WO2010054660A1

WO2010054660A1 - Double cannula system for anaesthetic needle

Info

Publication number: WO2010054660A1
Application number: PCT/DK2009/050296
Authority: WO
Inventors: Svend Lindenberg
Original assignee: Herlev Hospital
Priority date: 2008-11-11
Filing date: 2009-11-10
Publication date: 2010-05-20

Abstract

A double cannula system especially for oocyte retrieval is described. The double cannula system has an outer (1) and an inner (2) cannula, the inner cannula can operate freely within the outer cannula, the inner cannula can be removed from the outer cannula, and both cannulas have a tip which is sharp and bevelled. The tip of the inner cannula of the double cannula system is in front when introduced into an individual, and the inner cannula is used to locate one or more portions of anaesthesia when the inner cannula stepwise is introduced into the individual. The tip of the outer cannula follows behind the tip of the inner cannula. The inner cannula is removed before cells and/or body liquid is retrieved through the outer cannula.

Description

Title

Double cannula system for anaesthetic needle

All patent and non-patent references cited in the application, or in the present application, are also hereby incorporated by reference in their entirety.

Field of invention

The present invention relates to a double cannula system with an inner and an outer cannula for providing an anaesthesia e.g. a local anaesthesia within an individual through the inner cannula and removal of substances e.g. aspiration of cells, tissue and/or body fluids through the outer cannula when the inner cannula has been removed from the cannula system. Also disclosed is a method for providing a local anaesthesia and aspiration of cells with less pain compared to prior art methods of aspiration of cells from an individual. Especially the system and method is suitable for performing anaesthesia of female and aspiration of oocytes from the ovary with only a little pain for the female.

Background of invention

Performing a process including retaining of cells or body fluid from an individual often has the consequence of a painful experience for that individual. Total anaesthesia or local anaesthesia located in different areas of the tissue around the tissue to handle or no anaesthesia at all are often used in these processes.

In vitro fertilization (IVF) and embryo transfer (ET) are a well developed technique for the treatment of various forms of childlessness. At the majority of IVF clinics, egg aspiration is performed transvaginal^ with ultrasound guiding. Egg aspiration involves passing the aspiration needle through the vaginal wall for the purpose of puncturing follicles in the ovary. The procedure is relatively short and lasts between 20 and 30 minutes, among other things depending on the number of eggs and the position of the uterus and the ovary. The perception of pain during egg aspiration varies from individual to individual, but is described as relatively high if adequate analgesia is not administered. Analgesia in conjunction with egg aspiration today often consists of premedication 1-2 hours before the aspiration procedure in the form of a sedative preparation of some kind. A paracervical block (PCB), local anaesthesia with lidocaine, and possibly fast-acting morphine are administered intravenously during the procedure if the need arises. The alternative is for the procedure to be performed under general anaesthesia, although this is less common.

WO2005/025434 describes a method of egg aspiration from a female using a single cannula system. The system is based on an ultrasound guide and a needle with a length of which is sufficient to reach the patient's ovarian capsule from outside.

Cerne et al 2006 (Per-ovarian block versus paracervical block for oocyte retrieval, Human Reproduction Vol. 21 , No. 1 1 pp 2916-2921 ) compares two methods for pain relief during oocyte retrieval. For the pre-ovarian block method a POB™ needle 1.2 mm diameter was used.

The present invention is based on the detection that oocytes in the ovary are not damaged by the presence of anaesthetic within the ovary and that the oocytes is not damaged due to an increase in the pressure within the ovary due to the injection of anaesthetic into the ovary. Furthermore the use of the medical device or system as described herein and the method as described the patient experience much less pain when compared to methods of oocyte retrieval based on local anaesthesia.

As a consequence of the method described below much less anaesthetic is injected into a patient and therefore the risk of death due to an overdose of anaesthetic is decreased. No anaesthesia doctor need be present when retrieving oocytes from a female by the method described herein. The method and medical device described result in a pain-free or substantially pain-free experience by the patient hereby a female subjected to oocyte retrieval experience the operation as a good experience and is thus subjected to less stress.

Summary of invention

Disclosed is a medical device or a kit comprising at least one outer cannula (1 ), at least one inner cannula (2), wherein the outer cannula has an inner diameter which is larger than an outer diameter of the inner cannula, such that the inner cannula can be located within the outer cannula, the inner cannula can operate freely within the outer cannula, and wherein the outer cannula and the inner cannula both has a tip which is sharp and bevelled.

The medical device or kit described herein can be used for giving an anaesthesia to an individual, especially a local anaesthesia.

The double cannula system with an inner and an outer cannula is especially for providing an anaesthesia e.g. a local anaesthesia within an individual through the inner cannula and removal of substances e.g. aspiration of cells, tissue and/or body fluids through the outer cannula when the inner cannula has been removed from the cannula system.

With the use of the double cannula system individuals experience less pain compared to prior art methods for retrieval of cells, tissue and/or body fluids. Especially the system and method is suitable for performing anaesthesia of female and aspiration of oocytes from the ovary with only a little pain experience for the female.

Description of Drawings

Fig. 1 illustrates the tip of the double cannula medical device. An outer cannula (1 ) with an inner cannula (2) is illustrated.

Fig. 2 illustrates the bevelled tip of an outer cannula or an inner cannula.

Fig. 3 illustrates an outer cannula (1 ) in the form of a double lumen cannula with a first lumen and a second lumen.

Fig. 4 illustrates the vagina, the uterus, an ovary and a fallopian tube. An ultrasound guide with a double cannula system is illustrated.

Fig. 5 illustrates an enlarged part of fig. 4 with an ultrasound guide with a double cannula system located in the vagina, and the tip of the outer cannula (1 ) located in the tissue between the vagina and the ovary and the tip of the inner cannula (2) located in the ovary. Fig. 6 illustrates different possibilities for bevelled tips of cannulas.

