WO2024089566A1

WO2024089566A1 - Spinal needle

Info

Publication number: WO2024089566A1
Application number: PCT/IB2023/060634
Authority: WO
Inventors: Thomas Hemmerling
Original assignee: 9451-9337 Québec Inc. DBA Divocco Intelligence Artificielle
Priority date: 2022-10-24
Filing date: 2023-10-20
Publication date: 2024-05-02

Abstract

There is disclosed a spinal needle, comprising a first section including a distal tip and a first aperture, the first section having a first diameter less than 23 G, the first section having a length of less than 10 mm; a second section proximal to the first section, the second section having a second diameter that is larger than the first diameter; a sharp transition section between the first section and the second section with a transition angle of at least 40° and an inner channel connected to the first aperture, the inner channel extending longitudinally through the first section and the second section.

Description

SPINAL NEEDLE

TECHNICAL FIELD

[0001] The present disclosure relates to a needle, and more specifically to a spinal needle for spinal anesthesia.

BACKGROUND

[0002] Spinal anesthesia is a convenient form of anesthesia that is commonly used for surgery of the lower body.

[0003] The spinal anesthesia is induced by injecting small amounts of local anesthetic into the cerebro-spinal fluid (CSF). The injection is usually made in the lumbar spine below the level at which the spinal cord ends (L2). After a sterile prep and draping, local anesthetic is placed in the skin of the patient to numb the area where the spinal needle will be placed. The spinal needle pierces the skin and passes between the vertebrae of the spinal column through the ligaments, and then the dural membrane behind which the CSF is located. Once the placement of the needle is accomplished, confirmed by adequate CSF flow in the hub of the needle, medicines including a local anesthetic, and sometimes a narcotic and/or other drugs, are dispensed via the needle. The needle is then removed. The entire process typically takes anywhere from 2 to 20 minutes.

[0004] One of the complications of spinal puncture is post-puncture headaches. The risk for these is increased with increasing needle diameter. Therefore, two of the standard needle diameters are 25 G or 27 G. However, these needles, being so small, cannot be inserted directly through the skin. An introducer, a short needle with a larger diameter (usually 22 G), is inserted through the skin to a depth of about 3 cm. Then, the smaller, longer spinal needle (in general of a length of 90 mm) is inserted through this introducer needle. [0005] Even with the introducer, the needles with smaller diameter (25 G or 27 G) can bend between the introducer and the hand of the operator when the ligaments between the vertebrae are stiff.

[0006] Another drawback occurs when one does not enter the subarachnoid space but needs to change the needle direction. When this happens, the spinal needle needs to be withdrawn, then the introducer needle, after which the introducer needle is reinserted with a different direction, usually upwards, followed by the spinal needle.

[0007] Sometimes, anesthesiologists resort to bigger needles (for example, 22 G). These bigger needles can be inserted directly, without aid of an introducer, and if necessary can easily be withdrawn for any change in direction. They are also easier to insert in the ligaments with a smaller risk of bending the needle. However, this increases the risk of post-puncture headaches in patients.

[0008] Of interest is prior art article entitled “Evaluation of a tapered spinal needle”, published in 1974. This article discloses a tapered needle. This tapered needle comprises three parts, the distal tip, the middle tapered part and the proximal body. The distal tip is 25 G and has a length of 4.76 mm. The middle part is where the needle tapers, from the distal 25 G to the proximal 20 G. This transition is made over 3.18 mm, with a transition angle of approximately 10°.

[0009] A second example of tapered needle is manufactured by Terumo Medical under the name Temena Polymedic. This needle transitions between 27 to 22 G, 28 to 24 G or 29 to 25 G. The transition is made over a minimum of 1 mm, thus reaching a maximal transition angle of 30°.

