Pelvic organ prolapse (POP) is a distressing clinical condition that profoundly affects the quality of life, particularly in older and obese women with a history of multiple vaginal deliveries [1, 2, 3, 4]. The most common type of POP is the anterior vaginal wall prolapses with apical involvement, i.e., anterior/apical prolapse [5, 6]. Diagnosis and treatment of POP present unresolved challenges with widely varying outcomes, despite its high prevalence. While conservative treatment approaches may partially alleviate the symptoms, surgical interventions are key to managing POP [7]. However, there are contradictory data available in the literature on the selection criteria and efficacies of surgical methods for the treatment of POP [8].

Both vaginal and abdominal approaches have been utilized to perform POP surgeries [1, 4]. Although laparoscopic sacrocolpopexy is considered the gold standard in the surgical treatment of POP, it has disadvantages, such as requiring advanced surgical expertise and carrying a potentially high risk of serious complications [9, 10]. Therefore, alternative surgical techniques have been developed to treat POP with positive outcomes and without disadvantages [11, 12]. Among these techniques, laparoscopic lateral suspension (LLS) has gained popularity due to its technical advantages and lower incidence of complications in patients with apical and anterior vaginal wall prolapse [13]. On the other hand, vaginally performed sacrospinous ligament fixation (SSLF) stands out as a cost-effective surgical option in the treatment of POP with a high success rate and low risk of morbidity [7].

Several studies have compared the short- and long-term outcomes of the POP surgeries [14, 15]. However, there are limited studies explicitly comparing the effects of LLS and SSLF on POP symptoms and pelvic support restoration rates. This study was conducted to comprehensively assess and compare the outcomes and efficacy of SSLF and LLS surgeries in patients with POP.

The study included 91 patients: 47 in SSLF group and 44 in LLS group. The mean age of SSLF group was significantly higher than LLS group (p 0.001). Additionally, patients in SSLF group were more likely to be post-menopausal compared to those in LLS group (p = 0.001). Furthermore, the rate of patients who had delivered vaginally was significantly higher in SSLF group than in LLS group (p = 0.009). The distribution of patients’ demographic and clinical data by the study groups is given in Table 1.

The incidence of patients with different types of anatomical failure in the postoperative period are given in Table 2. Accordingly, the incidence of patients with anterior compartment failure was significantly lower in LLS group than in SSLF group (p = 0.005). The incidence of patients with anatomical failure was less, although not significantly, in LLS group than in SSLF group (18.2% vs. 31.9%, p = 0.132). The highest (100.0%) and lowest (68.5%) success rates for apical and posterior compartment failures were in LLS group.

PISQ-12 was administered to sexually active women in SSLF (n = 22) and LLS (n = 27) groups. P-QoL was administered to all patients in the groups. There was also no significant difference between the groups in preoperative P-QoL and PISQ-12 scores (p $>$ 0.050) (Table 3).

There was no significant difference between the groups in postoperative total and subscale scores of P-QoL and PISQ-12 (p $>$ 0.050). On the other hand, significant improvements were seen in postoperative total P-QoL and P-QoL subscale scores in both groups compared to preoperative scores (p 0.050).

There were significant changes in PISQ-12 physical and partner-related subscale scores in both groups after surgery compared to before surgery (p 0.050). Postoperative total PISQ-12 scores increased significantly in LLS group compared to preoperative scores (p = 0.009). On the other hand, there was no significant difference between the preoperative and postoperative total PISQ-12 scores in SSLF group (p = 0.111).

There were significant differences between the groups in terms of the frequency of concomitant operations (p 0.050). Accordingly, the number of patients with concomitant hysterectomy and stress urinary incontinence operations were significantly higher in SSLF group than in LLS group (p 0.001 and p = 0.028, respectively) (Table 4). The mean length of follow-up was 24.2 $\pm$ 3.9 months in SSLF group and 23.3 $\pm$ 3.5 months in LLS group (p = 0.322). There was no significant difference in the rates of de novo symptoms between the groups (p $>$ 0.050) (Table 5).

