RU2706144C1 - Method for closing a skull burr hole - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to neurosurgery, and can be used in surgical management of skull defects. A hemostatic sponge is placed on a dura mater. Then bone fragments mixed with plasma enriched with thrombocytes are rubbed into contact porous edge of disk-like implant. After hemostasis is achieved, the implant made of porous titanium nickelide is tightly inserted into the burr hole of the skull. Soft tissues are closed in layers.

EFFECT: invention provides complete restoration of integrity and protective function of skull, reduced liquorrhea and prevention of formation of scars and adhesions with dura mater, rigid fixation of the implant in a burr hole, acceleration of osteointegration, exclusion of toxic action, implant rejection, suppuration and other postoperative complications.

1 cl, 5 dwg

Description

The invention relates to medicine, namely to neurosurgery, and can be used in the surgical treatment of skull defects after applying a milling hole and conducting osteoplastic trepanation.

Indications for osteoplastic trepanation of the skull are brain tumors, the consequences of open and closed injuries to the skull and brain, brain abscesses, arachnoiditis, hydrocephalus.

The complete closure of the milling holes is important not only to eliminate cosmetic defects, but also to restore the protective function of the skull.

The main therapeutic indication for closing a skull defect is the need to seal the cranial cavity and protect the brain from external influences.

Given the increase in the number and complexity of surgical interventions performed on the brain, it is necessary to develop a simple and effective way to close the milling holes.

There are different ways to close milling holes.

A device for cranioplasty is known, which consists of a plate and at least three locking elements made in the form of cotter pins made of porous titanium nickelide, each of which has a flattened head with spikes and a trapezoidal rod with a diverging end (Copyright certificate. No. 1655477, "Device for cranioplasty ", Publ. 06/15/91).

The disadvantages are that the cranioplasty device is very bulky in size, this device uses two nickelide-titanium materials and self-hardening plastic, the graft from self-hardening plastic does not have bioinertness and, as a result, the graft is rejected. Moreover, to fix the device, it is necessary to additionally form holes on the side of the bones of the cranial vault for fixation of the graft.

There are various fixators for fixing endoprostheses that cover defects in the bones of the skull made of metal with shape memory: omega-shaped, S-shaped, wavy brackets (RF Patent No. 213113, publ. July 20, 1999).

Disadvantages:

- when installing these brackets, the graft may be shifted towards the place of fixation of the device;

- does not create reliable fixation and the possible displacement of the graft in the direction of the cranial cavity is not prevented;

- a significant thickness of these brackets sometimes creates the appearance of a foreign body under the skin of the patient’s head, which reduces the cosmetic properties of the operation;

- these fixatives do not fill the space (gap) between the bone graft and the edge of the bone defect of the cranial vault, which was previously sawn with a Jigley file;

- the fixation of the graft to the donor site occurs only on one side - the outside, which does not create sufficient strength and immobility of the graft;

- to install these fixatives, it is necessary to make additional holes in the graft and around the perimeter of the bone defect.

Known methods for closing milling holes by filling them with bone chips of a patient mixed with blood (Author's certificate SU No. 1222249, “Method for bone-plastic trepanation of the skull in children” Kazakh Research Institute of Pediatrics and Pediatric Surgery, published on 07.20.1999), and mixed with blood and saline solution (Method for cranial bone

reconstruction, Danaila Leon, appl. 26.02.1997, No.appl. RO019970000367, publ. 02.27.1998).

The use of the above methods in childhood is justified, since there is a risk of transplant migration during growth from non-resorbable material, including epidurally. These complications in some cases lead to repeated operations.

The disadvantage of this technique is the resorption of bone chips, in about 20% -40% of cases. In most cases, bone chips are gradually replaced by connective tissue, bone formation, as a rule, does not occur.

