WO2017138895A1

WO2017138895A1 - Blunt ended echogenic transforaminal cannula

Info

Publication number: WO2017138895A1
Application number: PCT/TR2017/000017
Authority: WO
Inventors: Serbulent Gokhan BEYAZ; Havva SAYHAN
Original assignee: Beyaz Serbulent Gokhan
Priority date: 2016-02-10
Filing date: 2017-02-10
Publication date: 2017-08-17
Also published as: TR201601767A2

Abstract

The invention is a blunt ended echogenic transforaminal cannula and it can be characterized as the presence of injection first outlet hole (4) and injection second outlet hole (5) on the angled end (2), presence of injection first outlet hole (4) and injection second outlet hole (5) on different directions of the angled end (2) surface, presence of injection first outlet hole (4) and injection second outlet hole (5) opposite of each other on the angled end (2) surface, presence of injection first outlet hole (4) and injection second outlet hole (5) opposite and transvers to each other on the angled end (2) surface, presence of injection first outlet hole (4) and injection second outlet hole (5) opposite of each other on the angled end (2) surface and in different distances from the closed cannula end (3), inclusion of a closed cannula end (3), presence of transforaminal needle marking lines with 10 mm intervals on the cannula (1), the closed cannula end (3) (not sharp) has a blunt end structure, the angled end (2) is 168,05° relative to the cannula (1), deformation of the cannula (1) surface with a custom made abrasive called grit, crashing of abrasives in the slurry to the cannula (1) with high speed by means of an assembly that has low amplitude and vibrates in high frequency, abrasion of the metal surface in micron level and application of ultrasonic cleaning thereafter.

Description

Blunt Ended Echogenic Transforaminal Cannula

Field Of The Invention

The invention is related to angles and dual hole cannula (needle) developed for transforaminal epidural steroid injection application that ensures administration of a specific drug into transforaminal epidural zone.

Background Of The Invention

Low back pain is one of the major morbidity reasons and causes serious medical and social-economic problems. It was shown that low back pain complaints of individuals had increased in industrialized societies and 80% of them had suffered from low back pain at least once in their lifetimes Conservative treatments such as moderate bed rest, medication treatment, lifestyle changes, physical treatment and exercising provide benefits for most of the patients suffering low back pain. Only 5-8% of these pains become chronic and surgical treatment may be necessary for 14% of chronic patients. However as complications dependent to surgical treatment continue to emerge, new treatment methods alternative to open surgery have started to be tried recently. As the result of these, transforaminal epidural steroid injection (TFE) that ensures administration of a more specific drug into transforaminal epidural zone has been developed. Transforaminal epidural steroid and local anaesthetic injection are applied accompanied with imaging systems in diagnosis and treatment of neck, arm, low back, leg and pelvis pains emerging as the result of pressure applied on nerves for various reasons. There is a significant increase in the number of transforaminal epidural injection recently all around the world and especially in the USA. Pains of patients showing radiculopathy symptoms can be decreased significantly with minimal invasive procedures. Transforaminal epidural steroid injection is one of the methods that are applied successfully for the treatment of chronic low back pain and it was developed from the idea of application on the nerve canal in the directly affected nerve zone. For example a patient suffering from hernia at right L 4-5 level can be treated by making a direct point shot at L 4-5 "nerve canal". Advantage of this method is that, only desired area is treated since shot is made to a single nerve canal. Adverse effects are seen less frequently since the medication is used in low dose. Since injection is made on directly affected nerve and hernia zone likelihood of getting benefit from the treatment and rate of success is higher. The most common indications of transforaminal epidural injections are disc herniation (bulging, protrusion, extrusion) dependent radiculopathy, foraminal stenosis and epidural fibrosis. Until today, needles for spinal-epidural entry purposes in different gauges, lengths and end shapes have been manufactured. Types of needles used in epidural applications can be classified as sharp end, pencil point and blunt ended (Quincke ended, Whitacre, Sprotte, Atravmatic ended, Pencil point) needles. Mostlu 25, 26, 27G pencil point needles are used but 26, 27, 29, 30, 32G Quincke needles are also used. As it can be seen, needle gauge can be extremely thinned. Since areas of application of epidural needles have increased, it was thought that it would be possible to reduce risk of vascular penetration and paresthesia by using suitably modified different needle designs and sizes. On the other hand there are not many research conducted on the effect of needle type used on reducing potential complications. Animal trials reported that probability of a blunt ended needle to penetrate into blood vessel and bleeding was lower when compared to traditional sharp end needle and it was suggested to use blunt ended need rather than a sharp one for reducing risk in intravascular injections. Sharp ended needle may damage different tissues encountered during advancement in epidural cavity due to its sharp end or may cause temporary (generally slight) or permanent (catastrophic) damage of the structure as the result of leading to mechanical tissue replacements. Therefore use of blunt ended needle seems to be more advantageous. In current art, angled or inclined end needles are started to be produced for allowing easy directing of the needle during its advancement.