A logistic regression analysis was conducted to assess the factors influencing anatomical success. The results indicated that none of the examined factors, menopausal status (p = 1.000), type of surgery (p = 0.998), previous cesarean section (p = 0.999), hypertension (p = 0.495), diabetes (p = 0.999), or concurrent hysterectomy (p = 0.480), were found to have a statistically significant impact on anatomical success. The analysis results are provided in Table 6.

While there was one case of bladder injury and one case of pulmonary embolism in SSLF group, no mesh-related complication was detected in LLS group. In SSLF group, four of the patients with anatomical failure underwent re-operation due to postoperative recurrence.

The study results demonstrated that LLS and SSLF are effective surgical procedures for reducing POP rates. Patients undergoing LLS and SSLF showed significant improvements in all P-QoL subscale ratings, and there was notable increase in both groups’ PISQ-12 physical and partner-related subscale ratings during the recovery period. The disparities in compartmental failure rates between the groups suggest that, while Group LLS had a lower overall rate of anatomical failure than Group SSLF, LLS may be more suitable for anterior and apical compartment failures, while SSLF may be better suited for posterior compartment failures.

Overall, the varying success rates of surgical approaches for treating anterior, apical, and posterior POP highlight the importance of considering the specific anatomical compartment of the prolapse when selecting the appropriate surgical approach. There is ongoing controversy on the best surgical method for treating POP, with the literature indicating that laparoscopic or abdominal sacrocolpopexy and LLS and SSLF have similar efficacies [3, 5, 12, 25].

In studies comparing transvaginal apical methods, SSLF was found to be effective as uterosacral ligament suspension in terms of surgical failure, symptom severity, and adverse events [26, 27]. While several studies have examined the effectiveness of different surgical procedures for treating POP [14, 15], there is limited research comparing the results of SSLF and LLS in terms of anatomical failure rates, impact on quality of life, and sexual activity. In a study by Baki Erin et al. [1], LLS and SSLF were compared in patients with apical compartment prolapse. The study also reported that while both procedures resulted in similar anatomical recovery rates, LLS was superior to SSLF in terms of improved sexual functions, fewer POP-related symptoms, lower reoperation rates, and fewer complications.

Campagna et al. [28] reported an overall anatomic success rate of over 90% in the apical compartment and over 88% in the anterior compartment for patients who underwent LLS due to POP. Aksin and Andan [4] reported an anatomic success rate of 78% in the apical compartment and over 73% in the anterior compartment for patients who underwent LLS. Another study reported an objective success rate of 87.3% in patients who underwent LLS due to anterior or apical POP after a mean follow-up duration of more than three years [9]. Our findings were comparable to those reported in the literature [1, 10, 28, 29]. Differences in success rates between studies may be attributed to the technical features of POP, operative details, and duration of follow-up.

POP classification based on anatomical compartments is essential for selecting the appropriate surgical technique and evaluating success rates. Notably, the success rates of LLS vary depending on differences in anatomic compartments.

We found a success rate comparable to that reported in the study by Baki Erin et al. [1], where the LLS’s anatomical recovery rate in patients who underwent LLS for apical prolapse was reported to be 96.1%. The success rate of LLS was higher than that of SSLF for anterior and apical compartment failures, whereas the success rate of SSLF was higher than that of LLS for posterior compartment failures. Similarly, Veit-Rubin et al. [10] reported optimal or satisfactory outcomes in 85% of patients who underwent LLS due to posterior compartment failure and in 91% and 93% of patients who underwent LLS due to anterior and apical compartment failures, respectively. These findings indicate that the anatomical location of POP failure should be considered when selecting the surgical technique for treating POP.

Anatomical recovery after surgery in POP patients leads to significant improvements in quality of life and sexual function [5]. Baki Erin et al. [1] reported significantly higher Female Sexual Function Index (FSFI) and Pelvic Organ Prolapse Symptom Scores (POP-SS) after LLS than after SSLF surgery. They attributed better postoperative sexual function to the preservation of the physiological axis and correction of the apical, posterior, and anterior compartments. Although we used different patient self-report tools, such as P-QoL and PISQ-12, we observed comparable postoperative outcomes in LLS and SSLF groups.

