More than 225,000 surgeries for pelvic organ prolapse (POP) are performed annually in the United States, and these include women with uterovaginal prolapse as well as posthysterectomy vault prolapse.1 Although the exact incidence of posthysterectomy prolapse is unknown, estimates ranged from 6% to 8%.2 In women planning to undergo surgery for apical POP, many surgeons elect to treat posthysterectomy or vault prolapse differently than uterovaginal prolapse, believing that a previous hysterectomy increases both prolapse recurrence risk and adverse events. Adverse events are thought to be more common in vault prolapse than uterovaginal prolapse repairs secondary to scarring, loss of surgical landmarks, and vaginal shortening related to the prior hysterectomy.3 On the other hand, many surgical trials for apical POP repair have included both women with uterovaginal prolapse and women with posthysterectomy vault prolapse under the assumption that the surgical repairs are equally efficacious and risks are similar, limiting data available for clinicians to make evidence-based decisions regarding surgical approach.4,5
The objectives of this study were to compare outcomes (anatomic and functional) and adverse events between women undergoing surgical repair of uterovaginal prolapse and women undergoing posthysterectomy vault prolapse. We hypothesized that surgical repair of women undergoing posthysterectomy vault prolapse results in increased risk of recurrence and of adverse events compared with women undergoing surgical repair of uterovaginal prolapse.
MATERIALS AND METHODS
A retrospective analysis was performed of women who participated in one of three Pelvic Floor Disorders Network POP surgery trials: Operations and Pelvic Muscle Training in the Management of Apical Support Loss,6 Colpopexy and Urinary Reduction Efforts,7 or Outcomes Following Vaginal Prolapse Repair and Midurethral Sling.8 All study sites had institutional review board approval and all women gave written informed consent. All participants underwent surgical correction of stage II–IV prolapse with apical repair by experienced pelvic surgeons at 17 study sites throughout the United States. We excluded patients who underwent transvaginal mesh procedures or colpocleisis and women whose only apical procedure was ligation of the peritoneal sac or trachelectomy. The cohort was divided into those women presenting with uterovaginal prolapse compared with vault prolapse.
Women who underwent McCall's culdoplasty, sacrospinous ligament suspension, uterosacral ligament suspension, or iliococcygeal repair were considered to have a vaginal apical suspension procedure. All women who underwent abdominal repair had an open sacral colpopexy with various mesh products as per study design. Vaginal approaches to repair of the anterior compartment included traditional anterior colporrhaphy and vaginal paravaginal repair; these approaches were grouped. Posterior repair included women who underwent traditional posterior colporrhaphy or perineorrhaphy. All women were followed for 1 year postoperatively and data were collected at 3, 6, and 12 months. For the Colpopexy and Urinary Reduction Efforts and Operations and Pelvic Muscle Training in the Management of Apical Support Loss trials, data were also provided at 24 months after apical repair.
As determined previously in the three trials, success was defined as absence of all of the following: 1) bothersome bulge symptoms as measured by the Pelvic Floor Distress Inventory Question 5 (defined as a response of “yes” to “Do you usually have a bulge or something falling out that you can see or feel in the vaginal area?” or “not at all” to “If yes, how much does it bother you”), 2) no prolapse beyond the hymen on pelvic organ prolapse quantification (POP-Q) examination, and 3) no subsequent retreatment for prolapse. Women failing to meet any of these three were considered surgical failures. Pelvic organ prolapse quantification examinations and Pelvic Floor Distress Inventory, Pelvic Floor Impact Questionnaire,9,10 and Pelvic Organ Prolapse Urinary Incontinence Sexual Questionnaire11 measures were administered at baseline and each follow-up visit. Secondary efficacy endpoints include the calculated subscores for the Pelvic Floor Distress Inventory, the Pelvic Organ Prolapse Distress Inventory, Urogenital Distress Inventory, Colorectal Anal Distress Inventory, and the Pelvic Floor Impact Questionnaire, including the Pelvic Organ Prolapse Impact Questionnaire, Urogental Impact Questionnaire, and Colorectal Anal Impact Questionnaire as well as the total Pelvic Organ Prolapse Urinary Incontinence Sexual Questionnaire score. All surgical trials measured all these outcomes in a similar fashion with assessors who were masked to patient allocation in the parent trial.
Intraoperative and postoperative complications and serious adverse events were recorded on standardized forms up to 6 weeks postoperatively and graded according to the Clavien-Dindo scale. The definition of a serious adverse event for all studies included adverse events that resulted in death, were life-threatening, required inpatient hospitalization (with the exception of hospitalization for stress incontinence surgery) or prolongation of existing hospitalization, resulted in persistent or significant disability or incapacity, resulted in a congenital anomaly or birth defect, or was another medically important condition. After 6 weeks, only serious adverse events were recorded and graded. Intraoperative and immediate postoperative complications up to 6 weeks postoperatively included blood transfusion, deep vein thrombosis, pulmonary embolus, and surgical injuries including ureteral, bladder, urethral, bowel, vascular, and nerve injuries.