Also known is a method of plasticizing the milling holes of the skull with an autograft (Author's certificate SU No. 1097291, Kiev Research Institute of Neurosurgery, publ. 06/15/1984). The milling hole is superimposed with a crown milling cutter with the formation of a bone ledge 2-3 mm wide. After carrying out the manipulations, the autograft is placed in the milling hole and wedged with a pin bitten out of the autograft.

When using a castelline milling cutter, there is a possibility of damage to the dura mater, any cut-off limiters are not provided. The technique is technologically not convenient and imperfect, since it is necessary to cut the bone incompletely, extract the cut out fragment and form a bone ledge.

The disadvantages of the technique include the high probability of autobone resorption, limited contact of the autograft and skull bones. This leads to a decrease in the likelihood of osseointegration and fusion with the bones of the skull.

The closest way (Patent US2012283771 (A1) - 2012-11-08) to close the milling hole is to use biodegradable implants made from materials such as collagen, polyglycolide, copolymers of lactic acid and glycolic acid, poly-L-lactide, poly-L- lactic acid, crystalline polymers. The period of biological degradation of such materials varies from 3 to 6 months. Spacer elements are provided on the lateral part of the implant to hold the implant in the hole. Spacer elements are made in different sizes for versatility and the ability to use the implant in holes of different diameters. The implant is made flexible and there is perforation in the area of contact with the bone to improve osseointegration. It is possible to use various biologically active substances to improve osseointegration.

The disadvantage of the technique can be considered the development of granulomas in the postoperative period, which occurs in about 10% of cases. This occurs as a result of an individual reaction to biological degradation and enzymatic hydrolysis of the graft. Material undergoing hydrolysis cannot be called biologically inert. With the development of granuloma, soft tissue edema, soreness and redness of the skin appear. These phenomena regress after about 12 months. Resorbable materials are mainly used in children, where the regenerative potential is significantly higher and there is growth potential. In adults, it is not proven that after resorption the implant is replaced by bone tissue. Accordingly, a milling hole will remain, which to some extent is closed by connective tissue.

Thus, the problem of plastic surgery of the milling hole of the skull is still relevant.

The objective of the invention is to develop an effective and safe method for the holistic closure of the milling hole after trepanation of the skull or after diagnostic access.

A method for closing a milling hole using an implant made of porous titanium nickelide, with a percentage of Ni-55%, Ti-45%. The material has been used for a long time in traumatology, the “shape memory" property has been successfully used, it has biological inertness and is an ideal material for creating implants biologically and mechanically compatible with the human body. Titanium nickelide is not a ferromagnet, does not harm patients, practically does not distort the magnetic resonance effect when performing MRI and CT of the brain and bioelectric activity of the brain. The implant microporosity is achieved by sintering titanium nickelide powder in ceramic forms at a temperature of about 1700 degrees. In structure, it resembles a spongy bone tissue. It has an open through porous structure close to the structure of the pores of bone tissue: porosity of 40-70% with a pore size optimal for the ingrowth of tissue elements. The pores and space in the implant are easily filled with bone tissue. The implant is perforated in order to improve osseointegration.

The thickness of the parietal, occipital and frontal bones was studied on 20 certified turtles. During the anatomical study, it was found that the average bone thickness in the area of the most frequent application of milling holes is: frontal bone 4.5 mm, parietal bone 6 mm, occipital bone 5 mm. Considering the experimental data, it is advisable to use nickelide titanium microporous implants made in the form of disks with a thickness of 3-5 mm. and with a diameter of 10 mm.

The patient’s sterilized bone chips are rubbed into the porous edges of the implant, with the addition of blood plasma enriched with platelets, and then the implant is tightly placed in the milling hole, due to the uneven rough structure, the implant is firmly and tightly fixed inside the milling hole.

The method is as follows.

Impose a milling hole. Bone chips are collected at the stage of formation of bone access and sterilized in a dry oven.

After trepanation, in the case of using the Dzhigli saw, 4-5 milling holes remain, when using automatic trepans, 1 milling hole. These holes are round bone defects of 12 mm diameter. Defects are visible on the convexital surface of the cranial vault.