[0010] The tapered needle suffers from many drawbacks. The most notorious drawback is the lack of any feedback resistance, felt by the operator when the tapered portion penetrates a stiffer ligament or membrane. In other words, there is no feedback resistance if the tapered portion penetrates the dura and increases the size of the puncture, therefore increasing the risk of post-dural puncture headache. [0011] As a matter of fact, it is disclosed in the article published in 1974 that the use of the step type needle (TN) for spinal anesthesia is not recommended due to an increase in post-dural puncture headache.

[0012] In response to the loss of feedback and risk of penetrating the dura with the larger portion of the needle, the obvious modification has been to lengthen the smaller-diameter portion of the needle, as suggested with the Temena Polymedic needle (see [009]).

[0013] This modified model suffers from a new drawback, which is the difficulty to pierce the skin without a prior insertion of an introductory needle. With a longer small diameter, the risk of penetrating the dura with the tapered portion is reduced, but the ability to properly pierce the skin is lost due to an excessively long and too thin needle.

[0014] An additional drawback from this design is that the lengthen smalldiameter portion increases the resistance to CSF flow according to Poiseuille’s law. CSF flow is used to confirm the adequate placement of the needle. By increasing the resistance to CSF flow, the delay before observing CSF flow can be excessive, and the operator might further insert the needle.

[0015] Accordingly, there is a need for a spinal needle that addresses at least some of the above identified drawbacks.

SUMMARY

[0016] It is an object of the present disclosure to provide a spinal needle that is less likely to cause headaches in patients and is also able to be inserted directly through the skin without an introducer needle.

[0017] It is an object of the present disclosure to provide a spinal needle of reduced thickness that does not require an introducer needle.

[0018] It is an object of the present disclosure to provide a spinal needle with a tip having a reduced thickness that reduces the risk of bending during use. [0019] According to a broad aspect, there is disclosed a spinal needle, comprising a first section including a distal tip and a first aperture, the first section having a first diameter less than 23 G, the first section having a length of less than 10 mm; a second section proximal to the first section, the second section having a second diameter that is larger than the first diameter; a sharp transition section between the first section and the second section with a transition angle of at least 40°; and an inner channel connected to the first aperture, the inner channel extending longitudinally through the first section and the second section.

[0020] In accordance with one or more embodiments, the inner channel has a constant third diameter.

[0021] In accordance with one or more embodiments, the inner channel connects the first aperture to a second aperture at a proximal end of the spinal needle.

[0022] In accordance with one or more embodiments, the spinal needle further comprises a connector at the proximal end of the spinal needle, the connector being in fluid communication with the inner channel.

[0023] In accordance with one or more embodiments, the connector is adapted to receive an end of a syringe therein.

[0024] In accordance with one or more embodiments, the connector is a Luer taper.

[0025] In accordance with one or more embodiments, the spinal needle further comprises a third section proximal to the second section, the third section having a fourth diameter larger than the second diameter.

[0026] In accordance with one or more embodiments, a length of the first section is between 2 mm and 10 mm.

[0027] In accordance with one or more embodiments, length of the first section is between 2 mm and 5 mm. [0028] In accordance with one or more embodiments, the length of the first section is between 5 mm and 10 mm.

[0029] In accordance with one or more embodiments, the length of the first section is 10 mm.

[0030] In accordance with one or more embodiments, the length of the first section is 5 mm.

[0031] In accordance with one or more embodiments, the sharp transition section forms an angle with the longitudinal axis of the spinal needle, the angle being between 80° and 90°.

[0032] In accordance with one or more embodiments, the sharp transition section forms an angle with the longitudinal axis of the spinal needle, the angle being about 45°.

[0033] In accordance with one or more embodiments, the spinal needle further comprises an obturator configured to be inserted inside the inner channel so as to block the first aperture and the inner channel.

[0034] According to a broad aspect, there is disclosed a spinal needle comprising a distal portion having a tip and a first aperture; a proximal portion; and an inner channel connected to the first aperture and extending longitudinally through the distal portion and the proximal portion; a thickness of the spinal needle increasing abruptly from the distal portion to the proximal portion so as to define a sharp transition portion between the distal portion and the proximal portion; a thickness of the distal portion being less than 23 G; and a thickness of the proximal portion greater than the thickness of the distal portion; the distal portion having a length of 2 mm to 10 mm.