Detailed description of the invention

In a first aspect the present invention relates to a medical device or a needle system comprising

• At least one outer cannula,

• At least one inner cannula, • Wherein the outer cannula has an inner diameter which is larger than an outer diameter of the inner cannula, such that the inner cannula can be located within the outer cannula,

• The inner cannula can operate freely within the outer cannula, and

• Wherein the outer cannula and the inner cannula each has a tip which is sharp and bevelled.

In a preferred embodiment the at least one outer cannula and/or the at least one inner cannula is straight and the inner cannula can be removed from the outer cannula. By straight is meant that the cannula is not intended to bend when in use. A little flexibility of the cannulas may be present, this is especially true in respect of the inner cannula which may be very thin.

Throughout this document the terms "outer" and "inner" are used to describe the location of the two cannulas when the medical device is assembled before use and/or when in use for the part of the operation or process where an inner cannula is to be located inside of an outer cannula. The inner cannula need not be located inside the outer cannula throughout the entire process as described elsewhere herein. To simplify the explanation of the invention, the terms "outer" and "inner" in respect of the cannulas are also used when the cannulas are not connected, where connected means when the inner cannula is located inside of the outer cannula.

The outer cannula can also be described as a first cannula and the inner cannula can be described as a second cannula. The outer and inner cannulas are preferably open in both ends to make it possible to have liquids and/or cells/tissue/body liquid to travel from one end of a cannula to the other end of the cannula and leaving the cannula. In a preferred embodiment the cannulas are suitable to let liquids and/or cells/tissue/body liquid both to enter and leave the inner or outer cannula when the cannulas have entered the individual and the tip of the respective cannula is located within the tissue of the individual. In a preferred embodiment the inner canula is used to locate anaesthesia in a specific location, and after removal of the inner cannula, the outer cannula is used to retrieve/aspirate cells e.g. oocytes from the individual.

In a preferred embodiment the inner cannula can be removed totally from the outer cannula. The inner cannula can be removed from the outer cannula when performing an operation to retrieve cells from an individual. The insertion into the outer cannula and removal of the inner cannula from the outer cannula can be performed without applying injuries to each other. Hereby the outer cannula is fully functional when the inner cannula has been removed. Especially the medical device can be manufactured or purchased with the two cannulas separated from each other, but also with the inner cannula located inside of the outer cannula. When the cannulas are purchased connected i.e. with the inner cannula located inside of the outer cannula, the cannulas are easier to handle before the cannulas are to be used. In the operation or process where the medical device with two cannulas is used, it is a benefit to have the possibility to remove the inner cannula and afterwards use the function of the larger outer cannula.

Both cannulas of the medical device have a tip which is sharp and capable of puncturing and/or cutting in the tissue of an individual. The bevelled tips may be any tips as described herein. Preferably the inner cannula is located in the outer cannula such that the bevelled parts of the tips are parallel or substantially parallel to each other as shown in Fig 1. The inner and outer cannula may have tips with a different sharpening of the bevelled tip e.g. of any of the types described herein. When the inner and outer cannulas have tips of a different type, these can still be located inside of each other such that the sharpened edges are substantially following each other i.e. the outmost part of the tips are located next to each other. The tip of the outer and/or inner cannula is bevelled and the tip may have any possible angle especially the tip may have an angle of at least 5 degree, such as at least 10 degree, e.g. at least 15 degree, such as at least 20 degree, e.g. at least 25 degree, such as at least 30 degree, e.g. at least 35 degree, such as at least 40 degree, e.g. at least 45 degree, such as at least 50 degree, e.g. at least 55 degree, such as at least 60 degree, e.g. at least 65 degree, such as at least 70 degree, e.g. at least 75 degree, such as at least 80 degree, e.g. at least 85 degree. The angle as described is illustrated by α in Fig. 2. Preferred is an angle α of the outer cannula of between 20 and 40 degree, making the tip a long-bevelled tip as indicated in Fig. 1 and Fig 2.

Other kinds of different bevelled tips are shown in Fig. 6, where the tips are shown in a side view ((a) and (b)) or seen from above ((c) to (e)). In (a) the tip is curved sharpened having a long thin tip, and in (b) the tip is sharpened with straight lines with different angles and also resulting in a long thin tip.

To obtain a long thin tip of the cannulas, the entrance may be e.g. as indicated in Fig. 6 (c) to (e). In (c) an elliptical entrance (when looking from the side of the cannula) of the cannula is ended in a tip with two straight sides (a "triangular" tip). In (d) a slightly tapered elliptical entrance of the cannula is ended in a rounded tip. In (e) a tapered elliptical entrance is ended in a "triangular" tip.

The angle of the inner and outer cannula may be similar. In a preferred embodiment the tip of the inner cannula has an angle which is larger than the tip of the outer cannula. The tip of the inner cannula may have an angle which is at least 5 degree larger that the outer cannula, such as at least 10 degree, e.g. at least 15 degree, such as at least 20 degree, e.g. at least 25 degree, such as at least 30 degree, e.g. at least 35 degree, such as at least 40 degree, e.g. at least 45 degree, such as at least 50 degree, e.g. at least 55 degree, such as at least 60 degree, e.g. at least 65 degree, such as at least 70 degree, e.g. at least 75 degree, such as at least 80 degree, e.g. at least 85 degree.

Depending on the purpose of the use of the cannula system, the outer cannula may have an angle of the tip which is larger than the tip of the inner cannula. The tip of the outer cannula may have an angle which is at least 5 degree larger that the inner cannula, such as at least 10 degree, e.g. at least 15 degree, such as at least 20 degree, e.g. at least 25 degree, such as at least 30 degree, e.g. at least 35 degree, such as at least 40 degree, e.g. at least 45 degree, such as at least 50 degree, e.g. at least 55 degree, such as at least 60 degree, e.g. at least 65 degree, such as at least 70 degree, e.g. at least 75 degree, such as at least 80 degree, e.g. at least 85 degree.

