WO1992005742A1

WO1992005742A1 - Ancillary material for percutaneous dissectomy in the treatment of slipped discs

Info

Publication number: WO1992005742A1
Application number: PCT/FR1991/000765
Authority: WO
Inventors: Pierre-Louis Peyrou; Georges Comte
Original assignee: Peyrou Pierre Louis; Georges Comte
Priority date: 1990-09-28
Filing date: 1991-09-30
Publication date: 1992-04-16
Also published as: FR2667238A1; CA2092813A1; AU8659791A; EP0550686A1

Abstract

The present invention relates to an ancillary material for percutaneous dissectomy in the treatment of slipped discs comprising essentially a needle (1) tracing the operation path, at least one coaxial tube (2) sliding on said needle for widening the path, a guiding tube (4) which is adjusted by sliding on said coaxial tube set in place and of which one extremity is provided with a reinforcement (5) allowing a removable handle (7) to be fitted, a trephine (18) insertable by means of a guiding and driving member into said guiding tube so that, by rotation, a hole is drilled through the vertebral ligament and the slipped disc, and finally a rincing-suction probe cooperating with the guiding tube for sucking pathological disc materials and, conveniently, the instillation of antibiotics, characterized in that the guiding and driving member for the trephine is flexible, said trephine which is machined or set in at the extremity of the distal part of the flexible member is also provided with an internal helical ramp (22a) for extracting cut materials.

Description

ANCILLARY PERCUTANEOUS DISCECTOMY MATERIAL IN THE TREATMENT OF DISCAL HERNIA.

The present invention relates to a set of ancillary instruments allowing percutaneous disc excision "more particularly intended for the treatment of disc sciatica.

For ten years, percutaneous disc excision has been an alternative to conventional surgical treatment in the treatment of rebellious disc sciatica to medical treatments previously treated with traditional surgery. It is known that such surgery presents all the risks of major surgery (general anesthesia, patient in ventral or lateral decubitus ...) because it is normally carried out by the intracanal route, that is to say by the vertebral canal, which runs the risk of injury to the nerve roots traveling through this canal and which constitute the termination of the spinal cord; moreover, even if the intervention succeeds perfectly, there is still a risk of postoperative fibrosis, relatively frequent, making reappear pains whose treatment is almost impossible.

The goal sought by percutaneous discectomy, in addition to the excision of pathological disc material consisting of fragmented and dissociated nucleus, is to obtain, by drilling a pertuis through the lateral vertebral ligament and the disc, a lasting decrease in intra pressures -discales and through it a decrease in the compression of the sciatic root.

Two major groups of ancillary equipment are known, corresponding in fact to two very different techniques, namely manual percutaneous discectomy and automated percutaneous discectomy: - manual percutaneous discectomy uses a cannula of variable diameter from 4 to 8 mm depending on the case, which is introduced through the lateral ligament and the annulus. We then introduce a long clamp allowing the removal of the desired disc material.

The drawbacks of such a manual percutaneous discectomy technique is that it requires relatively large fenestration in the fibrous ring, so that when the forceps pass through the cannula which produced the fenestration, disc material is often pushed back into the disc from which it can hardly be removed. This sometimes leads to hyper-pressure which can trigger a violent sciatica attack on the side of the hernia or even on the opposite side until then unharmed. In addition, in the event of too advanced introduction of the drilling tool, it can exceed the anterior part of the vertebra and penetrate through the vascular elements (aorta and vena cava or vascular elements arising from their bifurcation), causing serious bleeding complications.

On the other hand, the equipment used is of the straight type, in principle only allowing to aim at the center of the disc so that it passes almost obligatorily from the herniated area without any possibility of evacuation of the area. herniated itself. Finally, among the disadvantages, the most serious of them is that the right material used in such a technique does not allow reaching the inter-vertebral disc L5-S1 in at least 20% of the cases, even though herniated discs are frequently located there; moreover, the anatomical type of certain spine comprising an upper iliac crest and an oblique disc at the bottom and in front gives no possibility of reaching the disc with a straight material.

- the automated percutaneous discectomy consists in introducing a relatively flexible small diameter probe (about 2.8 mm), comprising an alternately cutting and suction side window which is actuated up to 180 times per minute by means of a system compressed air.

