A microbiological and immunohistochemical analysis of periurethral and vaginal tissue in women with de novo urge symptoms after mid-urethral sling procedures—a prospective case-controlled study

The aims were to determine whether bacteria-infection-elicited immune response after mid-urethral sling (MUS) may cause de novo urge symptoms (DNUS) and to evaluate the efficacy of suburethral sling excision for relieving the urgency. In a period of 40 months, 360 consecutive subjects with urodynamic stress incontinence had undergone one of three different MUS. Sixty-eight women with DNUS were included after exclusion. The suburethral sling of 24 of the 68 women needed to be excised because of refractory urgency. The excised vagina, or periurethral tissue, included sling of the study and control groups were sent for microbiological and immunohistochemical analyses. Statistically significant differences in the cell density percentage of CD68, CD25, CD4+CD25 and positive rate of Gram (+) bacteria were noted between two groups (p = 0.024, p = 0.053 and 0.016, respectively, p < 0.001). The success rate of sling excision was 80.2%. In conclusion, bacteria-infection-related immune hyperreactivity might explain the pathologic basis of DNUS after MUS.