The tip of a cannula can also be lancet-shaped with sharp cutting edges, which gives the assurance for optimal function. In a preferred embodiment the cannulas as described herein are straight. Hereby the cannulas in an embodiment may not be manufactured such that the forward part of the cannulas bent. Preferably both the inner and outer cannulas are constructed to remain straight when not used as well as when in operation.

The medical device as described herein with two cannulas may be operated with only one cannula i.e. either the inner or the outer cannula or with both cannulas at the same time. It is a benefit to have indicia close to the tip of the outer cannula and/or of the inner cannula for orientation of the cannulas. The indicia may be marks e.g. grooves making the marked parts of the cannulas visible in an ultra sound operation. In this case "visible" means that the tip of the cannulas can be seen on a screen used when performing an operation based on ultra sound orientation. The indicia or marks is for ultra sound guiding and can also be an echo-marking which is produced without altering the cannula surface.

The indicas may be made in the tip by cutting or milling in the tip, by corroding the tip e.g. with an acid or by use of a different alloy. The indicas may be located from the outermost edge of the tip to 3 cm below the lower part of the cutting edge. In an embodiment the indicas are located in the part of the tip outlined by the outermost part of the cutting edge and the lower part of the cutting edge, this area is indicated by "a" in Fig 2. In another embodiment the indicas are located from the lower part of the cutting edge and less than about 2 cm down the cannula, this area is indicated by "b" in Fig 2. It is also possible to have indicas in both areas "a" and "b" as indicated in Fig 2.

In an embodiment the outer cannula and the inner cannula both has a length of at least 10 cm, such as at least 15 cm, e.g. at least 20 cm, such as at least 25 cm, e.g. at least 30 cm, such as at least 35 cm, e.g. at least 40 cm. Each cannula can have a length such that 8-10 cm of the cannula can be introduced into tissue of the patient. In the process of retrieving oocytes in a transvaginal process, the cannula can be of a length suitable to be introduced into the vagina of a female and further 8-10 cm into the tissue of the female. The cannula further need to be of a length suitable for connection to a handle and/or syringe or other medical means for retrieving cells, body liquids or oocytes.

In a preferred embodiment the inner cannula is at least 1 cm longer than the outer cannula, such as at least 2 cm longer, e.g. at least 3 cm longer, such as at least 4 cm longer, e.g. at least 5 cm longer, such as at least 6 cm longer, e.g. at least 7 cm longer, such as at least 8 cm longer, e.g. at least 9 cm longer, such as at least 10 cm longer. Preferably the inner cannula is about 5, 8 or 10 cm longer than the outer cannula.

The length of the cannulas are determined in respect of the operation to perform, accordingly also the difference of the length of the inner and outer cannula is determined in respect of this operation.

When performing a process of retrieving oocytes from a female each cannula has a length of at least 20 cm, such as at least 25 cm, e.g. at least 30 cm, such as at least 35 cm, e.g. at least 40 cm. The process is further described herein. In a preferred embodiment the outer cannula is between 20 and 40 cm, and the inner cannula is 2 to 10 cm longer than the outer cannula. In a further preferred embodiment the outer cannula is between 25 and 35 cm and the inner cannula is about 5 cm longer than the outer cannula.

The cannula thickness of the medical device described herein may be any suitable for the processes where the cannulas are to be used, especially the outer cannula can be at least 12 G (gauge), such as at least 16G, for example 16.5G, such as 17G, for example 17.5G, e.g. 18G, for example 18.5G, such as 19G, for example 19.5G, e.g. 2OG, for example 20.5G, such as 21 G, for example 21.5G, e.g. 22G, for example 22.5G, such as 23G, for example 23.5G, e.g. 24G, for example 24.5G, such as 25G, for example 25.5G, e.g. 26G.

The inner cannula can be at least 18G, for example 18.5G, such as 19G, for example 19.5G, e.g. 2OG, for example 20.5G, such as 21 G, for example 21.5G, e.g. 22G, for example 22.5G, such as 23G, for example 23.5G, e.g.24G, for example 24.5G, such as 25G, for example 25.5G, e.g. 26G, for example 26.5G, such as 27G, for example 27.5G, e.g. 28G. Any combination of the thickness of the outer and inner cannula with the above mentioned thickness indications are possible as long the inner cannula can operate freely within the outer cannula. Examples of combinations of an outer cannula and inner cannula may be a difference of three or four e.g. 17G and 21 G, respectively. Any combination with a difference of three as just outlined is disclosed herein. Any combination with the difference of four is also disclosed herein e.g. 16G+20G; 16.5G+20.5G; 17.5G+21.5G; 18+22G. Also the difference may by 3.5, 4. 4.5 or 5. Any combination with a difference of 3.5, 4, 4.5 or 5 and based on the sizes of the outer or inner cannula as indicated above is possible.

Preferably the outer cannula is a 16G, a 17 G or a 18G needle.

The thickness of the cannulas may also be given in mm, where e.g. 16G corresponds to 1.6 mm, 16.5G to 1.5 mm, 17G to 1.4 mm, 18G to 1.2 mm, 19G to 1.0 mm, 21 G to 0.8 mm, 26G to 0.6 mm.

Preferably the cannulas are as thin as possible to decrease the pain imposed upon the individual when using the cannulas.

The inner cannula only needs an inner thickness making it possible to introduce the tip of the inner needle a short distance in front of the tip of the outer cannula and to deliver anaesthesia in the proper location of the body of the individual. For human oocyte retrieval procedure the outer diameter of the inner cannula is preferably from 0.6 mm to 1.2 mm, further preferably from 0.7 mm to 1.1 mm, more preferably from 0.8 mm to 1.0 mm, most preferably about 0.9 mm.

