Purpose: Meticulous excision of the stricture and any associated spongiofibrosis is critical to the success of urethral reconstruction. However, normal urethral limits are determined during surgical reconstruction based on macroscopic appearance only. We evaluated structural changes of the presumed healthy urethral ends.
Materials and methods: Samples were obtained from 29 patients with a mean age of 40 years who underwent end-to-end anastomotic urethroplasty. Suprapubic catheter drainage was performed for at least 30 days in 15 patients. After the urethral stricture was excised biopsy was performed of the proximal and distal healthy ends. Structural characterization was evaluated by staining histological sections with Masson's trichrome, Sirius red and Weigert's resorcin-fuchsin method. The control group consisted of 10 cadaver bulbar urethras.
Results: All samples of presumed normal urethral ends showed histological changes. Chronic and acute inflammatory reactions were the most common findings. In the proximal urethral end intense cellularity was found in 18 patients (62.1%). Fibroblast and inflammatory cells were most common and related to the lack of suprapubic cystostomy (p = 0.001). Between proximal urethral edges with and without a suprapubic urinary catheter the elastic fiber distribution and the ratio of collagen types III and I showed a significant change (p = 0.045 and <0.001, respectively).
Conclusions: The supposedly healthy urethral ends of end-to-end anastomotic urethroplasty show structural changes. Urethral obstruction and its relief by suprapubic urinary drainage can affect extracellular matrix turnover regulation. Therefore, these changes can lead to urethral remodeling in the proximal bulbar urethra.