Introduction

Uterine prolapse, a pelvic defect ailment, involves the descent or sagging of the uterus into the vagina, sometimes extending below the level of the ischial spine, and in severe cases, protruding partially or entirely outside the vagina1. The primary pathogenesis of uterine prolapse is often associated with pelvic floor neuromuscular dysfunction and pelvic floor fascia defects stemming from factors such as pregnancy, childbirth, increased abdominal pressure, and congenital anomalies2. While individuals with mild uterine prolapse may remain asymptomatic, moderate to severe cases can manifest as lumbosacral pain, feelings of pelvic heaviness, and potential complications like local ulceration, bleeding, and infection due to friction between the vaginal opening and clothing. Severe cases are often accompanied by vaginal wall bulging, stress urinary incontinence, urinary retention, and may necessitate manual assistance for urination, sometimes leading to urinary tract infections. Additionally, patients may experience swelling of the posterior vaginal wall, difficulty with defecation, and constipation, significantly impacting their overall health and quality of life3. Given the aging population in China, there has been a notable increase in the incidence of uterine prolapse over time, particularly among aging women who are at a higher risk of developing urinary incontinence. Consequently, the management of this condition has become a pressing issue within gynecological practice, drawing significant attention and research interest4.

Laparoscopic sacrocolpopexy (LSC) has long been regarded as the primary treatment modality for uterine prolapse due to its ability to effectively alleviate symptoms, boasting precision, low recurrence rates, and minimal impact on sexual function post-operation. However, the incidence of complications tends to rise with repeated surgeries, encompassing issues like constipation, exposure of vaginal stump mesh, and compensatory swelling of the posterior vaginal wall. In rare instances, severe complications such as paraplegia resulting from spinal infection and discitis may arise, posing significant challenges and casting doubts on the continued use of LSC5. In contrast, sacrospinous ligament fixation (SSLF) offers a compelling alternative to LSC, delivering noticeable efficacy with a more minimally invasive approach and fewer complications. Nonetheless, the recurrence rates following SSLF remain variable, ranging from 13 to 20%6. To address this concern, some researchers have endeavored to refine SSLF techniques to achieve lower recurrence rates in uterine prolapse cases. Building upon previous research and innovation efforts, we have developed bilateral mesh sacrospinous ligament suspension (MSSLS). This novel approach utilizes a self-designed polypropylene sling instead of traditional sutures, employing a pelvic floor puncture device to penetrate the sacrospinous ligament without directly suturing the vaginal wall. The mesh is then suspended at the apex of the vagina to achieve optimal tension adjustment. The MSSLS procedure offers simplicity, efficacy in reducing recurrence rates, and excellent anatomical restoration. Notably, no MSSLS-related complications have been reported to date.

Given the lack of systematic evaluation regarding recurrence rates and the impact on quality of life associated with MSSLS, our current study aims to investigate the efficacy of MSSLS in comparison to LSC for the treatment of uterine prolapse.

Methods and materials

Participants

Our study evaluated 98 patients diagnosed with uterine prolapse at our hospital between January 2021 and January 2023. Patients were randomly assigned into either the study group or the control group using a random number table. In the study group, participants’ ages ranged from 40 to 65 years, with an average age of (50.27 ± 11.29) years. Similarly, in the control group, ages ranged from 40 to 65 years, with an average age of (50.31 ± 12.09) years. There were no significant differences in general characteristics between the two groups (P > 0.05). This research protocol adhered to the principles outlined in the Helsinki Declaration of the World Medical Association.

Selection criteria

Inclusion criteria

  1. 1)

    Patients diagnosed with uterine prolapse based on the diagnostic criteria of Urogynecologic Transvaginal Surgery7.

  2. 2)

    Aged 40–65 years.

  3. 3)

    POP-Q score8: Ba ≤ 0 cm, C ≥ 2 cm, D ≥ 0 cm, Bp ≤ 0.

  4. 4)

    Normal blood coagulation and immune function.

  5. 5)

    No hormone treatment received within 3 weeks before the operation.