Preferably the outer cannula needs an inner thickness suitable to retrieve or aspirate cells or tissue from the individual. With retrieval of oocytes usually being 0.1 to 0.2 mm in diameter the size of the outer cannula is preferably less than 18G e.g. 12G, 13G, 14G, 15G, 16G, 17G when used for oocyte retrieval. An inner diameter of the outer cannula is preferred at least 0.9 mm to prevent destruction of the retrieved cells e.g. oocytes. A preferred inner diameter of the outer cannula may also be at least 1.0 mm, e.g. at least 1.1 mm, such as at least 1.2 mm. The diameter of the outer and inner diameter may be different in respect of different types of animals to treat. The diameters mentioned above are in respect of humans. The diameters may be modified when using the needle system for animals such as cows, sows, dogs, horses, mice, rats. Also the length of the needles can be modified to be suitable to the type of animal as well as the species of animal as the animals have different anatomy. The skilled person would by able to select suitable dimensions of the animals to determine the dimensions of the needles.

In a preferred embodiment the medical device as described herein can be used in a process visualised by ultra sound guidance and the outer cannula can thus be capable of being connected to a guide for guiding the cannulas. Ultra sound guides and connection devices connecting a cannula to an ultra sound guide are known by the skilled person.

The ultrasound guide can be a tranducer intended for ultrasound guiding.

The cannulas as described herein may in respect of both the outer cannula and/or the inner cannula in a cross section be of a form which is round to oval. In respect of oval cannulas, the features e.g. the thickness of the cannulas can be as indicated above i.e. the outer cannula can be between 12G and 21G, and the inner cannula thinner with the differences between the outer cannula and inner cannula as described above.

The cannulas as described herein may be of any suitable material for performing introduction into and/or removal of substances from an individual. Substances in this respect mean e.g. medicaments, body liquid, cells etc. The cannulas may be made of metal. Both cannulas may be produced from similar material but also different materials can be used. Examples of materials can be selected from the group of steel, platinum, alloys including platinum, polymer.

In respect of the outer cannula with any one of the features described elsewhere herein the outer cannula may be a double lumen cannula.

To describe the double lumen canual which can be used as the outer cannula as described herein, the double lumen cannula comprises a first lumen and a second lumen, the first lumen being a volume of the outer cannula defined by the inner side of the outer cannula and of a outer side of the second lumen, the first lumen is an oocyte pick-up lumen, the second lumen is a working lumen or a flushing lumen for inserting a flushing fluid into the follicle.

The material making up the second lumen or flushing lumen as described above can be a material which is flexible such that this material and the second lumen can be pressed together when the inner cannula is introduce into the outer cannula. The second lumen may unfold when the inner cannula is removed or when the second lumen is utilized in the process as described elsewhere herein. The second lumen may be produced from any suitable material for performing operations connected to an individual. The material can be selected from e.g. steel, carbon fibre or carbon composite, alloys of metal, platinum or polymer.

The outer cannula and/or the inner cannula can each be marked by a different colour code for easy recognition and thus for easy handling when the outer cannula is to be connected to the ultrasound guide and/or the inner cannula is to be recognized to be introduced into the outer cannula. In a preferred embodiment the colour code is located at the end of the cannula which is capable to be connected to a syringe. Any colours can be used for the inner and outer cannula as long as the difference of the two colours is such that the recognition is easy to perform.

Each of the outer cannula and/or inner cannula as described herein can be capable of being connected to a syringe or other devices to be used in the processes performed on the individual. The connecting point is the opposite end of the cannula than the bevelled tip. Hereby the inner cannula can be connected to a container or a syringe with an anaesthesia (a delivery system). The outer cannula can be connected to a system for retrieval of cells or body liquid which are to be retrieved, this system can be a container or syringe for retrieval of oocytes.

The combination of the cannulas to the delivery system or retrieval system may be in the form of e.g. a luer lock system or another suitable locking system. The delivery system or retrieval system may be a luer lock system or another suitable system.

Preferably the cannulas of the medical device are disposable, although also cannulas suitable to be re-used can be included in the medical device. For instance a re-useable outer cannula together with a disposable inner cannula is possible or vice-versa or both cannulas can be re-useable. For easy handling and for the security of the individual to be treated sterile, disposable cannulas are preferred.

The medical device described above may be an oocyte retrieval device and may comprises any one of the features described above, where these features may be combined in all possible combinations. The way to handle the device for oocyte retrieval is described below and further features being evident from this description may also be a feature for the medical device or oocyte retrieval device described herein.

In a preferred embodiment the cannulas of the needle system is not bent or flexed at any position that is to enter into the body of an individual.

In a further preferred embodiment the cannulas of the needle system do not have any openings along the side of the cannulas. In respect of the inner cannula openings may be present only at the position of the bevelled tip and at the basis of the cannulas. In respect of the outer cannula when being a single lumen cannula, openings may be present only at the position of the bevelled tip and at the basis of the cannulas. In respect of the outer cannula when being a double lumen cannula, an entrance for the flexible part of the cannula may be located in the part of the cannula being opposite of the tip of the cannula.

In a preferred embodiment the cannulas do not have fastening or holding means such as excision fingers at the tip region. No fastening or holding means need be present in the region of the cannulas to be entered into the individual. In this respect "entered into" means from the point where the skin of the individual is punctured and the cannulas are guided into the tissue.

In another preferred embodiment no stylet or penetration tip is present within the inner cannula. A stylet or penetration tip is used to enter into the tissue and press the tissue to the sides before the cannula enters into the region of the tissue.

In a preferred embodiment the tips of the inner and outer cannula are not tapered i.e. the tips are not cone-shaped to have a smaller opening in the outmost part of the tip. Kit

Another aspect of the invention relates to a kit comprising

• at least one outer cannula, • at least one inner cannula,

• wherein the outer cannula has an inner diameter which is larger than an outer diameter of the inner cannula, such that the inner cannula can be located within the outer cannula,

• the inner cannula can operate freely within the outer cannula, and • wherein the outer cannula and the inner cannula both has a tip which is sharp and bevelled.