In order to avoid intravascular injections, various methods such as use of blunt ended needles instead of short inclined or sharp ones, syringe aspiration, applying anaesthetic dose test, simultaneous Fluoroscopy or injection with digital subtraction angiography (Smuck M, Fuller BJ, Yoder B, Huerta J, Incidence of simultaneous epidural and vascular injection during lumbosacral transforaminal epidural injections; The Spine Journal. 2007; 7:79-82). It was especially indicated that sharp inclined end needles allowed use of smaller gauge and provided directing advantage however they can easily cause vascular and nerve damage. Blunt ended needles do not cause direct nerve and vascular damage since it is hard for them to pass through skin, ligaments and other dense tissues. An angled end has been designed for overcoming directing difficulties (Heavner JE, Racz GB, Jenigiri B, Lehman T, Day MR, Sharp versus blunt needle: a comparative study of penetration of internal structures and bleeding in dogs.; Pain Pract. 2003;3(3):226- 31). It is very difficult to change direction of flat needles in deep tissues. In order to change direction of a flat needle, it is necessary to withdraw it till the tissues close to surface and re-enter. Over angled moves cause bending and deformation of the needle so that it becomes though or impossible to advance in any direction. Extraordinary and recurrent bending may even cause rupturing of needle. In angled needles on the other hand, it is sufficient to rotate the needle around its axis or make slight changes in the needle's direction. On the other hand Sosis MB et all. reported that insufficient spinal anaesthesia had occurred as the result of propagation of some part of the anaesthetic substance outside of the lumbar dura with thickness of 1 mm since the hole on the 24 gauge single hole pencil point spinal needle was large. (Sosis MB, Braverman B, Toppses A. An in vitro evaluation of the new shorter orifice Sprotte spinal needle. Anesth Analg 1994;78:S410) Therefore they modified pencil point spinal needle and reduced hole diameter by 44% and reported that no decrease had happened in BOS flow. There is a single hole on cannulas used for transforaminal epidural method and dual hole system has been applied to epidural cannulas.

Lipov et all. reported in their tests performed by making injection with a spinal needle in bpth lateral and axial direction that, the needle end had deformed in both situations. (Lipov EG, Sosis MB, McCarthy RJ, Ivankovich AD. Does the Design of the Sprotte Spinal Needle Reduce the Force Needed to Deform the Tip?", J. Clin. Anesth., vol. 6, pp.411—13,1994) They determined that lateral and axial force necessary for deforming Sprotte ended needle (22-24 gauge) was less than the force necessary for Whitacre (22-25 gauge) and Quincke (22-25 gauge) needles and that Whitacer and Quincke needled were bended from the connection point whereas the Sprotte needle was bended from the point where holes were located. Lipov et all. concluded that weakness of the Sprotte needle against lateral and axial forces was caused by it structural design. (Lipov vd,. 1994) In our design, holes placed on the needle end are located in a way that they are not reciprocal.

There is a single hole in transforaminal epidural injection cannula available in current art. This makes injection impossible when hole opening coincides to nerve and may even damage it. The invention, which is requested to be registered, has two holes. Therefore when one hole occludes during injections, the operation can be performed easily thanks to other hole. Angular value at the end of the cannula in current art is limited in directing to target tissue. This angle has been increased and thereby directing is facilitated in the invention, which is requested to be registered.

