Effect of intraoperative manipulation and preservation on fascia temporalis used in tympanoplasty.

Fascia temporalis (FT) is generally used as grafting material for primary or revision surgery for chronic ear disease. In the latter case, homologous FT, stored in various solutions after the intraoperative preparation, that aims to dehydrate, is often used. In this study, an ultrastructural analysis of FT has been carried out in order to determine whether its structure is affected by the different steps that take place before its application as a homograft. As well as light, transmission and scanning electron microscopy, immunoperoxidase technique for testing monoclonal antibodies against different collagen types was performed. The surface appearance of FT proved to be increasingly affected by the intraoperative manoeuvres. Moreover, 10% formalin proved to give a better preservation of the surface appearance of FT than did 70% alcohol which, also after a short period of preservation (15 days), caused severe surface alterations. No particular changes in the ultrastructural appearance of FT were noticed that could have been attributed to the length of preservation. Type IV collagen was detected in the 30-day samples of both alcohol- and formalin-preserved specimens. From these results, one can speculate that, despite the major ultrastructural changes induced in FT by the intraoperative preparation and by its preservation, this tissue is still able to maintain a proper connective network. This finding could explain the reliability of homologous FT for the repair of tympanic membrane perforations.