The kit may further include any other features as mentioned herein. The kit may also include features such as syringe and/or connection tubes and/or test tubes and/or a sucking or aspirating unit.

Method

A further aspect of the invention relates to a use of the medical device as described above as a medical device or as a kit for giving anaesthesia to an individual, especially a local anaesthesia.

To introduce anaesthesia into an individual the inner cannula is connected to a container with anaesthesia, the inner cannula is introduced into the outer cannula before the tip of the outer cannula is brought in contact with the individual to give the anaesthesia, or the inner cannula is introduced into the outer cannula when the tip of the outer cannula is brought in contact with the individual to give the anaesthesia. The inner cannula when being located in the outer cannula is introduced into the individual and an amount of anaesthesia is injected into the individual. The inner cannula can be further introduced into the individual and another amount of anaesthesia can be injected into the individual and/or the outer cannula can be introduced into the individual nearly as long as the inner cannula has been introduced before another amount of anaesthesia is injected into the individual or the inner cannula can be further introduced into the individual before an amount of anaesthesia is injected into the individual. Thus a step-wise introduction of the inner cannula and the outer cannula together with one or more injections of an amount of anaesthesia can be used to perform a local anaesthesia of an individual.

Depending on the purpose of the operation and the method used for injection of an amount of anaesthesia as well as retrieval of cells or substances from the individual the inner cannula may be located inside of the outer cannula before introduction of the cannula system into a cavity e.g. a vagina of an individual or before introduction of the outer cannula or inner cannula into the individual i.e. before penetration of the skin or the inner cannula can be located inside of the outer cannula after the outer cannula has been penetrated the skin of an individual.

Also depending on the purpose of the operation and the method used for injection of an amount of anaesthesia as well as retrieval of cells or substances from the individual the inner cannula may be removed from the outer cannula before the outer cannula is introduced into the area or organ from where cells or substances are to be retrieved or after the outer cannula has been introduced into the area or organ from where cells or substances are to be retrieved. It is also possible to introduce the outer cannula into an area or organ of an individual and simultaneous removing the inner cannula from the outer cannula such the tip of the inner cannula exchange its position with the tip of the outer cannula.

A further aspect of the invention relates to a use of the medical device as described above as a medical device or as a kit for giving anaesthesia to an individual, especially a local anaesthesia and retrieving cells or body liquid from an individual. The path for performing the anaesthesia and retrieving cells or body liquid from an individual is described elsewhere herein.

A yet further aspect of the invention relates to a method of giving a local anaesthesia to an individual before retrieving cells and/or body liquid from the individual, the method comprising

• Providing an individual from who cells or body liquid are to be retrieved,

• Providing a device or a kit as described elsewhere herein comprising an outer cannula and an inner cannula,

• Positioning the outer cannula close to the individual or introducing the outer cannula into the individual, • Introducing the inner cannula into the individual,

• Introducing anaesthesia into the individual through the inner cannula,

• Optionally repeatedly introducing the inner and/or outer cannula further into the individual and optionally introducing anaesthesia again through the inner cannula into the individual,

• Optionally introducing anaesthesia into an organ of the individual, from which organ cells and/or body fluids are to be retrieved,

• Bringing the outer cannula into the organ of the individual, from which organ cells and/or body fluids are to be retrieved, • Removing the inner cannula entirely from the outer cannula,

• Removing cells and/or body fluids from the organ through the outer cannula, and

• Hereby retrieving cells and/or body fluids from the individual.

When repeatedly introducing the inner and/or outer cannula further into the individual and optionally introducing anaesthesia again through the inner cannula into the individual, the inner cannula is in the front i.e. the cannula which first enters into a part of the tissue not yet entered by any of the cannulas of the cannula system.

In an embodiment the inner cannula may be reintroducing into the outer cannula, and anaesthesia can be introducing again into the individual through the inner cannula. Reintroducing of the inner cannula as described just above can be performed before and/or after retrieving cells and/or body fluids from the individual. Reintroduction of the inner cannula together with injection of an amount of anaesthetic may also be performed between two session of retrieving cells and/or body fluids from the individual.

Reintroduction of the inner cannula together with injection of another amount of anaesthetic may be performed at least 2 times, such as 3 times, e.g. 4 times.

An aspect of the invention relates to a method for retrieving oocytes from a female, the method comprising

• Introducing anaesthetic through a inner cannula into a female by the use of a medical device as described elsewhere herein, • Retrieving oocytes from the female being under local anaesthesia. Another aspect of the invention relates to a method for retrieving oocytes from a female, the method comprising

• Providing an individual from who oocytes are to be retrieved, • Providing a device as described elsewhere herein,

• Introducing the outer cannula with the inner cannula located inside of the outer cannula into the vagina of the female ,

• Introducing the inner cannula into the individual to a location close to the capsule of an ovary or through the capsule of an ovary, • introducing an amount of anaesthetic close to the ovary and/or into the ovary,

• Removing the inner cannula entirely from the outer cannula,

• Repeatedly puncturing a follicle of the ovary and aspirating the oocyte of the follicle through the outer cannula until a number of oocytes are obtained, • hereby retrieving oocytes from a female.

A further aspect of the invention relates to a method for retrieving oocytes from a female, the method comprising

• Introducing the inner cannula through the vaginal mucous membrane of the individual and introducing an amount of anaesthetic into the reached tissue, • Introducing the outer cannula through the vaginal mucous membrane in an area of the vagina located close to an ovary,

• Introducing the inner cannula further into the tissue between the vagina and the oocyte,

• Optionally introducing an amount of anaesthetic into the tissue between the vagina and the oocyte,

• Positioning the inner cannula close to the ovary but outside of the ovary, just inside of the ovary or within the ovary,

• introducing an amount of anaesthetic outside of the ovary, just inside of the ovary or within the ovary, • introducing the outer cannula into the ovary, • Removing the inner cannula entirely from the outer cannula,

• Repeatedly puncturing a follicle of the ovary and aspirating the oocyte of the follicle through the outer cannula until a number of oocytes are obtained,

• Removing the outer cannula from the female, • Hereby retrieving oocytes from a female.

