WO2012151622A1

WO2012151622A1 - Surgical instrument and method

Info

Publication number: WO2012151622A1
Application number: PCT/AU2012/000493
Authority: WO
Inventors: Russell Victor DALTON
Original assignee: Rv Dalton Pty Ltd
Priority date: 2011-05-09
Filing date: 2012-05-09
Publication date: 2012-11-15

Abstract

A surgical instrument suitable for gynaecological procedures, such as laparoscopic and abdominal hysterectomy, comprising: a) a handle portion having located at an end thereof b) a cervix engaging portion having i) a fomices engaging lip, ii) an inside for cupping the cervix and iii) an outside which is tapered towards the handle portion, c) wherein long axes of said portions are aligned and the lip is substantially perpendicular to the long axes.

Description

Title: Surgical Instrument and Method

Field of Invention

The invention relates to an instrument for use in, and method for performing laparoscopic gynaecological surgery, specifically laparoscopic and abdominal hysterectomy.

Background

Conventional hysterectomy surgical procedures typically involve one of four approaches: vaginal hysterectomy, total abdominal hysterectomy (TAH), total laparoscopic hysterectomy (TLH), and laparoscopically assisted vaginal hysterectomy (LAVH).

TLH is probably the most technically difficult option for hysterectomy, but confers significant benefits to patients undergoing the procedure. The most difficult aspects of TLH are securing the uterine arteries, separating the bladder from the cervix, and separating the cervix from the vaginal tissues. A number of instruments for performing this type of surgery have been proposed. These include those disclosed in US Patents No 5520698 by Koh, 5840077 by Rowden et al and 6572631 by McCartney. Products on the market include the Koh uterine manipulator and the McCartney tube.

The Koh manipulator has a number of disadvantages such as a tendency to allow leakage of C0₂ after colpotomy is performed, difficulties with cleaning and sterilising, and significant cost in replacing the disposable components of the instrument

The McCartney tube is also of limited application. It is cumbersome and unsuitable for use in a number of women due with smaller vaginal calibre (due to physical size or age), and has limited capacity for movement during the hysterectomy procedure. The McCartney tube is a single use disposable device of considerable cost. Despite the above and other proposals there remain a need for an instrument which allows clear identification of the junction between the cervix and vagina, so that the uterus can be safely separated without the risk of damage to the bladder or ureters. Further there remains a need for an instrument which allows a wide range of movement within the vagina during such procedures, but at the same time maintaining a consistent seal to reduce the escape of intraperitoneal gas (C0₂) during the colpotomy. in at least one embodiment the present invention seeks to fulfil at least one of these needs.

The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art.

Summary

In a first aspect the invention provides a surgical instrument suitable for gynaecological procedures, such as laparoscopic and abdominal hysterectomy, comprising: a) a handle portion, having located at an end thereof; b) a cervix engaging portion having I) a fomices engaging lip, ii) an inside for cupping the cervix and iii) an outside which is tapered towards the handle portion; c) wherein long axes of said portions are aligned and the lip is substantially perpendicular to the long axes.

The present inventor has surprisingly found that the combination of a tapered cervix engaging portion with a centrally located and aligned handle provides a maximum amount of movement within the vagina allowing for easier identification of the cervix/vagina junction. Further the inventor has found that by making the cervix engaging portion in a range of sizes the instrument may be used with good success on women with different sized and/or shaped gynaecological anatomy. This is particularly important for use with menopausal and nulliparous women.

In another aspect, the invention provides an improved system for identification of the junction between the vagina and the cervix in patients with different sized and/or shaped gynaecological anatomy, said system comprising: providing the instrument of the invention described above with a detachable handle portion and a range of different sized cervix engaging portions; selecting the appropriate sized cervix engaging portion, assembling the instrument and using it to identify said junction. In another aspect, the invention provides an improved method of performing a hysterectomy said method comprising:

I) providing a surgical instrument suitable for identification of the junction between the cervix and the vagina said instrument comprising: i) a detachable handle portion and locatable at an end thereof ii) a cervix engaging portion having iii) a fomioes engaging lip, iv) an inside for cupping the cervix and v) an outside which is tapered towards the handle portion, wherein, when assembled vi) long axes of said portions are aligned and the lip is substantially perpendicular to the long axes when the instrument is assembled, thus allowing a range of movement of the instrument within the vagina such that identification of the junction between the cervix and the vagina may be achieved;

II) providing a range of different sized cervix engaging portions;

110 selecting the appropriate sized cervix engaging portion, assembling the instrument and;

IV) performing the colpotomy and hysterectomy. Preferably the cervix engaging portion Is conical or frusto-conical in shape.

Preferably the taper of the cervix engaging portion is at an angle of between about 5^* and 15^s.