[0035] In accordance with one or more embodiments, the distal portion has a length of at 5 mm to 10 mm.

[0036] In accordance with one or more embodiments, the distal portion has a length of 10 mm. [0037] In accordance with one or more embodiments, the distal portion has a length of 5 mm.

[0038] In accordance with one or more embodiments, the thickness of the spinal needle increases uniformly from the distal portion to the proximal portion.

[0039] In accordance with one or more embodiments, the spinal needle further comprises a connector at the proximal end of the spinal needle, the connector being in fluid communication with the inner channel.

[0040] In accordance with one or more embodiments, the connector is adapted to receive an end of a syringe therein.

[0041] In accordance with one or more embodiments, the connector is a Luer taper.

[0042] In accordance with one or more embodiments, the sharp transition forms an angle with the longitudinal axis of the spinal needle, the angle being at least 40°.

[0043] In accordance with one or more embodiments, the spinal needle is made of one of steel and titanium.

[0044] It will be appreciated that one or more embodiments of the spinal needle disclosed herein are of great advantage with respect to the prior art.

[0045] More precisely, a first advantage of one or more embodiments of the spinal needle disclosed herein is that a resistance feedback is provided to the operator when the tapered portion of the needle attempts to penetrate a stiff structure, notably the dura, which will prompt the physician to confirm the needle placement prior to further inserting the needle. It will be appreciated that this advantage is derived from the fact that the transition between the smaller and larger gauge portion of the needle is at an angle greater than 40°. [0046] A second advantage of one or more embodiments of the spinal needle disclosed herein is that it can pierce the skin without introductory needle and risk of bending the needle tip due to the skin resistance. It will be appreciated that this advantage is derived from the fact that, by providing higher resistance feedback with a transition angle over 40°, it is possible to rely on other safety mechanism than prolonging the small diameter portion of the needle. Therefore, the small-diameter portion can be shorter, which enables adequate skin piercing without risk of bending.

[0047] A third advantage of one or more embodiments of the spinal needle disclosed herein is that the CSF flow within the spinal needle is increased, enabling a faster identification of the proper placement of the spinal needle. It will be appreciated that this advantage is derived from the fact that a shorter smaller- diameter portion lowers the resistance to CSF flow.

[0048] A fourth advantage of one or more embodiments of the spinal needle disclosed herein is that less material is required to perform the spinal anesthesia. It will be appreciated that this advantage is derived from the fact that the shorter small-diameter portion can adequately pierce the skin, and therefore, that no introductory needle is needed.

[0049] A fifth advantage of one or more embodiments of the spinal needle disclosed herein is that by eliminating the introductory needle, the number of maneuvers (as described in [006]) required to perform a spinal anesthesia is reduced. By reducing the number of maneuvers, the time required to perform the spinal anesthesia is also reduced.

[0050] A sixth advantage of one or more embodiments of the spinal needle disclosed herein is that by eliminating the introductory needle, the risk of inadvertently puncturing the dura with the introductory needle and the associated high risk of post-dural puncture headache due to the large-gauge of the needle, is eliminated. BRIEF DESCRIPTION OF THE FIGURES

[0051] Embodiments of the disclosure will be described by way of examples only with reference to the accompanying drawings, in which:

[0052] Fig. 1 is a schematic cross-section view of a spinal needle in accordance with a first embodiment of the present disclosure;

[0053] Fig. 2 is a schematic cross-section view of a spinal needle in accordance with a second embodiment of the present disclosure;

[0054] Fig. 3 is a schematic cross-section of view of a spinal needle in accordance with a third embodiment of the present disclosure;

[0055] Figs. 4A, 4B and 4C are schematic side and top views of examples of the first section and aperture of the spinal needle; and

[0056] Fig. 5 is a schematic elevation view of a spinal needle in accordance with a fourth embodiment of the present disclosure.

