Composite outcomes following posterior colporrhaphy with and without biologic graft augmentation

Abstract

Objectives:

To compare subjective and objective failure following posterior colporrhaphy with and without biologic graft augmentation.

Methods:

We conducted a retrospective chart review and telephone survey of patients who underwent a posterior colporrhaphy with and without biologic graft augmentation from 2005-2019. Patients who underwent a sacrocolpopexy, uterosacral ligament suspensions, or anterior sacrospinous ligament fixation were excluded. Objective failure was defined as the need for retreatment as reported by the patient or identified in review of the medical records, or clinical exam with POPQ point Ap or Bp to the level of the hymen or beyond. Subjective failure was defined as a symptomatic vaginal bulge.

Results:

There were 137 patients who met eligibility criteria for inclusion in the study. A total of 56 did not have valid contact information and therefore were excluded from the study. Of the 81 we were able to reach by telephone, 67 (83%) agreed to participate. There were 24 (36%) who had a native tissue repair and 43 (64%) who had biologic graft augmentation. Median telephone follow-up was 73 months (IQR 36 to 117). Objective failure rates were similar for the biologic graft (37%) and the native tissue (42%) groups (p=0.72). Subjective failure was twice as likely among the biologic graft group (60%) compared with the native tissue group (33%, p=0.03). Patients with a biologic graft reported a median PFDI-20 improvement of 31 (IQR 8 to 33), while those with a native tissue repair reported a median improvement of 45 (IQR 4 to 46). Overall, 78% were satisfied, 85% would recommend the procedure and 84% reported symptomatic improvement. Reoperation occurred for 15% of patients.

Conclusion(s):

While biologic graft-augmented posterior colporrhaphy may be a safe and effective treatment option, the use of biologic grafts in the posterior compartment does not appear to confer a significant long-term benefit to traditional posterior colporrhaphy.

INTRODUCTION

Pelvic organ prolapse is the herniation of pelvic organs through the vagina, and women have a 11% lifetime risk of requiring surgery for treatment of pelvic organ prolapse.¹ In fact, the surgical repair of prolapse is one of the most common inpatient procedures performed on older women.² Surgical treatment for prolapse aims to restore normal anatomy and improve quality of life. Despite the fact that surgery for pelvic organ prolapse is common, surgical outcomes leave much to be desired and failure following primary prolapse surgery frequently exceed 30%^3–5 In an attempt to address the high rates of failure, some surgeons may augment the surgical repair with synthetic or biologic grafts. Transvaginal synthetic grafts have recently been withdrawn from the market by the U.S. Food and Drug Administration. While synthetic grafts are a permanent implant with long-terms risks of mesh erosion and exposure, biologic grafts are replaced over time with host tissue and therefore do not carry these same risks. Historically, three types of biologic grafts have been used to help augment prolapse repair; autografts, allografts and xenografts.^4,6,7 The goal of this study was to compare the composite outcome of subjective or objective failure after native tissue compared to biologic graft-augmented posterior colporrhaphy.

MATERIALS AND METHODS

We conducted a retrospective chart review and telephone survey of patients who had undergone a posterior colporrhaphy with and without biologic graft augmentation from 2005- to 2019. We used Current Procedural Terminology codes 57250, 57260 and 57265 to identify patients who underwent a posterior colporrhaphy at our institution and reviewed medical records to confirm the coding was accurate. While patients with a concurrent anterior repair or synthetic sling procedures were eligible for inclusion in the study, we excluded patients who had placement of synthetic transvaginal mesh or underwent a more extensive surgery, including an abdominal (including laparoscopic or robotic) sacrocolpopexy, uterosacral ligament suspension, or anterior sacrospinous ligament fixation. Patients were also excluded if they had no valid contact information and thus unable to consent to inclusion in the study or complete the telephone survey. Patients who had surgery less than six months before the study onset were also excluded.

To minimize bias, the telephone survey was conducted by an independent physician who was not involved in the index surgery. A standardized script was used and verbal consent was obtained.

