WO2009101539A2

WO2009101539A2 - Percutaneous interspinous distraction device

Info

Publication number: WO2009101539A2
Application number: PCT/IB2009/050202
Authority: WO
Inventors: Gianfranco Bidoia; Alberto Alexandre
Original assignee: Leader Medica S.R.L.; European Neurosurgical Institute Srl
Priority date: 2008-02-12
Filing date: 2009-01-20
Publication date: 2009-08-20
Also published as: WO2009101539A3; ITPD20080042A1

Abstract

A new device for the application of an interspinous distraction device, comprising one or more percutaneous entry cannulae (1), of appropriate dimension and suitable for passage of the various instruments such as (2 - 3 - 7 - 9 -13 -14 -15) and one or more introducer rods (2 - 3) adapted at the outset or adaptable elastically to said cannula/cannulae slightly longer than the same and terminating in a preferably ogival tip (4), from sharp, for example, to three-quarters (6C), or in other shapes which are suitable for the purpose of passing or favouring the passage through human tissue.

Description

PERCUTANEOUS INTERSPINOUS DISTRACTION DEVICE

The human spinal column is an organ which, due to its extreme complexity and the workload it is required to withstand, for example, situations of stress, age, occupation, physical environment, traumatic and/or pathological situations, can be subject to various pathologies, ranging from ordinary to serious, of a temporary or chronic nature.

In many of these pathologies surgery can be performed, both for correction by removal of tissue (in the case of slipped discs, for example) and by the contribution and/or insertion of external elements. In some cases surgery is performed with the insertion of homologous bone tissue, in other cases with bone tissue of other origin, also animal, previously treated in order to avoid as far as possible problems of rejection. In other cases, which are the majority, surgery is performed with artificial elements of various origin, for example of synthetic origin, the latter being reabsorbable or non-reabsorbable, or of mineral origin, for example, but not exclusively, titanium, stainless steel, various types of metal alloys, all having the necessary characteristic of biocompatibility and non-toxicity.

In surgery of the spinal column, two fundamental systems can be distinguished in the current state of the art:

A) the first system is the traditional system also called "open", technique, indicating that the parts to be treated can be directly seen from the outside. This system begins with a fairly large artificial opening made by cutting through the various outer tissues until the area to be treated is reached; this opening is obtained by artificial mechanical means, scalpels and/or other cutting instruments, and is kept open by other artificial means of various types, such as dilators and/or retractors or other systems dedicated to this function, in any case all systems that originate outside the human body. With this system, the operating instruments, in the required number, directly reach the parts to be treated without having to follow particular channels which substantially limit their use, dimension, form and any other parameter necessary for the purpose.

B) The second system is that of laparoscopic or minimally invasive surgery, cloned from traditional thoracic/abdominal surgery, performed by introducing special cannulae (trocars), normally with round section, percutaneously through the various tissues near the spinal column until reaching the part to be treated. Since the external cutaneous tissue cannot be seen directly, it is displayed externally by electronic systems such as the miniaturised TV cameras and internal lighting systems which normally enter the above-mentioned cannulae and project the image on external monitors. The surgical instruments for performing the various operations required during and through to completion of surgery are inserted via said entry channels. The choice of said instruments obviously depends on the number, form and dimension of the artificial access paths. The advantages of this technique are: greater surgical precision as the area involved in the operation is highlighted better and more accurately due to the fact that the images are transferred to a monitor which amplifies them without loss of precision; on the contrary, it increases precision and also highlights the various tissues more effectively; the area involved is affected very little by the surgery, consequently bleeding is reduced with rapid functional recovery and limited scarring; less pain than that caused by a large incision; faster recovery of patient functions and return to everyday living.

On the other hand, the disadvantages are: greater specialisation is required, loss of tactile contact with certain areas, replaced only by greater visibility, higher costs of the equipment and greater deterioration thereof, dimensional limits of the equipment, since they have to pass through rigid tubes, reduced mobility of the instruments which can only follow predefined paths.

In our specific case, and more precisely when one vertebra has to be moved away from another and said position has to be maintained, permanently or almost, the market currently offers various solutions, all requiring open surgery.

