Cushion for holding an element of grafted skin

A cushion for pressing an element of grafted skin against the body surface, wherein the portion (2) to be applied to the body has a window or opening (4) the dimensions of which approximately equal that of the graft. The edges (6) of the window (4) are attached to the skin so as to be impervious to air or liquids. The filling medium of the cushion (air or a liquid) is maintained under pressure.

FIELD OF THE INVENTION 
The present invention relates to a cushion for pressing skin grafts to the 
surface of the human body. 
BACKGROUND OF THE INVENTION 
In the surgical grafting of skin portions, especially when a full-thickness 
skin transplantation is performed, it is of critical importance that 
uniform pressure be applied to the graft over the entire area thereof to 
press the transplanted skin firmly against the respective surface area of 
the human body. Such evenly applied pressure must be maintained from six 
to eight days, with slight individual variations being permissible. It is 
known to use for this purpose a pressure dressing which includes a cushion 
which is larger than the section of the grafted skin so that the graft 
over its entire surface area is evenly pressed against the lesion. (Ferris 
Smith: Plastic and Reconstruction Surgery, W. B. Saunders Co., 1950, pages 
26 and 27. ) 
This procedure, however, has certain disadvantages. Since the familiar 
cushions are made of rubber, the accumulation of albumin secretions 
between the cushion and the surface of the graft is encouraged, and the 
cushion prevents air from reaching the surface of the graft. Moreover, 
even with the most scrupulous care it is not always possible to protect 
the surface area of the cushion in contact with the grafted skin from the 
effects of the pressure exerted by the bandage, resulting in the formation 
of folds in the cushion, especially when the skin portion is grafted onto 
a strongly curved body part. Such folds in the cushion cause corresponding 
impressions or similar folds on the transplanted skin which remain visible 
even after complete healing. 
SUMMARY OF THE INVENTION 
It is the object of the present invention to overcome the foregoing 
disadvantages and to provide a pressure dressing for use with skin grafts. 
This is accomplished according to the invention in that the cushion is 
provided with a cutout or window on the side facing the body, and that the 
window is at least approximately as large as the grafted skin section. 
In applying the pressure dressing, the cushion is placed in such a manner 
that its aperture or window comes to lie over the skin graft. The edge of 
the window is adhesively fastened to the skin. It may additionally be 
stitched onto the skin and the points of stitching may further be sealed 
off with an adhesive or the like if the stitches are located in the region 
of the window edge so as to ensure a complete sealing thereof. 
The cutout or window is of the same general shape as the skin graft. Some 
embodiments of the invention provide for the cutout to be somewhat smaller 
than the skin graft so that the edge of the cutout or window is disposed 
on the skin graft. Alternatively, the window may be slightly larger than 
the skin graft in which case the window edge is disposed on the heathly 
skin. The graft may in conventional fashion be sutured along the edge of 
the wound. However, suturing is not required if, according to the first 
embodiment of the invention, the edge of the window is adhesively attached 
not only to the edge of the skin graft, but also to the surrounding 
healthy skin. 
The benefits of the cushion according to the invention are, first, that the 
area of the skin outlined by the open window will not perspire, and the 
secretion of albumin and other substances is either prevented or will not 
lead to skin irritations, because the area of the skin graft is ventilated 
through the window. Furthermore, it is possible to supply the grafted skin 
through the window with oxygen or a nutrient solution, to promote or 
appropriatedly direct the healing process. Finally, it will be appreciated 
that there will be no fold formation in the cutout area of the cushion, 
namely, over the grafted skin, so that this disadvantage of the prior art 
cushion is eliminated. If the side of the cushion opposite the open 
communication afforded by the window, i.e. facing away from the body 
surface is made of a transparent material, the window will permit a visual 
observation of the healing process, i.e. the degree of blood circulation 
in the grafted skin section. If necessary, corrective action may be taken 
by introducing an appropriate treatment agent into the cushion. For this 
reason, one embodiment of the invention provides for the side of the 
cushion opposite the window to be made of a transparent material, such as 
a suitable plastic, or the like. 
The window in the cushion may be cut out in the shape of the skin graft 
immediately before applying the pressure dressing. For the healing process 
to proceed, however, it is not required that the window edge exactly 
coincide with the edge of the grafted skin section. Rather, the edge of 
the window in the cushion may extend both partly over the grafted skin and 
partly over the healthy skin. The window may also be considerably larger 
than the transplanted skin section without adversely affecting the healing 
process. Thus, cushions having windows of various dimensions may be made 
in advance and kept in storage for ready use by the surgeon. In such 
cases, the edge of the window may be provided with an adhesive to attach 
the cushion to the skin or the skin graft, respectively. 
Some of the emobodiments of the invention provide for a valve on the 
cushion for adjusting the pressure inside the cushion. Connected to the 
valve may be devices, known per se, for producing, controlling and/or 
maintaining the pressure in the cushion. 
One emobodiment of the cushion according to the invention is provided on 
the side opposite the side in contact with the body with a rigid plate 
which may be transparent to accommodate the embodiment described in the 
foregoing. The plate may conform to the contour of the part of the human 
body to which the cushion is applied. This embodiment of the invention has 
the advantage that any danger of fold formation in portions of the cushion 
is substantially reduced. 