In a preferred embodiment the inner cannula of the medical device is introduced through the capsule of an ovary and an amount of an anaesthetic is injected into the ovary, before oocytes are retrieved by the outer cannula.

Before oocyte retrieval a treatment of the female can be performed where multiple oocytes are stimulated or manipulated to mature within the ovary. Processes to stimulate or manipulate oocytes to mature are know in the art. In a preferred embodiment the oocyte retrieval process is performed without a stimulation of oocytes i.e. no hormones are used to mature oocytes. The process can be described as a 0- stimulation process (zero stimulation or null stimulation).

It is usually to perform a pre-medication with a sedative preparation of a woman within 1-2 hours before aspiration of oocytes. This need not be performed with the retrieving method described herein. No general anaesthesia need be performed of the female before aspiration of oocytes.

Just prior to or during the oocyte retrieval process a fast-acting morphine can be administered intravenously into the female to retrieve oocytes from.

The oocyte retrieval is performed by passing a hollow needle system as described herein through the wall of the vagina into the ovary with the inner cannula as the leading part all the time. The needle is guided into the ovary with the use of a vaginal ultrasound probe. The inner and/or outer cannula can be guided into the follicle where the egg resides. The egg itself is not visible with the ultrasound. The fluid including oocytes can be aspirated from the follicle with the outer cannula and deposited into a test tube.

In the anaesthesia process the inner cannula is support by the outer cannula, hereby the inner cannula can be of a thickness which would be too thin to operate alone with the risk of bend or break. A cannula which bends uncontrolled is not suitable when performing an operation as described herein. The small thickness of the inner cannula reduces the bleeding process of the individual when the cannula is entered into tissue of this individual also the thin cannula reduces the pain experienced by the individual.

The outer cannula support the inner cannula as described above and at the same time it positions or supports the tissue where the inner cannula is to be further introduced into.

In a preferred embodiment a injection of anaesthetic is provided in the vaginal wall.

The distance from the vaginal wall to the outer part of the ovary can be e.g. 0.5 to 5 cm. Within this distance an amount of anaesthetic may be injected for each cm. The number of times anaesthetic is injected into the tissue between the vaginal wall and the ovary may thus be 0, 1 , 2, 3, 4, 5. Preferably anaesthetic is injected into the tissue between the vaginal wall and the ovary at 1 or 2 locations. More preferably the injections are provided by a step-vise process as described elsewhere herein. In the sentence "the tissue between the vaginal wall and the ovary" this include the paravarielle tissue, the paravaginal tissue and vaginal vault.

Within the ovary 0, 1 , 2, 3 amounts of anaesthetic may be injected. Preferably an amount of anaesthetic is injected in the ovary at 1 or 2 locations.

In an embodiment an amount of anaesthetic is injected in the vaginal wall, in the tissue between the vaginal wall and the ovary and into the ovary at 1 , 2, 3, 4, 5, 6, 7 or 8 locations in total. In a preferred embodiment an amount of anaesthetic is injected in the vaginal wall, in the tissue between the vaginal wall and the ovary and into the ovary at 2, 3, 4, or 5 locations in total. In a more preferred embodiment an amount of anaesthetic is injected in the vaginal wall, in the tissue between the vaginal wall and the ovary and into the ovary at 3 or 4 locations in total.

In an embodiment the local anaesthesia when performing a process for retrieval of oocytes may be pre-ovarial, peri-ovarial and/or intra-ovarial. The process for performing this local anaesthesia in one or more of the mentioned regions may be performed step-wise as described elsewhere herein. An amount of anaesthetic can be administered by the inner cannula precisely adjacent to a follicle. The inner cannula can then be removed and the follicle can be punctured with the tip of the outer cannula, then the follicular fluid with an oocyte can be aspirated through the outer cannula. Another follicle can then be punctured and the content aspirated by the outer cannula. If needed e.g. if the outer cannula has to be moved to another part of the ovary the inner cannula can be re-introduced into the outer cannula for injecting anaesthetic close to another follicle to be punctured and aspirated with the outer cannula when the inner cannula has been removed.

When performing the method as described herein with injection of anaesthetic in the tissue between the vagina and the oocyte and optional also within the oocyte, the amount of anaesthetic used is reduced to 20-30% of the amount of anaesthetic used in prior art methods based on a number of local anaesthesia located in different areas of the tissue the around ovary. In the prior art method described the amount of anaesthesia could be e.g. 2-4 ml. A total amount of anaesthetic used when retrieving oocytes from a single ovary may thus be about 0.5-1 ml. The anaesthetic used for performing the local anaesthesia can be lidocaine®, xylocaine® or citanest® or another suitable composition.

The double cannula system as described herein can be used in a method of performing a biopsy, where an individual is given a local anaesthetic by introducing the anaesthetic through the inner cannula, the inner cannula is removed from the outer cannula, and the biopsy is performed by the outer cannula. The double cannula system as described herein may also be used in a method for cancer diagnostic, aminocentesis, biopsy including e.g. brain biopsy.

With the use of a double cannula system as described herein for the performance of local anaesthesia and retrieval of oocytes a minimum amount of anaesthetic is obtained in the retrieved follicular liquid as the cannula for injection anaesthetic is removed before aspiration of the follicular liquid comprising oocyte.

Previous it has been believed that the oocytes of the ovary can not survive if anaesthetic was injected into the ovary. It has turned out that the oocytes are not damaged by the presence of anaesthetic within the ovary and that the oocytes is not damaged due to an increase in the pressure within the ovary due to the injection of anaesthetic.