This is due mainly to the fact that the space that has to be obtained to perform and maintain this "divarication" varies, albeit within a limited range, in the order of a hypothetical initial thickness of 8 mm up to a thickness approximately 40-50% greater than said initial size, a smaller space or size being deemed, in surgical terms, not strictly necessary and not envisaged. Therefore interspinous retractor devices exist, hereinafter called distraction devices, measuring 8 mm, 9 mm, 10 mm, 11 mm and up to even 12 mm, rarely 13 mm.

This means that currently the only type of procedure possible for the interspinous insertion of spacers is open surgery since currently no cannula systems exist that can be dilated to permit the passage of distraction devices with varying sizes.

A further problem consists in the fact that the distraction devices currently marketed have fixed sizes, normally in steps of one millimetre, without the possibility of obtaining all the intermediate sizes, which are very useful in numerous cases in which said intermediate sizes are necessary, or at least useful, for improving the surgical result.

To help solve the above-mentioned problems, a new interspinous distraction device has been studied having the following objectives: the possibility of using it in laparoscopic or minimally invasive surgery, percutaneously, both directly on the part to be treated and/or laterally, i.e. starting from areas or zones near those to be treated, thus reducing the subsequent postoperative trauma; use it as a distraction device that adapts to the majority of needs, since it can expand from an initial size at least, but not limited, to the additional percentage as previously highlighted, without having to change the system described previously; - provide a distraction device, the expansion of which comprises all those intermediate sizes that may be necessary; provide a distraction device which in the event of breakage can be easily re-set to its initial dimension, thus maintaining or preserving a sufficient expansion; - provide a distraction device which can be used according to the surgical techniques and systems known in the state of the art.

Description of the device

The new device is illustrated in its main parts in the accompanying drawings.

Table 1 shows the device with ogival head; with cutting head; with video camera and light source.

Table 2 shows a further solution with cutting head.

Table 3 shows the device with working heads, with expander measurer.

Table 4 shows the device with expandable interspinous distraction device and related details.

Table 5 shows in detail the expandable interspinous distraction device. The new device that can be used in laparoscopic or minimally invasive surgery comprises in its essential parts: one or more percutaneous entry cannulae (1), of appropriate size and suitable for the passage of the various instruments (2 - 3 - 7 - 9 - 13 - 14 - 15 ) for achieving the object of the invention; one or more guide cannulae (1) of appropriate diameter, either of the disposable or re-usable type, made of materials suitable for medical use, of preferably curved form, but acceptable also in other forms, for example straight, which can reach the area to be treated; one or more introducer rods (2 - 3) adapted at the outset or adaptable elastically to the cannula/cannulae as per the preceding point, slightly longer than the same and terminating in a preferably ogival tip (4), from sharp, for example, to three-quarters (6C), or in other shapes which are suitable for the purpose of passing or favouring the passage through human tissue and where said introducer rods are suitable for supporting, controlling and positioning an expandable interspinous distraction device. The tip of the introducer rod which, as said, is preferably ogival, can have, preferably sliding and/or retracting inside it, a sharp tip or a cutting blade (5) or any other shape suitable for cutting and/or perforating more easily, for example, fibrous or tougher tissue such as scar tissue, once it is pushed out of its seat inside the introducer rod (6b), said seat having the function of preventing said end causing undesired lesions. In the same way, one single specific introducer rod can have said type of end, but of the fixed and not sliding type (4 - 6C).

One or more of these introducer rods can be provided at their end (9) with a system for measuring the interspinous space, in which the distraction device is then inserted. This system can be preferably, but not only, of the "pantograph" type with a reading system outside the guide cannula (19), which can be correlated, among other possibilities, with rotation of the expansion system of the measuring device (9). Said measuring device, once it has performed its function, can be returned to its original dimension so that it can be extracted from and through the guide cannula (1). One or more of these introducer rods can be fitted at their end with an interspinous distraction device of the expandable type (10 - 11). The expansion of said distraction device (10 - 11) can be performed preferably mechanically, but also pneumatically or in any other way deemed suitable for the purpose. Said expansion can be obtained by passing directly through the guide cannula (1) with the introducer rod (7). Said expandable interspinous distraction device will have a system for fitting (e.g.: 12) to the end part of the introducer rod (7) and detaching from it as required by the operator once the necessary expansion has been obtained.

