Treatment success of apical compartment prolapse with bilateral anterior sacrospinous hysteropexy using Splentis was 89.2% after a median follow-up of 17 months. Additionally, QoL and prolapse-related symptoms improved significantly after surgery. There were three (2.9%) patients with mesh exposure of which two (1.9%) required revision surgery and one (1.4%) was treated conservatively. One (1.4%) patient required further surgery due to dyspareunia and the formation of a granulation polyp. No patient required repeat surgery or a pessary due to recurrence of an apical or anterior prolapse.
In comparison to traditional posterior sacrospinous fixation, SSL suspension with Splentis is performed using single-use instruments to place an anchor with attached sutures to each SSL. Uterine suspension is facilitated by placing a mesh in a sling-like configuration anteriorly to the cervix and suspended to the SSL bilaterally using the sutures attached to the anchors. In comparison, there are several hysteropexy techniques that may be differentiated in regard to the surgical route (vaginal vs. abdominal) and the utilization of native tissue or synthetic mesh for uterine fixation[4]. Formerly, several synthetic meshes were available for the use via the vaginal route and indicated for apical POP. These meshes had a larger surface area and were attached to the anterior vaginal wall to address the apical and anterior compartments simultaneously. However, the surface size and the attachment of mesh directly to the vaginal wall has been identified as crucial risk factors for mesh-related morbidity[12] which led to a discreditation of these meshes [13]. Furthermore, apical POP repair by sacrocolpopexy or hysteropexy techniques still often include the utilization of a mesh and these techniques have not been affected by the FDA mesh ban due to the lower risk of mesh-related morbidity. In contrast, Splentis is not attached to the vaginal wall, the mesh surface is significantly smaller and the indication is limited to apical compartment prolapse. Therefore, Splentis does not fall into the scope of mesh-augmented anterior POP repair.
Treatment success was achieved in 89.2% patients in the current investigation. No patient required repeat surgery, which is consistent with the results of other hysteropexy techniques using mesh or sutures via the abdominal or vaginal route. The overall objective treatment success rate of apical compartment repair, including any kind of transabdominal laparoscopic hysteropexy technique, was 85.3% according to a recent meta-analysis [14]. The rate of subjective treatment success has been reported range from 73 – 10%, with repeat surgery performed in 0 – 28% of patients [14]. Taking into consideration only studies that used a synthetic mesh for uterine suspension via the abdominal route, the pooled success rate was 92% [15]. Considering any native tissue repair performed via the vaginal route, the rate of treatment success in the apical compartment was reported to range from 70.2 – 89.8% [16, 17]. In particular, the reported success rate for transvaginal sacrospinous fixation ranges from 51 - 91% [4, 17, 18] with a pooled rate of repeat surgery of 3.4% [18].
In contrast to traditional posterior SSL fixation, the anterior access with Splentis ensures physiological positioning of the cervix, maintaining the possibility of common cancer screening and potentially reducing the risk of subsequent anterior prolapse. The first description of an anterior approach by Winkler et al. [19] demonstrated a restoration of the physiological horizontal axis of the vagina. Another study by Goldberg et al. [20] reported several advantages of using an anterior approach compared to a posterior approach, including a longer average total vaginal length, less anterior vaginal wall relaxation, and a more proximal vaginal apex. Posterior sacrospinous vaginal vault suspension leaves the vagina at a downward and posterior angle and may lead to a significant rate of cystoceles recurrence (22–25%) [21].
In contrast, unilateral sacrospinous hysteropexy may result in unphysiological horizontal positioning of the cervix by deflecting the vaginal axis posteriorly. Thus, the prevention and diagnosis of cervical or vaginal cancer may be reduced or even impossible because the cervix may no longer be accessible [18]. Additionally, deflection is considered to be the cause for the high rate of subsequent anterior prolapse [17] and the success rate of treatment of the anterior compartment is only 65.1% [18]. Furthermore, advanced stages of POP are correlated with increased failure rates of native tissue repair by SSL fixation [17].
However, the majority of women in the current investigation presented with a POP-Q stage of 3, indicating a cohort with a higher risk of failure for traditional transvaginal SSL fixation. Nevertheless, the treatment success rate remained high despite the advanced POP-Q stages in the current study.
