After-treatment. The outer dressing may be changed every second day, but the wound itself is not interfered with until the eighth day. If asepsis has been obtained, the posterior wound has usually completely healed, so that the stitches can be removed at the first dressing. Owing to the secretion from within the cavity there may be a certain amount of odour, and as a rule some purulent discharge from the meatus. Under good illumination the strip of gauze is gently removed through the meatus and afterwards the small pellets of cotton-wool. In order to make certain that all are removed, a note should be made at the time of transplanting the graft as to how many were inserted in the wound cavity. The ear is now syringed out gently with a weak solution of hydrogen peroxide and afterwards dried by mopping it out with small wicks of cotton-wool.
A speculum is next inserted into the meatus and the cavity thoroughly examined. Any portions of the graft not in absolute contact with the bone or which overlap the skin of the meatus will have died, and can be removed by forceps. Care, however, must be taken not to pull off these portions too forcibly, as in doing so other pieces of the graft may be torn away. The external meatus is then plugged with a tiny piece of gauze and a dry dressing applied. If the graft has not taken and has died, it will be expelled at the first dressing on syringing.
Further treatment consists in syringing and afterwards drying the cavity daily. From day to day the outer layer of the graft will gradually come away piecemeal. At the end of the second week the patient can usually go home and carry out the treatment for himself, but he should be seen by the surgeon at least once a week until complete healing has taken place. If the graft has not taken uniformly over the surface of the bone, small patches of granulations may be seen covering these areas. Under cocaine anæsthesia these patches should be curetted. If the granulations recur repeatedly, it means that there is some underlying carious bone, and that healing will not take place until the tiny fragment is eventually exfoliated.
Results. Statistics vary. There is no doubt that the results are better according to the experience of the surgeon with regard to grafting. If it be only applied in those cases in which it is certain that all the diseased bone has been eradicated at the primary operation, then the percentage of success with relation to failure is very high. If, however, skin-grafting be adopted as a matter of routine, the ultimate result is probably not so good as in a similar series of cases in which grafting has not been done.
Skin-grafting through the external meatus. This has been advised chiefly in order to avoid a second operation.
The technique of applying the graft is practically the same as that for transplanting a large graft. The same care must be taken to get the interior of the mastoid cavity aseptic and dry. To avoid a general anæsthetic, the small grafts may be removed from the arm or leg under local anæsthesia produced by a subcutaneous injection of Schleich’s solution. The graft is transferred from a small spatula to the edge of the meatus and then coaxed into position within the cavity by means of probes. The grafts are kept in position by small pellets of cotton-wool covered with gauze. If successful, the grafting may shorten the duration of the after-treatment. It is not, however, so satisfactory a procedure as applying a large graft directly through the post-aural wound.
In order to keep the grafts in position, Drew has suggested laying the graft on sterilized gold-beater’s skin, and in this way applying it to the interior of the mastoid cavity.
More recently, Stoddart Barr of Glasgow has introduced an ingenious method of getting the grafts into position. The graft is manipulated over the end of a suitably-bent glass tube, having attached to the other end a piece of rubber tubing with a glass mouthpiece or small rubber bag. The graft at the end of the tube is passed through a wide speculum to the inner wall of the tympanum, when, by blowing air through the tube, the graft is spread out over the inner surface, including the tympanic walls, aditus, and antrum.
AFTER-TREATMENT OF THE CASE
If the posterior wound has been closed. Provided the temperature keeps normal and there be no pain and no head symptoms, the first dressing need not take place until the fifth or sixth day. By this time the edges of the skin incision have usually united, so that the stitches can be removed, although occasionally the wound may have to be opened up to permit of drainage on account of septic infection. The withdrawal of the gauze from the auditory canal may cause considerable pain, which, however, can be prevented by continuous irrigation of the ear before and during its removal (see [p. 315]).