Said distraction device can also be controlled after its introduction into the interspinous cavity, if and where it is clinically necessary to reduce or increase its dimension, as required by the operator. The above-mentioned distraction device can for example have a "pantograph" (11) or "double wedge" (10) form, although it is not limited to these configurations. In any case, it must be able to modify one or more of its dimensions, as required, and maintain them once one of these dimensions has been reached.

Various elements, fixed or movable (20 - 21), can be provided on and connected to the distraction device, suitable for ensuring that said distraction device maintains the required interspinous position, whether lateral and/or antero-posterior. Other elements that can pass through the guide cannula/cannulae during surgery could be, among others, optical elements, with or without lighting (13), for connection to video systems in order to transfer the image of the internal part to the outside, instruments (14) suitable for cutting, pushing, scraping or any other surgical function necessary for obtaining a cavity or freeing a cavity from foreign elements or elements not necessary or deemed as such by the operator.

Said elements, wholly or partly, can be disposable or re-usable and made of materials that comply with the technical and product specifications intended for said purpose.

At the end of the description of the basic composition of the present device, it can therefore be affirmed that the same complies with and achieves the set objectives, eliminating many of the problems now existing with the current systems and offering wholly or at least partly the advantages cited and highlighted above.

Therefore with reference to the preceding description and the accompanying drawings the following claims are made.

Claims

1. Device for the application of an interspinous distraction device characterised in that it comprises: one or more cutaneous entry cannulae (1), of appropriate size and suitable for passage of the various instruments such as (2 - 3

_ 7 _ 9 _ 13 _ 14 _ 15) one or more introducer rods (2 - 3) adapted at the outset or adaptable elastically to said cannula/cannulae, slightly longer than the same and terminating in a tip which is preferably ogival (4), from sharp, for example, to three-quarters (6C), or in other shapes which are suitable for the purpose of passing or favouring passage through the human tissue.

2. Device for application of an interspinous distraction device, according to claim 1 , characterised in that it comprises introducer rods adapted at the outset or adaptable elastically to said cannula/cannulae, slightly longer than the same and comprising devices suitable for supporting, controlling and positioning an interspinous distraction device, and wherein said guide cannulae (1), of appropriate diameter, are wholly or partly curved and/or wholly or partly straight.

3. Device for application of an interspinous distraction device according to claim 1 , characterised in that it is of the disposable type and suitable for the passage of surgical and/or optical devices.

4. Application device according to claims 1, 2, 3, characterised in that it comprises one or more cannulae (1), one or more introducer rods (4 - 5 - 7) passing inside said cannulae (1) and wherein said introducer rods can have a movable internal system (6) or fixed external system (4 - 6c) for cutting and/or perforating tough and/or scar tissue.

5. Application device according to claims 1 , 2, 3, 4, characterised in that said introducer rods are suitable for supporting at their terminal end a system (9) that can be controlled from the outside (19) for measuring the internal interspinous cavity.

6. Application device according to claims 1, 2, characterised in that said cannulae and/or said introducer rods are suitable for supporting at their terminal end a distraction device (10 - 11) suitable for being expanded, by means of a regulation device (15) and mechanical systems or head (12), and left in situ.

7. Interspinous distraction device (10 - 11) characterised in that it is suitable for being positioned on mechanical systems (12) and being inserted with said application device (7) for reaching the areas to be treated percutaneously via at least one of said guide cannulae (1), preferably curved.

8. Interspinous distraction device (10 - 11) according to the preceding claim, suitable for being expanded from an initial size (10A) to subsequent sizes (10B) and able to maintain the size obtained by means of regulation device (15) and head (12).

9. lnterspinous distraction device according to the preceding claims, with form that can be expanded by mechanical systems (12) from the outside (15+18) and/or by other systems, and wherein said form can be a pantograph (11) or double wedge (10) in any case suitable for being expanded by said mechanical systems (12) from the outside (15+18) and/or by said other systems.

10. Distraction device according to the preceding claims which is able to maintain at least its initial dimension (10A) in the event of breakage or malfunctioning subsequent to the insertion thereof.

11. Distraction device according to the preceding claims, characterised in that it is provided with systems for blocking (20 - 21) and positioning in the insertion area.