Reanalysis of a randomized trial of 3 techniques of anterior colporrhaphy using clinically relevant definitions of success




Objective


The purpose of this study was to reanalyze the results of a previously published trial that compared 3 methods of anterior colporrhaphy according to the clinically relevant definitions of success.


Study Design


A secondary analysis of a trial of 114 subjects who underwent surgery for anterior pelvic organ prolapse who were assigned randomly to standard anterior colporrhaphy, ultralateral colporrhaphy, or anterior colporrhaphy plus polyglactin 910 mesh from 1996−1999. For the current analysis, success was defined as (1) no prolapse beyond the hymen, (2) the absence of prolapse symptoms (visual analog scale ≤2), and (3) the absence of retreatment.


Results


Eighty-eight percent of the women met our definition of success at 1 year. One subject (1%) underwent surgery for recurrence 29 months after surgery. No differences among the 3 groups were noted for any outcomes.


Conclusion


Reanalysis of a trial of 3 methods of anterior colporrhaphy revealed considerably better success with the use of clinically relevant outcome criteria compared with strict anatomic criteria.


Approximately 200,000 women undergo surgery for pelvic organ prolapse (POP) annually in the United States, at an estimated cost of >$1 billion. The anterior vaginal wall is the most common segment of the vagina to prolapse and is the segment that is most likely to fail long-term after surgical correction. Anterior colporrhaphy has been used for the past century as a surgical technique to correct anterior vaginal prolapse. However, few randomized trials have evaluated the relative success of this technique.




For Editors’ Commentary, see Table of Contents



A randomized trial that compared 3 different methods of surgical correction of anterior vaginal prolapse was conducted between 1996 and 2001 by Weber et al. A PubMed search of anterior colporrhaphy trials from 1979 to the present revealed that this was the first controlled clinical trial to compare different techniques of anterior colporrhaphy for prolapse repair. The study found that, at 23 months of follow up, patients with 70% of the traditional anterior colporrhaphy, 54% of the “ultralateral” anterior colporrhaphy, and 58% of the absorbable mesh-augmented colporrhaphy had recurrent descent of the anterior vaginal wall to within 1 cm of the hymenal ring (POP-quantification [POP-Q] stage 2 prolapse), although most patients were asymptomatic. No statistically significant difference in outcomes was noted among the 3 groups. This trial has been cited frequently in the literature since its publication (196 citations; Scopus search Oct. 4, 2010) and, given the relatively low success found in the trial, often has been used as evidence that anterior colporrhaphy should either be augmented by synthetic mesh or another approach used (eg, sacrocolpopexy) for treatment of anterior vaginal prolapse.


The definition of success that was used in the trial was based on recommendations of the 2001 National Institutes of Health (NIH) Workshop on Standardization of Terminology for Researchers in Pelvic Floor Disorders. The workshop noted that these definitions were made arbitrarily and without the benefit of adequate knowledge of the epidemiology and natural history of POP or the relationship between anatomic support and pelvic floor symptoms. Since this workshop, advances in research have revealed these purely anatomic definitions to be too strict, because >75% of women who had annual gynecologic examinations without symptoms of POP would not meet the definition of “optimal anatomic outcome” and almost 40% of the women would not meet the definition of “satisfactory anatomic outcome.” Thus, studies that use even the NIH “satisfactory” anatomic outcome as their definition of treatment success, such as the trial in this analysis, classify a substantial number of women within the spectrum of normal anatomy as treatment failure.


Moreover, recent evidence suggests that the absence of vaginal bulge symptoms after surgery has a significant relationship with a patient’s assessment of overall improvement; anatomic success alone does not. As such, the National Institute of Child Health and Human Development (NICHD) Pelvic Floor Disorders Network has recommended that (1) any definition of success after POP surgery should include the absence of bulge symptoms in addition to anatomic criteria and the absence of retreatment and (2) the use of the hymen as a threshold for anatomic success seems a reasonable and defensible approach. The objective of this study was to use the existing data that were collected by Weber et al to reanalyze the results of the trial with these contemporary definitions of success after prolapse surgery to provide clinically relevant estimates of treatment effect for the 3 techniques that were used in the trial.


Materials and Methods


This is a secondary analysis of the clinical trial performed by Weber et al. This trial was performed in the Department of Obstetrics and Gynecology at the Cleveland Clinic between June 1996 and January 2001; all of the original case report forms were reviewed, and the data were abstracted for this reanalysis. When pertinent data were not present on the original data-collection forms, the medical records were reviewed to obtain the missing data when available and included any data on retreatment or anatomic or subjective failure at time points beyond that in the original study. Study subjects were not recontacted for this analysis.