[0057] Similar reference numerals used in different Figures denote similar components.

DETAILED DESCRIPTION

[0058] Generally stated, the non-limitative illustrative embodiments of the present technology provide a spinal needle that can be used for spinal anesthesia or spinal analgesia. The spinal needle generally has a first small diameter section that includes the tip and aperture, and a second larger diameter section. The spinal needle has an inner channel that operates as an injection channel extending longitudinally therethrough, suitable for administering a fluid such as an anesthetic.

[0059] In spinal anesthesia and spinal analgesia, the spinal needle only needs to be inserted a short distance beyond the dural membrane, for example 2-5 mm, and a deeper insertion is discouraged. In addition, only a small amount of anesthetic or other fluid (typically about 1 to 4 cc) needs to be administered. Thus, a thin spinal needle is preferred, to reduce the incidence of post-puncture headaches. A typical choice of spinal needle for spinal anesthesia is 25 G or 27 G. However, as discussed above, a thin spinal needle that can reach the dural membrane, which may be 120 mm long or more, is subject to bending and must be inserted using an introducer.

[0060] In contrast, for a lumbar puncture, a spinal needle must be inserted deeper into the subarachnoid space (typically 10 to 20 mm), in order to observe the pressure of the CSF and potentially remove up to 30 cc of CSF. A spinal needle thinner than 22 G and longer than the 20 mm needed to penetrate the subarachnoid space would require the use of an introducer to avoid bending or otherwise damaging the spinal needle. Thus, a thicker spinal needle such as 22 G is typically preferred, both to avoid the need for an introducer and to allow for a more efficient removal of CSF, thereby improving patient comfort and convenience.

[0061] Both the length and the diameter of a spinal needle contribute to its likelihood of bending. Thus, there is a desire to provide a spinal needle thin enough to be used in spinal anesthesia, and rigid enough to be used without an introducer.

[0062] Now referring to Fig. 1 , there is shown a first embodiment of a spinal needle. The spinal needle 1 consists of a first section 10 at a distal end, having a first diameter less than 23 G, for example between 25 G and 30 G and a second section 20 at a proximal end having a second diameter that is larger than the first diameter, for example 22 G, separated by a sharp transition section 30.

[0063] It will be appreciated that the first section 10 comprises a first aperture 14. [0064] It will be appreciated that the sharp transition section 30 between the first section 10 and the second section 20 has a transition angle of at least 40° relative to the longitudinal axis of the spinal needle 1 . It will be appreciated by the skilled addressee that any suitable diameter may be chosen for the first section 10, and any suitable larger diameter may be chosen for the second section 20.

[0065] Now referring to Fig. 2, there is shown another embodiment of a spinal needle. In this embodiment, the spinal needle T has a sharp transition section 30’ with an angle between about 80° and 90° relative to the longitudinal axis of the spinal needle T.

[0066] Now referring to Fig. 3, there is shown another embodiment of a spinal needle. In this embodiment, the spinal needle 1 ” having a sharp transition section 30” with a convex curved shape.

[0067] It will be appreciated that the shape of the sharp transition section 30 is not limited to the embodiments described and that any other suitable shape or angle may be used as long as the transition section enables an abrupt increase between the first section 10 and the second section 20.

