DEVICE FOR SECURING A CRANIAL LIMB TO THE CRANIAL TOP AND FOR SIMULTANEOUSLY CLOSING CRANIOTOMY HOLES, AND PROCESS FOR USING IT

The present invention refers to a device, preferably made of biocompatible plastic elastic material, for securing a cranial limb and for simultaneously closing holes obtained for performing the craniotomy. The present invention further refers to a process for using such device.

As known, the craniotomy, namely the incision and cutting of a bone limb of the cranial top, is the compulsory neuro-surgical procedure for treating any intra-cranial lesion.

The bone limb is obtained by cutting one or more drill holes, according to two preferred procedures. The first one provides that a cutting blade or a perforating device is used applied to the pneumatic drill, that, with free hands, from the key hole detaches the dura mater below and simultaneously etches the bone. The second procedure, instead, provides that the dura mater is dissected, with a curved periosteum-detaching device, from the bone between a drill hole and the other and afterwards, using a guide, by

passing a saw wire, which, when pulled upwards at its ends with wide hands, etches the bone one segment at a time.

At the end of the neuro-surgical intervention, after having sutured the dura mater and suspended the edges to the bone, the limb is rested again into the opening and is secured with detached metal or wire staples, passed through small drill holes paired on the free edge of the cranial bone.

It is however clear that a solution of this type generally does not allow an aesthetically acceptable closure, since it is not always able to avoid that the bone limb can project, collapse, get slanted or rotate.

Object of the present invention, therefore, is solving the above prior art problems, by providing a device for securing a cranial limb to the cranial top that allows correctly ossifying the bone limb to the cranial top edge and simultaneously closing the holes obtained for craniotomy.

Another object of the invention is providing a device that allows having a lower tension on the brain, even if a brain edema occurs after an operation.

In order to prevent such brain edema, a hole has been pre-arranged in the upper part of the device, that can be easily opened with a dedicated instrument, to allow inserting a drainage.

These and other objects are obtained with a device for securing a cranial limb to the cranial top and for simultaneously closing the craniotomy holes as described in claim 1. Further features of the invention are defined in the dependent claims.

Further objects and advantages of the present invention will be clear from the following description and the attached drawings, provided merely as a non-limiting example, in which:

- figure 1 shows a perspective view of a preferred embodiment of the device for securing a cranial limb to the cranial top and the simultaneous closure of the craniotomy holes according to the present invention;

- figure 2 shows a view of the device of Fig. 1 in a first step of its use;

- figure 3 shows a view of the device of Fig. 1 in a second step of its use;

- figure 4 shows a view of the device of Fig. 1 in a further step of its use; and

- figure 5 shows a view of the device of Fig. 1 in the final step of its use.

With particular reference to the cited figures, the device for securing a cranial limb to the cranial top and for simultaneously closing the craniotomy holes, according

to the present invention is globally designated with reference number 10.

The device 10 has a lower ring 11, linked to the cortical riser 12 by two elastic arms 13 and an upper plate 14 (fig. 4), which will have to be inserted into the upper part of the cortical riser 12.

The cortical riser 12 will be equipped with a handle 15 and a ring 16 for securing 16 that will be used for inserting the upper plate 14 (fig. 4).

The cortical riser 12, as connection between the lower ring 11 and the upper plate 14, due to the elasticity of the arms 13, allows using only few sizes related to the bone thickness, for example three different sizes, while the circular shape allows any rotation and even the non-parallel positioning of the ring 11 with respect to the plate 14.

Finally, even if it can be seen in all the Figures, in Fig. 5 a hole 22 is expressly shown and better illustrated, which allows passing probes to suck liquids, for extravasations, drainages, etc., such hole 22 being a further advantageous feature of the device 10 of the present invention.

Explaining in more detail the application modes of the cranial securing device 10 of the invention, it can be noted that the instrument operator prepares the amount of devices adapted to secure the craniotomy in its various sizes.

Such operations are performed by choosing the most suitable sizes for the cranial top 17 thickness and the most suitable number of devices 10, depending on the craniotomy largeness and shape.

Moreover, if it will be necessary to insert a drainage, in one of the devices the hole 22 pre-arranged in the securing ring 16 will have to be opened, through suitable drilling pliers (not shown) .

The surgeon, with the already assembled catching pliers (not shown) , inserts the lower ring 11 in the space between the cranial top 17 and the dura mater 18, so that the cortical riser 12 is at the centre of the hole obtained in the cranial top 17.

The bone cover 19 is abutted onto the lower ring 11 of the device 10, as shown in figure 3.

Afterwards, the surgeon verifies the correct position of the cover 19 and stretches, by means of the handle 15, the cortical riser 12 and the elastic arms 13 to be able to insert the upper plate 14 into the securing ring 16, like in fig. 4. Finally, he removes the handle 15 with a scalpel (fig. 5) .

The cranial securing device 10 of the invention is advisable in all craniotomy cases, since its shape and the different sizes in which it can be made, according to the bone thickness, allow keeping the bone limb stretched on

board the cranial top, both on the internal and on the external margins, in order to allow the right ossification and to close the holes obtained for the craniotomy.

At the same time, the elasticity of the used biocompatible plastic material guarantees, after the operation, namely when brain edema, and therefore brain swelling, conditions could occur, a lower tension on the brain.

From the above description, the features of the device for securing a cranial limb to the cranial top and for simultaneously closing the craniotomy holes, object of the present invention, appear clear, as well as its resulting advantages .

It is finally clear that numerous variations can be made to the device for securing a cranial limb to the cranial top and for simultaneously closing the craniotomy holes, of the present invention, without departing from the novelty principles contained in the inventive idea.

Finally, when putting the invention into practice, materials, shape and sizes of shown details could be various, according to needs, and they could be replaced with other technically equivalent details.