The process of retrieval of oocytes takes less than 20 minutes when the medical device and the method as described herein are used. Usually the process of retrieval of oocytes takes less than 15 minutes, such as about 10 minutes.

A good egg retrieval with stimulation of oocyte maturation and local anaesthetic performed at different locations around the ovary may obtain between 10 and 20 oocytes from each ovary. Without stimulation of oocyte maturation and with the local anaesthesia at different locations around the ovary the number of oocytes aspirated from each ovary is usually between 4 and 10. Without stimulation of oocyte maturation and with the local anaesthesia as described herein between 6 and 15 oocyte can usually be retrieved. The increased number of retrieved oocytes is due to less pain to the female and thus a more peaceful atmosphere within the clinic, such that more mature oocytes can be localised without performing a painful operation.

An oocyte retrieval process according to the method described herein typically takes 10-15 minutes in total, sometimes less e.g. 6-9 minutes. Afterwards, the woman is suitable to leave within less than half an hour after completing the retrieval. Thus by the transvaginal oocyte retrieval method as described herein the female requires neither hospitalization nor general anaesthesia. Furthermore local anaesthesia need not be localised in a plurality of places around the ovaries.

Detailed description of the drawings

Fig. 1 illustrates the tip of the double cannula medical device according to the invention described herein. An outer cannula (1 ) with an inner cannula (2) is illustrated. The tip of the inner cannula (2) is protruding from the outer cannula (1 ).

Fig. 2 illustrates the bevelled tip of an outer cannula or an inner cannula. The cannula is sharp to be able to penetrate the tissue of an individual and puncturing a follicle of an ovary. Illustrated is also the angle of the tip by the symbol α. The lines "a" and "b" indicate areas of the tip which may include indicas or markings as described above. Fig. 3 illustrates an outer cannula (1 ) in the form of a double lumen cannula with a first lumen (5) and a second lumen (6). The second lumen (6) can be used to introduce e.g. a liquid when cells, tissue and/or body fluids are being aspirated from the individual through the outer cannula (1 ).

Fig. 4 illustrates the vagina (a), the uterus (b), an ovary (c) and a fallopian tube (d) of a female. An ultrasound guide (4) with a double cannula system is illustrated. The ultrasound guide (4) is supporting the double cannula system as well as providing a ultrasound image on a screen (not indicated) hereby an accurate operation of the double cannula system is possible. The double cannula system is about to penetrate the tissue between the vagina (a) and the ovary (c) to reach the ovary (c) to retrieve oocytes. The tip of the inner cannula (2) is located in the tissue between the vagina (a) and the ovary (c), whereas the tip of the outer cannula (1 ) is located in the membrane of the vagina. An anaesthetic is injected by the inner cannula (2) before the outer cannula (1 ) is introduced further into the individual.

Fig. 5 illustrates an enlarged part of fig. 4 with an ultrasound guide (4) with a double cannula system located in the vagina (a), and the tip of the outer cannula (1 ) located in the tissue between the vagina and the ovary (c) and the tip of the inner cannula (2) located in the ovary. Four follicles (e) are illustrated, but only a single follicle is marked with an "e". The drawn stars (^*) indicate locations where anaesthetic can be introduced through the inner cannula (2). The numbering of the stars (^*1 , ^*2, ^*3 and ^*4) indicates possible successive injections of an anaesthetic. The illustrated possible injections of an anaesthetic are in the vaginal wall (^*1 ), in the tissue between the vaginal wall and the ovary (^*2), in the ovary (^*3) and further inside of the ovary (^*4). The injection of an anaesthetic illustrated by ^*2 in the tissue between the vaginal wall and the ovary may comprise more than one injection of an anaesthetic as described elsewhere herein. In respect of the injections of an anaesthetic illustrated by ^*3 and ^*4, the inner cannula (2) may be removed from the outer cannula (1 ) after injection of an anaesthetic illustrated by ^*3, the follicles (e) located between the areas indicated by ^*3 and ^*4 can be punctured by the outer cannula (1 ) and the oocytes (not illustrated) can be aspirated through the outer cannula (1 ). When the follicles (e) located between the areas indicated by ^*3 and ^*4 have been emptied, the inner cannula (2) can be reintroduced into the outer cannula (1 ) and in an area as e.g. illustrated by ^*4 another injection of an anaesthetic can be performed followed by removal of the inner cannula (2) and aspiration of follicle(s) (e).

Fig. 6 illustrates different possibilities for bevelled tips. The tips are shown in a side view ((a) and (b)) and seen from above ((c) to (e)). In (a) the tip is curved sharpened and in (b) the tip is sharpened with straight lines with different angles. In (c) an elliptical entrance of the cannula is ended in a tip with two straight sides (a "triangular" tip). In (d) a slightly tapered elliptical entrance of the cannula is ended in a rounded tip. In (e) a tapered elliptical entrance is ended in a "triangular" tip.

Example

Ultrasound guided oocyte pickup procedures with local analgesia.

In a prospective open study three doctors performed the direct ultrasound guided application of local analgesia in the vagina and pre-ovarian tissue method (POP procedure) and one doctor continued the old blind para-cervical technology.

From 1 October 2008 to 1 July 2009 all patients with a short antagonist protocol and less than 35 yrs of age were recruited for this study. 510 consecutive oocyte retrievals were collected: 343 by the new technology (POP procedure) and 167 by the old technology (Old procedure).

We would like to measure safety for the patient and safety for the oocyte.

A total of 25 patients previously having had the old method performed were scoring the POP procedure concerning pain. 90% claimed that the new method were better i.e. they had less pain.

This technology for the POP procedure is easy, fast and safe and is a patient friendly approach to oocyte pick-up procedure.