[0068] It will be appreciated that the sharp transition section 30 provides safety benefits for the patient. A typical spinal anesthesia procedure involves the anesthetist only inserting the needle until he can feel it entering the spinal sac, sometimes to a depth of only 1 -2 mm. The sharp transition section 30 abutting against the dural membrane provides an additional tactile feedback to the anesthetist that the tip 12 of the spinal needle 1 has penetrated the spinal sac to a depth equal to the length of the first section 10, which may in some embodiments be 5 or 10 mm. It will be appreciated by the skilled addressee that this additional tactile feedback may advantageously help to prevent the spinal needle 1 from reaching the spinal cord, which is typically located at a depth of about 15mm beyond the dural membrane. [0069] When performing spinal anesthesia or spinal analgesia, the first section 10, which extends from the tip 12 to the sharp transition section 30, at least partially enters the subarachnoid space, making a small hole in the dura mater. Thus, only the small diameter section of the spinal needle 1 (the first section 10) is inserted into the subarachnoid space, forming a smaller size hole than would have been created by using a 22 G spinal needle directly. In one or more embodiments, the first section 10 is less than 10 mm in length. In one or more embodiments, the first section 10 is between 2 mm and 10 mm in length. In one or more embodiments, the first section 10 is between 2 and 5 mm in length. In one or more embodiments, the first section 10 is between 5 and 10 mm in length. In one or more embodiments, the first section 10 is 5 mm in length. In one or more embodiments, the first section 10 is 10 mm in length. It will be appreciated that the length of the first section 10 as described herein is determined from the end of the tip 12 to the beginning of the transition section 30.

[0070] The second section 20, because of its larger diameter, is more rigid than the first section 10. In one or more embodiments, the combination of the short length of the first section 10 and the larger diameter of the second section 20 gives the spinal needle 1 enough stability so that it can be inserted directly, through the skin and the various anatomical structures, until the subarachnoid space is reached, without the aid of an introducer needle. The spinal needle 1 may be inserted up to the point at which the first section 10 barely penetrates the dural membrane and can administer the fluid via injection channel 32, by which point the second section 20 will have penetrated the patient’s skin.

[0071] It will be appreciated that the inner channel or injection channel 32 extends longitudinally through the first section 10 and the second section 20, from the first aperture 14 to the proximal end of the spinal needle 1 . Although the outer diameters of the first 10 and second 20 sections are different; it will be appreciated that in one or more embodiments, the inner diameter, i.e. the diameter of the inner channel or injection channel 32, is the same diameter in both the first section 10 and the second section 20. For example, the inner diameter of the injection channel 32 may be a typical inner diameter for a spinal needle the size of the first section 10 (generally approximately 0.260-0.320 mm for a 25 G needle or, alternatively, 0.210 mm for a 27 G needle). However, the inner diameter of the injection channel 32 may be any suitable size that is appropriate for the outside diameters of the spinal needle 1. Through this injection channel 32, fluids such as anesthetics can be injected (as for spinal anesthesia or spinal analgesia). It will be appreciated that in order to assist in this function, the proximal end of the spinal needle 1 may have a port or connector (not shown in Figs. 1 -3) adapted to receive an end of a syringe therein or any other suitable instrument. In one or more embodiments, the connector is a Luer taper, sometimes known as a Luer lock. It will be appreciated that the connector is in fluid communication with the inner or injection channel 32.

[0072] It will be appreciated that in one or more embodiments an obturator 34 is provided. It will be appreciated that the obturator 34 is configured to be inserted inside the inner or injection channel 32 so as to block the aperture 14 and the inner or injection channel 32. In fact, the obturator 34 is sized to be inserted into the injection channel 32, such that the obturator 34 blocks the aperture 14 and the injection channel 32 within the spinal needle 1 during insertion of the spinal needle 1 through the tissue.

[0073] Now referring to Figs. 4A, 4B and 4C, it will be appreciated that the aperture 14 of the tip 12 of the first section 10 can be of various types, for example Quincke with tip 12a and aperture 14a (see Fig. 4A), Sprotte with tip 12b and aperture 14b (see Fig. 4B) or Whitacre with tip 12c and aperture 14c (see Fig. 4C). It will be appreciated by the skilled addressee that other types of tips and apertures may be used.

