MANUAL OF SURGERY

CHAPTER I

REPAIR

Introduction—­Process of repair—­Healing by primary union—­Granulation
    tissue—­Cicatricial tissue—­Modifications of process of
    repair—­Repair in individual tissues—­Transplantation or grafting
    of tissues—­Conditions—­Sources of grafts—­Grafting of individual
    tissues—­Methods.

INTRODUCTION

To prolong human life and to alleviate suffering are the ultimate objects of scientific medicine.  The two great branches of the healing art—­Medicine and Surgery—­are so intimately related that it is impossible to draw a hard-and-fast line between them, but for convenience Surgery may be defined as “the art of treating lesions and malformations of the human body by manual operations, mediate and immediate.”  To apply his art intelligently and successfully, it is essential that the surgeon should be conversant not only with the normal anatomy and physiology of the body and with the various pathological conditions to which it is liable, but also with the nature of the process by which repair of injured or diseased tissues is effected.  Without this knowledge he is unable to recognise such deviations from the normal as result from mal-development, injury, or disease, or rationally to direct his efforts towards the correction or removal of these.

PROCESS OF REPAIR

The process of repair in living tissue depends upon an inherent power possessed by vital cells of reacting to the irritation caused by injury or disease.  The cells of the damaged tissues, under the influence of this irritation, undergo certain proliferative changes, which are designed to restore the normal structure and configuration of the part.  The process by which this restoration is effected is essentially the same in all tissues, but the extent to which different tissues can carry the recuperative process varies.  Simple structures, such as skin, cartilage, bone, periosteum, and tendon, for example, have a high power of regeneration, and in them the reparative process may result in almost perfect restitution to the normal.  More complex structures, on the other hand, such as secreting glands, muscle, and the tissues of the central nervous system, are but imperfectly restored, simple cicatricial connective tissue taking the place of what has been lost or destroyed.  Any given tissue can be replaced only by tissue of a similar kind, and in a damaged part each element takes its share in the reparative process by producing new material which approximates more or less closely to the normal according to the recuperative capacity of the particular tissue.  The normal process of repair may be interfered with by various extraneous agencies, the most important of which are infection by disease-producing micro-organisms, the presence of foreign substances, undue movement of the affected part, and improper applications and dressings.  The effect of these agencies is to delay repair or to prevent the individual tissues carrying the process to the furthest degree of which they are capable.