In a more preferred embodiment, the taper of the cervix engaging portion is such that the diameter consistently reduces from its maximum diameter to its minimum diameter at the end which is attached to the handle portion.

For the 50mm cervix-engaging portion, the taper rate is preferably 0.5mm diameter per mm of length.

For the 40mm cervix engaging portion, the taper rate Is preferably 0.33mm diameter per mm of length.

For the 30mm cervix engaging portion, the taper rate is preferably 0.167 mm diameter per mm of length.

Preferably the fomices engaging lip is non-tapered, annular rim.

Preferably the handle is relatively thinner or narrower than the cervix engaging portion which allows the instrument a wide range of movement within the vagina (particulariy at the mid-vagina and at the level of the perineum) such that identification of the junction between the cervix and the vagina may be conveniently achieved.

More preferably, the handle is in the form of a narrow shaft. Even more preferably, the handle is detachable from the cervix engaging portion.

Still more preferably, the instrument is provided in a kit with several different sized cervix engaging portions and a detachable handle. Detailed Description of Illustrative Embodiments of the Invention

The invention will now be described with reference to the following non limiting illustrative drawings.

Figure 1 (a) shows a 3D perspective view of the assembled instrument with the smaller cervix engaging portion.

Figure 1 (b) shows the section A-A of the smaller sized cervix engaging portion of the assembled instrument.

Figure 1 (c) shows a side view of the assembled instrument

Figure 1 (d) shows an end view of the assembled instrument. Figure 2(a) shows a 3D perspective view of the medium sized cervix engaging portion.

Figure 2 (b) shows a side view of the medium sized cervix engaging portion.

Figure 2 (c) shows the section A-A the medium sized cervix engaging portion.

Figure 2 (d) shows an end view of the cervix engaging portion.

Figures 3 (a) to (c) show the same views as Figures 2 (a) to (c) for the large sized cervix engaging portion of the instrument.

Figure 4 (a) shows a side view of the handle portion of the instrument. Figure 4 (b) shows a 3D perspective view of the handle portion of the instrument

Figure 4 (c) shows an end view of the handle portion of the instrument. The assembled instrument 10 is constructed very simply of two parts: cervix engaging portion 20 and handle portion 70.

Cervix engaging portion 20 has outside 25 and inside 28. Cervix engaging portion shown in the figures is in the form of f rustoconical member or attachment 30 which has large end 40 opposite small end 50.

Large end 40 has fornices engaging lip 45 which, on the outside, is an un- tapered, annular fiat rim of constant diameter which has at one end, leading edge 47 and the other end, following edge 49 which is simply the lower end of the un- tapered annular rim, and marks the point of commencement of the tapered section. Leading edge 47 is suitably dimensioned and filleted or curved to fit snugly within the vaginal fornices.

Small end 50 has an internal threaded section 55 for attachment of handle portion 70.

Outside 25 cervix engaging portion 20 tapers from adjacent following edge 49 to small end 50. The angle and length of the taper may vary according to the particular shape and size of gynaecological anatomy being considered. The angle of taper is approximately 5^s for the smaller cervix engaging portion, 8" for the medium cervix engaging portion and 15" for the targe cervix engaging portion having a taper rate of 0.5mm, 0.33mm and 0.167 mm diameter per mm of length respectively. The taper of the cervix engaging portion is such that, the diameter consistently reduces from its maximum diameter to its minimum diameter of 21mm at the end which is attached to the handle portion.

Inside 28 of cervix engaging portion 20 is tapered along its entire length. This is essentially for ease of. manufacture. Handle portion 70 is in the form of cylindrical shaft 80 and has complementary threaded section 85 at one end. Complementary threaded section 85 mates with threaded section 55 of frustoconical member 30 such that the long axes of the frustoconical member 30 and shaft 80 are aligned and lip 45 is substantially at right angles to the axes.

Cylindrical shaft 80 is relatively narrow compared to the diameter of lip 45. This and the alignment described above gives a great degree of lateral, ventral and dorsal movement within the vagina.

In its preferred form the instrument is made from an extensively re useable 20mm polypropylene shaft, and includes 3 conical attachments measuring 30, 40 and 50 mm. The conical attachments are made from limited reusable polyoxymethylene. As it is reusable, it is significantly cheaper than other products.

The variable conical attachments allow a surgeon to choose the size, which accurately corresponds with a patient's cervix size. This permits highly accurate incision of the vagina and markedly reduces the size of the colpotomy, (the hole in the top of the vagina once the cervix has been removed), and, according to recently gathered data, leads to reduced incidences of trauma to the bladder and ureters.

The unique taper and design of the outline of the frusto-conical attachments provide for maximum seal and a wide range of movement of the device during surgery. This in turn allows for a smaller colpotomy to be performed.

