Hypothesis / aims of study
Slings are an established surgical treatment for post-prostatectomy stress urinary incontinence
(PPI) and nonadjustable slings (NAS) are the most investigated and used type. However, a significant portion of patients experience postoperative failure. Urodynamic features have been investigated in several previous studies as potential predictors of sling failure. We aimed to summarize the published evidence about the impact of urodynamic findings on NAS outcomes by systematic review and meta-analysis.
Study design, materials and methods
PubMed, Web of Science, Scopus, and Cochrane databases were searched from inception to December 2022 for observational or randomized studies evaluating the efficacy NAS for PPI, with at least 6 months follow-up and 30 analyzed patients. Study quality was assessed using QUIPS tool. A random-effect model was used to pool adjusted (primary meta-analysis) and unadjusted (supplementary meta-analysis) odds ratios (OR). Outcome measures were the failure of cure (FoC) and the failure of overall success (FoS). I^2 statistics was used to assess heterogeneity.
Results
Pooled effect estimate was in favour of a statistically significant association between detrusor overactivity and FoS (2 studies, OR 3.78; 95%Cl 1.44-9.98; p=0.007; I^2 =0%); there was a trend toward an association with FoC (2 studies, OR 6.4; 95%CI 0.95-43.26; p=0.06; I^2 =29%). Results of the supplementary meta-analysis were similar (8 studies, OR 2.39; 95%CI 1.60-3.56; p=0.001;
I^2 =0% for FoS; 5 studies, OR 2.35; 95%Cl 0.97-5.68; p=0.055; I^2 =18% for FoC).
For a lower Valsalva leak point pressure, a statistically significant association was observed with FoS (2 studies, pooled OR per 10 cmH20 decrease, 1.53; 95%CI 1.17-2.01; p=0.002; I^2 =27%) but not with FoC (5 studies, pooled OR per 10 cmH20 decrease, 1.49; 95%CI 0.89-2.5; p=0.10; I^2 =78%) in primary analysis. At supplementary meta-analysis, pooled effect estimates per 10 cmH2O decrease were not statistically significant (4 studies, pooled OR 1.11; 95%CI 0.88-1.41; p=0.25; I^2 =10% for Fos, and four studies, pooled OR 1.28; 95%CI 0.60-2.74; p=0.38; I^2 =87% for FoC).Two studies evaluated the association of a reduced compliance with FoS by univariable analysis resulting in a statistically significant association (pooled OR 5.91; 95%CI, 2.6-13.4; p<0.001; I^2 =0%).
None of the meta-analyses assessing bladder capacity, Retrograd Leak Point Pressure (2 studies), Qmax (3 studies), PdetQmax (2 studies) and maximal urethral closure pressure (3 studies) yielded in a statistically significant association with continence outcomes.
Interpretation of results
Our results indicate that at least some urodynamic features may significantly affect NAS efficacy, although the strength of the evidence (GRADE) is from low to very low. As a result, our findings need to be interpreted with caution.