DETRUSOR OVERACTIVITY FOLLOWING MIDURETHRAL SLING PROCEDURES

S.M. Botros, Y. Abramov, R.P. Goldberg, A. Nickolov, S. Ghandi, J.J. Miller, P.K. Sand

Evanston Continence Center, Evanston, IL; Northwestern University, Feinberg School of Medicine, Chicago, IL

OBJECTIVE:  Previous studies have suggested that rates of voiding dysfunction and de novo detrusor overactivity (DO) following TVT may not differ significantly from other anti-incontinence procedures.  We sought to compare the rates of resolution, persistence and de novo detrusor overactivity between transvaginal midurethral slings and transvaginal bladder neck slings.

MATERIALS AND METHODS: We identified 320 subjects with urodynamic stress or mixed urinary incontinence that underwent transvaginal midurethral slings (n=125) or transvaginal bladder neck sling anchored to Cooper’s ligament (n=195) procedures. All subjects had a routine office evaluation including a detailed history and subjective assessment of urge incontinence using Likert’s scale, physical exam, urinalysis, postvoid residual, Q-tip test and multichannel urodynamic testing pre- and 3 months postoperatively.  Comparisons were made using Student’s t-test, McNemar’s test and Chi-Square test.  Multivariate logistic regression was performed to detect possible confounding factors.  P-value <0.05 was considered statistically significant for all comparisons.  Data was analyzed with SAS.

RESULTS: Subjects in the bladder neck sling group were significantly older, had greater use of HRT and more prior anti-incontinence surgeries. (Table 1). Preoperatively, subjects who underwent bladder neck slings had higher rates of subjective urge urinary incontinence (85% vs 68% p=0.002) and DO (75% vs 60%, p=0.0046)  as well as low Pressure Urethra (61% vs 10% p<0.001).  Of patients who had DO preoperatively more patients in the midurethral sling group had resolution of DO than in the bladder neck sling group (37.7% vs.14.6%, p<0.001).  In addition, subjects in the midurethral sling group had significantly lower rates of de novo DO than subjects in the bladder neck sling group (28.8% vs. 61.9%, p=0.003).  The only significant predictors of postoperative DO were preoperative DO (p<0.001) and sling type (p<0.001).  After adjusting for preoperative DO, bladder neck slings significantly increased the risk for persistent DO (OR 3.7).

CONCLUSION:  Our study indicates that patients who undergo midurethral slings have increased rates of resolution of DO and lower rates of de novo DO than those who undergo the transvaginal bladder neck sling procedure.

Table 1.  Demographic data

	Transvaginal Bladder Neck Slings	Midurethral slings	P value
Age	66.9	57.7	<0.001
Menopause	160(83%)	71(77%)	0.2121
HRT	115(58%)	43(23%)	<0.001
Parity	3	2	0.0774
Prior anti- incontinence surgery	52(27%)	21(14%)	0.0068
Anterior wall Prolapse (POP-Q)           Stage 0	6(5%)	9(8%)	0.3575
Stage 1	14(12%)	36(32%)	0.001
Stage 2	66(55%)	48(42%)	0.0565
Stage 3	34(28%)	21(18%)	0.0799

Key Words: midurethral slings, detrusor overactive, transvaginal bladder neck slings

Disclosure – Speakers Bureau: P.K. Sand, Alza/Ortho-McNeil, Watson, American Medical Systems; Advisory Board: P.K. Sand, Alza/Ortho-McNeil, Watson, American Medical Systems, Indevus, Yamanouchi, Roche, Pfizer, Bioform, Lilly, Boeringer-Ingelheim, Mentor, Novasys; Grant/Research: P.K. Sand, Alza/Ortho-McNeil, Watson, American Medical Systems, Indevus, Yamanouchi, Roche, Pfizer, Bioform, Lilly, Boeringer-Ingelheim, Mentor, Novasys.