REIMPLANTATION

From Big Medical Encyclopedia

REIMPLANTATION [lat. re-the prefix meaning repetition, resuming, + in(im) - in, inside + plantatio planting, change; synonym repeated implementation] — repeated operation with the purpose of replacement or movement of the materials which are earlier fixed in an organism or devices (implants).

At implantation in an organism of the materials or devices compensating the functions defined, lost by any body there is a difficult interaction between an organism and implant (see). On the one hand, material of an implant affects surrounding fabrics, with another — fabrics, adjacent to an implant, exert impact on it. This process is followed by diffusion of ions on both sides of border of contact of body tissues and an implant and causes specific reaction. Nature of reaction and morfol. a picture depend on the chemical properties of metal defining its affinity to fabrics, valency, atomic weight (weight), electrochemical activity, and at use polymeric materials (see) — from features of a polymer structure. Ions of the metals which are contained in body tissues diffuse in structure of the implanted material on depth up to 0,05 mm, breaking durability of a surface layer and changing equipotentiality of a surface of an implant. On the other hand, the organism reacts to functioning of an implant, its hemodynamic, electrophysiologic, etc. influences, i.e. there is a continuous interaction in the «organism — an implant» system which is defined by properties of an implant and features of reaction of an organism of the patient to an implant and material from to-rogo it is made. This interaction is the most active in the place of contact of an implant with surrounding fabrics, causing inflammatory reaction, degree the cut varies over a wide range — from the minimum reaction to a necrosis.

Distinguish the emergency and planned River. The emergency R. is carried out in case of danger of development of heavier complication or direct threat to life of the patient, napr, at dysfunction of a pacemaker (see. Cardiostimulation ) or a prosthesis of the valve of heart (see. Prosthetics of valves of heart ).

The indication to planned R. is need of replacement of an implant in connection with the termination of term of its functioning (e.g., exhaustion of power supplies in a pacemaker), danger of emergence of such complications, at to-rykh further stay of an implant in an organism can cause heavier changes. Allocate the following complications arising after implantation of materials or designs in an organism and demanding reimplantation: the expressed inflammatory reaction to an implant in the field of operation, dysfunction of an implant, suppuration in the field of an implant (infection), dislocation of an implant.

Rubles make at expressed: reaction of fabrics to an implant, education in its area of decubituses or at an aggravation of general diseases of connecting fabric. At acute reaction with development of a necrosis it is originally shown obkalyvany areas of an implant by the solution containing a hydrocortisone and antibiotics of a broad spectrum of activity, Butadionum, Diazolinum, Dimedrol. At inefficiency of this conservative treatment carry out River. If inflammatory reaction protekayeg as chronic, R. carry out in an old bed, at acute reaction on an implant establish it in a new bed. Reliable fixing of an implant to connecting fabric or bone educations, in a fascial bed of muscles, warning an excessive prelum fabrics of an implant, its excess mobility etc. is necessary.

Makropreparat of heart with thrombosis of the implanted prosthesis mitral - the valve (cavities of auricles are opened): the arrow specified trombotichesky masses on the surface of a mitral valve prosthesis turned into a cavity of the left auricle.

Real danger of development of inflammatory reaction with formation of the expressed capsule, napr, around myocardial electrodes of a pacemaker, formation of blood clot on a prosthesis of the valve of heart (fig.) arises at an aggravation or development hron. general diseases of connecting fabric. For the purpose of prevention of these complications conduct a course of antiinflammatory treatment.

Continuous mechanical load on fabric can be caused by the sole weight of an implant, napr, a pacemaker, its hypermotility under the influence of external loading (an intra bone nail, a bone plate, an artificial joint, an electrode, a prosthesis of the valve of heart), strong tightening of the fixing seams. In these cases urgent removal of an implant and its movement or its replacement on functionally more suitable is necessary.

At destruction of an implant its replacement is in most cases necessary.

The absolute indication to R. is suppuration of a bed of an implant as a result of, e.g., disturbance of an asepsis, corrosion of an implant or formation of decubitus. At the same time the implant is deleted or moved to a new bed. Replacement of a prosthesis of the valve of heart at a septic endocarditis is completed leading directly to it a catheter for local introduction of antibiotics. In some cases R. can be carried out later a nek-swarm time after removal of an implant, during to-rogo use temporary devices — tires, temporary stimulators, etc.

Dislocation of an implant in interfascial space is observed at the wrong fixing of a pacemaker, the doser of pharmaceuticals, a bone plate, intra bone nailing, etc. that also demands carrying out reimplantation.



Bibliography: Williams D. F. and Rouf R. Implants in surgery, the lane with English, M., 1978; Malinovsky H. N and Konstantinov B. and. Repeated heart operations, M., 1980.


V. I. Shumakov.

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