  6. 6)

    Normal cognitive function.

  7. 7)

    No previous history of pelvic floor repair surgery.

Exclusion criteria

  1. 1)

    Patients who refused to use mesh.

  2. 2)

    Patients with anterior or posterior vaginal wall prolapse of stage II or higher.

  3. 3)

    Patients over 65 years old with cardio-cerebrovascular disease who could not tolerate surgery.

  4. 4)

    Patients with severe organic injury.

  5. 5)

    Patients with malignant tumors or other serious diseases.

Methods

The study group was treated with MSSLS. Epidural anesthesia was administered, and 40 ml of normal saline was injected into the vesicovaginal space between the anterior fornix of the vagina and the bladder neck. A 5 cm incision was made on the anterior vaginal wall, extending laterally along the vaginal wall to accommodate the mesh. The bone margin of the inner corner of the obturator was explored using the index finger on both sides, while the ischial spine was examined bilaterally from behind. The puncture point was 3 cm lateral and inferior to the anus on both sides. The puncture needle was inserted through the designated puncture point. A special puncture device was used to draw the superficial branch of the mesh through the obturator, with 2/0 micro-geoline, starting near the inner corner of the obturator (Fig. 1A). The needle then penetrated from a second puncture point, guided by the finger through the medial sacrospinal ligament of the ischial spine, and pulled the mesh (GYN-ECARE GYNEMESH PS, 15 cm × 10 cm) through the skin using 2/0 micro-geoline (Fig. 1B). The mesh was then trimmed (Fig. 1C), tightened, and led out of the puncture point. The mesh was positioned to ensure proper tension, then fixed under the cervix and urethra with No.4 silk thread. The vaginal wall was sutured with 2/0 micro-geoline after irrigation. The cervix was repositioned to the proper height within the vagina, and the external anterior vaginal wall was tightened to a satisfactory position using the mesh strap, with excess strap cut off. After confirming there was no bleeding, the vagina was packed with gauze, and the skin incision was dressed (Fig. 1D).

Figure 1
figure 1

Illustrative images depicting the MSSLS surgical procedure. (A): Utilization of Liu’s deep hook piercer; (B): Application of the finger sleeve hanging method; (C): Deployment of the self-cutting net; (D): Illustrative diagram showcasing surgical outcomes.

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The control group underwent LSC. After administering epidural anesthesia, the peritoneum was opened lateral to the sacral ligament. The sacral ligament was folded and sutured to the ipsilateral vaginal stump, 4 cm from the sacral promontory. The anterior and posterior arms of the Y-shaped mesh were sutured and fixed in the bladder space of the anterior vaginal wall and the rectal space of the posterior vaginal wall, respectively. The posterior peritoneum was incised to reveal the sacral promontory, following which the Y-shaped mesh wall was sutured and anchored within the avascular region of the anterior longitudinal ligament of the sacrum using non-absorbable sutures, ensuring the mesh remained tension-free. Absorbable sutures were utilized to close the retroperitoneum.

Postoperative Treatment: A routine indwelling catheter was used postoperatively. Patients were monitored for urination after catheter removal, and residual urine was measured if necessary. Antibiotics were administered to prevent infection, and patients were advised on a balanced diet to ensure unobstructed defecation. Patients were instructed to avoid heavy physical labor, sexual activity, and tub baths for three months post-surgery. Additionally, measures were taken to prevent chronic cough and constipation.

Observation indicators

The operation conditions (operation time, bleeding volume, indwelling catheter time, exhaust time, hospital stay), stage of pelvic organ prolapse, postoperative recurrence rate, pain severity, quality of life, postoperative pelvic floor function, impact on sexual life, complications, and recurrence rate of the two groups were statistically analyzed.

Stage of pelvic organ prolapse

Before and six months after the operation, patients were placed in the lithotomy position after emptying their bladders and performed the Valsalva maneuver. The Pelvic Organ Prolapse Quantification (POP-Q)8 system was used to evaluate the following measurements:

  • Aa: Distance of the central line of the anterior vaginal wall 3 cm from the hymen.

