Volume 1

The science and art of surgery : a treatise on surgical injuries, diseases, and operations / by John Eric Erichsen.

John Eric Erichsen

Date:: 1895

Credit: The science and art of surgery : a treatise on surgical injuries, diseases, and operations / by John Eric Erichsen. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

323/1274 (page 291)

$FORMATION OF SCAB TISSUE. , varying from four hours to eighteen days. These obsei'vers concluded that I the fihn of connective-tissue which formed in the clianiber was derived, not • from the leucocytes, but from larger plasma cells, which were also ]-)rosent, I and were presumably derived from the fixed tissue cells. The results of experiment, together witli a study of the mode of repair of epithelium, may t thus be said to support the view that the new tissue formed in the process of ■ repair is derived from the original connective-tissue of the damaged parts. ^ The exact mode of origin of the fibres of the scar-tissue is another disputed I point: it is uncertain whether they are formed by a change in the proto- i plasm of the cells or by a process of fibrillation in the intercellular ground i substance. Sherrington and Ballance were unable to satisfy themselves on this • point, but inclined to the belief that the fibres were formed in an intercellular > substance secreted by the cells. The time occupied in the process of repair is not accurately defined. \We have already seen that the formation of the plastic exudation, or ■•lymph, commences' immediately after the injury, and under favourable .•circumstances is finished by the end of the first twenty-four hours. According •■to Billroth, new vessels can be seen commencing to form within forty-eight :hours, and by the end of a week a complete communication is established 'between the capillaries on each side of the wound. Early in the second week f.the cells have lengthened out, and the development of fibrous tissue has commenced ; and by the end of the second week the superabundant vessels have been partly obliterated, and the new tissue has assumed a considerable degi'ee of firmness. The final obliteration of the vessels in the cicatricial tissue is a slow process, lasting many months. Until this is completed the scar remains redder than the surrounding skin, though afterwards it becomes jOpaque and white. It is evident that these changes can be seen on microscopic examination only in those wounds in which the surfaces have been separated from each other by an appreciable layer of plastic exudation or coagulated blood. When the apposition of the surfaces has been more perfect, the layer of uniting material may be so thin as to be scarcely recognisable, and foui- days after the infliction of the wound it may be almost impossible to detect any bond of union, the line of the incision being marked only by the presence of a few rt'andering cells and some traces of unabsorbed red corpuscles. That true jianion, however, in such a case has not definitely taken place at this time is ■jhown by the care which is necessary, in preserving the specimen for micro- ■jcopic examination, to prevent the surfaces from separating from each other. We have thus traced the development of a scar, and shown that in its 'ormation new blood-vessels, epithelium, and fibrous tissue are developed, and •IS a rule these structures alone form the bond of union after division of the !oft parts. In wounds of cartilage, muscle and central nervous tissue, no Regeneration of the original tissues takes place, the scar being composed solely )f fibrous tissue. Large vessels when completely divided are obliterated and converted into a fibrous cord as far as the nearest collateral branch. As we haU see hereafter, bone is repaired by bone, and under favourable circum- tances large nerves are completely united by normal nerve-tissue. In large cars, however, the development of new nervous tissue is very imperfect, if it iccurs at all. Little is known of the formation ol' lymphatics in old scars; but ajectious show that they are wanting in granulation-tissue and young scars. u 2$