Optimal surgical management of stage 3 and 4 pelvic organ prolapse

Transvaginal mesh: An effective, durable option for POP repair

Vincent R. Lucente, MD, MBA, and Jessica B. Ton, MD

Dr. Lucente reports that he has received grant or research support from Advanced Tactile Imaging, Boston Scientific, Coloplast, and Valencia; is a consultant to Coloplast; is a speaker for Allergan, Boston Scientific, Coloplast, and Shionogi; and serves as an expert witness for American Medical Systems and C.R. Bard. Dr. Ton reports no financial relationships relevant to this article.

As baseline health in the elderly population continues to improve, the number of women in the United States with symptomatic POP will increase by approximately 50% by 2050.³⁹ Unfortunately, after native tissue repair (NTR) the rate of prolapse recurrence is extremely high: approximately 40% regardless of approach, as demonstrated in the OPTIMAL (Operations and Pelvic Muscle Training in the Management of Apical Support Loss) trial by Barber and colleagues.⁶ The authors of that clinical trial recently revealed that at the 5-year follow-up, these failure rates progressed to 70% for sacrospinous ligament fixation and 61% for uterosacral ligament suspension (data presented at the Society of Gynecologic Surgeons Annual Scientific Meeting 2018, Orlando, Florida). This establishes that NTR is not durable enough to meet the increasing physical demands of this age group and that mesh augmentation must be considered.

For patients at increased risk of prolapse recurrence, using transvaginal mesh (TVM) is the most minimally invasive approach and is an excellent option for mesh augmentation. Avoiding adverse events during placement of TVM depends largely on optimal surgical technique.⁴⁰ (VIDEO: “Demonstration of an anterior vaginal wall dissection into the true vesicovaginal space”)

The evidence on TVM versus NTR

Several studies have examined whether TVM has a measurable benefit over NTR.

A 2016 Cochrane review by Maher and colleagues included 37 randomized trials (4,023 women) that compared TVM and biologic grafts with NTR.⁴¹ Three primary outcomes were defined: awareness of prolapse, recurrence, and repeat surgery. Compared with women treated with NTR, those treated with synthetic nonabsorbable TVM exhibited a greater reduction in awareness of prolapse (risk ratio [RR], 0.66; 95% confidence interval [CI], 0.54-0.81), decreased recurrence in the anterior compartment (RR, 0.33; 95% CI, 0.26-0.40), and decreased reoperation for prolapse (RR, 0.53; 95% CI, 0.31-0.88). The overall calculated exposure rate was 12%, with a range of 3.2% to 20.8%.⁴¹ As we will discuss, this wide range most likely is attributed to a suboptimal, split-thickness dissection. There were no differences in other key secondary outcomes, including dyspareunia, operating time, and estimated blood loss.⁴¹

Longitudinal studies are emerging as almost 2 decades have passed since TVM was introduced. In a study of 5-year follow-up after TVM placement, Meyer and colleagues reported that patients had continued significant improvements in both subjective and objective outcomes.⁴² The mesh exposure rate was 6%, attributed to severe vaginal atrophy.⁴² A 10-year observational study by Weintraub and colleagues demonstrated a recurrence rate of only 2.6% in the anterior compartment, 7.6% in the posterior (nonaugmented) compartment, and no exposures or extrusions after anterior TVM placement.⁴³

In contrast to the Cochrane review, in the 2017 multicenter PROSPECT (Prolapse surgery: Pragmatic evaluation and randomized controlled trials) trial, Glazener and colleagues found no difference in desired outcomes with TVM compared with NTR.⁴⁴ There was an overall 6% to 7% exposure rate over 2 years.⁴⁴ To reflect "real-world" practice, however, this study was intentionally designed without rigorous standardization of surgical technique. The authors reported that "appropriately experienced surgeons" performed the procedure, but it is unclear how experience was determined given that 20% of the cases were performed by "registrars," the equivalent of US residents or fellows.⁴⁵