Claims

1. A medical device comprising

• At least one straight outer cannula (1 ), • At least one inner cannula (2),

• The inner cannula can operate freely within the outer cannula, • The inner cannula can be removed from the outer cannula, and

• Wherein the outer cannula and the inner cannula both has a tip which is sharp and bevelled.

2. The medical device according to claim 1 , wherein the outer cannula and/or the inner cannula have indicia (3) close to the tip for orientation of the cannula.

3. The medical device according to claim 1 or 2, wherein the outer cannula and the inner cannula both has a length of at least 10 cm, such as at least 15 cm, e.g. at least 20 cm, such as at least 25 cm, e.g. at least 30 cm.

4. The medical device according to any of the preceding claims, wherein the outer cannula is at least 16g, such as 17g, e.g. 18g, such as 19g, e.g. 2Og, such as 21g, e.g. 22g, such as 23g, e.g. 24g, such as 25g, e.g. 26g.

5. The medical device according to any of the preceding claims, wherein the inner cannula is at least 18g, such as 19g, e.g. 2Og, such as 21 g, e.g. 22g, such as 23g, e.g.24g, such as 25g, e.g. 26g, such as 27g, e.g. 28g.

6. The medical device according to any of the preceding claims, wherein the outer cannula is capable of being connected to a guide (4) for guiding the cannulas.

7. The medical device according to claim 6 wherein the guide is a tranducer intended for ultrasound guiding.

8. The medical device according to any of the preceding claims, wherein the outer cannula and/or the inner cannula in a cross section is round to oval.

9. The medical device according to any of the preceding claims, wherein the outer cannula and/or the inner cannula are made of steel, platinum, alloys including platinum, polymer.

10. The medical device according to any of the preceding claims, wherein the outer cannula is a double lumen cannula.

1 1. The medical device according to claim 7, wherein the double lumen cannula comprise a first lumen (5) and a second lumen (6), the first lumen being defined by the inner side of the outer cannula and of a outer side of the second lumen.

12. The medical device according to any of claims 6-7, wherein the second lumen is made of steel, carbon fibre or carbon composite, alloys of metal, platinum or polymer.

13. The medical device according to any of the preceding claims, wherein the outer cannula and/or the inner cannula each are marked by a different colour code for easy recognition.

14. The medical device according to any of the preceding claims, wherein the outer cannula and/or the inner cannula is capable of being connected to a syringe.

15. The medical device according to claim 14, wherein the syringe is for holding substances for performing an anaesthesia or for retrieving cells and/or body fluids from an individual.

16. The medical device according to any of the preceding claims, wherein the cannulas are disposable.

17. An oocyte retrieval device comprising the features of claim 1 and optionally further comprising the features of any one of claims 2-16.

18. A kit comprising

• at least one straight outer cannula,

• at least one inner cannula,

• the inner cannula can operate freely within the outer cannula,

• The inner cannula can be removed from the outer cannula, and

19. The kit according to claim 18 further including the features of any one of claims 2-17.

20. Use of a medical device according to any one of claims 1 -19 or of the kit according to claim 19 for giving an anaesthesia to an individual, especially a local anaesthesia.

21. Use according to claim 20 for retrieving cells or body liquid from an individual.

22. A method of giving a local anaesthesia to an individual before retrieving cells and/or body liquid from the individual, the method comprising

• Providing an individual from who cells or body liquid are to be retrieved,

• Providing a device of any one of claims 1 to 19, • Introducing the outer cannula close to the individual or into the individual,

• Introducing the inner cannula into the individual,

• Introducing anaesthesia into the individual through the inner cannula,

• Bringing the outer cannula into the organ of the individual, from which organ cells and/or body fluids are to be retrieved, • Removing the inner cannula entirely from the outer cannula, • Removing cells and/or body fluids from the organ through the outer cannula, and

• Hereby retrieving cells and/or body fluids from the individual.

23. The method according to claim 22 further comprising the steps of

• Reintroducing the inner cannula into the outer cannula,

• Introducing anaesthesia into the individual through the inner cannula, wherein the reintroducing of the inner cannula can be performed before and/or after retrieving cells and/or body fluids from the individual.

24. The method according to claim 23 wherein the reintroduction is performed at least 2 times, such as 3 times, e.g. 4 times.

25. A method of performing a biopsy, comprising the steps of • Providing a device of any one of claims 1 to 19,

• Giving an individual a local anaesthetic by introducing the anaesthetic through the inner cannula,

• Removing the inner cannula from the outer cannula,

• Performing a biopsy by the outer cannula.

26. A method for retrieving oocytes from a female, the method comprising

• Introducing anaesthetic through a inner cannula into a female by the use of a medical device according to claim 1 to 19,

• Retrieving oocytes from the female being under local anaesthesia.

27. A method for retrieving oocytes from a female, the method comprising

• Providing an individual from who oocytes are to be retrieved,

• Providing a device of any one of claims 1 to 19,

• Introducing the outer cannula with the inner cannula located inside of the outer cannula into the vagina of the female,

• Introducing the inner cannula through the capsule of an ovary,

• introducing an amount of anaesthetic into the ovary,

• Removing the inner cannula entirely from the outer cannula,

28. A method for retrieving oocytes from a female, the method comprising

• Providing an individual from who oocytes are to be retrieved, • Providing a device of any one of claims 1 to 19,

• Introducing the inner cannula further into the tissue between the vagina and the ovary,

• Optionally introducing an amount of anaesthetic into the tissue between the vagina and the ovary,

• Introducing the outer cannula through the capsule of an ovary,

• introducing an amount of anaesthetic into the ovary,

• introducing the outer cannula into the ovary,

• Removing the inner cannula entirely from the outer cannula, • Repeatedly puncturing a follicle of the ovary and aspirating the oocyte of the follicle through the outer cannula until a number of oocytes are obtained,

• Removing the outer cannula from the female,

• Hereby retrieving oocytes from a female.