Using a 5-point Likert scale, participants were asked 1) “How satisfied are you with your procedure?” and 2) “How likely would you be to recommend the same surgical procedure to someone else?” We considered women who reported that they were “very satisfied” and “somewhat satisfied” as satisfied, and those who reported they were “neither satisfied nor dissatisfied,”, “somewhat dissatisfied”, or “very dissatisfied” as less than satisfied. Participants completed the Patient Global Impression of Improvement (PGI-I)⁸ which is a single-item questionnaire with scores ranging from 1 (very much better) to 7 (very much worse). Improvement was defined as a PGI-I score of 1, 2 or 3. We also asked participants to complete a modified Decision Regret Scale (DRS),⁹ a questionnaire designed to measure regret after health care decisions.¹⁰ The modified DRS has been validated for patients with pelvic floor disorders.⁹ Scores range from 0 to 100 with higher scores indicating high regret. There are no definitive cut-off scores for the DRS; in this study, scores of 25 or less were considered low regret and higher scores were considered high regret.

Participants completed the Pelvic Floor Distress Inventory (PFDI-20) and Pelvic Floor Impact Questionnaire (PFIQ-7). The PFDI-20 has three subscales; the six-item Urinary Distress Inventory (UDI-6), the six-item Pelvic Organ Prolapse Distress Inventory (POPDI-6), and the eight-item Colorectal-Anal Distress Inventory (CRADI-8) and has been validated for administration by telephone.^11,12 Each subscale is scored from 0 (least distress) to 100 (greatest distress). The sum of the three scores is the PFDI-20 score, which ranges from 0 to 300.¹³ The PFIQ-7 has seven questions for each of the three scales (Urinary Impact, Pelvic Organ Prolapse Impact, and Colorectal-Anal Impact). Total PFIQ-7 scores are measured on a 0 to 300 scale with higher scores indicating greater pelvic floor impact.¹³ Patients also were asked if they required additional treatment for prolapse, including a referral to pelvic floor physical therapy, use of a pessary or a repeat surgery.

Medical records of participants were reviewed to abstract clinical and demographic information. This included data from the initial clinical visit, such as a thorough history and physical exam and baseline pre-operative questionnaires, including the PFDI-20 and the PFIQ-7.

Objective failure was defined as the need for retreatment with a pessary or surgery as reported by the patient during the telephone survey, or descent of point Ap or Bp to the level of the hymen or beyond as assessed by the Pelvic Organ Prolapse Quantification (POP-Q) System scores from the most recent clinical visit. Subjective failure was defined as an affirmative answer to question 3 on the PFDI-20; “Do you usually have a bulge or something falling out that you can see or feel in your vaginal area?” Composite failure was defined as having either objective or subjective failure.

Descriptive data is presented as median with interquartile range (IQR) or proportion, depending on data type and distribution. Categorical data were compared using a chi-square or Fisher’s exact test. Continuous data were compared using the Wilcoxon rank-sum test or Wilcoxon signed-rank test. Multivariable regression was used to estimate the risk ratio (RR) and 95% confidence interval (CI) for the primary outcomes of composite failure and the secondary outcomes of objective and subjective failure. A priori, we decided to adjust for prior prolapse surgery and baseline POPDI-6 scores as these are potential indicators of the severity of prolapse and the potential risk of failure. We also assessed body mass index, prior hysterectomy, and baseline prolapse stage as potential confounders. All tests were two sided and p-values <0.05 were considered statistically significant. Data were analyzed with SAS 9.4 (SAS Institute, Cary, North Carolina). The institutional review boards at Mount Auburn Hospital and Beth Israel Deaconess Medical Center approved this study.

RESULTS

We identified 137 patients who underwent a posterior colporrhaphy with and without biologic graft augmentation. We excluded 54 who did not have current contact information and two who were not conversant in English. Thus, 81 patients were eligible for the study, and 67 (83%) agreed to participate. There were 24 (36%) participants who had a native tissue repair and 43 (64%) who had biologic graft augmentation. Baseline demographics were similar in both surgical groups, although those who had biologic graft augmentation were more likely to have undergone a prior prolapse procedure (49%) compared to those who had a native tissue repair (38%). Those who had biologic graft augmentation also had a lower median preoperative PFDI-20 score (76; IQR 46-125) compared to those who had a native tissue repair (103; IQR 48-141) although this difference was largely driven by differences on the UDI-6 and not by differences on the POPDI-6. Baseline POPQ scores were similar between groups and most patients had stage II prolapse. Baseline demographic and clinical characteristics are shown in Table 1.

