Every surgeon is occasionally faced with the problem of closing a defect of the abdominal wall in which lack of tissues precludes primary repair. Such a defect may be the result of resection of a tumor of the abdominal wall, loss of substance due to missiles or other trauma, or unusually large hernias. Attempts to close these large defects by various plastic procedures, including relaxing incisions, all too frequently result in a hernia or a recurrence of a hernia because the factor of tension is disregarded. Surgeons are usually reluctant to use a prosthesis for fear of wound complications and a natural disinclination to use "foreign materials." There is, however, no other recourse in the types of cases just described, and the surgeon should be prepared to use such materials to their best advantage. A common technique for repairing these hernias has been to perform primary closure of as much