Fig. 2.

Urethral histology 1, 4, 10, and 21 days after injury. A: control urethra shows tightly packed external urethral sphincter (EUS) muscle fibers. B: 1 day after vaginal distension (VD) shows edema in the EUS. C: 1 day after pudendal nerve crush and VD (PNC+VD), disruption of EUS muscle fibers is evident. D: 10 days after PNC, EUS muscle fibers were wavy and disrupted, indicating denervation injury. Dark blue indicates fibrosis near the EUS. E: 10 days after VD, the EUS showed edema, fiber disruption, and mild waviness. F: 21 days after PNC+VD, the EUS fibers remained disrupted and wavy with fibrosis, indicative of incomplete recovery. SM, smooth muscle. Stain: Masson's trichrome. Bar = 100 μm.