Mesh-augmented anterior POP repair with Calistar S demonstrated a favorable risk/benefit ratio in non-fertile women with recurrent POP or primary complex POP with high risk of recurrence. Treatment success was 76.0% according to the composite endpoint and 98.0% according to the anatomical criteria POP-Q ≤ 1. No intraoperative complications occurred, no patient required repeated surgery for POP, and QoL increased significantly after the intervention. Importantly, postoperative complications were rare, and none of the patients that developed mesh exposure required further surgery. Further surgery for stress urinary incontinence was performed in nine (8.4%) patients. Due to the inclusion of women with recurrent and primary complex POP, in accordance with the SCENIHR recommendations [3], the current investigation reflects valuable results from clinical daily practice in the use of mesh-augmented transvaginal repair of anterior POP with Calistar S.
The anatomical success rate was consistent with previously reported success rates for mesh-augmented anterior POP repair, which range between 83 and 100% with a follow-up time of up to 36 months [13,14,15,16,17]. Despite the strict definition of no subjective vaginal bulge symptom in the composite endpoint, success was still achieved in 76% of the patients. Although a composite endpoint is still rarely utilized in reporting POP repair outcomes, there are several recommendations for this strategy, which includes anatomical and subjective components as well as the need for retreatment [12]. Unsurprisingly, success rates decrease if a composite endpoint is utilized [18]. Previous studies in mesh-augmented anterior POP repair report success rates between 60.8 and 87.0% when utilizing a composite endpoint [2, 14, 16], so that our results are in line with previous publications.
In contrast to previous reports of mesh-augmented repair, it is important to note that the vast majority of our patients presented with recurrent or complex POP instead of a primary POP, so that the overall complexity of our cohort was considerably higher, despite similar success rates.
Two subjects in this investigation experienced objective failure, as defined by POP-Q grade 2. However, neither of these patients required an additional surgery for POP up to the follow-up, reporting no or only infrequent prolapse symptoms.
Regarding the intraoperative course, the mean duration of surgery was 37.7 minutes, which is consistent with other reports in the literature and significantly faster than native tissue repairs or other repair procedures [2]. Intraoperative complications are generally rare in transvaginal mesh repair, and the most frequent complication is bladder injury, with a reported incidence of between 1 and 4 % [2, 19]. No intraoperative complications occurred in this investigation.
Vaginal mesh exposure occurred in 5.6% of the patients in our study, and the estimated exposure-free rate was 93% after 20 months. Since none of our patients required further surgery up to the follow-up, all exposures could be managed conservatively. The reported exposure rates in the literature range between 3.2 and 14% [2, 13,14,15,16,17, 20,21,22,23,24,25]. Exposure rates have decreased successively in the last decade because of stricter patient selection, advancements in mesh compounds and design and improvement of surgical techniques. Importantly, exposure rarely requires further surgery [2, 13,14,15,16,17, 20,21,22,23,24]. Our results are consistent with the literature, despite the relatively high mean age of our patients (70 years), which is associated with reduced estrogen levels and an increased risk for vaginal atrophy [19], which ultimately increases the risk for mesh exposure.
A single patient required further surgery because of folding/wrinkling. In this patient, the mesh was trimmed during an elective suburethral sling implantation to treat stress urinary incontinence. Nonetheless, folding and wrinkling are known complications that can occur after mesh implantation for POP [26]. Mesh folding is usually identified by imaging methods alone. Nevertheless, the implication of this finding is still unclear. There are contradictory reports that mesh folding is associated with an increased risk for exposure, and it remains unclear whether this results from mesh contraction or weak fixation points. To reduce this complication, the anchors of Calistar S were developed to resist a force exceeding four times the maximum abdominal pressure.
Due to persistent postoperative bladder dysfunction, 3.7% of patients required intermittent catherization. This pre-existing dysfunction was observed at baseline and is likely due to neuronal or structural tissue damage and not caused by the surgical POP repair. Consistent with the literature, de novo stress urinary incontinence occurred in 10.2% and worsening of urinary incontinence in 8.3% of patients [19]. These results could be explained by the pathophysiology of the disease, as occult urinary stress incontinence is commonly present in POP patients, particularly those with higher degrees of POP [27]. Bladder function improved in the majority of patients in our investigation.
Pain levels were low with a mean VAS score of 0.13. Dyspareunia was reported by 4.1% of cases, although this condition was already documented in 3.1% of patients at baseline. Therefore, only one (1.0%) patient reported de novo dyspareunia after the operation. Dyspareunia is reported to occur in between 2.7% and 10% of patients in the literature [15, 20, 23], which is consistent with our results. It is important to note that the number of patients participating in regular sexual activity was only 13.3% in our cohort. The mean age of patients in the current trial was 70 years, and sexual activity may be reduced by lack of libido, physical limitations or lack of a partner [28]; consequently, the impact of sexual impairment will differ compared with other populations.
We acknowledge potential bias due to the funding source of this trial. However, the investigators had the ultimate authority over each activity in this clinical investigation. Due to their focus on urogynecology, the participating hospitals have documented baseline characteristics consistently and accurately for years, as reflected by the low amount of missing data. Nevertheless, we acknowledge limitations in the study design affecting the amount and quality of baseline data. Bias due to different perioperative assessments and surgeons cannot be completely excluded, although results are consistent with those in the literature, and complications were rare. All involved institutions were experienced in the treatment of transvaginal POP repair and therefore represented the current standard of care. Finally, the current trial provides only mid-term data. Despite these limitations, the results reflect current routine clinical practice and provide valuable information regarding the performance of Calistar S in the intended population.
In conclusion, considering the SCENIHR recommendations for a suitable mesh implant, adequate patient selection and surgeon experience in transvaginal pelvic floor reconstruction, our study demonstrates that mesh-augmented transvaginal repair with Calistar S is an effective and safe option in women with recurrent or primary complex anterior compartment prolapse. Although the majority of our patients had recurrent prolapses, success rates remained high and re-intervention rates for recurrence or adverse events were deniable in this select population.