The PROSPECT study protocol described the TVM procedure as "a standard repair with a nonabsorbable mesh inlay to support the stitches," implying that there was no apical attachment of the mesh to the sacrospinous ligament.⁴⁵ This is a suboptimal use of TVM because it does not address a detachment-type defect common in advanced prolapse. The PROSPECT study reinforces the need for better surgical training and standardization of the TVM procedure.⁴⁴

How TVM compares with sacrocolpopexy

When comparing the use of TVM with sacrocolpopexy, our experience has been that TVM yields similar outcomes to sacrocolpopexy with additional benefits. We completed a 1-year retrospective cohort study comparing robot-assisted laparoscopic sacrocolpopexy (RALS) with TVM in a total of 86 patients, with both approaches performed by the same surgeon. Both treatment groups showed statistically significant improvements in nearly all functional and quality-of-life measures, including urinary symptoms, sexual function, and POP-Q scores.⁴⁰  In particular, points Aa and Ba on the POP-Q score were significantly improved with TVM as compared to RALS. This suggests that TVM can achieve both lateral and apical support, where sacrocolpopexy addresses only the apex.⁴⁰ This has clinical significance when considering DeLancey and colleagues' dynamic magnetic resonance imaging study, which demonstrated advanced prolapse results from both lateral and apical detachment.⁴⁶ In addition, TVM placement also was considerably faster than RALS by approximately 96 minutes and could be performed using regional anesthesia. Only 1 mesh exposure in each study arm was reported.⁴⁰

Finally, as with other vaginal procedures, patients who undergo TVM placement require minimal to no pain medication postoperatively and report faster return to daily activities. Almost none of our patients require narcotics, which is a significant benefit in the face of the ongoing national opioid crisis.

Gutman and colleagues compared laparoscopic mesh hysteropexy with TVM; they demonstrated comparable cure rates and, again, significantly longer operative times for the laparoscopic approach (174 vs 64 minutes; P<.0001).⁴⁷ This multicenter study reported mesh exposure rates of 2.7% for laparoscopy and 6.6% for TVM,⁴⁷ again likely due to a split-thickness dissection.

Safety of TVM depends on the surgeon factor

Because of the reported complications associated with TVM, in 2011 the US Food and Drug Administration (FDA) issued an update on the safety and efficacy of TVM augmentation and mandated postmarket studies.⁴⁸ While we do not dispute that the mesh exposure rates were accurate at the time the FDA document was issued, we recognize that exposure has been erroneously attributed to inherent properties of the mesh.

Mesh exposure rates reported in the literature vary widely, ranging from 0% to 30%, even when surgeons used identical mesh products.⁴⁹ This clearly establishes that the main contributing variable is surgical technique. It is critically important to recognize the "surgeon factor" as a confounder in trials that compare surgical procedures.⁵⁰ Studies on TVM have shown that low-volume surgeons had significantly higher reoperation rates, while high-volume surgeons achieved a 41% reduction in reoperations.^51,52 When TVM is performed by expert surgeons, the reported mesh exposure rates for TVM are noticeably lower.^{40,42,43,53,54}

Decreasing mesh exposure rates would reduce the most common adverse event associated with TVM, thus improving its safety. The critical step to successful TVM placement is the initial dissection. Gynecologists traditionally have performed a split-thickness, colporrhaphy-style dissection to place the mesh within the layers of the vaginal wall.⁵⁵ Placement within these planes, however, is too superficial and increases the risk of exposure. By contrast, by consistently performing a full-thickness vaginal wall dissection (FIGURE 10) and placing the mesh in the true vesicovaginal space,⁵⁶ we have achieved a TVM exposure rate as low as 0% to 3%.^40,54 If we can standardize the dissection component across our subspecialty, the rate of mesh exposure undoubtedly will decrease.

The PROSPECT investigators readily admitted what the study was not: a trial conducted "exclusively by the most experienced surgeons in the highest volume centres¬with a highly protocolised technique."⁴⁴ In reality, that is the kind of rigorous study on TVM that our subspecialty demands. We must hold ourselves accountable and ensure that only the most qualified surgeons are placing TVM.

Keep the mesh option available

We support the position of the American Urogynecologic Society in opposing an outright ban of TVM because such a restriction would deny our patients access to an effective, durable, and minimally invasive approach for prolapse repair.⁵⁷

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