**4.4 Transurethral ultrasound (TUUS) guided injection of stem cell**

At the beginning of the cell injection, the TUUS probe (8 Ch, 15– 20 MHz) was carefully inserted into the urethra. The urethral wall and the rhabdosphincter were visualized. A specially designed patent-pending injection device was used for precisely adjusted injection of several small portions. First, 15–18 portions of the myoblast suspension were injected directly into the omega-shaped rhabdosphincter at two different levels. Then, 25–30 depots of the fibroblast/collagen suspension were injected into the submucosa circumferentially at three levels (Figure 13). After implantation of the cells the patients were instructed to perform PFT and FES for 4 wk postoperatively to support integration of the cells and to improve formation of new muscle tissue **(Strasser et al, 2007).** 

Fig. 13. Cross-sectional ultrasonography images of the urethra and the rhabdosphincter (A) The tip of the needle (marked with an arrow) is positioned at the inner aspect of the rhabdosphincter (RS) for injection of myoblasts. (B) The tip of the needle is placed at the outer aspect of the submucosa (SM) for injection of fibroblasts **(Strasser et al, 2007b).**
