Chernov A.V., Radchenko S.A., Iryanov U.M., Chernov V.F.
“Clinical diagnostic center of gastroenterology” Kurgan.
Authors comment: for the experiment authors of the article were supplied with the material “Titanium silk”.
Background. Development of implant technologies is still one of the actual aspects in modern medicine. Different biocompatible implant materials are significantly different from each other in their mechanical and physicochemical properties, that’s why they are used according to their experimental and clinical objective. It goes without saying the effectiveness of different constructions implanted into the organism depends on implantation conditions and morph functional peculiarities of living tissue.
Objective of the research. In order to work out better technologies for the soft tissue repair we have an objective to study the importance of biocompatible implant materials integration into the living body tissue.
Materials and methods. In the experimental and clinical conditions implant properties of some modern materials for soft tissue repair have been tested, biocompatibility of these materials is surely proved. They are: polytetraphtorethilen (PTPE) in a film form (24 experiments), reperen in a form of thin perforated film (9), mesh implants-prolene (24), thin wire implants –titanium VT- 1.00 (12) and titanium nikelid TN-10 (32). Those implant materials were selected as materials with minimal size of film thickness and threads- from 60 to 200 mkm., but different in their physical and technical characteristics of surfaces roughness , in the titanium and titanium nikelid materials those characteristics are almost the same as nanostructures. Muscle aponeurotic layer defects of abdominal wall were formed in experimental animals (dogs, cats, rabbits). They were detected and implants of standard size were inserted. Alongside the clinical observations some macro and micro morphological observations of reinforced implant segments of newly formed connective tissue were done in the short and long time period. Implant shift, changing of their forms and topographic relationship between implant and surrounding tissues were studied with ultrasound examination, X-ray and computer tomography. Architectonic and micro topography of reinforced newly formed tissue were studied with light and scanning electron microscopy methods. Sequence of observation time was 1, 2 weeks, 1, 3, 6 months, 1 year. Maximum time of observation for titanium VT-1.00, titanium nikelid and with titan nikelid mesh TN -10 for soft tissue defects including 53 with severe purulent abdominal wall infection (eventration, peritonitis, intestinal fistula).
Results. Clinical observations in the short post operative period of time reflect universal non specific general and local body reaction to the implantation of the bio compatible foreign body. In later periods the results mainly depend on physical and chemical properties of the implanted material and implant constructive peculiarities. It’s established that connective capsule is formed around the film implants in soft tissues where the implant is in free non fixed position. PTPE film is easily removed from the capsule at any time.
Polymer meshes with smooth thread surface are visually motionless in the scar and are fixed in the newly formed connective tissue due to growth through the construction cells leaving micro slits (only in scar tissue around the threads surface. Some cases of implant twisting are noted which is the proof of their not fully achieved fixation in the tissue.
Much tighter fixation in soft tissues is noted with titanium VT -1.00 meshes. In cases of titanium nikelid TN -10 almost fully intergrowth is observed. Removal of the construction or any separate threads of it is impossible without tissue rupture on the implant field.
Morphological investigation with microscopy and scanning electron microscopy showed a principal difference of connective tissue tectonics with implants of different surfaces. In cases of full surface film polymers (PTPE) capsule around the implant is always well seen in the same way as the cavity between implant and capsule, so the fixation on the surface of the material itself is not present.
In cases with mesh construction made of implanted material with polished surface (perforated film-reperen, polished thread –prolene) connective tissue fixation is observed by the type of growth over the construction at the crossing sites. Although on the smooth parts of the threads connective tissue growth happens by the type of capsule with a splint between implant and living tissue. Contraction of reinforced newly formed tissue and shrinking of polymer construction may lead to the formation of one common capsule around the whole construction or separate large segments of implant.
With titanium VT-1.00 meshes and titanium nikelid TN -10 meshes having absolutely different surface properties, connective tissue growth happens with firm fixation of its’ elements on the rough surface both separate segments and the whole construction(full integration).
It’s necessary to mention titanium nikelid full integration under the conditions of infection independently of contamination degree and wound defect infection. Other polymer materials were rejected. There was no necessity to remove T.N implant from the infected wound. Morphological instigations showed that this material presence does not complicate the granulation tissue growth and connective tissue scar formation.
Polymer implants appeared to be not able to integrate under the conditions of open wound, infection and purulent inflammation. It happened also due to inevitable damage to polymer while using antiseptics containing active oxygen, chlorine and iodine.
Discussion. Character and intensity of integration process inevitably appearing in implantation are the result of plastic material and alive tissue interaction which activity arises in the connective tissue growth as a response to implantation. Thus, implant settle is the result of not only biochemical and bio mechanical compatibility but also the integration of the whole construction into the tissue. So according to the data obtained we should define the term “ biocompatibility of the implanted material surface ” as its adequacy an proportionality to growing and formed tissue elements. Being a unique reinforcing base for the newly formed tissue implant material must create favorable conditions for fixation and growth of newly formed connective tissue. Integrity reliability and the result of the whole implantation depend on the firm fixation. On the other hand fixation durability is directly connected with material surface.
In general we think It’s necessary to mention the following factors connected with material construction and determining its’ integration ability:
- Whole volume of implant material.
- Whole Square of implant surface.
- Biocompatibility of implant surface.
- Bio mechanical compatibility of implant construction and its’ elements.
- 3 D Construction.
Implant construction integration can be both partial and full depending on
the elements’ fixation stability in the tissues.
In the case of film structure implant fixation is absent, the encapsulation of
biocompatible whole material as a foreign body is observed. In the case of mesh construction the degree of implant integration depends on biocompatibility of implant surface. Prove of integration ability for implant construction is the usage of mesh made of titanium nikelid TN -10 under the conditions of purulent inflammation. The following material and mesh 3 D construction provide safe healing of large soft tissue defects complicated with purulent infection. It happens due to implant covering with the newly formed connective tissue without rejection signs and with purulent process reduction. Maximum full integration in the condition of high physical and chemical stability of material in the aggressive media is the key factor for healing of infected wound reinforced with implant.
- Integration ability of implant, which means construction and implant material ability to form the complex “alive tissue – implant” as a united reinforced area of connective tissue, is the key factor, condition and indicator of implant “settlement” in the alive tissue.
- degree of implant integration depends on biocompatibility of implant material surface which must be adapted to the growth and firm fixation of newly formed connective tissue on each stage of its’ formation.
- “ Settlement” properties are present only in the materials able fully integrate into the alive tissue.