 10. This increased scrutiny greatly increases the likelihood of the sterilising technician recognising that this instrument is disposable and should not be sterilised. This greatly reduces the chance of the equipment being reused after inadequate cleaning/sterilisation. It may also reduce the likelihood of the tool being inadvertently put into sterilisation equipment in a manner which may result in damage to 0 the sterilisation equipment, for example if the plastic handles were to melt. Not all plastics melt at sterilisation temperatures. It is also contemplated that a plastic which 14 deforms under sterilisation conditions (e.g. in an autoclave) could be used to further reduce the risk of inappropriate reuse of the forceps 10. By way of example, one or more handles may be formed of a material predetermined to so deform. Another precautionary measure would be to make handles in a distinctive colour, for example a 5 yellow or green bile colour. It will be realised that this concept of adding a feature that is difficult to sterilise could be implemented using a purpose designed structural feature formed into or added to the device. This construction allows the cholangiogram forceps to be supplied on a cost-effective 3 single use basis. In a preferred arrangement, the forceps are sterilised by the manufacturer using their specialised equipment and supplied to hospitals in sterilised wallets such that hospital sterilisation departments do not need to sterilise the forceps. The manufacturer might outsource the step of sterilisation. For example, a manufacturer could produce the forceps and a sterilisation facility could package and sterilise the 5 forceps. The forceps could be produced cost effectively in a facility lacking the necessary sterilisation accreditations. A separate sterilising facility having the necessary accreditations would then package and sterilise the forceps. This has been found to be a particularly cost-effective arrangement. It will be understood that the invention disclosed and defined in this specification 0 extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.