Then, an implant made of porous titanium nickelide with a diameter of 10 mm and a thickness of 3-5 mm, depending on the thickness of the bone of the cranial vault, is tried on to the milling hole. During the surgery, there are implants of different thicknesses. The implant is pre-sterilized by autoclaving at standard temperature conditions.

During the operation, plasma-rich platelets are prepared according to the following procedure. The technique provides for 2-stage centrifugation.

Stage 1: centrifugation 3600 rpm 4 minutes, a break of 2 minutes.

Stage 2: centrifugation 3600 rpm for 2 minutes. Then, with a syringe, a layer of plasma enriched in platelets is collected.

Bone shavings are rubbed into the lateral contact porous surface of the implant, into which blood plasma enriched with platelets is added.

A hemostatic sponge is placed in the milling hole on the dura mater, an implant is placed on top. Then the soft tissues are sutured in separate stitches in layers.

Due to the uneven rough surface structure, the titanium nickelide implant is firmly and tightly fixed inside the milling hole. And due to the fact that previously bone chips are added to the contact surface with the addition of blood plasma enriched in platelets, the rate of osseointegration increases. This is confirmed by experimental data. The formation of scars, fusions with the dura mater and the development of postoperative liquorrhea is prevented by the use of a protective layer from a hemostatic sponge. Osteointegration is also accelerated through the use of in-lay implant placement techniques. In-lay technique is implemented by inserting the implant into the milling hole so that the implant and the skull surface are at the same level without a step. Only in this case, the porous surface of the implant is in maximum contact with the cancellous bone of the skull.

The technical result of the application of the proposed method is to achieve complete restoration of the integrity and protective function of the skull. Through the use of bionert material, toxic effects, implant rejection, suppuration, and other complications are eliminated. Due to the use of a hemostatic sponge, the level of liquorrhea decreases and the formation of scars and adhesions with the dura mater is prevented. An advantage is also that due to the rough lateral surface of the implant edges and the rubbing of the bone chips, it is possible to obtain rigid fixation and maximum contact of the implant with the skull bone. And due to the porosity of the implant, germination of the implant is achieved by bone already on the 40th day of the experiment in 100% of cases.

Moreover, the use of this technique does not increase the operation time, since bone chips are collected at the stage of bone access formation, and implants of different thicknesses are easily available for use by the surgeon in the required quantities and do not require complex and lengthy preparation for use.

In addition, when using the proposed method, cosmetic defects are eliminated, which favorably affects the patient’s quality of life and significantly reduces the risk of postoperative liquorrhea.

During experimental operations on plastic surgery of the skull defect in rabbits using porous titanium nickelide, it was found that a skull defect in diameter of 10 mm with an average bone thickness of 0.9 mm using the in-lay technique completely heals on the 24th day in 50% of observations and on 40th day in 100% of observations.

A brief description of the drawings.

The photo shows the experimental trepanation in a rabbit (Fig. 1).

As a result of cranioplasty, an experimental implant made of porous titanium nickelide was installed (Fig. 2).

Taking histology on the 24th day after cranioplasty (Fig. 3).

Visible is an experimental implant made of porous titanium nickelide, overgrown with bone.

Taking histology on the 40th day after cranioplasty (Fig. 4). The arrow indicates the location of the experimental trepanation closed with a porous implant. An experimental implant made of porous titanium nickelide is completely overgrown with bone.

Tube with PRP plasma after centrifugation. (Fig. 5)

Claims (1)

A method of closing the milling hole of the skull, comprising introducing a porous nickelide implant into the milling hole, characterized in that a hemostatic sponge is placed on the dura mater, then bone chips mixed with platelet-rich blood plasma are rubbed into the contact porous edge of the disk-shaped implant, and then to achieve hemostasis, the implant is inserted tightly into the milling hole; after that, soft tissues are sutured in layers.

Images