We estimated that data from approximately 300 women who underwent vault prolapse repair and 600 women who underwent uterovaginal prolapse repair would be available for at least some follow-up visits. Although longitudinal model-based approaches for analyses were planned, conservative estimates of power were calculated based on cross-sectional approaches at follow-up years 1 and 2. Based on the fact that at least 85% of the participants provided adequate data at 1 and 2 years to evaluate the primary outcome and the overall treatment success at 1 year was approximately 80%, we estimated that our sample size would provide more than 90% power to detect any difference in our primary outcome as defined a priori to be 6% or greater. For the 2-year outcome, based on the finding that the overall treatment success at 2 years was approximately 60% for the vaginal surgery cohorts, the sample size provides more than 90% power to detect a difference between the two groups of 10% or more in our primary outcome.
Participant baseline characteristics were compared between treatment groups using analysis of covariance or Kruskal-Wallis tests for continuous or interval measures, as appropriate, Mantel-Haenszel mean score tests using modified ridit scores for ordinal categorical measures, and Cochran Mantel-Haenszel χ2 tests for a general association for categorical measures. For outcomes obtained at multiple follow-up visits, the proportion of participants considered a treatment success and change from baseline in quality-of-life scores, analyses were conducted using extensions of generalized linear models with generalized estimating equations using empiric variance estimates to account for multiple time points and longitudinal mixed-effects models, respectively. These models included adjustments for center where possible as well as age, body mass index (BMI, calculated as weight (kg)/[height (m)]2), baseline POP-Q stage, apical repair procedure performed, prior prolapse repair, and performance of a concurrent anterior and posterior repair. Additionally, models for quality-of-life scores controlled for the corresponding baseline quality-of-life score. Interval estimates and P values for these outcomes were obtained using contrast statements for assessing whether differences existed for the two groups across study follow-up and at each time point. As a result of low rates of occurrence of specific complications, the percent of participants experiencing those complications during the perioperative and 6-week postoperative period were compared between treatment groups using a Fisher exact test without adjustments. Only the difference in the primary outcome at 1 year was considered to be a formal hypothesis test and all other P values are considered descriptive and hypothesis-generating, so no formal adjustments were made for multiple testing. However, P values should be interpreted cautiously given the number of comparisons presented.
The methods and results of Colpopexy and Urinary Reduction Efforts, Outcomes Following Vaginal Prolapse Repair and Midurethral Sling, and Operations and Pelvic Muscle Training in the Management of Apical Support Loss have been previously published.6–8 For the current analyses, 1,022 women met inclusion criteria; 421 underwent vault prolapse and 601 uterovaginal prolapse repair. In the uterovaginal prolapse group, 585 (97%) of women underwent hysterectomy with or without oophorectomy. We included 321 women from Colpopexy and Urinary Reduction Efforts, 365 from Operations and Pelvic Muscle Training in the Management of Apical Support Loss, and 336 from Outcomes Following Vaginal Prolapse Repair and Midurethral Sling (Fig. 1). By definition, no woman in the vault prolapse group underwent hysterectomy, but 85 (20%) underwent oophorectomy at the time of prolapse repair. The vault prolapse cohort was older (P<.001), more likely to be white (P<.001), and had lower mean BMIs (P=.034). In addition, the vault prolapse group was more likely to have undergone prior urinary incontinence or prolapse repair, had more advanced prolapse, and reported more bother from their prolapse as measured by baseline Pelvic Organ Prolapse Distress Inventory scores when compared with the uterovaginal prolapse group (Tables 1 and 2).
Surgical approaches varied between the vault prolapse and uterovaginal prolapse groups, depending on the protocol to which the patient was enrolled. The vault prolapse group was more likely to undergo sacrocolpopexy (54% vs 15%), whereas the uterovaginal prolapse group was more likely to undergo vaginal apical suspension (85% vs 46%, P<.001). Women in the vault prolapse group were less likely to undergo anterior repair (45% vs 52%, P<.001), but were equally likely to undergo posterior repair (43% vs 41%, P=.45) as the uterovaginal prolapse group. Similarly, women in the vault prolapse group were more likely to undergo Burch retropubic urethropexy, whereas women in the uterovaginal prolapse group were more likely to undergo a retropubic midurethral sling procedure as a result of the parent study designs (Table 3).
Although success rates declined over time, we found no evidence of differences between the vault prolapse and uterovaginal prolapse groups after adjusting for differences between groups in baseline characteristics and surgical interventions performed. Similarly, results for points Bp, C, and bothersome bulge symptoms showed no differences between groups beyond the 3-month time point. Point Ba was better supported in the uterovaginal prolapse group overall, but the difference of 0.4 cm was small. Few women in either group underwent retreatment for prolapse and most women in both groups had support of their prolapse above the hymen at 1–2 years postoperatively (Table 4). To more fully explore changes in pelvic floor function and quality of life, we compared change scores in Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire subscales between groups over time. Subscale scores did not vary between groups over time. Among women who reported sexual function, no difference was observed between groups (Table 5).