The cushion according to the invention may be pressed against the body 
surface by means of an elastic bandage, whereby the rigid plate may or may 
not be included. For tightly holding the cushion to the extremities, an 
elastic hose has proven useful. 
Another embodiment of the invention is provided not only with one valve to 
generate, maintain or control the pressure inside the cushion and/or to 
fill the cushion with a liquid, but features two valves to permit the air 
and a liquid to be exchanged in the cushion without affecting the pressure 
in the cushion to any appreciable extent. By introducing air through one 
valve passage, a liquid contained in the cushion may be forced out through 
the other passage and, conversely, air in the cushion may be vented 
through the other opening. The two valve openings may also be used 
continuously to renew the fluid or air under pressure in the cushion or to 
have the air or fluid circulate through a medium for effecting special 
treatment of such air or liquid as, for example, withdraw moisture from 
the air to prevent perspiration or wound water from collecting in the 
cushion. It is obvious that fluid may also be suctioned off through one of 
the valves. 
In yet another embodiment of the invention, the cushion contains an agent 
which binds moisture and hence dries the air in the cushion. Such a 
dehumidifier may be kept separate from the hollow interior of the cushion 
by a semipermeable partition made, for example, of a suitable plastic 
material. The partition will allow moisture to permeate only in the 
direction of the dehumidifying agent.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
In the embodiment illustrated in FIGS. 1 and 2, a pillow-shaped cushion 2D 
is comprised of two sheets or foils 1 and 2 of latex rubber or some other 
suitable resilient plastic material. The sheets or side walls 1 and 2 are 
joined at their edges by a seam 3. The side wall 2 of the cushion 2D which 
is in contact with the body surface 16 as the pressure dressing or bandage 
12, 13, 14, 15 is applied, is provided with a cutout, window or opening 4. 
Close to the edge of the cushion 2D, the sheet 1 has welded therein a 
valve 5. The window 4 is larger than the element 17 of grafted skin so 
that the edge or marginal portion 6 directed toward and surrounding the 
window in this embodiment of the invention is adhesively attached to the 
body surface 16, as by means of adhesive 22, 23 completely outside the 
range of the suture by which the skin graft 17 is attached to the body 
surface 16. The valve 5 is so constructed that conventional means for 
producing 31, maintaining 32 and controlling 33 the pressure inside the 
cushion 20 may readily be connected thereto. The foil or outer side wall 1 
is transparent to permit observation of the skin graft 17 through the 
transparent foil 1 and the window open 4 without requiring removal of the 
dressing or bandage 12, 13, 14, 15. It will be understood that the part of 
the dressing 12, 13, 14, 15 arranged above the cushion 20 may also be 
provided with a window or opening to permit such visual observation, or 
that this portion of the dressing 12, 13, 14, 15 may likewise be 
transparent. 
The embodiment of the invention illustrated in FIG. 3 is distinguished from 
the embodiment of FIGS. 1 and 2 by a rigid plate 7 which is welded, 
adhesively attached or in some other manner fixed in position to a cushion 
21. This plate 7 conforms to the contours of the surface area of the body 
part 8 being covered and may likewise be transparent to facilitate a 
visual inspection of the grafted skin. The degree of rigidity and the size 
of the plate 7 are so selected as to enable the plate to distribute the 
pressure exerted by it evenly over the entire surface of the cushion 21 to 
prevent the formation of folds in the region of the sheet 2 at the 
underside of the cushion 21. 
The valve 5 is so constructed that it may also serve as a passage for the 
introduction of a treatment agent into the cushion 21, while maintaining 
the adjusted pressure in the cushion 21, if possible. It is also feasible 
to provide an additional valve on the cushion 21 for this purpose. 
FIG. 4 shows an embodiment comprising a cushion 24 which has two supply 
lines 9 and 10 leading to the interior of the cushion 24. These two lines 
or tubes may be fitted with devices of any kind by which the medium 
contained in the cushion 24 may be replaced without causing a drop in 
pressure, may be cleansed, or may be maintained at the desired adjustable 
pressure. Merely by way of demonstration, FIG. 4 shows extremely straight 
forward regulating means 11 on the tubes 9 and 10 which may obviously be 
replaced by more suitable means as the actual practice may require. 
Regardless of the size of the window in the embodiment of the cushion 21 
illustrated in FIG. 1, the dimensions of the window 4 may be such that its 
edge 6 may extend over both part of the healthy skin and part of the 
grafted skin, or it may extend solely over the grafted skin. 
The cushion 20, 21, 24 may be pressed against the skin graft 17 with the 
aid of a bandage 12, 13, 14, 15 or an elastic hose. Also, either of the 
two sheets 1 and 2, notably the bottom sheet 2, may be made substantially 
larger than the other sheet so that it extends beyond the seam 3 to be 
used to secure the cushion 20, 21, 24 in place. 
The cushion 20 in FIG. 1 may also contain any known or suitable moisture 
binding agent 24' which is preferably separated by any known or suitable 
semipermeable partition 25 from the interior of the cushion 20 which is in 
open communication with the skin graft 17 through the opening 4.