An additional metric used to assess the performance of POP-related procedures is the reoperation rate. The literature reports that the reoperation rate following POP-related operations ranges from 3.4% to 11% [9, 12]. In a recent meta-analysis that reviewed data from twelve studies, the recurrence rate for SSLF was found to be 11.34% [30]. Variations in reoperation rates following POP surgery across studies have been attributed to differences in methodology, such as whether the reoperations were performed within the same or different compartments, and to discrepancies in follow-up periods [3, 30]. In our study, anatomic failure was observed in 15 patients undergoing SSLF, with anterior compartment failure in 14 cases. Apical failure was seen in three patients, all of whom also had anterior and posterior failures, and posterior compartment failure was seen in five patients. Among these, three patients with apical failure underwent colpocleisis due to symptomatic presentation, two patients had anterior defects extending beyond the hymen and one undergoing anterior colporrhaphy. When colpocleisis patients were excluded, none of the two patients with posterior compartment defects had defects extending beyond the hymen. There were a total of eight patients with anatomical failure in the group treated with LLS surgery, of which two patients had a defect extending 1 cm beyond the hymen and were asymptomatic; hence, they did not undergo re-operation. In two recent meta-analyses, preserving the uterus during apical defect repair in POP surgery has been shown to offer certain advantages [31, 32] compared to its removal, which increases the risk of vault prolapse [33]. Although vaginal vault prolapse was more frequently observed in cases where concomitant hysterectomy was performed in our study, there was no observed negative effect on anatomical success, regardless of whether the uterus was preserved or removed.

Randomized controlled trials may enable more definitive conclusions. However, the development of patient groups with comparable features maybe hindered by patient and physician preferences, primarily due to concerns over mesh.

The strength of the study is that it is one of the first to compare outcomes between LLS and SSLF for apical compartment prolapse. However, a limitation of the study is the potential selection bias due to differences in age, comorbidities, and sexual activity between the patient groups. The preference for uterine preservation directly influenced the choice of surgical approach, resulting in differences in age and comorbidities between the groups. These differences may be particularly limiting when assessing sexual function. To reduce this bias, we used the PISQ-12 only in sexually active patients. A logistic regression analysis was performed to examine the factors influencing anatomical success. The variable examined, including menopausal status, type of surgery, previous cesarean section, hypertension, diabetes, or concurrent hysterectomy, did not show a statistically significant impact on anatomical success. Finally, the current surgeries were not compared with a group that included sacrocolpopexy, which is considered the gold standard for apical prolapse. This is another limitation of the study.

The study results showed that both LLS and SSLF lowered POP rates and enhanced the quality of life in patients. However, for anterior and apical compartment abnormalities, the success rate of LLS was greater than that of SSLF, while for posterior compartment defects, the success rate of SSLF was higher than that of LLS. As a result, LLS and SSLF should be customized based on the anatomical and clinical presentation of the patient. More randomized controlled studies are needed to examine the long-term efficacies and safety profiles of both approaches in order to draw more definitive conclusions.

The authors of the study are custodians of the data in anonymous form, which can possibly be provided to anyone who makes a motivated and reasoned request.

Conceptualization: EY, AB, BK, and AT; methodology: EY, AB, and BK; formal analysis: EY, AB, and AT; investigation: EY, BK and BS; data curation: EY, BK, and BS; writing—original draft preparation: EY, AB and AT; writing—review and editing: EY, AB and AT; visualization: EY, BK and BS; supervision: AT; project administration: EY. All authors contributed to editorial changes in the manuscript. All authors read and approved the final manuscript. All authors have participated sufficiently in the work and agreed to be accountable for all aspects of the work.

The study protocol was approved by the local ethical committee of Düzce University (2022/53) The study was conducted in accordance with the ethical considerations outlined in the Declaration of Helsinki. Written informed consent was obtained from each patient included in the study.

This research received no external funding.

The authors declare no conflict of interest. Andrea Tinelli is serving as one of the Editorial Board members and Guest editors of this journal. We declare that Andrea Tinelli had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to Emanuele Perrone.