Is There a Role for Synthetic Meshes or Biological Grafts in Vaginal Prolapse Surgery?

“…until further robust evidence is available to support the use of mesh in vaginal prolapse surgery, we cannot justify its role in routine clinical practice.”

Urogenital prolapse is a common, distressing and disabling condition affecting up to 30% of the parous women attending gynecology outpatient clinics and 2% of young nulliparous women in a study performed in the Swedish population [1]. The incidence of urogenital prolapse increases with advancing age, menopause and parity [2]. Although there is little epidemiological data regarding urogenital prolapse, it has been reported to be the most common reason for hysterectomy in women over the age of 50 years. It has also been estimated that approximately 225,000 operations for urogenital prolapse are performed annually in the USA [3].

Pelvic floor repair involving anterior and/or posterior colporrhaphy has been the established treatment for pelvic organ prolapse over the last century. However, it carries with it a high rate of recurrence [4]. Over the last decade, the use of synthetic mesh has become increasingly popular, mainly for secondary procedures, in order to reduce the recurrence rates of urogenital prolapse. Recently, a number of prolapse repair mesh devices have been designed by different companies and extensively marketed as a minimally invasive approach for pelvic floor repair. However, reliable long-term data on the role of meshes in pelvic organ prolapse surgery are still lacking. Nevertheless, several meshes and graft material in various sizes and shapes, as well as different techniques, have been developed, described and marketed to complement, reinforce or replace the native tissue. This contributes to making the interpretation of the available scientific evidence even more difficult.

Mesh repair devices have been introduced to allow the majority of clinicians to perform vaginal prolapse surgery without the need of specialist surgical skills. Therefore, instead of urogynecologists being the driving force behind the introduction of new surgical devices for the treatment of urogenital prolapse, general gynecologists have been the main target for marketing devices.

It is worrying that newly introduced meshes have been introduced and then withdrawn from routine clinical practice prior to their efficacy being established in well-designed controlled trials.

We also need to acknowledge that there is still no consensus regarding a gold-standard technique for primary anterior and posterior repairs. This should be established prior to experimenting and developing mesh augmentation for prolapse repair.

Further research is also needed to determine the impact of mesh biomechanical properties such as pore size, stiffness, elasticity and tissue compatibility on the ultimate surgical result and the complication rate. Patient characteristics and surgical technique also influence the success rate and complications of mesh augmentation surgery.

Vaginal prolapse is not a life-threatening condition and prolapse surgery is aimed at improving a patient's quality of life. Nevertheless, the number of women requiring multiple surgical interventions for mesh-related complications is increasing. The intraoperative complications of visceral and vascular injury, as well as the postoperative morbidity, are higher with mesh augmentation repairs than with standard fascial repairs. These mesh complications include pain, infection, voiding difficulties, bleeding, hematoma, visceral injury, dypareunia, mesh exposure, mesh erosion and fistula, amongst anothers [5]. Some of the complications are uncommon but can be life-threatening and require input from specialists in other disciplines such as urologists, vascular surgeons, colorectal surgeons and interventional radiologists. It is possible that complete symptom resolution is not possible and patients might be left with detrimental side effects. Therefore, it is important that when new procedures or techniques are introduced for improving the outcome of prolapse surgery, the patient should be counseled on the nature and magnitude of risks and complications, even if they are rare, as well as the absence of long-term data.

Guidance from national and international advisory as well as regulatory bodies must also be considered in this difficult area. A recent Cochrane systematic review on surgical management of pelvic organ prolapse in women has stated that although the use of mesh or graft inlays at the time of anterior vaginal wall repair may reduce the risk of objective recurrent anterior vaginal wall prolapse, improvement of subjective outcomes, including patient satisfaction, quality of life and reduced reoperation rates for recurrence, have not yet been demonstrated.

In addition, there is no evidence that the addition of a mesh to posterior vaginal wall repair results in improved outcomes.

“It is worrying that newly introduced meshes have been introduced and then withdrawn from routine clinical practice prior to their efficacy being established in well-designed controlled trials.”

The National Institute for Health and Clinical Excellence (NICE) in the UK provided guidance on the surgical repair of vaginal wall prolapse using meshes in June 2008, and stated that mesh repair should be used only with special arrangements for clinical governance, consent, audit or research. NICE has advised that patients should be informed about the lack of long-term data, the risk of complications and that the procedure should be carried out by gynecologists who have the special expertise in the surgical management of pelvic organ prolapse. Clearly the guidance has been translated to all types of mesh, with or without introducer kits.

In November 2008 the Society of Gynecological Surgeons (SGS) concluded that supportive evidence for transvaginal mesh is limited and called for adequately powered randomized control trials evaluating anatomic and symptomatic efficacy as well as adverse events.

The US FDA is less stringent with the approval of prosthetic devices compared with medications. Studies on humans are not required prior to introduction and the main prerequisite is to demonstrate equivalency to existing devices [6]. Paradoxically, a public health notification from the FDA regarding serious complications associated with transvaginal placement of surgical mesh repair of pelvic organ prolapse and stress urinary incontinence was issued in 2008.

In conclusion, although there are several studies reported in the literature on prolapse mesh repair as well as different national and international guidelines on the use of meshes in vaginal surgery, it is difficult to draw meaningful conclusions that are relevant to the clinician.

To our knowledge the main weakness is that the available scientific evidence is based on poorly conducted trials, in which there is no standardization of surgical techniques, a lack of uniformity in assessing outcomes, an absence of long-term data and under-reported complications. There are several unanswered questions that need to be answered prior to using mesh materials in vaginal prolapse surgery.

While awaiting the results of adequately powered randomized controlled trials, such as The Prolpase Surgery, Pragmatic Evaluation by Randomized Controlled Trial (PROSPECT) study funded by Health Technology Assessment in the UK to evaluate the long-term safety and anatomic and symptomatic efficacy, organizations such as the International Urogynecological Association, and its affiliated societies such as NICE, should formulate clearer guidance for urogynecologists with the existing evidence. In the meantime, the use of a national registry for mesh usage, reporting complications and monitoring outcomes should be mandatory. This will also help in monitoring the compliance to national guidance.

It is also imperative that only gynecologists with adequate surgical expertise perform mesh augmentation procedures, if necessary, in a well-equipped unit.

Applying the principles of the Hippocratic Oath ‘Do no harm’, the aim of vaginal prolapse surgery should be restoration of anatomical support without detrimental effects on visceral and sexual function. Therefore, until further robust evidence is available to support the use of mesh in vaginal prolapse surgery, we cannot justify its role in routine clinical practice.