Here again, the disadvantage of nucleotomy automated is not to allow drilling a hole of sufficient diameter (greater than 2.8 mm); However, the resulting windowing appears to many practitioners as largely insufficient to decompress the disc. Another disadvantage is to risk a rapid sealing of the window by scarring. Similarly, the risk of intra-disc hyperpressure during the passage of the aspiration cannula exists as with the straight drilling tool mentioned above. Finally, the exam is quite long, 30 to 45 minutes on average, and the equipment used is for single use, which also requires an outdoor suction console. On the other hand, the probe used which has the shape of a curved cannula allows a much easier approach to the L5-S1 disc and there is little or no risk of damaging the pre-vertebral vessels.

The aim of the present invention is to remedy all of these drawbacks by proposing ancillary equipment for percutaneous discectomy in the treatment of disc sciatica by decompression of disc hernias and removal of pathological disc materials, essentially comprising:

- a needle tracing the route of intervention,

- a set of coaxial interlocking tubes enτ sliding on said needle to widen the intervention path,

- a last guide tube, which is adapted by sliding on the last tube previously put in place, and which has a sharp end for precutting the vertebral ligament,

- a toothed trephine which can be introduced by means of a flexible guide and drive member into said guide tube, so that, by rotation, a hole is drilled through the vertebral ligament and the disc with hernia,

- optionally a conventional forceps which can then be introduced into said guide tube ending the excision of the disc fragments located at a distance from the pertuis drilled by the trephine,

- finally, a rinsing-aspiration probe which can be introduced into said guide tube for the aspiration of the remaining pathological disc materials and, the instillation of antibiotics at the end of the intervention to combat the risk of infection.

According to a fundamental characteristic of the invention, the ancillary material, in accordance with the detailed description which follows, usually of the straight type following the conventional execution of the manual discectomy material, is advantageously of the curved type, that is to say that all needles, coaxial tubes, guide tube clamp and material ^• rinsing all have an identical curvature, preferably according to a circular arc having the same radius as a direct result of the way of retaining surgical access and general anatomy ; the drilling member, made up as we have seen of a toothed trephine, is machined or attached at the end of the distal part of a hose whose proximal part is embedded in a knurled part facilitating the rotational movements and in translation of said trephine.

A second essential characteristic of the ancillary material according to the invention is that the internal face of at least the terminal part of the distal end or of the hose carrying the trephine is provided with a helical ramp whose relief of the threads ensures the extraction of the disc material as the teeth of the trephine penetrate, during its rotational movement in a positive direction, in the manner of a worm.

The advantages of the ancillary equipment according to the invention are mainly the following:

- absence of risk of additional intra-disc hyperpressure due to the internal helix of the trephine.

Indeed, the pellet constituting the lateral vertebral ligament as well as the annulus and nucleus core are extracted by winding around said terminal propeller of the trephine during its rotational movement. The passage of the forceps, after the drilling of the hole by the trephine, inside the guide tube, which is left in place during all the intervention, therefore no longer risks repressing the disc material inside the disc as is often the case with the usual trephines without internal propeller.

- We have already seen that the classical right ancillary material fails to approach the L5-S1 disc in at least 20% of the cases, taking into account the morphology of the patients; however, the curved material according to the invention makes it possible to approach the disc L5-S1 in all cases. Indeed, the trephine travels in the curved guide tube exactly as if it were rectilinear and makes it possible to remove the decompression core in excellent conditions.

- The curved ancillary material, in accordance with the invention, even if it is accidentally pushed too far, which is unfortunately a real possibility, can only go to get lost in the lateral-vertebral muscle masses ultimately creating only minor lesions compared to what can be the lesion of a pre-vertebral vessel on the trajectory of a right cannula.

- Ancillary equipment, in accordance with the invention, allows a direct approach to the pathological area. This is particularly advantageous because for the herniated disc to be at the origin of sciatica by radicular compression this must be posterior, posterolateral or foraminal (at the passage of the root in the conjugation hole); however, the right ancillary material allows, at best, only the central-disc approach. Conversely, the curved trephine according to the invention makes it possible, by an approach opposite to the hernial zone, to take the carrot at the location of the hernia. - It is also possible with the equipment according to the invention to perform a suction-rinse and an instillation of antibiotics. We have noticed the frequency of post-operative infections in Percutaneous discectomies resulting from the fact that the disc is an area with little or no vascularity and therefore cannot defend itself against infections. However, the equipment proposed according to the invention comprises a rinsing-aspiration probe with physiological serum containing antibiotics, with the fortunate consequence of almost eliminating the risk of local infection.

