|Adjuvant materials in anterior vaginal wall prolapse surgery: a systematic review of effectiveness and complications
|Foon R, Toozs-Hobson P, Latthe PM
This review concluded that the evidence for the use of biological adjuvant materials in anterior vaginal wall prolapse surgery showed trends towards the reduction of objective recurrence at 12 months. This review was generally well conducted and the authors’ conclusion is likely to be reliable.
To evaluate the efficacy and safety of using extra materials in the surgical treatment of anterior vaginal wall prolapse.
The Cochrane Incontinence Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL and the National Library for Health were searched. Search dates varied across sources, spanning 1966 to September 2007, and the search terms were reported. The reference lists of relevant articles were checked to identify additional studies. Conference proceedings from 2004 to 2007 for two relevant organisations were handsearched and authors of included studies were contacted for additional information. No language or publication restrictions were applied.
Randomised controlled trials (RCTs) that compared surgery using adjuvant materials with standard surgery for anterior vaginal wall prolapse, were eligible for inclusion. The outcomes of interest were objective recurrence, dyspareunia, voiding difficulties, adjuvant material erosions, prolapse symptoms, and reoperation rates.
In the included trials, all operations were for primary repairs and they were described as using standard or traditional techniques. The adjuvant materials varied, but included biological and synthetic (absorbable and non-absorbable) materials. Trials were excluded if they included anterior and posterior vaginal repairs and these data could not be separated. Outcomes were assessed at time points ranging from three to 24 months. Recurrence was reported in a number of different ways, including Ba (the furthest point of the anterior vaginal wall) greater than or equal to minus one, and this definition was used in this review.
Two reviewers independently selected trials for inclusion.
Assessment of study quality
Trial quality was assessed on randomisation method, allocation concealment, loss to follow-up, use of intention-to-treat analysis, and use of a power calculation. These were rated as being adequate or inadequate.
Two reviewers independently assessed quality.
Data on the number of outcomes in the intervention and comparator groups were extracted, by two independent reviewers, using a pre-designed data extraction form. The odds ratio (OR) and 95% confidence interval (CI) were calculated for dichotomous data using intention-to-treat data where available. For trials with multiple publications, only the most up-to-date or largest dataset was included. Attempts were made to contact the authors for additional information.
Methods of synthesis
Data were combined using the Peto-modified Mantel-Haenszel method to obtain pooled ORs and 95% CIs. The number needed to treat (NNT) for recurrence was calculated and heterogeneity was assessed using the I2 test.
Results of the review
Ten RCTs were included and five of these were in abstract form. Total participant numbers were unclear; in the text the number was 1,087 and in the table this appeared to be 1,175. Four RCTs (n= 493 patients) used biological adjuvant materials and six (n=682) used synthetic materials, with absorbable in two of these (n=269) and non-absorbable in four (n= 413). These trials were of mixed quality. Three reported adequate allocation concealment, seven reported adequate randomisation method, seven were analysed by intention-to-treat, five used a power calculation, and eight had at least 85% follow-up.
Efficacy: The use of biological adjuvant material significantly reduced the odds of recurrence of prolapse at 12 months compared with standard surgery (OR 0.56, 95% CI 0.34 to 0.92; NNT 13, 95% CI 6.5 to 85.3; three RCTs, n=450). Likewise the use of synthetic (absorbable polyglactin) adjuvant material significantly reduced the odds of recurrence of prolapse at 12 months compared with standard surgery (OR 0.44, 95% CI 0.21 to 0.89; NNT 6, 95% CI 3 to 33.8; one RCT, n=143). There was no evidence of statistically significant heterogeneity.
Safety: There were no significant differences between the intervention and comparator groups for the outcomes of voiding difficulties, dyspareunia, prolapse symptoms, and reoperation rates. Erosion rates were reported as being 0.67% (1/150; one RCT) for biological adjuvant material, 14% (21/150; two RCTs) for non-absorbable adjuvant material and 2.9% (1/35; one RCT) for absorbable adjuvant material. The statistical significance and CIs were not reported.
The evidence for the use of biological adjuvant materials in anterior vaginal wall prolapse surgery showed trends towards the reduction of objective recurrence at 12 months.
This review addressed a clear question with well-defined inclusion criteria. The authors searched a number of relevant sources without language restrictions. Some attempts were made to locate unpublished material to reduce the potential for publication bias, which was not investigated due to low trial numbers. Appropriate criteria were used to assess trial quality and results provided for each criterion for each trial. Steps were taken to reduce the risk of bias by having two reviewers independently select trials, extract data, and assess quality, but it was unclear how any disagreements were resolved.
The characteristics of included trials were reported in detail, but there appeared to be some discrepancies in the reporting, such as the total number of patients, which differed in the text to the numbers presented in the table. The quality of included trials was mixed and some were published only as abstracts. Appropriate statistical methods were used to pool trial data and assess for heterogeneity, but, due to different postoperative follow-up times and ways of assessing outcomes, only a small number of trials were included in the meta-analysis.
This review was generally well-conducted and the authors’ conclusion is likely to be reliable.
Implications of the review for practice and research
Practice: The authors stated that patients, who are undergoing surgery using adjuvant materials, should be advised that long-term effectiveness and safety data are not available. Ideally, data for audit purposes should be collected by clinicians undertaking these operations.
Research: The authors stated that methodologically sound and adequately powered RCTs, with a longer follow-up, are required to resolve the issues of effectiveness and safety. The requirement for a standardised outcome measure is also important. An individual patient data meta-analysis, including data from these trials and from ongoing trials, may address some uncertainty.
Foon R, Toozs-Hobson P, Latthe PM. Adjuvant materials in anterior vaginal wall prolapse surgery: a systematic review of effectiveness and complications. International Urogynecology Journal 2008; 19(12): 1697-1706
Subject indexing assigned by NLM
Acetamides; Female; Gynecologic Surgical Procedures /methods; Humans; Prostheses and Implants; Recurrence; Surgical Mesh; Treatment Outcome; Uterine Prolapse /surgery
Date bibliographic record published
Date abstract record published
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.