Experimental study on vagina reconstruction with tissue-engineering biological material.

Abstract

To investigate the effect of vagina reconstruction using tissue-engineering biological material (acellular dermal matrix) in an animal model. Vagina excision and vagina reconstruction with tissue-engineering biological material were performed in 12 Chinese experimental miniature pigs. The control group was matched with two of normal vagina specimens resected. At week 1, 2, 4, 6, 8, 12 after surgery, the animals were sacrificed, respectively, and the neovaginas were prepared for immunohistochemical and Van Gieson (VG) staining to evaluate the status of various layer growth of vagina. Epithelial broad spectrum of monoclonal antibodies of AE1/AE3 and alpha-actin were used to test the existence of epithelial and smooth muscle tissue by immunohistochemical staining. The ultrastructure of neovagina was studied by transmission electron microscope at week 1 and 12 after surgery. Contractile function of isolated smooth muscle of neovagina was evaluated by chemical and electronic stimulation after 12 weeks' reconstruction. (1) Epithelization of 2/3 neovaginal mucosa was observed within 1 week. Only 1 - 2 layer epitheliums were observed under the light microscopy and epithelial cells with characteristics of loose and disarrangement were shown with the electron microscopy. Within 4 - 6 weeks, epithelization in mucosa of neovaginal canal was intensified to 4 - 5 layers. After 12 weeks, the differences between the neovagina and the native vagina were harldy noted either in the gross or microscopically. (2) After 4 weeks, a few smooth muscle cells were observed with VG and immunohistochemical staining, and homogeneous muscle bundle was formed. (3) After 12 weeks, similar contractile responses between neovagina and native vagina were observed when KCl and electrical stimulation with different frequency and voltage were given [(2.96 +/- 0.29) g vs. (3.14 +/- 0.30) g, (3.43 +/- 0.34) g vs. (4.65 +/- 0.73) g, (4.92 +/- 0.38) g vs. (4.89 +/- 0.44) g]. The tissue-engineering biological material might be an ideal graft used in the reconstruction of vagina.