This systematic review was performed to investigate the ethical justification, methodological quality, validity and safety of placebo controls in randomized placebo-controlled surgical trials.Central, MEDLINE, and EMBASE were systematically searched to identify randomized controlled trials comparing a surgical procedure to a placebo. "Surgical procedure" was defined as a medical procedure involving an incision with instruments. Placebo was defined as a blinded sham operation involving no change to the structural anatomy and without an expectable physiological response in the target body compartment.Ten randomized placebo-controlled controlled surgical trials were included, all of them published in high-ranking medical journals (mean impact factor: 20.1). Eight of 10 failed to show statistical superiority of the experimental intervention. Serious adverse events did not differ between the groups (rate ratio [RR] 1.38, 95% confidence interval [CI]: 0.92-2.06, P = 0.46). None of the trials had a high risk of bias in any domain. The ethical justification for the use of a placebo control remained unclear in 2 trials.Placebo-controlled surgical trials are feasible and provide high-quality data on efficacy of surgical treatments. The surgical placebo entails a considerable risk for study participants. Consequently, a placebo should be used only if justified by the clinical question and by methodological necessity. Based on the current evidence, a pragmatic proposal for the use of placebo controls in future randomized controlled surgical trials is made.
Background: To minimise the rate of recurrent prolapse after traditional native tissue repair (anterior colporrhaphy), clinicians have utilised a variety of surgical techniques. Objectives: To determine the safety and effectiveness of surgery for anterior compartment prolapse. Search methods: We searched the Cochrane Incontinence Group Specialised Register, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In Process (23 August 2016), handsearched journals and conference proceedings (15 February 2016) and searched trial registers (1 August 2016). Selection criteria: Randomised controlled trials (RCTs) that examined surgical operations for anterior compartment prolapse. Data collection and analysis: Two review authors independently selected trials, assessed risk of bias and extracted data. Primary outcomes were awareness of prolapse, repeat surgery and recurrent prolapse on examination. Main results: We included 33 trials (3332 women). The quality of evidence ranged from very low to moderate. Limitations were risk of bias and imprecision. We have summarised results for the main comparisons. Native tissue versus biological graft Awareness of prolapse: Evidence suggested few or no differences between groups (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.52 to 1.82; five RCTs; 552 women; I2 = 39%; low-quality evidence), indicating that if 12% of women were aware of prolapse after biological graft, 7% to 23% would be aware after native tissue repair. Repeat surgery for prolapse: Results showed no probable differences between groups (RR 1.02, 95% CI 0.53 to 1.97; seven RCTs; 650 women; I2 = 0%; moderate-quality evidence), indicating that if 4% of women required repeat surgery after biological graft, 2% to 9% would do so after native tissue repair. Recurrent anterior compartment prolapse: Native tissue repair probably increased the risk of recurrence (RR 1.32, 95% CI 1.06 to 1.65; eight RCTs; 701 women; I2 = 26%; moderate-quality evidence), indicating that if 26% of women had recurrent prolapse after biological graft, 27% to 42% would have recurrence after native tissue repair. Stress urinary incontinence (SUI): Results showed no probable differences between groups (RR 1.44, 95% CI 0.79 to 2.64; two RCTs; 218 women; I2 = 0%; moderate-quality evidence). Dyspareunia: Evidence suggested few or no differences between groups (RR 0.87, 95% CI 0.39 to 1.93; two RCTs; 151 women; I2 = 0%; low-quality evidence). Native tissue versus polypropylene mesh Awareness of prolapse: This was probably more likely after native tissue repair (RR 1.77, 95% CI 1.37 to 2.28; nine RCTs; 1133 women; I2 = 0%; moderate-quality evidence), suggesting that if 13% of women were aware of prolapse after mesh repair, 18% to 30% would be aware of prolapse after native tissue repair. Repeat surgery for prolapse: This was probably more likely after native tissue repair (RR 2.03, 95% CI 1.15 to 3.58; 12 RCTs; 1629 women; I2 = 39%; moderate-quality evidence), suggesting that if 2% of women needed repeat surgery after mesh repair, 2% to 7% would do so after native tissue repair. Recurrent anterior compartment prolapse: This was probably more likely after native tissue repair (RR 3.01, 95% CI 2.52 to 3.60; 16 RCTs; 1976 women; I2 = 39%; moderate-quality evidence), suggesting that if recurrent prolapse occurred in 13% of women after mesh repair, 32% to 45% would have recurrence after native tissue repair. Repeat surgery for prolapse, stress urinary incontinence or mesh exposure (composite outcome): This was probably less likely after native tissue repair (RR 0.59, 95% CI 0.41 to 0.83; 12 RCTs; 1527 women; I2 = 45%; moderate-quality evidence), suggesting that if 10% of women require repeat surgery after polypropylene mesh repair, 4% to 8% would do so after native tissue repair. De novo SUI: Evidence suggested few or no differences between groups (RR 0.67, 95% CI 0.44 to 1.01; six RCTs; 957 women; I2 = 26%; low-quality evidence). No evidence suggested a difference in rates of repeat surgery for SUI. Dyspareunia (de novo): Evidence suggested few or no differences between groups (RR 0.54, 95% CI 0.27 to 1.06; eight RCTs; n = 583; I2 = 0%; low-quality evidence). Native tissue versus absorbable mesh Awareness of prolapse: It is unclear whether results showed any differences between groups (RR 0.95, 95% CI 0.70 to 1.31; one RCT; n = 54; very low-quality evidence), Repeat surgery for prolapse: It is unclear whether results showed any differences between groups (RR 2.13, 95% CI 0.42 to 10.82; one RCT; n = 66; very low-quality evidence). Recurrent anterior compartment prolapse: This is probably more likely after native tissue repair (RR 1.50, 95% CI 1.09 to 2.06; three RCTs; n = 268; I2 = 0%; moderate-quality evidence), suggesting that if 27% have recurrent prolapse after mesh repair, 29% to 55% would have recurrent prolapse after native tissue repair. SUI: It is unclear whether results showed any differences between groups (RR 0.72, 95% CI 0.50 to 1.05; one RCT; n = 49; very low-quality evidence). Dyspareunia: No data were reported. Authors' conclusions: Biological graft repair or absorbable mesh provides minimal advantage compared with native tissue repair. Native tissue repair was associated with increased awareness of prolapse and increased risk of repeat surgery for prolapse and recurrence of anterior compartment prolapse compared with polypropylene mesh repair. However, native tissue repair was associated with reduced risk of de novo SUI, reduced bladder injury, and reduced rates of repeat surgery for prolapse, stress urinary incontinence and mesh exposure (composite outcome). Current evidence does not support the use of mesh repair compared with native tissue repair for anterior compartment prolapse owing to increased morbidity. Many transvaginal polypropylene meshes have been voluntarily removed from the market, and newer light-weight transvaginal meshes that are available have not been assessed by RCTs. Clinicans and women should be cautious when utilising these products, as their safety and efficacy have not been established.