Objective of Invention Purpose of the Invention is to increase rate of success in pain treatment by means of a needle special for certain nerve and nerve root targets for use in transforaminal epidural injection purposes and to consequently ensure patient satisfaction.

Another purpose of the invention is to ensure that transforaminal epidural injection needle easily reaches to target nerve root and injection area.

Another purpose of the invention is to make an application without causing any deformation in any tissue by the needle end during transforaminal epidural injection.

Another purpose of the invention is to prevent occlusion of holes located on the needle end by nerve tissue, fibrotic tissue or any other reason during transforaminal epidural injection. Another purpose of the invention is to ensure that injection is not subject to excessive pressure during transforaminal epidural injection, to reduce, prevent nerve damage in case of any exposure and to ensure a comfortable injection.

Another purpose of the invention is to assure that transforaminal epidural injection needle has high visibility (echogenic) features that are convenient for application accompanied by ultrasonography.

Another purpose of the invention is to ensure advancement of transforaminal epidural injection needle to the application area and observance of drug distribution simultaneously with ultrasound. Therefore use of fluoroscopy can be reduced and exposure to unnecessary radiation to both the operator and the patient can be prevented.

Transforaminal epidural injection needle that has been developed for realizing purposes mentioned above can be transformed into blunt ended with end closure operation. Therefore closed cannula end (3) can be obtained. Upon needle hole drilling operation, injection first outlet hole (4) and injection second outlet hole (5) are opened close (3) to the end. The invention has been brought ultrasound visibility feature. There are transforaminal needle marking lines on the invention. Angled end (2) is 168,05° inclined compared to cannula (1). Injection first outlet hole (4) with diameter of 0,38 mm and and injection second outlet hole (5) placed opposite but transverse to each other are located on the angled end (2)

Description of Figures

Figure - 1 is the general view of the cannula (1).

Figure- 2 is the detailed view of the angled end (2).

Figure- 3 is the sectional view of the angled end (2).

Figure- 4 is the transparent view of the angled end (2).

Figure - 5 is the general view of the cannula (1) and the injector (10).

Figure - 6 is the view of the cannula (1), stiletto plastic (6) and the cannula plastic (7).

Numbers and names of main parts of the invention are given below.

(1) Cannula

(2) Angled end

(3) Closed cannula end

(4) Injection first outlet hole

(5) Injection second outlet hole

(6) Stiletto plastic

(7) Cannula plastic

(8) Hub

(9) Hose

(10) Injector

Detailed Explanation of the Invention

This invention is important in terms of performing injection in transforaminal epidural injection with a needle special for certain nerve and nerve root targets, increasing success rate in pain treatment, ensuring patient satisfaction and reducing costs. Presence of two holes instead of one for the first time in angled needle designed modified for transforaminal epidural injection, being the first transforaminal needle design visible under ultrasonography, reducing exposure to unnecessary radiation to both the operator and the patient thanks to its applicability with USG come to the forefront as basic elements of the invention.

In the invention, needle in sizes suitable for transforaminal needle dimensions is supplied and it is transformed into a blunt needle with end closure operation. Therefore closed cannula end (3) can be obtained. Upon needle hole drilling operation, injection first outlet hole (4) and injection second outlet hole (5) are opened close (3) to the end. The invention has been brought ultrasound visibility feature. There are transforaminal needle marking lines with 10 mm intervals on the cannula (1).

In order to ensure visibility of the needle under USG; deformation of cannula (1) surface is ensured by using a custom made abrasive substance called grit. Abrasion of sensitive parts is performed in small and enclosed systems. Abrasives contained in a slurry are crashed onto the needle cannula (2) with high speed by means of an assembly that has low amplitude and vibrates in high frequency. Metal surface is abraded in micron level. Theni ultrasonic cleaning operation is performed. If no clear image is obtained under USG, surface is deformed again by using a coarser abrasive and ultrasonic cleaning is repeated. The length from the cannula (1) end to the HUB (8) is 165 mm, from the