  • Ba: Maximum distance of anterior vaginal wall prolapse from the hymen.

  • Ap: Distance of the posterior vaginal wall prolapse 3 cm from the hymen.

  • Bp: Maximum distance of posterior vaginal wall prolapse from the hymen.

  • C: Maximum descent of the cervix or vaginal stump after hysterectomy.

Pain severity

The pain severity of the patients was assessed using the Numeric Rating Scale (NRS)9 on the 1st, 3rd, and 5th days post-operation. The NRS scores range from 0 to 10, with higher scores indicating more severe pain.

Quality of life

The quality of life of the patients was assessed using the Pelvic Floor Impact Questionnaire-7 (PFIQ-7)10 before and six months after the operation. This questionnaire evaluates the impact of prolapse symptoms on daily life, social relationships, and mood or emotions. The PFIQ-7 scores range from 1 to 4 points per item, with a total possible score ranging from 0 to 300 points. Higher scores indicate a poorer quality of life.

Status of pelvic floor function

The recovery of pelvic floor function was evaluated using the Pelvic Floor Distress Inventory-20 (PFDI-20)11 before and three months after the operation. This questionnaire includes 20 items related to pelvic organ prolapse (POP) symptoms, divided into three subscales: the Pelvic Organ Prolapse Distress Inventory (POPDI), the Colorectal-Anal Distress Inventory (CRADI), and the Urinary Distress Inventory (UDI). The total score is converted to a 100-point scale, with higher scores indicating more severe clinical symptoms.

Sexual life

The Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire-12 (PISQ-12)12 was used to assess sexual life quality before and after the operation. The questionnaire consists of 12 questions, each scored from 1 to 5 points. Higher scores indicate better quality of sexual life.

Complications

Complications such as thigh pain, new-onset urinary incontinence, abdominal distension, urinary retention, and pain during sexual intercourse occurring within six months post-treatment were recorded.

Postoperative recurrence rate

Recurrence was defined as the vaginal wall or vaginal vault reaching stage II or higher at any point six months after the operation. The recurrence rate of prolapse was monitored for one year post-operation.

Statistical analysis

We used SPSS 21.0 software for data analysis and Excel to establish the database. Measurement data conforming to the normal distribution were expressed as mean ± standard deviation (\(\overline{x}\) ± s). One-way ANOVA was used for the overall comparison of data across groups, and the LSD method was employed for pairwise comparisons between and within groups. Additionally, counting data were expressed as percentages (%) and compared using the chi-square (χ2) test. A P-value of less than 0.05 was considered to indicate a statistically significant difference.

Ethics approval and consent to participate

The study protocol was approved by the Ethics Committee of Anqing Municipal Hospital. Informed consent was obtained from all the study subjects before enrollment.

Results

Comparison of clinical data

There were no significant differences between the two groups in terms of age, pregnancy history, delivery history, course of disease, or degree of uterine prolapse (P > 0.05), as shown in Table 1.

Table 1 Comparison of clinical data.
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Comparison of operation conditions

The operation time, bleeding volume, indwelling catheter time, exhaust time, and hospital stay were significantly lower in the study group compared to the control group (P < 0.05), as laid out in Table 2.

Table 2 Comparison of operation conditions (\(\overline{x}\) ± s).
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Comparison of pelvic organ prolapse stages

Before the operation, no significant differences were observed in the Aa, Ba, Ap, Bp, and C measurements between the two groups (P > 0.05). However, six months after the operation, these five indexes were significantly lower in the study group compared to the control group (P < 0.05), as shown in Table 3.

Table 3 Comparison of stage of pelvic organ prolapse (\(\overline{x}\) ± s), cm).
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Comparison of pain severity

Before the operation, there was no significant difference in pain severity between the two groups (P > 0.05). However, six months post-operation, the pain severity was evidently lower in the study group compared to the control group (P < 0.05), as shown in Table 4.

