The success of skin-grafting depends largely upon the care with which the grafts are handled at the time of operation and subsequently. There are three distinct methods.Minute grafts may be obtained either by snipping bits out of the skin or by scraping and macerating particles from the outer layers of thick epidermis. They have not generally yielded good results. The little islands of epidermis which they produce will often melt away unless the epidermis growing from the side of the ulcer reaches and surround them.
Sheets of skin shaved off with a razor, and of sufficient thickness to include the deeper layers of the epidermis and possibly some of the dermis itself (so-called Thiersch grafts) have yielded far better results. The site from which the grafts are taken should be cleansed with soap and hot water and washed with sterile normal salt solution (0.8 per cent). The anterior surface of the thigh or the outer side of the upper arm are favorite places from which to take grafts. The skin should be drawn tight and smooth with the fingers or hooks. With a sharp razor, preferably grown flat on its under surface, strips of skin an inch wide and an inch or more in length and of a fairly uniform thickness can be shaved off. The surface to which these are to be applied should be fresh, but should be wiped free from blood. If it is a freshly made wound, hemorrhage should first be controlled by pressure as a blood clot under a graft will absolutely prevent its union. If the surface is a granulating one, the granulations may be shaved off with a razor or simply wiped with sponges wrung out in hot sterile saline solution until the granulations are clean and fresh. Here, too, oozing of blood must be at a standstill before the grafts are applied. As the grafts have a tendency to shrink even though kept moist, it is necessary that they should fully cover the surface. Over them may be laid strips of rubber tissue which are to be covered with compresses constantly kept moist with saline solution, or the tissue may be omitted and the compresses laid directly on the grafts. In either case light pressure should be maintained by a bandage in order to insure a continuous application of the grafts to the underlying surface. Some surgeons do not apply any dressing whatever for several hours, so that the drying of the serum shall firmly attach the graft to the underlying granulations. After that a dressing of dry or moist gauze or rubber tissue is applied.
The subsequent treatment varies. The dressing may be changed daily, great care being observed to keep the grafted area constantly moist and protected from any pressure which would cause the graft to slip. Another plan is to change the dressing in three or four days. Still another plan is to cover the grafts with moist or dry gauze, and not to change the dressing for two or three weeks. Some surgeons apply a plaster of Paris bandage to protect the part from injury.
It will be evident in three or four days whether the grafts have become attached, but even those which appear to be loose should not be too hastily removed, since their deeper portions may have united with the underlying granulations. In a week or more the grafts and portions of graft which have not attached themselves will have become disintegrated, or will be washed away with the pus.
The new skin obtained by minute or Thiersch grafts will never be the equal of normal skin. It is easily distinguished from the surrounding skin years afterward. It may resemble the surrounding skin under ordinary circumstances, but it does not react in the same way to temperature changes. In this respect Wolfe grafts and plastic operations are superior to Thiersch grafts.
The third method of skin-grafting consists in the use of grafts composed of the entire thickness of the skin. In some instances success has followed this method when a graft eight inches long and two and a half wide has been employed. The names of Wolfe and also of Krause have been given to this method of grafting. These large grafts are nourished at first by effusion, and then minute vessels make their way into the grafts, and in some instances communicate with the vessels already existing.
The technique is similar to that employed for applying a Thiersch graft. Asepsis without the use of germicidal solution and the control of hemorrhage by pressure are important points. The grafts should be freed of fat. They may be stitched into position, but this is not absolutely necessary. it is of the utmost importance that the grafts should not be moved for several days. Some operators apply dry sterile gauze, and do not change it for weeks unless there is a purulent discharge. Before attempting to remove the dressing, the part should be soaked for an hour in warm boracic acid solution. Other operators cover the grafts with rubber tissue and moist gauze.
According to the results which have been reported, one may expect success with about three-fourths of the grafts employed. Some of the grafts attach themselves in part, other parts becoming necrotic. Equally good results have been obtained by using the skin of a healthy person who has died from an accident only an hour or so previous.
If a Wolfe graft once becomes united, it is far superior to a Thiersch graft. It has all the characteristics of normal skin, and prevents in great measure the contraction of the underlying scar tissue. hence, Wolfe grafts are especially serviceable to cover defect about the joints.
Karl Thiersch -- German surgeon, 1822 -- 1895.
John R Wolfe – Glasgow ophthalmologist, 1824 – 1904.
Fedor Krause -- German surgeon, 1857-1937.