Introduction
Pelvic organ prolapse (POP) is the sign of descent of one or more of the following: the anterior vaginal wall, the posterior vaginal wall, the uterus (cervix) or the apex of the vagina (vaginal vault or cuff scar after hysterectomy) [
1]. Its prevalence is currently estimated to be approximately 40% in women 45–85 years of age, and around 30% of these women are symptomatic [
2]. Symptomatic patients may complain of urinary, bowel, or sexual symptoms as well as symptoms of vaginal pressure, heaviness, or pain [
3]. These symptoms have a major impact on patients’ physical and emotional well-being [
4].
The pelvic organs can descend, as mentioned in the definition, in any of the three different anatomical compartments: the anterior, the posterior, and the apical, or in more than one compartment. The degree of pelvic organ descent was initially quantified using the Baden–Walker halfway scoring system [
5]. However, the POP-Q grading system [
6], with proven interobserver and intraobserver reliability [
7], is more commonly used in the literature in the past few years [
8].
Treatment of POP is commonly surgical [
9] and the lifetime risk of undergoing a pelvic reconstruction surgery is estimated at about 11.8% by the age of 80 years [
10]. The surgical prolapse repair aims primarily at restoring the anatomy of the structures supporting the pelvic organs. These structures have been described and classified in three different levels in the landmark paper by DeLancey [
11].
Several techniques are available for pelvic organ prolapse repair. Depending on the material used to restore pelvic organ support, these techniques are classified as “native tissue repairs” when only pelvic organ support tissues are used or “reinforced or augmented repairs” when some other material is used to reinforce the defective support system. These include autologous or heterologous biological or synthetic, absorbable or non-absorbable, materials. As native tissue repairs showed discouraging rates of surgical failure in early studies [
12,
13], reinforced repairs, using mainly synthetic mesh materials, became more popular [
14]. This trend was facilitated by the marketing of numerous mesh kits (containing meshes and special introducing instruments), which were mainly used by the transvaginal route [
15]. Approximately a decade later, complications of mesh usage started to emerge [
16], leading to the US Food and Drug Administration (FDA) safety warnings regarding mesh complications, especially for meshes placed transvaginally [
17].
Given the dilemmas regarding mesh use in pelvic reconstructive surgery, we aimed to summarize reasons for and against it based on a review of the current literature. The literature search was conducted in Scopus and PubMed databases until May 2016, for English-language papers on the efficacy and safety of native tissue versus non-absorbable, synthetic mesh prolapse repairs. Randomized controlled trials were included. Results of systematic reviews and meta-analyses were also included without reporting individual trials, for reasons of brevity. As the balance of benefits and disadvantages from native tissue or mesh augmented repairs may vary according to the prolapsed compartment, evidence is organized under anterior, posterior, and apical compartment prolapse.
Compliance with Ethics Guidelines
This article is based on previously conducted studies and does not involve any new studies of human or animal subjects performed by any of the authors.
Discussion
The main advantage of mesh-augmented pelvic reconstruction is superior efficacy and durability of results compared to native tissue repairs. Indeed, the majority of studies confirm the benefits of mesh use in terms of increased success rates.
Nevertheless, interpreting such evidence and using it in clinical decision-making are not straightforward. First of all, there is significant variation in the definition of surgical success among studies [
51]. Using different outcomes may have considerable impact on the results even of a single study. As an example, in a recent randomized controlled trial comparing vaginal mesh repair to anterior colporrhaphy, anatomic cure rates were 74.4% and 51.1%, respectively at 2 years, but dropped to 40% for each group when the definition of a successful outcome was changed from postoperative prolapse POP-Q stage 2 or less to stage 1 or less [
27].
Caution is also advised when reoperation rates are interpreted as a measure of success. Very often reoperation rates for mesh repairs include procedures for stress urinary incontinence and mesh complications in addition to those for prolapse recurrence. The 2016 Cochrane systematic review and meta-analysis on vaginal prolapse repairs [
18], for example, showed a significantly higher reoperation rate with mesh procedures (11.4% versus 4.8% with native tissue repairs) but this was driven predominantly, even though not exclusively, by reoperations due to mesh-related complications: reoperations for prolapse recurrences, specifically, were only slightly more common with mesh repairs (3.2% versus 1.7% in the native tissue group) while anti-incontinence procedures were similar (2.8% in the mesh group and 2.6% in the native tissue group).
Another issue when interpreting literature results on efficacy of repairs is that there is not a direct and predictable relationship between objective anatomical cure and subjective improvement of prolapse symptoms or overall patient satisfaction. Hopefully, future trials will indicate “how much anatomical correction” is needed if we are aiming primarily for satisfied women.
The increased efficacy of mesh-augmented repairs over native tissue ones comes with a cost of increased complications. Mesh exposure, in particular, is a mesh-specific complication and represents the most important safety concern. Fear of this complication has considerably altered clinical practice in recent years. It has to be admitted that mesh complications may have significant negative impact on patients’ quality of life and require multiple, on occasions, complex operations for their management. On the other hand, it has to be argued that not all mesh exposures require surgical intervention. Many of those are asymptomatic and are discovered incidentally during regular follow-up clinical examinations. In most cases such asymptomatic exposures do not require a surgical intervention and, in fact, the American Association of Urology recommends against mesh removal in asymptomatic patients [
52].
As there are pros and cons in using a mesh in each vaginal compartment repair, the question whether to use it or not should be answered on an individual basis. When there is higher risk for prolapse recurrence, it becomes more reasonable to use a mesh repair. Prolapse stage 3 or 4 (POP-Q), age less than 60 years, diabetes mellitus, and recurrent prolapse are all factors associated with increased failure of native tissue repairs [
53] and should be taken into consideration. On the other hand, it is of paramount importance to minimize complications, mesh exposure in particular, when mesh is used. Surgeon- and patient-related risk factors should be carefully addressed [
54,
55].
Appropriate patient selection and information are the only current means of overcoming the dilemmas regarding the use of mesh in prolapse repairs. Data from ongoing and future trials will hopefully provide information for safer evidence-based decisions.
Conclusion
In the anterior compartment, mesh repairs are associated with better objective and subjective results, compared to native tissue repairs. In the same compartment, mesh-related complications, higher rates of de novo stress incontinence, and bladder injury are arguments against use of mesh. With regards to isolated posterior compartment prolapse, lack of high-quality evidence does not allow us to reach safe conclusions. In the apical compartment, sacrocolpopexy offers better results compared to the other surgical options and causes fewer mesh-related complications than transvaginal procedures, but is an invasive procedure. Minimally invasive, laparoscopic or robot-assisted, sacrocolpopexy promises to reproduce results of the open procedure.
Acknowledgments
No funding or sponsorship was received for this study or publication of this article.
All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this manuscript, take responsibility for the integrity of the work as a whole, and have given final approval for the version to be published.