Because of the large differences in surgical approach between the two groups, we performed a subanalysis of women who underwent apical repair only with a vaginal approach. For these analyses, 701 women were included; 193 underwent vault prolapse repair, and 508 underwent uterovaginal prolapse repair. Again, no differences in success rates were observed; few women underwent retreatment and most women reported absence of bothersome bulge symptoms and had support above the hymen at 1–2 years after surgery (Appendix 2, available online at http://links.lww.com/AOG/B68).
Adverse events were rare and did not vary between groups (Appendices 3 and 4, available online at http://links.lww.com/AOG/B68).
Data obtained from three large surgical trials performed in the Pelvic Floor Disorders Network provided us with a unique opportunity to compare outcomes in two cohorts of women undergoing apical prolapse surgery commonly encountered in clinical practice: women who had previously undergone a hysterectomy and those with uterovaginal prolapse. Using a multicomponent outcome measure consisting of anatomic, symptom-specific distress and retreatment, we found no difference in success rates between groups at 1–2 years postoperatively. Similarly, when comparing surgical success in women undergoing a vaginal approach for these two conditions, no differences were noted in success rates. Furthermore, no significant differences were noted between groups in adverse events or serious adverse events reported including blood transfusion, cystotomy, deep vein thrombosis, pulmonary embolism, or visceral injuries between vaginal prolapse and uterovaginal prolapse groups. This is a robust comparison of surgical treatment outcomes between women undergoing vault prolapse compared with uterovaginal prolapse repair. It provides reassurance to women who develop prolapse after hysterectomy that surgical interventions are likely to result in similar outcomes compared with women who undergo a hysterectomy as part of their prolapse repair. Our findings support that the outcomes after apical repair posthysterectomy prolapse are not different from repair of uterovaginal prolapse repair in the hands of experienced surgeons 1–2 years postoperatively.
Postvaginal vault prolapse repair has been thought to be a more difficult repair in a survey of pelvic surgeons.3 Direct comparisons of prolapse repair in women with vault and uterovaginal prolapse are lacking. Increasingly, pelvic reconstructive surgeons have recognized that suspension of the vaginal apex is critically important in optimizing overall vaginal prolapse treatment outcomes.12–15 Until now, very little was known about the differences in outcomes between women with uterovaginal prolapse and vault prolapse, particularly in regard to the success of repair and adverse events, to help guide these choices.
Although not the primary focus of this investigation, the question of the optimal apical approach (abdominal vs transvaginal) for vault prolapse or uterovaginal prolapse is controversial and continues to evolve. Our study included women enrolled in three surgical trials, all of which explored techniques of apical repair in the presence or absence of the uterus.6–8 To further explore whether sacrocolpopexy with graft significantly influenced our conclusions, a sensitivity analysis was performed of those women who underwent apical repair with a transvaginal approach only, excluding patients undergoing sacrocolpopexy. This analysis found that success and adverse event rates were similar to those reported for the entire cohort, which further supports our conclusions.
The strengths of our study are the large, diverse, and well-characterized patient population with standardized surgical interventions, outcome measures, and adverse events. This is particularly important because women often weigh the risks of adverse events against the possible success of surgery when making decisions to undergo elective surgery. Limitations include the inherent risk of systematic bias of any retrospective analysis; surgical approach for an individual woman was guided by the protocol into which she was enrolled. In addition, our comparison focused on a comparison of vault compared with uterovaginal prolapse repairs, and outcomes may have been influenced by surgeon experience, length of different surgical approaches, and performance of concomitant procedures, although these cases were performed by experienced surgeons and surgical approach was standardized between study sites. Most women enrolled in these trials were white, which limits generalizability to other ethnicities. Our patient population differed significantly between groups, and although we controlled for baseline differences, there could still be significant biases that remain unmeasured including that the surgical intervention would be influenced by these baseline differences. We also did not correct for multiple comparisons. Other limitations include that the majority of women underwent a vaginal approach to their repair, regardless of whether or not a uterus was present. These analyses did not directly compare abdominal and vaginal approaches to repair, which is of clinical interest to the practicing gynecologist. Finally, there was attrition over time in all cohorts and we cannot account for the women who did not give data at all time points, and our study only includes outcomes up to 2 years after surgery; many recurrences of prolapse occur outside of this timeframe. Although not a limitation of the study, these data do not inform the decision for women with uterovaginal prolapse whether or not a hysterectomy or uterine-sparing procedure should be performed.
In summary, we found that prolapse success rates, quality of life, symptom scales, nor adverse events varied between women undergoing vaginal vault or uterovaginal apical prolapse repair.
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