PREFABRICATION OF MUCOSA-LINED FLAPS - A PRELIMINARY-STUDY IN THE PIGMODEL

There is a need in reconstructive surgery for flaps lined by nonkerati zing stratified squamous epithelium or mucous membrane. Applications c ould be found in nasal, oral, genital, and esophageal reconstruction a nd even in reconstruction of hollow intra-abdominal tubes. Prefabricat ion of lined flaps has so far been limited to a pretransfer grafting o f split-thickness skin. However, in certain situations this does not s atisfy the primary requirement of replacing ''like with like.'' Also, the availability of donor sites for harvesting mucosa is limited. The present study involves prefabrication of mucosa-lined flaps without ca using donor site morbidity. The study was carried out on six mini-Hart ford pigs. Buccal mucosa was harvested from the cheeks; the sheet was divided into several smaller graft pieces of 1 to 2 cm(2) area. These graft pieces were then applied to the deep fascia at a distance of 5 t o 15 mm from one another, also to galea, and to the undersurface of sk in flaps. The grafted area was isolated from the opposing surface with a silicone sheet or Marlex mesh. The grafts were allowed to take and, it was hoped, merge together to form a sheet graft of dimensions grea ter than those of the original. Two to 7 weeks after the initial graft ing, the skin flap was elevated; the mucosal grafts were observed macr oscopically for take and surface area and microscopically to confirm t hat the lining was indeed mucosa. The mucosa took well on both the fas cia and galea and also on the undersurface of the skin; it enlarged in size, and the small pieces became confluent to form a single sheet. T he increase in surface area varied from 33 percent at 11 days postgraf ting to a maximum of 238 percent after 7 weeks. All pigs had positive cultures from the mucosa before implantation but only one developed gr oss infection leading to partial graft loss.