OBJECTIVES: The combination of prolapse surgery with an incontinence procedure can reduce the incidence of stress urinary incontinence (SUI) after surgery, but may increase adverse events. We compared the effectiveness and safety of prolapse surgery versus combined prolapse and incontinence surgery in women with pelvic organ prolapse.
DESIGN AND SETTING: Pubmed, EMBASE, DARE, the Cochrane Library and the register of Current Controlled Trials were searched for randomised trials (restricted to Burch colposuspension and midurethral sling as incontinence procedure) from 1995 to 2013 limited to the English literature.
METHODS: Two reviewers selected eligible articles and extracted the data. Pooling for SUI was based on three patient groups: (1) women with coexisting SUI; (2) women asymptomatic for SUI; and (3) women with occult SUI. For adverse events, pooling was based on incontinence procedure.
MAIN OUTCOME MEASURES: The primary outcome was SUI. The secondary outcomes were treatment for SUI, bladder storage symptoms, obstructive voiding and adverse events.
RESULTS: Seven trials were included. Pooling for women with coexisting SUI was possible for objective SUI with two studies and showed no difference. Statistical (I(2) = 95%) and clinical heterogeneity was, however, high. The largest study showed a lower incidence of persisting SUI (5% versus 23%) and treatment for this (0% versus 57%) in women who underwent prolapse repair with a midurethral sling. The second study did not find a difference in women undergoing a sacrocolpopexy with or without Burch colposuspension. In asymptomatic women, combination surgery resulted in a lower incidence of de novo subjective SUI (two studies; 24% versus 41%; relative risk [RR], 0.6; 95% confidence interval [CI], 0.3-0.9; I(2) = 36%) and the need for subsequent anti-incontinence surgery (three studies; 2% versus 7%; RR, 0.4; 95% CI, 0.2-0.8; I(2) = 13%). For the outcome objective SUI, pooling was possible for five studies, but statistical heterogeneity was high (I(2) = 82%) and the difference was not statistically significant. In the subgroup of women with occult stress incontinence, we found a lower incidence of objective SUI after combination surgery (two studies; 22% versus 52%; RR, 0.4; 95% CI, 0.3-0.8; I(2) = 32%). There were no differences in bladder storage symptoms, urgency incontinence or long-term obstructive voiding symptoms. Adverse events (two studies; 15% versus 10%; RR, 1.6; 95% CI, 1.0-2.5; I(2) = 0%) and prolonged catheterisation (three studies; 6% versus 1%; RR, 4.5; 95% CI, 1.5-13.3; I(2) = 0%) were more frequent after vaginal prolapse repair with a midurethral sling.
CONCLUSIONS: Combination surgery reduces the risk of postoperative stress incontinence, but short-term voiding difficulties and adverse events were more frequent after combination surgery with a midurethral sling.
This systematic review was performed to investigate the ethical justification, methodological quality, validity and safety of placebo controls in randomized placebo-controlled surgical trials.Central, MEDLINE, and EMBASE were systematically searched to identify randomized controlled trials comparing a surgical procedure to a placebo. "Surgical procedure" was defined as a medical procedure involving an incision with instruments. Placebo was defined as a blinded sham operation involving no change to the structural anatomy and without an expectable physiological response in the target body compartment.Ten randomized placebo-controlled controlled surgical trials were included, all of them published in high-ranking medical journals (mean impact factor: 20.1). Eight of 10 failed to show statistical superiority of the experimental intervention. Serious adverse events did not differ between the groups (rate ratio [RR] 1.38, 95% confidence interval [CI]: 0.92-2.06, P = 0.46). None of the trials had a high risk of bias in any domain. The ethical justification for the use of a placebo control remained unclear in 2 trials.Placebo-controlled surgical trials are feasible and provide high-quality data on efficacy of surgical treatments. The surgical placebo entails a considerable risk for study participants. Consequently, a placebo should be used only if justified by the clinical question and by methodological necessity. Based on the current evidence, a pragmatic proposal for the use of placebo controls in future randomized controlled surgical trials is made.
Systematic Review Question»Systematic review of interventions