Table 1:

Baseline characteristics of patients undergoing posterior colporrhaphy

Characteristic	Biologic graft (n=43)	Native tissue (n=24)
Age, years	59 (52 – 64)	54 (49 – 63)
Body Mass Index, kg/m2	27 (23 – 32)	29 (25 – 32)
Follow up, months	73 (46 – 120)	73 (31 – 113)
Comorbidities
Diabetes	2 (5)	2 (8)
Tobacco use	2 (5)	3 (13)
Hypertension	8 (19)	6 (25)
Surgical history
Hysterectomy	24 (56)	10 (42)
Anti-incontinence procedure	11 (26)	8 (33)
Prolapse procedure	21 (49)	9 (38)
Baseline Pelvic Floor Distress Inventory	76 (46 – 125)	103 (48 – 141)
Baseline Colorectal-Anal Distress Inventory	19 (6 – 44)	19 (9 – 41)
Baseline Urinary Distress Inventory	21 (8 – 46)	38 (17 – 50)
Baseline Pelvic Organ Prolapse Distress Inventory	29 (17 – 58)	31 (21 – 46)
Baseline Pelvic Floor Impact Questionnaire	29 (5 – 100)	52 (14 – 86)
Concurrent Surgery
Anterior colporrhaphy	2 (5)	1 (4)
Synthetic midurethral sling	19 (44)	17 (71)
Hysterectomy	1 (2)	0 (0)
Prolapse stage
Stage I	0 (0)	3 (15)
Stage II	30 (88)	17 (85)
Stage III/IV	4 (12)	0 (0)
Baseline Pelvic Organ Prolapse Quantification System scores
Ap	0 (−1-1)	−0.5 (−1-0)
Bp	0 (0-1)	−0.5 (−1-0)
C	−5 (−7 - −4)	−5 (−7 - −4)
Gh	4 (3-4)	3 (3-4)
Pb	4 (3-4)	3 (3-4)

Data presented as median (interquartile range) or n (%)

Median telephone follow-up was 73 months (IQR 46 to 120) in patients who had a biologic graft augmentation and 73 months (IQR 31 to 113) in those who had a native tissue repair. The biologic graft group was more likely to experience composite failure (74%) than the native tissue group (54%). Although the crude RR was not statistically significant (RR: 1.4; 95% CI: 0.91-2.1), after adjusting for prior prolapse surgery and pre-operative POPDI-6 score, the RR suggested a significant increase in risk of composite failure for the biologic graft group (RR: 1.8, 95% CI: 1.1-2.8). None of the potential confounders appreciably altered the RR. The difference in composite failure primarily was driven by a difference in the incidence of subjective failure, which was nearly twice as high in the biologic graft group (60%) compared with the native tissue group (33%), yielding a crude RR of 1.8 (95% CI: 0.98-3.4) and an adjusted RR of 2.9 (95% CI: 1.4-5.8). Among patients who had a native tissue repair, 21% had both objective and subjective failure. Among patients with biologic graft augmentation, 23% had both objective and subjective failure.

Objective failure incidence was similar between those with biologic graft augmentation (37%) and native tissue repair (42%), with both crude (RR: 0.89; 95% CI: 0.48-1.6) and adjusted (RR: 1.1; 95% CI: 0.55-2.1) RRs demonstrating no association. While postoperative POP-Q scores were not available for five participants, among those with a postoperative POP-Q score, all patients with Ap or Bp at the level of the hymen or beyond (POP-Q point Ap or Bp of ≥0) had retreatment of prolapse. We did not find a significant correlation between POPQ scores and patients who had a symptomatic bulge. In the telephone survey, the overall incidence of reoperation was 15%, including 16% in the biologic graft augmentation group and 13% in the native tissue repair group. Participants were asked if they had repeat surgery during the telephone survey. We found that relying on the telephone survey to determine rates of reoperation had greater sensitivity and captured patients who had reoperation both at our institution and at an outside institution. Review of the medical records did not identify any cases of reoperation that were not already obtained during the telephone survey. Participants who had a native tissue repair underwent reoperation a median of 29 months (IQR 6 to 89) after their initial surgery compared with 18 months (IQR 12 to 42) for those who underwent biologic graft augmented repair, although this difference was not statistically significant (p=1.00).

