Intraoral wound closure with tissue engineered mucosa - new perspectives for urethra reconstruction

In urethra reconstruction, the forming of a new urethra from an free oral mucosa graft is an established surgical technique. The oral mucosa is taken simultaneously during the urethra reconstruction procedure. Depending on the size of graft required, the intraoral wound is closed primarily or left to secondary healing. The latter limits this technique leading to scars strictures which have a negative impact on the intraoral soft tissue condition. Therefore, in a pilot study with 12 patients tissue engineered mucosa was tested for covering intraoral defects in order to avoid drawbacks mentioned above. To tissue engineer mucosa grafts a biopsy from the hard palate, diameter size 2 to 4 mm, was taken approximately 4 weeks before the operation. In addition, 30 ml autogenous serum was produced out of a venous whole blood sample. The primary cultures were incubated in Dulbecco's modified Eagles Medium, Nutrient Factor F 12 containing the usual additives as well as autogenous serum. After a period of 3 weeks subcultivation was performed to engineer mucosa transplants consisting of several layers of keratinocytes on a support foil. After thorough intraoperative blood coagulation, 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 by an intraoral dressing for 8-10 days which was also fixed onto the wound surface by single suture loops. Primary intraoral wound closure with tissue engineered mucosa is possible to cover defect sizes up to 11.0 x 4.0 cm. This new method provides better perspectives for both urethra reconstruction and reconstruction of intraoral tissue defects. Intraoral scars strictures are diminished. This is of special interest for the reconstruction of the functional unit oral cavity including soft tissue and cosmetic conditions (e.g. in case of prosthetic rehabilitation). In comparison to primary wound closure with local tissue this technique reduces postoperative pain and allows faster rehabilitation of the patients basing on a better wound healing process. Furthermore, better mobility of intraoral soft tissue structures is achieved. Keywords: tissue engineering, oral reconstruction, hypospadia