[0074] It will be appreciated that the total length of the spinal needle 1 can be of any suitable length, for example 70 mm, 90 mm, 103 mm and 120 mm. It should be understood that the total length of the spinal needle 1 can be of any other length, and that even longer spinal needles may be required for larger patients. [0075] Referring now to Fig. 5, a spinal needle 101 will be described according to an embodiment. It should be understood that the spinal needle 101 is only shown schematically, and that some details such as the tip 112 and the injection channel are not shown for simplicity. These features may be similar to those of the embodiments of Figs. 1 -3.

[0076] The spinal needle 101 has a first section 110 at a distal end thereof, having a first outer diameter which may be smaller than 23 G, for example 25 G or 27 G. The distal end of the first section 110 has a tip and an aperture (not shown), which may be as described above.

[0077] The spinal needle 101 has a second section 120, proximal to the first section 110 that has a larger diameter than the first section 110, for example 22 G.

[0078] The first section 110 and the second section 120 are separated by a sharp transition section 130 which is not shown in detail, and may be any of the shapes described above.

[0079] The spinal needle 101 further comprises a third section 140, proximal to the second section 120, that has a larger diameter than the second section 120, for example 20 G.

[0080] The second section 120 and the third section 140 are separated by a transition section 150 which may be any of the shapes described above for the transition section 130.

[0081] In one or more embodiments, the spinal needle 101 is further provided with a connector 160, shown schematically, such as a Luer taper, preferably provided at the proximal end of the spinal needle 101.

[0082] It will be appreciated that in one or more embodiments, an obturator, not shown, may optionally be provided that is sized to be inserted in the injection channel, not shown. [0083] When performing spinal anesthesia or spinal anesthesia, the first section 110, which extends from tip 112 to the sharp transition section 130, at least partially enters the subarachnoid space, making a small hole in the dura mater. Thus, only the small diameter section of the spinal needle 101 (first section 110) is inserted into the subarachnoid space, forming a smaller size hole than would have been created by using a 22 G spinal needle directly. In one or more embodiments, the first section 110 is less than 10 mm in length. In one or more embodiments, the first section 110 is between 2 mm and 10 mm in length. In one or more embodiments, the first section 110 is between 2 and 5 mm in length. In one or more embodiments, the first section 110 is between 5 and 10 mm in length. In one or more embodiments, the first section 110 is 5 mm in length. In one or more embodiments, the first section 110 is 10 mm in length. The length of the first section 110 as described herein is determined from the end of the tip 112 to the beginning of the transition section 130.

[0084] In one or more embodiments, the second section 120 has a diameter smaller than 22 G, for example the first section 110 has a diameter of 27 G and the second section 120 has a diameter of 25 G. In one or more embodiments, , the second section 120 is between 2 mm and 10 mm in length. In one or more embodiments, the second section 120 is between 2 and 5 mm in length. In one or more embodiments, the second section 120 is between 5 and 10 mm in length. In one or more embodiments, the second section 120 is 5 mm in length. The length of the second section 120 as described herein is determined from the beginning of the transition section 130 to the beginning of the transition section 150.

[0085] The second section 120, because of its larger diameter, is more rigid than the first section 110. The third section 140, because of its larger diameter, is more rigid than the second section 120. In one or more embodiments, the combination of the short length of the first section 110 and the larger diameter of the second section 120 and the third section 140 gives the spinal needle 101 enough stability so that it can be inserted directly, through the skin and the various anatomical structures, until the subarachnoid space is reached, without the aid of an introducer needle. The spinal needle 101 may be inserted up to the point at which the first section 110 barely penetrates the dural membrane and can administer the fluid via the injection channel, by which point the second section 120 and the third section 140 will have penetrated the patient’s skin.

[0086] It will be appreciated that there is therefore also disclosed a spinal needle comprising a distal portion having a tip and a first aperture. The spinal needle also has a proximal portion and an inner channel connected to the first aperture and extending longitudinally through the distal portion and the proximal portion. The thickness of the spinal needle increases abruptly from the distal portion to the proximal portion so as to define a sharp transition portion between the distal portion and the proximal portion. The thickness of the distal portion is less than 23G and the thickness of the proximal portion is greater than the thickness of the distal portion. The distal portion has a length of 2 mm to 10 mm.

