Prefabrication of Mucosa-Lined Flaps: A Preliminary Study in the Pig Model

Abstract

There is a need in reconstructive surgery for flaps lined by nonkeratizing stratified squamous epithelium or mucous membrane. Applications could be found in nasal, oral, genital, and esophageal reconstruction and even in reconstruction of hollow intra-abdominal tubes. Prefabrication of lined flaps has so far been limited to a pretransfer grafting of split-thickness skin. However, in certain situations this does not satisfy 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 causing donor site morbidity. The study was carried out on six mini-Hartford pigs. Buccal mucosa was harvested from the cheeks; the sheet was divided into several smaller graft pieces of 1 to 2 cm2 area. These graft pieces were then applied to the deep fascia at a distance of 5 to 15 mm from one another, also to galea, and to the undersurface of skin 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 greater than those of the original. Two to 7 weeks after the initial grafting, the skin flap was elevated; the mucosal grafts were observed macroscopically for take and surface area and microscopically to confirm that the lining was indeed mucosa. The mucosa took well on both the fascia 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. The increase in surface area varied from 33 percent at 11 days postgrafting to a maximum of 238 percent after 7 weeks. All pigs had positive cultures from the mucosa before implantation but only one developed gross infection leading to partial graft loss.

Juvenile Swine Surgical Alveolar Cleft Model to Test Novel Autologous Stem Cell Therapies

“…Swine models are currently being used in multiple medical and surgical disciplines, [33][34][35][36] suggesting that swine models as a proxy for human conditions are reasonable. Further benefits to the use of swine, include recent completion of the swine genome project, with steady increases in the number of swine transgenic models, 37,38 including a green fluorescent protein model 39 and a severe combined immunodeficiency model 40 ; these models yield exciting possibilities for preclinical trials in swine that were previously limited to rodent and primate models.…”

“…Brackets clarify the location of the bone defect. Color images available online at www.liebertpub.com/tec oral reconstruction 34 ; however, only a single study has used a swine model to study a critical-sized maxillary defect, which was treated with distraction osteogenesis. 45 Our study describes the creation of a critical-sized maxillary defect in swine to test novel tissue-engineered therapies.…”

Effects of Subepithelial Fibroblasts on Epithelial Differentiation in Human Skin and Oral Mucosa: Heterotypically Recombined Organotypic Culture Model

“…The use of prefabricated flaps with oral mucosa or tissueengineered mucosa for the reconstruction of intraoral defects was reported. [12][13][14][15][16] However, the question of whether the differentiation of epithelia is influenced by underlying mesenchymal tissues remains. In this study using organotypic cultures, the cells used were free of contamination.…”

“…9 The possible use of mucosal epithelial cultures as a source of epithelial sheets for skin repair was reported, 10,11 and more recently, the use of prefabricated flaps of oral mucosa or tissue-engineered mucosa for the reconstruction of intraoral defects was reported. [12][13][14][15][16] These methods were generally successful, but the question of the cellular origin of regenerated epithelia and the question of whether the differentiation of regenerated epithelia is influenced by underlying mesenchymal tissues remain. The aim of this study was to elucidate the effects of subepithelial fibroblasts on the differentiation of oral or cutaneous keratinocytes.…”

Prefabrication of Composite Grafts for Long-Segment Tracheal Reconstruction

“…Some investigators have experienced the efficiency of strips or small patches of mucosa scattered over the graft's surface, but with variable results. 17,19,27 Grafting of meshed oral mucosa can be considered as an efficient and easy way to expand the surface of mucosal coverage.…”