Furthermore, the surgery time is reduced by using the vaginal route instead of the transabdominal approach [16, 22]. The mean surgery time via the vaginal route was reported to be 90 minutes including any native tissue repair technique[16] and 54.5 minutes for sacrospinous hysteropexy[18]. In contrast, the mean duration for laparoscopic mesh sacrohysteropexy was 174 minutes [23].
In summary, treatment success of this clinical investigation is consistent with previously reported results in the literature. Furthermore, bilateral anterior sacrospinous hysteropexy with Splentis ensures physiological positioning and mobility of the cervix, maintaining the possibility of common cancer screening.
During the perioperative course, no adverse events occurred in the current trial. Intraoperative complications, particularly visceral injuries, are rare in POP repair [18, 22]. In a large cohort trial including 507 women who were treated with laparoscopic hysteropexy, the rate of intraoperative adverse events was <1% [24]. Thus, the current results are consistent with those in the literature.
Mesh exposure occurred in three (2.9%) patients, and only two (1.9%) patients required revision surgery which is consistent with other hysteropexy techniques including mesh placement for uterine suspension. According to a recent meta-analysis of transabdominal hysteropexy using synthetic mesh, a mean exposure rate of 3.8% was reported [16, 24]. In a prospective trial investigating vaginal versus abdominal hysteropexy techniques, the reported mesh exposure rate was 2.7% and 6.6%, respectively, without a significant difference between the groups. However, the vaginal technique included the attachment of a larger area of the mesh to the anterior vaginal wall, as previously described. Another meta-analysis comparing mesh sacrocolpopexy and vaginal native tissue repair reported a mesh complication rate of 4.2% [22]. Regarding the current investigation, the mesh exposure rates are consistent with those of other hysteropexy techniques, including mesh placement for uterine suspension.
Other adverse events, particularly those associated with transvaginal mesh-augmented POP repair for anterior prolapse [25], did not occur in the current investigation. This may be related to the mesh design and, in particular, fixation of the mesh to the uterus and sparing the vaginal wall. Only one patient (0.9%) required partial mesh excision due to dyspareunia and the formation of a granulation polyp.
Dyspareunia is one of the most commonly reported adverse events after mesh-augmented vaginal procedures [26]. However, a Cochrane meta-analysis identified only little or no difference in the dyspareunia rate between mesh-augmented and native tissue apical POP repair [27]. In the current investigation, de novo dyspareunia occurred in two subjects (1.8%), and importantly, dyspareunia, which was present at baseline, resolved after surgery in six (5.5%) patients. A recent prospective randomized trial comparing laparoscopic sacrohysteropexy with mesh and sacrospinous hysteropexy with sutures reported de novo dyspareunia in 8.1% and 13.2% of patients, respectively [28]. Considering any type of vaginal native tissue hysteropexy technique, the mean dyspareunia rate was 12.3% [15]. In comparison to unilateral sacrospinous suspension, there might be an increased risk for dyspareunia due to distortion of the vaginal configuration [18]. Therefore, Splentis might be beneficial for sexual activity due to maintenance of the physiological axis of the vagina and preservation of the uterus per se [7]. However, there was no statistically significant difference in sexual function according to the POP-Q between baseline and follow-up.
We acknowledge the current limitations of this investigation. The results of objective anatomical success are not present for the cohort. Furthermore, asymptomatic findings, such as small exposure or contractures, might have been missed because vaginal examination is often performed by the patients gynecologist. However, it should be considered the current recommendation for treatment success in POP repair focus in combined endpoints, including patient report outcome[10] and solely anatomical failure does not represent indication for retreatment. It could be demonstrated that the hymen is a relevant cut-off-point as women with prolapse beyond the hymen have more POP symptoms and are more likely to report a vaginal bulge symptom which identified this question to be crucial for defining outcome success [10]. Thus, this investigation included in particular this question at interview follow-up and additionally, the patients were also asked for any further surgery performed since last follow-up. Therefore, clinically relevant results have been collected completely. Finally, the analysis of risk factors for failure or exposure may be associated with the chance of a type II error since the number of adverse events and the anatomical failure rate were low.