As the device has the option of a 30 mm frusto-conical attachment, it can be used for older women during laparoscopic hysterectomy.

The leading edges of the frusto-conical attachments have been developed to optimize the incision of the vaginal tissues to facilitate the hysterectomy. In one of its preferred forms the invention provides a limited re use instrument which may be fitted into the upper vagina during laparoscopic hysterectomy. It is a simple modular instrument with a 20mm x 270mm polypropylene shaft, and three optional frusto-conical attachments with diameters of 30mm, 40mm or 50 mm. The shape and contour of the conical attachments have been developed and refined to allow close fitting to suit individual patients, maximal movement during surgery, optimizing the incision of the vaginal tissues (colpotomy), ease of assembly, ease of cleaning and sterilization and durability.

As mentioned above, conventional hysterectomy surgical procedures typically involve one of four approaches-vaginal hysterectomy, total abdominal hysterectomy CTAH), total laparoscopic hysterectomy (TLH), and laparoscopically assisted vaginal hysterectomy (LAVH). TLH is probably the most technically difficult option for hysterectomy, but confers significant benefits to patients undergoing the procedure. Injury to surrounding organs such as the bladder and ureter may occur in up to 22% of cases. The most difficult aspect of TLH is the step, which involves securing the uterine arteries, separating the bladder from the cervix, and the step which involves separating the cervix from the vaginal tissues.

After selection of the best sized frusto-conical attachment the instrument is placed in the vagina, and positioned to allow the surgeon to clearly identify the correct place for securing and separating the uterine arteries, reflecting the bladder safely and incising the vaginal tissues to divide the cervix from the vagina during the TLH procedure.

When compared to other devices in the field of laparoscopic surgery, the instrument of the present invention provides the following advantages:

Simple modular design with variable sizes enables exact fitting of the device to patient anatomy. This gives the surgeon an accurate indicator of the area in which to make the incision to detach the cervix from the vagina during the more complex step of TLH. By selecting the smallest frusto-conical attachment, the smallest possible colpotomy is made, minimizing the risk of trauma to surrounding tissues. The length, taper and thickness of edges of the frusto- conical member of the invention in association with the thinner shaft section, allow for a wide range of movement of the device during surgery. This feature allows the surgeon to move the area of incision to the maximum distance from surrounding structures, such as the ureter and bladder, thus reducing the risk of injury to these. Once the vaginal tissues are incised, there is a risk that C0₂, which is used to inflate the peritoneal cavity during surgery, could escape. The frusto-conical member of the invention has been developed to negate the likelihood of this happening. The feature provides additional safety to the patient compared to other devices. In work leading up to developing the preferred embodiments of the present invention the following challenges were addressed:

1. Sizes of frusto-con leal attachments

The initial design had one size, but in order to achieve accurate incision margins for the majority of patients, three sizes were developed. 2. Taper of frusto-conical attachment

The length and taper of the frusto-conical sections were developed specifically, so that movement of the device remained at maximum, but a clear seal and definite platform for dissection was maintained.

3. Length of "straight" lip at the top of the frusto-conical attachment This was developed to enhance sealing of the device to retain

intraperitoneal gas.

4. Thickness and contour of the leading edge of the frusto-conical member

This was developed to provide for a wide enough target for the surgeon to aim the incision, but narrow enough to be accurately detected through the thickness of the vaginal skin and muscle. 5. Construction materials

The original design was of single piece stainless steel with powder coating insulation. This was heavy and had low levels of durability. The final materials provide a light product, which is highly durable and insulated throughout the life of the device.

6. Solid design of the shaft section

The original polypropylene shaft had a hollow design. This presented challenges for cleaning and durability, with some shafts failing at the level of the attachment threads. The solid shaft design is immensely strong, light and easy to clean.

7. Insulated materials from which the Invention is constructed.

The frusto-conical section on the invention is made from

Polyoxymethylene which is a thermoplastic, which is light, and durable. The shaft is made of Polypropylene which is a heat resistant plastic. Example

Use of the Instrument in Laparoscopic Hysterectomy

The patient is anaesthetised, prepared with aseptic wash, catheterised and placed in low lithotomy position.

The surgeon performs a bimanual vaginal examination to determine the size of the patient's cervix.

The appropriate sized frusto-conical attachment is selected and attached to the polypropylene shaft

A small amount of lubricant is applied to the device and it is inserted into the vagina as far as possible. This has the effect of allowing the cervix to sit inside the frusto-conical attachment and for the leading edge and combined straight and frusto-conical contours of the frusto-conical attachment to delineate the vaginal fomices .