- A percutaneous discectomy performed using ancillary equipment according to the invention does not require any equipment external to the patient (contrary to what has been seen in the techniques of automated percutaneous discectomy); this facilitates the operative gesture and consequently decreases the handling times and therefore minimizes the septic risk. Other advantages will emerge more clearly from the description which follows, given below by way of a preferred although non-limiting example, of ancillary equipment in accordance with the invention with reference to the appended drawings in which: - Figure 1 represents a needle, in front view, entering the ancillary equipment according to the invention making it possible to trace the route of intervention.

- Figure 2 schematically shows an example of curved coaxial tubes according to the invention allowing widening of the intervention path by successive sliding sockets.

- Figure 3 is a light perspective view of a guide tube with its gripping instrument according to the invention. - Figures 4 show views of the trephine and its guide and drive device according to the invention (Figure 4a) and a partial sectional view of the end of the trephine provided with its helical ramp (Figure 4b ). - Figure 5 is a schematic view of the probe for irrigation and rinsing in accordance with the ancillary equipment of the invention.

As an illustration of ancillary equipment according to the invention intended to perform percutaneous discectomies, the variant with curved cannulas will be described below with reference to all of the figures.

Ancillary equipment conforming to this variant first comprises a curved needle 1 in the shape of an arc of a circle whose radius R is equal to 412 mm. With a diameter of 3 mm and a length of 250 mm, the needle 1 is made of stainless steel, for example 304L stainless steel. We have seen that the needle 1 is intended to trace the intervention route on the patient who is for this occasion in prone position on a table transparent to X-rays. The tip of the needle 1 is introduced at a skin point d entry located about 4 cm from the midline flush with the iliac crest, so that the tip of said needle 1 arrives inside the disc in the immediate vicinity of the herniated disc that is to be absorbed. It will also be noted that the advance position of the needle 1 is constantly checked by a face and profile image intensifier. From the correct position of the needle 1, a first mandrel 2 is threaded onto the needle 1 and guided by sliding until the entry of the disc to be treated. In accordance with FIG. 2, the mandrel 2 consists of an “n” tube with an internal diameter slightly greater than the diameter of the needle 1 and its general shape is identical to the shape of the needle 1. The mandrel 2 of a length 180 mm therefore has a radius of curvature R equal to 412 mm and is preferably made of 304L stainless steel. Several mandrels or coaxial tubes 3, similar to the mandrel 2, can be successively fitted into each other in order to gradually widen the intervention path. Each tube 3 is such that its curvature is identical to the previous tube and its internal diameter is barely greater than the external diameter of the preceding tube so as to slide just on the latter. The length of the successive tubes decreases as the diameter of the intervention path increases. All tubes 3 are also produced in the same material, preferably 304L stainless steel.

In accordance with FIG. 3, a last tube is then introduced, hereinafter called "guide tube" 4, the general curvature of which is identical to the previous coaxial tubes 2, 3 on which it just fits by sliding. The guide tube 4 with a length of 140 mm and an internal diameter of 5.15 mm for an external diameter of 6 mm has a reinforcement 5 constituted by a stainless steel crown in the center of which the end is embedded of the tube 4. This reinforcement 5, the diameter of which is approximately 14 mm and the thickness of 8 mm, will fit into a housing 6 provided for this purpose in the distal part of the handle 7 of the ancillary material according to 1 ' invention (Figure 3).

A diametrical boss 8 protrudes from the outer face of the reinforcement piece 5 at the end of the guide tube 4 in accordance with the perspective view shown in FIG. 3. This boss 8 serves in fact as a polarizing member to prevent any untimely rotation of the assembly between the guide tube 4 and the handle 7; in fact, the boss 8 has a sufficient relief to fit into a longitudinal slot 9 provided for this purpose in the middle part of the handle 7. It will be noted in this regard that the slot 9 comes opposite a first slot 10 in the distal part of the handle 7 intended to receive the guide tube 4 during the fitting of the reinforcement piece 5 into the housing 6 of the handle 7.