[0087] In one or more embodiments, the distal portion has a length of at 5 mm to 10 mm. In one or more embodiments, the distal portion has a length of 10 mm. In one or more embodiments, the distal portion has a length of 5 mm.

[0088] In one or more embodiments, the thickness of the spinal needle increases uniformly from the distal portion to the proximal portion.

[0089] In one or more embodiments, the spinal needle further comprises a connector at the proximal end of the spinal needle, the connector being in fluid communication with the inner channel. In one or more embodiments, the connector is adapted to receive an end of a syringe therein. In one or more embodiments, the connector is a Luer taper.

[0090] In one or more embodiments, the sharp transition forms an angle with the longitudinal axis of the spinal needle, the angle being at least 40°.

[0091] It will be appreciated that one or more embodiments of the spinal needle may be made of various materials. In one or more embodiments, the spinal needle is made of a metal such as steel or titanium, however it will be appreciated by the skilled addressee that other suitable materials or combinations of materials may be used.

[0092] It will be appreciated that one or more embodiments of the connector at the proximal end of the spinal needle may be made of various materials. In one or more embodiments, the connector, if provided, is made of plastic or any other suitable material. It will be appreciated by the skilled addressee that other suitable materials or combinations of materials may be used for the connector.

[0093] In some of the above described embodiments, the distal end of the spinal needle is narrow enough to reduce the risk of post-puncture headaches, and short enough that it can be used for spinal anesthesia or spinal analgesia without the use of an introducer needle when supported by the increased width and rigidity of the proximal portion of the spinal needle.

[0094] It will be appreciated that one or more embodiments of the spinal needle disclosed herein are of great advantage with respect to the prior art.

[0095] A first advantage of one or more embodiments of the spinal needle disclosed herein is that a resistance feedback is provided to the operator when the tapered portion of the needle attempts to penetrate a stiff structure, notably the dura, which will prompt the physician to confirm the needle placement prior to further inserting the needle. It will be appreciated that this advantage is derived from the fact that the transition between the smaller and larger gauge portion of the needle is at an angle greater than 40°.

[0096] A second advantage of one or more embodiments of the spinal needle disclosed herein is that it can pierce the skin without introductory needle and risk of bending the needle tip due to the skin resistance. It will be appreciated that this advantage is derived from the fact that, by providing higher resistance feedback with a transition angle of at least 40°, it is possible to rely on other safety mechanism than prolonging the small diameter portion of the needle. Therefore, the small-diameter portion can be shorter, which enables adequate skin piercing without risk of bending.

[0097] A third advantage of one or more embodiments of the spinal needle disclosed herein is that the CSF flow within the spinal needle is increased, enabling faster identification of the proper placement of the spinal needle. It will be appreciated that this advantage is derived from the fact that a shorter smaller- diameter portion lowers the resistance to CSF flow.

[0098] A fourth advantage of one or more embodiments of the spinal needle disclosed herein is that less material is required to perform the spinal anesthesia. It will be appreciated that this advantage is derived from the fact that the shorter small-diameter portion can adequately pierce the skin, and therefore, that no introductory needle is needed.

[0099] A fifth advantage of one or more embodiments of the spinal needle disclosed herein is that by eliminating the introductory needle, the number of maneuvers required to perform a spinal anesthesia is reduced. By reducing the number of maneuvers, the time required to perform the spinal anesthesia is also reduced.

[00100] A sixth advantage of one or more embodiments of the spinal needle disclosed herein is that by eliminating the introductory needle, the risk of inadvertently puncturing the dura with the introductory needle and the associated high risk of post-dural puncture headache due to the large-gauge of the needle, is eliminated.