Subjects were included in the trial if they underwent operation for anterior vaginal prolapse at the Cleveland Clinic from June 1996 to May 1999 and provided institutional review board–approved informed consent. Patients were excluded if they underwent any incontinence procedure other than suburethral plication (Burch colposuspension, sling, or needle suspension). Based on clinical parameters determined by the urogynecologist, women with either no incontinence or mild or latent incontinence were eligible for participation in the study. Concurrent procedures for prolapse did not prohibit participation and did not affect group assignment.


One hundred fourteen patients were assigned randomly (1:1:1) to 1 of 3 surgical techniques for anterior vaginal prolapse with the use of a computer-generated random numbers table: standard anterior colporrhaphy (n = 38), ultralateral colporrhaphy (n = 38), and standard anterior colporrhaphy plus mesh (n = 38). Patients completed questionnaires about prolapse symptoms and underwent physical examination before and after operation at approximately 6 months, 1 year, and 2 years. Visual analog scales (VAS; 0-100 mm) were used to assess the presence or absence of various pelvic floor symptoms. The POP-Q staging system was used to assess pelvic organ support; all POP-Q examinations were performed by a blinded examiner. Data that were collected from intraoperative evaluation included physical examination, type of bladder neck plication, associated procedures, and any relevant complications. Further details of inclusion, data collection, and the randomization process can be found elsewhere.


The original publication sought to determine whether there was a difference in the cure of anterior vaginal prolapse among the 3 different surgical techniques of anterior colporrhaphy. Stage of prolapse was defined at point Aa, point Ba, and the most advanced prolapse at any vaginal site. The primary outcome of anatomic success was defined as optimal when both points Aa and Ba were at stage 0 (-3 cm). Outcome was satisfactory when both points Aa and Ba were at stage 1 (≤–2 cm) and improved from preoperative staging. Cure was defined as either optimal or satisfactory anatomic outcome. Failure or unsatisfactory outcome was when either point Aa or Ba were >–2 cm.


In this reanalysis, we used outcome measures of treatment success that recently have been recommended by the NICHD Pelvic Floor Disorders Network. Our primary outcome was anatomic success as defined by POP-Q measurements Ba, Bp, and the most dependent part of the vagina at ≤0 cm. At follow-up examination, subjects completed a prolapse symptom VAS: “How much are you bothered by symptoms related to vaginal prolapse?” (range, 0 [not at all] to 100 [extremely]). A priori, we defined clinically relevant prolapse symptoms as VAS of >20 mm. This cut-point was chosen rather than 0 because VASs are known to have end-aversion bias, at which respondents are often unwilling to mark extreme health states on continuous scales and because the VAS has been shown to have an imprecision of ± 20 mm on postoperative evaluations. Retreatment success included the absence of retreatment (including pessary use or surgery for treatment of POP) within 40 months after surgery. For the analysis of the primary outcome of anatomic success (Ba, Bp, and most dependent part of the vagina at ≤0 cm), patients were analyzed in the group to which they had been assigned randomly (intention-to-treat analysis). Only subjects with prolapse beyond the hymen (Ba, Bp or C >0 cm) before surgery were included in our analysis of anatomic outcomes, which resulted in the exclusion of 2 subjects who provided postoperative anatomic data in the original analysis. Unlike the original study, all other outcomes (absence of bulging symptoms, retreatment/reoperation) were also analyzed according to randomization group. To minimize the impact of missing data, our primary analysis assessed treatment success at 1 year. For subjects without 1-year data but with follow-up evaluation beyond 1 year, we used the last-observation-carried-backward method for imputation. Group comparisons of baseline and demographic characteristics were made with χ 2 or Fisher’s exact tests for categoric factors; t tests or Wilcoxon rank sum tests were used for continuous factors, as appropriate. Because of differences in follow-up time in the primary outcome measure, the Kaplan-Meier method was also used to estimate the proportion of successes at follow-up evaluation and the log-rank test for comparison of success. This study was originally powered to detect a 30% difference among groups with 80% power and alpha of .05. Given that no significant differences were noted among groups in the original trial, we did not anticipate finding differences between groups for this analysis. As such, the primary analysis was performed on all subjects in aggregate to determine the overall proportion of subjects who experienced anatomic recurrence beyond the hymen, symptomatic recurrence, or required retreatment. Between-group comparisons were also performed, however.

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May 28, 2017 | Posted by in GYNECOLOGY | Comments Off on Reanalysis of a randomized trial of 3 techniques of anterior colporrhaphy using clinically relevant definitions of success

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