The handle 7, in accordance with FIG. 3, in addition to its distal part making it possible to receive and embed the guide tube 4, comprises in its proximal region a metallic mass 11 well suited to gripping the tool constituted by the handle 7 and the guide tube 4, the distal part 12 of which is sharp so as to become embedded in the lateral vertebral ligament in order to cut there a positioning patch for said tube 4. In accordance with FIG. 4, an assembly 13 is shown allowing the drilling a hole in the intervertebral disc to be treated from the positioning performed as it was said just before.

This assembly 13 consists in its central part of a guiding and driving member 14, cylindrical and flexible, over a length of about 155 mm, produced from a ribbon of constant thickness equal to 0.8 mm and of width equal to 5.1 mm made of stainless steel wound flat on a tool of shape following a propeller 10 with contiguous turns 15 of constant cross section of diameter 5.6 mm, following a pitch to the left equal to 10 mm. It will be observed that the pitch of 10 mm from the helix of the flexible member 14 has only a very small importance on the general functioning of the instrument insofar as it is only decisive for the flexibility of the 'organ 14; on the other hand, the material constituting the spiral ribbon has been carefully chosen since it must simultaneously guarantee qualities of total sanitization, good mechanical strength and exceptional quality, of elasticity to allow the assembly 13 to function in any position including bent when driven inside the guide tube 4.

Under these conditions and although any other material, even non-metallic, having the same essential characteristics cannot be excluded, stainless steel type 304 was used for the production, not only of the flexible member 14, but also of the entire instrument as will now be described with reference to Figures 4a. and 4b_: - the distal end of the flexible member 14 consists of a cylinder 16 of height equal to 17 mm, of external diameter substantially equal to that of the flexible member 14 to which it is secured, for example, by welding; the cylinder 16 which has an internal diameter identical to that of the member 14 with which it cooperates to form a continuous channel, is conventionally machined, in its terminal part, over its entire thickness to form a set of six teeth 17 of which the part cutting edge 17a is collinear with the longitudinal axis of the cylinder 16 and extends over a height close to 1.5 πim.

The trephine 18 thus obtained is such that all of these teeth 17 operate in the manner of a band saw whose motor torque is provided by the flexible member 14 working, in this case, all its turns 15 in contact . The other end 19 of the flexible member 14 is embedded inside a cylindrical proximal part 20 comprising a longitudinal knurling to facilitate the rotational drive of the flexible member 14 and thereby the rotation of the trephine 18. It will also be noted that the proximal cylindrical part 20 is itself axially hollowed out so as to extend the central channel intended to facilitate the extraction of the materials cut by the trephine 18 and rising inside the organ. flexible 14 by means of a suction, for example mechanized, connected at the outlet of the proximal part 20 by a standard nozzle 21. It is clear that the assembly 13, as just described, can operate indifferently along a rectilinear or curved cutting axis by means of its spiral drive member 14.

In accordance with FIG. 4b_ and according to the essential characteristic of the invention, it is fixed for example by welding on the internal face 16a. from the cylinder 16, attached to the end of the flexible member 14, a stainless steel wire 22 with a diameter equal to 0.36 so that it constitutes a helical ramp 22a. with a pitch of 2 mm in the same direction as the pitch of the propeller 10 of the member 14. The helical ramp 22a. originates at the base of the teeth 17 of the trephine 18 so as to entrain the materials cut by said trephine 18 towards the inside of the cylinder 16 for the purpose of their final extraction.

Naturally, the helical ramp 22a. extending over the entire internal surface 16a. of cylinder 16, could be obtained in any other way, for example, by machining in the mass of said cylinder 16 whose original thickness would have been provided accordingly.

Likewise, a person skilled in the art would no doubt be able, more costly, to machine the distal part of the flexible member 14 directly to form the teeth 17 of the trephine 18, by fitting inside said distal part. a helical ramp 22a., for example, by adding material or any means known to the same person skilled in the art.

The percutaneous discectomy equipment according to the invention finally comprises an irrigation-aspiration probe 23 allowing rinsing of the area treated with physiological serum advantageously containing antibiotics.