HUB (8) to starting point of the angled end (2) is 155,5 mm, inner diameter of the needle is 20 Gauge and outer diameter of the needle is 22 Gauge . Closed cannula end (3) (not sharp) has a blunt end structure. Angled end (2) is 168,05° inclined compared to cannula (1). Injection first outlet hole (4) with diameter of 0,38 mm and and injection second outlet hole (5) placed opposite but transverse to each other are located on the angled end (2) Needle tube, in other words the cannula (1) is made of grade 304 stainless steel. During puncture, steel guide wire made of grade 304 stainless steel, conforming to end structure, inner diameter and length of the needle (stiletto) is used for preventing entry of tissues into the cannula (1). Cannula plastic (7) is a transparent, easy to grab and handle plastic hub suitable for LUER locking, located at unsharpened end of the cannula (1) and mounted on the cannula (1). This product is made of transparent ASB raw material. Stiletto plastic (6) is a plastic hub made of ABS plastic, which is located on base of the steel guide wire (stiletto) (6) and mounted on the steel guide wire.

The patient in lad on the operating table in pron position for transforaminal injection. Although it varies depending on the experience of the practitioner, the physician is located in the left side of the operating table and C-arm scopy and USG device is located on the right side of it. Cannula (1) entry point is displayed with C-arm scopy and USG. Then the cannula (1) is advanced to transforaminal epidural area with USG. Meanwhile, both echogenecity of the cannula (1) and efficiency in directing the angled end (2) are evaluated. If bone theme is obtained while advancing the cannula (1), cannula (1) is rotated and tried to be rescued from the bone since angled end (2) of the cannula (1) is inclined. When the cannula (1) is seen to have entered transforaminal epidural cavity, its location is displayed with scopy by administering opaque substance. Meanwhile, exit of the opaque substance from injection first outlet hole (4) and injection second outlet hole (5) and its distribution is observed. In lateral imaging, it is seen that radio opaque substance is seen to have spread to superior and inferior between the pedicle and vertebral bridge. After verifying the location, drug injection is made with USG and its distribution around the nerve root is observed simultaneously. Since closed cannula end (3) is blunt, it can push the nerve root without giving any damage to it. One of the most important aspects of the invention is its visibility under

USG. Thus, synchronous image can be obtained with the guidance of USG and unnecessary radiation exposure can be prevented. Furthermore, due to the anatomic structure at LS/S 1 level, it is seen that angle of the angled end (2) relative to the cannula (1) facilitates directing the needle during the operations Therefore by increasing the angle of the angled end (2) relative to the cannula (1), its directing to the target tissue has been facilitated.

Claims

C L A I M S

A transforaminal epidural steroid injection cannula characterised in that; injection first outlet hole (4) and injection second outlet hole (5) are located on the angled end (2).

A cannula mentioned in claim 1 characterised in that; injection first outlet hole (4) and injection second outlet hole (2) are located in different directions of the angled end (2) surface.

A cannula mentioned in claim 1 characterised in that; injection first outlet hole (4) and injection second outlet hole (2) are located opposite to each other on the angled end (2) surface.

A cannula mentioned in claim 1 characterised in that; injection first outlet hole (4) and injection second outlet hole (2) are located opposite and transvers to each other on the angled end (2) surface.

A cannula mentioned in claim 1 characterised in that; injection first outlet hole (4) and injection second outlet hole (2) are located opposite to each other on the angled end (2) surface and their distances to closed cannula end (3) are different.

A cannula mentioned in claim 1 characterised in that; it contains a closed cannula end (3).

A cannula mentioned in claim 1 characterised in that; there are transforaminal needle marking lines with 10 mm intervals on the cannula (1).

A cannula mentioned in claim 1 characterised in that; the losed cannula end (3) (not sharp) has a blunt end structure

9. A cannula mentioned in claim 1 characterised in that; angled end (2) is 168,05° inclined compared to cannula (1).

10. A cannula mentioned in claim 1 characterised in that; cannula (1) surface is deformed with a custom made abrasive called grit, abrasives contained in a slurry are crashed onto the needle cannula (1) with high speed by means of an assembly that has low amplitude and vibrates in high frequency and ultrasonic cleaning is applied thereafter.