Patients in both groups reported improvement and the extent of improvement was similar between groups across measures. Regardless of the surgical approach, nearly 80% were satisfied with their procedure and over 80% would recommend the procedure to someone else. Improvement in PFDI-20 and PFIQ-7 were also similar between groups. Patients with biologic graft augmentation reported a 59% improvement in the POPDI-6 subscale, while those with a native tissue repair reported an 81% improvement. Similarly, patients with a biologic graft reported a 47% improvement on the CRADI-8 subscale while those with a native tissue repair reported a 68% improvement from baseline. Postoperative outcomes are shown in Table 2.

Table 2:

Outcomes following posterior repair survey

	Biologic graft (n=43)	Native tissue (n=24)	p
Additional treatment
Conservative management	11 (26)	9 (38)	0.31
Surgical treatment	7 (16)	3 (13)	0.51
Patient Global Impression of Improvement (1-7 scale)			1.00
Improved (scores 1-3)	36 (84)	20 (83)
Not improved (scores 4-7)	7 (16)	4 (17)
Satisfaction			0.70
Satisfied	34 (79)	18 (75)
Less than satisfied	9 (21)	6 (25)
Recommend procedure			0.76
Somewhat or very likely	37 (86)	20 (83)
Neither likely nor unlikely	3 (7)	1 (4)
Somewhat or very unlikely	3 (7)	3 (13)
Decision Regret Scale (0-100 scale)			1.00
High regret (scores >25)	7 (16)	4 (17)
Low regret (score ≤ 25)	36 (84)	20 (83)
Change in PFDI-20 Score*	31 (11 – 90)	45 (21 – 86)	0.25
Change in CRADI-8 score	9 (0 – 28)	13 (0 – 38)	0.80
Change in UDI-6 score	4 (−4 – 17)	19 (0 – 33)	0.09
Change in POPDI-6 score	17 (8 – 33)	25 (4 – 46)	0.59
Change in PFIQ-7 score†	17 (0 – 48)	38 (10 – 71)	0.29

Data presented as median (interquartile range) or n (%)

^*PFDI-20: The pelvic floor distress inventory (PFDI-20) involves three subscales. the six-item Urinary Distress Inventory (UDI-6), the six-item Pelvic Organ Prolapse Distress Inventory (POPDI-6), and the eight-item Colorectal-Anal Distress Inventory (CRADI-8). Each subscale is scored from 0 (least distress) to 100 (greatest distress). The sum of the three scores is the PFDI-20 score, which ranges from 0 to 300

^†PFIQ-7: The Pelvic Floor Impact Questionnaire (PFIQ-7) has seven questions for each of the three scales (Urinary Impact, Pelvic Organ Prolapse Impact, and Colorectal-Anal Impact). Total PFIQ-7 scores are measured on a 0-300 scale with higher scores indicating greater pelvic floor impact

DISCUSSION

While we found that the adjusted risk of composite failure was nearly twice as high for patients who had a biologic graft augmented-posterior colporrhaphy compared to those who had a native tissue posterior colporrhaphy, this difference was largely driven an increased risk of subjective failure. The groups were similar regarding the risk of objective failure. This study is unique in that the median telephone follow-up was over five years for both groups, allowing us to not only assess short-term success, but more importantly, the long-term durability of these surgical repairs.