In accordance with FIG. 5 representing the probe 23, this essentially comprises a bent tube 24 of the same radius of curvature R as the guide tube 4 inside which it can be installed insofar as its outside diameter does not exceed 1.4 mm. The tube 24 is itself secured to a cylindrical base 25 from which it emerges to be connected to an external irrigation system by a standard nozzle 26.

The cylindrical base 25 has an axial bore 27 open on the side of the tube 24 which extends outwards substantially from the center of the same bore 27. A central channel 28, made axially in the cylindrical base 25, puts the bore 27 with the outside through an orifice 29 capable of being connected to a source of irrigation by a standardized nozzle.

The bore 27 is provided in such a way that the proximal reinforcement 5 of the guide tube 4 can come into it exactly after total penetration of the tube 24 inside said guide tube 4, making the irrigation probe 23 integral -suction with the same guide tube 4; this latter tube 4 then functions as a return channel by aspiration from a standardized tip 29, from an irrigation of physiological saline advantageously supplemented with antibiotics, instilled by the tube 24 from its tip 26. This last rinsing-aspiration operation being completed, the assembly is removed and the patient's skin closed with a skin point.

It is obvious that any variant concerning an instrument forming the ancillary material in accordance with the invention obtained by minor modifications, in particular as regards the non-functional shapes or the size of the instruments which have just been described, would not go beyond the present invention.

Claims

1 - Ancillary equipment for percutaneous discectomy in particular for the treatment of herniated discs comprising a trephine (18) which can be manipulated by means of a guide and drive member (14) so that by rotation, drilling is carried out. '' a leak through the vertebral ligament and the disc presenting the hernia, characterized in that the guide and drive member (14) of the trephine (18) is flexible, said trephine (18) being machined or attached at the end of the distal part of said flexible member (14), the proximal part (19) of which is advantageously embedded in a preferably knurled part (20) facilitating the rotational and translational movements of said trephine (18).

2 - Ancillary equipment according to claim 1, characterized in that the flexible member (14) of the trephine (18) is designed to adapt to the curvature of fixed guide instruments (1, 2, 3, 4) . 3 - Ancillary equipment according to the preceding claim, characterized in that the curvature of the fixed guide instruments (1,2,3,4) is an arc of a radius R, depending on the surgical access route. 4 - ancillary equipment according to claim 3, characterized in that the flexible member (14) of the trephine (18) is made from a ribbon of elastic material of constant thickness, wound flat according to a spiral helix contiguous (15) of constant cross section following a step to the left so that each turn (15) comes into positive contact with neighboring turns when the trephine (18) requires engine torque.

5 - ancillary equipment according to one of claims 1 to 4, characterized in that the internal face of at least the terminal part of the distal end of the flexible member (14) of the trephine (18) is provided with '' a helical ramp (22) whose pitch and relief of the threads are such that they ensure the extraction of the disc material as the teeth (17) of the trephine (18) penetrate.

6 - ancillary equipment according to any one of claims 1 to 4, characterized in that the trephine (18) is machined at one of the ends of a cylinder (16), secured to the flexible member (14) by its other end, said cylinder (16) having an internal diameter advantageously identical to that of said flexible member (14) with which it cooperates to form a continuous channel.

7 - ancillary equipment according to the preceding claim, characterized in that the cylinder (16) is provided on its internal face (16a.) With a helical ramp (22a.) Originating at the base of the teeth (17) and the relief and pitch of the threads (22) are such that they extract the material cut by the teeth (17) from the trephine (18) inside the flexible member (14). 8 - ancillary equipment according to the preceding claim, characterized in that the helical ramp (22a.) Is made from a stainless steel wire (22) fixed, for example by welding, on the internal face (16a.) Of the cylinder (16). 9 - Ancillary equipment according to any one of the preceding claims, characterized in that the proximal part (20) of the cylindrical flexible member (14) of the trephine (18) is axially hollowed out to ensure, thanks to a nozzle (21 ), a complementary suction of the disc material extracted by the work of the trephine (18), going up through the flexible member (14).

10 - Ancillary equipment according to any one of the preceding claims, characterized in that the flexible member (14) of the trephine (18) is made of stainless steel, preferably of stainless steel 304 having simultaneously good elastic qualities and mechanical strength .