Intraoral wound closure with tissue-engineered mucosa: New perspectives for urethra reconstruction with buccal mucosa grafts

In urethra reconstruction, the creation of a new urethra from a free oral m ucosa graft is an established surgical technique. The oral mucosa is remove d at the same time that the urethra reconstruction procedure is performed. Depending on the size of graft required, the intraoral wound is closed prim arily or left to heal secondarily. The latter method limits this technique by leading to scars or strictures, which have a negative impact on the cond ition of the intraoral soft tissue. Therefore, in this study, a pilot study involving 12 patients, tissue-engineered mucosa was tested for covering in traoral defects to avoid the drawbacks mentioned above. For mucosa tissue-g raft engineering, a biopsy; sample 2 to 4 mm in diameter was removed from t he hard palate approximately 4 weeks before the urethra reconstruction proc edure was to be performed. In addition, 30 mi of autogenous serum was extra cted from a venous whole-blood sample. The primary cultures were incubated in Dulbecco modified Eagle's medium and nutrient factor F 12 (Gibco Co., Eg genstein, Germany), containing the usual additives and autogenous serum. Af ter a period of 3 weeks, subcultivation was performed to engineer mucosa tr ansplants consisting of several layers of keratinocytes on a support foil. After thorough intraoperative blood coagulation had occurred, the cultured mucosa graft on the carrier foil was applied on the wound surface and fixed by single sutures. Additionally, the cultured mucosa graft was covered for 8 to 10 days by an intraoral dressing, which was also fixed onto the wound surface by single suture loops. It is possible to perform primary intraora l wound closure with tissue-engineered mucosa to col er defect sizes as lar ge as 11.0 x 4.0 cm. This new method provides a better prospect for both ur ethra reconstruction and the reconstruction of intraoral tissue defects. Th e number and size of intraoral scars and strictures are diminished. This is of special interest for the reconstruction of the functional unit oral cav ity, including soft tissue and cosmetic conditions (e.g., in case of prosth etic rehabilitation). In comparison to primary wound closure with local tis sue, the technique presented in this study reduces the severity of postoper ative pain and allows faster rehabilitation in patients because of a better wound-healing process. Furthermore, better mobility of intraoral soft tiss ue structures is achieved.