Table 4 Comparison of pain degree (\(\overline{x}\) ± s), points).
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Comparison of quality of life

There were no significant differences in the quality of life between the two groups before the operation, at 6 months, and at 12 months post-operation (P > 0.05, Table 5).

Table 5 Comparison of quality of life (\(\overline{x}\) ± s), points).
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Comparison of pelvic floor function

There were no significant differences in pelvic floor function between the two groups before the operation, at 6 months, and at 12 months post-operation (P > 0.05, Table 6).

Table 6 Comparison of pelvic floor function (\(\overline{x}\) ± s), min).
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Comparison of sexual life quality

There were no significant differences in the quality of sexual life between the two groups before the operation, at 6 months, and at 12 months post-operation (P > 0.05, Table 7).

Table 7 Comparison of sexual life quality (\(\overline{x}\) ± s), points).
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Comparison of complications and recurrence rates

All patients were followed up for 12 to 14 months, with an average follow-up time of (13.02 ± 1.36) months. The incidence of complications in the study group was significantly lower than in the control group (P < 0.05). However, there were no recurrences in either group, and thus the difference was not statistically significant (P > 0.05, Table 8).

Table 8 Comparison of complications and recurrence rates (\(\overline{x}\) ± s), points).
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Discussion

Pelvic organ prolapse is a prevalent condition among middle-aged and elderly women. Previous studies have reported a high prevalence rate of female pelvic prolapse, reaching up to 14.2%. Among these cases, anterior pelvic prolapse accounts for 34.3%, while posterior pelvic prolapse constitutes 18.6%13. The onset of this condition is closely linked to age-related changes and traumas affecting the female reproductive organs. Weakness in the pelvic floor ligaments, muscles, and supporting tissues can lead to alterations in anatomical structure. Early intervention is crucial for patients with pelvic prolapse to prevent disease progression and alleviate clinical symptoms. These symptoms may include low back pain, sensations of abdominal sagging, increased vaginal secretions, and, in severe cases, swelling of the vaginal anterior and posterior walls. Such symptoms can significantly impact patients’ physical and mental well-being, resulting in a reduced quality of life. Current treatments for uterine prolapse primarily focus on strengthening the key supportive structures of the pelvic floor to address underlying dysfunction. Notably, preserving at least one-third of the vaginal paravaginal support is deemed essential for the prevention and treatment of uterine prolapse14.

Surgery is generally considered the primary approach for treating uterine prolapse, with LSC gaining recognition since it was first reported by Nezhat in 199415. LSC offers several advantages, including high efficacy in suspending and securing the prolapsed top of the vagina to the anterior longitudinal ligament of the sacrum S1 in a tension-free manner. Early studies have demonstrated its high cure rate, low recurrence rate, and subjective and objective reduction in complications related to transvaginal mesh procedures16,17. Pelvic prolapse often involves prolapse of the anterior and posterior vaginal walls. LSC allows for the simultaneous separation of the vesicovaginal and rectovaginal spaces to the lower part of the prolapse. This technique enables the mesh to extend downward to the far end of the prolapse plane, with the lowest posterior wall positioned on the perineal body and the anterior wall placed at the bladder-urethra junction, achieving simultaneous repair. LSC yields excellent anatomical outcomes, effectively restoring the vaginal axis, maintaining vaginal length, and preserving bladder and rectal functions. Moreover, it has been shown to improve patients’ quality of life and sexual function. LSC offers the advantage of providing a clear surgical field and facilitating rapid postoperative recovery. Consequently, it has become one of the preferred surgical methods for patients with moderate symptomatic fornix prolapse, severe pelvic prolapse, and previous failures of pelvic floor reconstruction17. Despite its efficacy, LSC is associated with certain drawbacks, including the risk of intraoperative injury to presacral vessels and nerves, as well as postoperative complications such as mesh exposure, erosion, infection, pain, and new-onset urinary incontinence and defecation dysfunction18. In an effort to address these issues, we explored the use of MSSLS with sling. During the MSSLS procedure, we employed a patented surgical instrument designed by Liu Lubin (patent No. ZL201720961332.5) and developed the “finger cuff thread hanging method.” This approach facilitated deep sacrospinal ligament puncture, ensuring simplicity, reliability, and ease of operation. Using a self-cutting mesh, we suspended the main sacral ligament complex or vaginal stump to the sacrospinal ligament. By passing the sling puncture through the sacrospinal ligament and fixing only one end, we could adjust the mesh tension freely during the operation. This technique formed a secure adhesive joint at the two anchor points, significantly reducing postoperative pain caused by excessive tension after suturing the sacrospinal ligament and lowering the recurrence rate. Bilateral sacrospinous ligament suspension corrected vaginal axial deviation, improved postoperative pain, and promoted patient recovery. According to Lu et al.19, compared to the SSLF group, the LSC group exhibited longer operation times (149.0 ± 48.8 min vs. 61.3 ± 29.4 min), lower intraoperative bleeding (48.3 ± 10.1 ml vs. 55.6 ± 15.4 ml), and shorter indwelling catheter durations (1.8 ± 0.6 d vs. 2.9 ± 0.6 d) (P < 0.05). However, there was no significant difference in the prolapse recurrence rate six months post-operation (2.2% vs. 4.4%) (P > 0.05). Despite the slightly longer operation time, LSC demonstrated better post-operative sexual and overall quality of life for patients. Consistent with these findings, our study revealed that the operation time, bleeding volume, indwelling catheter duration, time to exhaust, and hospital stay were all significantly lower in the study group compared to the control group (P < 0.05). This suggests that MSSLS effectively reduces operation time, indwelling catheter duration, time to exhaust, hospital stay, and bleeding volume in patients with uterine prolapse, promoting their overall recovery.