To date, studies evaluating outcomes following the use of biologic grafts have shown mixed results and systematic reviews have concluded that there is insufficient evidence to recommend the use of biologic graft compared to traditional posterior colporrhaphy native tissue repair.¹⁴ However, most of these studies have limited follow-up. Moreover, most studies assessing the use of biologic grafts have focused primarily on the anterior compartment. Within the anterior compartment, there seems to be minimal differences between traditional native tissue anterior colporrhaphy and biologic graft augmented repairs.¹⁵ Studies that included the use of a biologic graft in the posterior compartment often analyzed results in aggregate, combining those who had a biologic graft in the posterior compartment with those who had it placed in the anterior compartment. For example, one randomized controlled trial found that anatomical and subjective outcomes between biologic graft augmentation and conventional native tissue colporrhaphy were similar; however, on further analysis, less than a quarter of patients in the study had a biologic graft in the posterior compartment.¹⁶ Because of the limited available data, some have suggested that in a more selected population, biologic graft augmentation may have merits.¹⁷

While there was not a significant difference in subjective failure rates between groups in the unadjusted model, there was a significant difference in the adjusted model. Our definition of subjective failure was based on the response to question 3 from the PFDI-20 which has historically been used as an indicator of subjective failure. However, other measures used in this study further support the difference we found in subjective failure. The minimum clinically important difference (MCID) for the PFDI-20 is 45 and for the PFIQ-7 is 36. Patients in the native tissue group had an improvement of 45 on the PFDI-20 and 38 on the PFIQ-7 and therefore, on average patients in the native tissue group met the established MCID threshold.¹³ On the other hand, patients who had a biologic graft augmented repair had improvements of 31 on the PFDI-20 and 17 on the PFIQ-7 which did not meet the established MCID threshold for either measure.

Repair of the posterior compartment inherently has a high risk of failure with both groups reporting over 50% composite failure. Those who had augmentation of the posterior colporrhaphy with a biologic graft underwent repeat surgery 11 months earlier than those who had a native tissue repair. This may speak to the fact that patients undergoing a biologic graft augmented repair have a higher baseline risk of recurrence. However, given the small number of patients who ultimately required additional treatment, it is difficult to draw definitive conclusions.

The strengths of this study include the ability to assess long-term outcomes given that each group had a median telephone follow-up of more than five years. Moreover, among patients we were able to contact, over 80% agreed to participate in the study and the high response rate adds validity to the findings reported in this study. Despite the high response rate, however, 39% of potentially eligible patients did not have valid contact information and thus were excluded from the analysis. One of the other limitations of the study is in the subjective and objective measures of failure. Patients are rarely able to distinguish symptoms of posterior prolapse from symptoms of anterior prolapse or apical prolapse and therefore patient reported bulge symptoms may in fact be due to prolapse recurrence in the apical or anterior compartment. This limitation, however, is true not only for this study, but any study reporting subjective prolapse failure. Similarly, our definition of retreatment did not rely specifically on retreatment of the posterior compartment. Treatment options for prolapse often address multiple compartments. For example, the most common criteria retreatment in our study was a pessary and retreatment with a pessary simultaneously addresses the anterior, apical, and posterior compartments. Moreover, for patients who had repeat surgeries, some had procedures at outside institutions, and we were not always able to determine what compartment was addressed at the time of surgery. Because of these inherent limitations, we were unable to determine the retreatment specifically of the posterior compartment. An additional limitation of this study is that it is observational.. As such, the decision to use a biologic graft was individualized based on an assessment of clinical risk factors for recurrence, including a subjective assessment of the fascial integrity at the time of surgery. It is possible that patients who were judged to have deficient fascia in the rectovaginal space at the time of surgery were more likely to receive a biologic graft. Further compounding this issue, patients who had a biologic graft augmented repair were more likely to have failed a prior repair. While we attempted to address these limitations by controlling for pre-operative prolapse severity and prior prolapse surgery, prior surgical failure may impact patient’s expectations and thus their reporting of subjective failure.

In conclusion, while composite failure rates were similar between groups, after controlling for baseline difference, patients who had a biologic graft augmented repair in the posterior compartment reported higher subjective failure rates. Without a prospective randomized controlled trial it may not be possible to definitively determine the long-term impact of biologic grafts in the posterior compartment, however in our study the use of biologic grafts in the posterior compartment does not seem to confer a significant benefit to traditional repairs with long-term follow-up.