[00101] Although the present disclosure has been described with a certain degree of particularity and by way of an illustrative embodiments and examples thereof, it is to be understood that the present disclosure is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope and spirit of the disclosure as hereinafter claimed.

Claims

CLAIMS:

1. A spinal needle, comprising: a first section including a distal tip and a first aperture, the first section having a first diameter less than 23G, the first section having a length of less than 10 mm; a second section proximal to the first section, the second section having a second diameter that is larger than the first diameter; a sharp transition section between the first section and the second section with a transition angle of at least 40°; and an inner channel connected to the first aperture, the inner channel extending longitudinally through the first section and the second section.

2. The spinal needle as claimed in claim 1 , wherein the inner channel has a constant third diameter.

3. The spinal needle as claimed in any one of claims 1 to 2, wherein the inner channel connects the first aperture to a second aperture at a proximal end of the spinal needle.

4. The spinal needle as claimed in claim 3, further comprising a connector at the proximal end of the spinal needle, the connector being in fluid communication with the inner channel.

5. The spinal needle as claimed in claim 4, wherein the connector is adapted to receive an end of a syringe therein.

6. The spinal needle as claimed in claim 4, wherein the connector is a Luer taper.

7. The spinal needle as claimed in any one of claims 1 to 6, further comprising a third section proximal to the second section, the third section having a fourth diameter larger than the second diameter.

8. The spinal needle as claimed in any one of claims 1 to 7, wherein a length of the first section is between 2 mm and 10 mm.

9. The spinal needle as claimed in claim 8, wherein the length of the first section is between 2 mm and 5 mm.

10. The spinal needle as claimed in claim 8, wherein the length of the first section is between 5 mm and 10 mm.

11. The spinal needle as claimed in claim 8, wherein the length of the first section is 10 mm.

12. The spinal needle as claimed in claim 9, wherein the length of the first section is 5 mm.

13. The spinal needle as claimed in any one of claims 1 to 12, wherein the sharp transition section forms an angle with the longitudinal axis of the spinal needle, the angle being between 80° and 90°.

14. The spinal needle as claimed in any one of claims 1 to 12, wherein the sharp transition section forms an angle with the longitudinal axis of the spinal needle, the angle being about 45°.

15. The spinal needle as claimed in any one of claims 1 to 14, further comprising an obturator configured to be inserted inside the inner channel so as to block the first aperture and the inner channel.

16. A spinal needle comprising: a distal portion having a tip and a first aperture; a proximal portion; and an inner channel connected to the first aperture and extending longitudinally through the distal portion and the proximal portion; a thickness of the spinal needle increasing abruptly from the distal portion to the proximal portion so as to define a sharp transition portion between the distal portion and the proximal portion; a thickness of the distal portion being less than 23G; and a thickness of the proximal portion being greater than the thickness of the distal portion; the distal portion having a length of 2 mm to 10 mm.

17. The spinal needle as claimed in claim 16, wherein the distal portion has a length of at 5 mm to 10 mm.

18. The spinal needle as claimed in claim 17, wherein the distal portion has a length of 10 mm.

19. The spinal needle as claimed in claim 17, wherein the distal portion has a length of 5 mm.

20. The spinal needle as claimed in any one of claims 16 to 19, wherein the thickness of the spinal needle increases uniformly from the distal portion to the proximal portion.

21. The spinal needle as claimed in any one of claims 16 to 20, further comprising a connector at the proximal end of the spinal needle, the connector being in fluid communication with the inner channel.

22. The spinal needle as claimed in claim 21 , wherein the connector is adapted to receive an end of a syringe therein.

23. The spinal needle as claimed in claim 21 , wherein the connector is a Luer taper.

24. The spinal needle as claimed in any one of claims 16 to 23, wherein the sharp transition forms an angle with the longitudinal axis of the spinal needle, the angle being at least 40°.

25. The spinal needle as claimed in any one of claims 1 to 3 and 16 to 20, wherein the spinal needle is made of one of steel and titanium.