The POP-Q system, developed by the American Gynecological and Obstetrical Society (AGOS) in 19958, serves as an established evaluation tool for pelvic organ prolapse (POP). Its widespread use in clinical practice is attributed to its objective, meticulous, and proven reliability and repeatability. Studies, such as the one conducted by Jia et al.20, have demonstrated the effectiveness of LSC in treating moderate and severe uterine prolapse, leading to significant improvements in the stage of pelvic organ prolapse and achieving low recurrence rates post-operation. Another recent study21 highlighted the notable reduction in POP-Q scores and restoration of pelvic function following LSC treatment for uterine prolapse. Consistent with these findings, our study revealed that six months post-operation, the Aa, Ba, Ap, Bp, and C measurements in the study group were significantly lower than those in the control group (P < 0.05). This indicates that MSSLS effectively restores the physiological and anatomical structure of the pelvic floor and improves pelvic floor function in patients with uterine prolapse.

Postoperative pain represents a complex physiological and psychological response to tissue injury and repair, which is a significant issue affecting surgical patients9. Therefore, addressing postoperative pain in patients with uterine prolapse is a crucial aspect of clinical practice. Another earlier study22 showed that LSC can effectively alleviate postoperative pain in patients with uterine prolapse. Similarly, our study observed that the degree of pain in the study group was lower than that in the control group 6 months post-operation (P < 0.05), indicating that MSSLS can effectively relieve pain in patients with uterine prolapse. This outcome may be attributed to the MSSLS technique, wherein the surgical sling punctures through the sacrospinal ligament with only one fixed end, allowing for adjustable mesh tension during the operation. The mesh forms a secure bond at the two anchor points, which significantly reduces pain caused by excessive tension after suturing the sacrospinal ligament, thereby contributing to a significant reduction in the recurrence rate. Additionally, the use of bilateral sacrospinous ligament suspension corrects vaginal axial deviation and improves postoperative pain.