Total laparoscopic hysterectomy is then commenced according to the surgeon's usual technique. In order to open the uterovesical fold and mobilise the bladder from the anterior fornix, the instrument is positioned under guidance of the surgeon to allow the clear definition of the surgical planes. In utilising the wide range of possible movement of the instrument in the upper vagina, the surgeon is able to move dissection and incision planes as far away from critical structures, such as the bladder and ureters.

In order to identify and dissect out the uterine vessels, the instrument is directed cephalad and to the contralateral side of the patient's pelvis.

Once identified, the uterine vessels are secured according to the surgeon's preference, using the instrument as a guide. An assistant holds the uterus forward, and a posterior colpotomy performed using the instrument as a guide. Anterior-posterior and lateral movement is utilised to allow the accurate separation of the cervix from the vagina with the smallest possible colpotomy.

Once the dissection planes are taken to 3 O'clock and 9 O'clock, the anterior colpotomy is then performed, using the same feature of mobility of the instrument to allow accurate dissection and separation of the dissection plane from important nearby structures.

Once the cervix is completely separated from the vagina, the specimen is removed through the vagina, and kept in the vagina to seal it off whilst the vaginal vault is closed according to the surgeon's usual technique.

The instrument is then taken apart, and sent for sterilisation. The frusto-conical section of the instrument can be re used between 3-5 times depending on abrasion of the leading edges of the frusto-conicat section.

Throughout this specification and the claims that follow, unless the context requires otherwise the words "comprise", "comprises", "comprising" will be understood to mean the inclusion of the stated integer, step or group of integers or steps but not the exclusion of any of other integer, step or group of integers or steps.

Claims

Claims The claims defining the invention are as follows:

1. A surgical instrument suitable for gynaecological procedures, such as laparoscopic and abdominal hysterectomy, comprising: a) a handle portion having located at an end thereof; b) a cervix engaging portion having i) a fomioes engaging lip, ii) an inside for cupping the cervix and iii) an outside which is tapered towards the handle portion; c) wherein long axes of said portions are aligned and the lip Is substantially perpendicular to the long axes.

2. The instrument of claim 1 wherein the cervix engaging portion is conical or frustoconical in shape.

3. The instrument of claim 1 or claim 2 wherein the taper of the cervix engaging region is at an angle of between about 5° and 15".

4. The instrument of any preceding claim in which the taper of the cervix engaging portion, is such that the diameter consistently reduces from its maximum diameter to its minimum diameter at the end which is attached to the handle portion.

5. The instrument of claim 4 in which a 50mm cervix-engaging portion has a ^' taper rate of 0.5mm diameter per mm of length.

6. The instrument of claim 4 in which a 40mm cervix engaging portion has a taper rate of 0.33mm diameter per mm of length.

7. The instrument of claim 4 in which a 30mm cervix engaging portion has a taper rate of 0.167 mm diameter per mm of length.

8. The instrument of any previous claim in which the fomices engaging lip is a non-tapered, annular rim.

9. The instrument of any previous claim in which the handle is relatively thinner or narrower than the cervix engaging portion which allows the instrument a wide range of movement within the vagina (particularly at the mid-vagina and at the level of the perineum) such that identification of the junction between the cervix and the vagina may be conveniently achieved.

10. The instrument of any previous claim in which the handle is in the form of a narrow shaft.

11. The instrument of any previous claim in which the handle is detachable from the cervix engaging portion.

12. The instrument of any previous claim in which the instrument is provided in a kit with several different sized cervix engaging portions and a detachable handle.

13. An improved system for identification of the junction between the vagina and the cervix in patients with different sized and/or shaped gynaecological anatomy said system comprising providing the Instrument of claim 1 with a detachable handle portion and a range of different sized cervix engaging portions; selecting the appropriate sized cervix engaging portion, assembling the instrument and using it to identify said junction.

14. An improved system for identification of the junction between the vagina and the cervix in patients with different sized and/or shaped gynaecological anatomy said system comprising providing the instrument of claim 12; selecting the appropriate sized cervix engaging portion, assembling the instrument and using it to identify said junction.

15. An improved method of performing a hysterectomy said method comprising:

I) providing a surgical instrument suitable for identification of the junction between the cervix and the vagina said instrument comprising: i) a detachable handle portion and locatable at an end thereof; ii) a suitable cervix engaging portion having; iii) a fomices engaging lip; iv) an inside for cupping the cervix and; v) an outside which is tapered towards the handle portion; vi) long axes of said portions are aligned and the Hp is substantially perpendicular to the long axes when the instrument is assembled, thus allowing a range of movement of the instrument within the vagina such that identification of the junction between the cervix and the vagina may be achieved; II) providing a range of different sized suitable cervix engaging portions;

III) selecting the appropriate sized cervix engaging portion, assembling the instrument and;

IV) performing the colpotomy and hysterectomy.