PFIQ-7 is a simplified version of the PFIQ and is one of the most widely used and internationally verified questionnaires for assessing the quality of life among patients with pelvic organ prolapse10, as recommended by the International Continence Society (ICS). Although there is no grade A questionnaire available, the grade B questionnaire has proven reliable for evaluating the distress caused by the disease on the pelvic floor and its impact on daily activities such as housework, travel, social interactions, and emotional well-being. It has been widely promoted internationally. Sijin et al.23 reported that LSC significantly improves pelvic floor function and the quality of sexual life in patients with uterine prolapse. Our study found that the quality of life in both the MSSLS and LSC groups was comparable at 6 and 12 months post-surgery (P > 0.05), indicating that both procedures effectively enhance the quality of life for these patients. PFDI-20 is another crucial scale for evaluating the recovery of pelvic floor function11. Chen S.24 also noted that LSC significantly enhances both pelvic floor function and sexual life quality in patients with uterine prolapse. Consistent with these findings, our study showed comparable improvements in pelvic floor function at 6 and 12 months post-operation in both groups (P > 0.05), suggesting that the pelvic floor function can be improve by both MSSLS and LSC among patients with uterine prolapse. PISQ-12 is a scale used to evaluate pelvic organ prolapse and urinary incontinence function, with its clinical application becoming increasingly extensive12. LSC has been identified as a safe and effective approach for improving the quality of sexual life in patients with severe pelvic organ prolapse, particularly those with significant pelvic defects25. Our study results indicated that both MSSLS and LSC significantly improved the quality of sexual life at 6 and 12 months post-operation (P > 0.05). Li et al.26 found a complication rate of 13.33% (4/30) for LSC in treating uterine prolapse, and a recent study reported no recurrence of uterine prolapse post-LSC operation27. In our study, patients were followed up for 12–14 months, with an average follow-up of 13.02 ± 1.36 months. The incidence of complications in the study group was significantly different (P < 0.05), but there was no recurrence in either group (P > 0.05), aligning with previous research and suggesting that MSSLS is safe and does not cause complications or recurrence in treating uterine prolapse. This safety profile is likely because MSSLS uses a mesh sling that is not in the vaginal wall, thus avoiding complications and not affecting sexual life postoperatively. Compared to presacral fixation, MSSLS does not alter the vaginal axis and reduces the compensatory bulge of the anterior and posterior pelvic cavity after correcting pelvic defects.

Mesh has been controversial since it was put into use in the medical field28. The FDA issued two warnings in earlier years about the use of mesh for pelvic floor surgery due to complications. However, for patients with uterine prolapse, the self-tissue has been relaxed and weak, and it is easy to relapse without the help of implant repair. Relevant studies have also confirmed that vaginal implantation surgery can increase the healing response, vascularization and collagen metabolism compared with autologous tissue repair, thus increasing the mechanical properties of tissues28. At the same time, for patients who cannot tolerate open surgery or recurrent prolapse of the anterior vaginal wall, the use of mesh implants is the best choice. The FDA's warning against the use of mesh, which relates to high-weight mesh, has now been withdrawn from the market. In recent years, the mesh synthesized by using new materials, such as titanide repair mesh, is lighter per unit area and can provide strong support for pelvic floor tissue. However, a large amount of clinical evaluation is still needed to determine its long-term effect29. On the other hand, many researchers have been looking for more suitable vaginal implants to treat uterine prolapse. As gynecologists, we should strengthen our professional skills and adjust the mesh according to the individual needs of each patient. The purpose of MSSLS using mesh is to form a tension-free suspension and, more importantly, to reconstruct a strong artificial "ligament" between the sacrospinous and principal ligaments, which allows the weak cervical ring and principal sacral ligaments to be anatomically repositioned with the help of the strong sacrospinous ligaments. In the follow-up cases of this study, no obvious stinging, infection, and mesh erosion occurred, which is a relatively satisfactory treatment effect, but the long-term efficacy needs to be further followed up and observed with increasing sample size.

However, this study has several limitations. The age range of patients included was 40–65 years old, excluding those over 65 with uterine prolapse. Additionally, the follow-up period was relatively short. Future studies that include a wider age range and have longer follow-up periods could provide a stronger theoretical basis for determining the value of MSSLS in patients with uterine prolapse.

Conclusion

Therefore, MSSLS emerges as a promising and efficacious approach for treating uterine prolapse, characterized by favorable safety profiles and a low recurrence rate. Its merits render it deserving of widespread clinical adoption and promotion.