POP is a common disease in elderly women, whose incidence tends to increase with age. It was reported that about 30–50% of older women over 60 years of age suffered from different degrees of pelvic floor disorders [6]. Although this disease is not life-threatening, it can seriously affect the quality of life in elderly women and impose additional financial burdens on patients. Surgery is an essential method for the treatment of moderate and severe POP. There are many surgical techniques in the treatment of POP, but still no consensus on the most effective and safe surgical approach so far. Many techniques have been proposed, especially for the treatment of vaginal vault prolapse, and the diversity of these techniques illustrates the difficulty and complexity of vaginal vault suspension.
Vaginal apex fixation is considered a critical step in reconstructive pelvic surgery. Attaching the top of the vagina so as to firm up anatomical structures can improve anterior vaginal prolapse and posterior vaginal prolapse. Currently, the accepted operations used in vaginal apex fixation are sacrospinous ligament fixation (SLF), high uterosacral suspension (HUS), sacral colpopexy (SC), SLF, among which HUS relies on the use of native tissues in reconstructive pelvic surgery.
Sacrospinous ligament fixation (SSLF) is an effective surgical treatment for the middle compartment defect that has been defined as the most popular approach for the restoration of the vaginal apex. The sacrospinous ligament, which is located in the posterior pelvic cavity with a constant position, can be clearly touched through the vagina and rectum, and it is an effective point for fixation. SSLF is usually vaginally performed due to the relatively deep position of the sacrospinous ligament and the important nerves, blood vessels, and organ around it. Since vaginal SSLF may be difficult, special and often expensive instruments, such as Deschamps needle, and the Capio suturing device, are needed to complete the operation. SSLF can also be performed abdominally. Pollak’s study showed that passing the suture through the sacrospinous ligament under direct visualization when SSLF was performed through the abdominal approach resulted in less Intra and postoperative complications [7]. SSLF through the transabdominal approach has the advantages of large space, clear field of vision, and simple procedure; however, it may lead to severe trauma after abdominal surgery, the slow postoperative recovery, and the long hospital stay. With the development of laparoscopic surgery, the anatomical structure of the pelvic floor above levator ani muscle can be clearly obtained by laparoscopy since laparoscopic approach has excellent intraoperative visualization of pelvic anatomy, decreased blood loss, shorter hospital stay and quick postoperative recovery.
LSSLF involves two approaches to be performed: an anterior approach and a posterior approach. The anterior approach is performed by dissecting the retropubic space, paravaginal space, and lateral pelvic sidewall space to reach and identify the sciatic spine. Then posterior tissues are bluntly dissected to expose the coccygeus muscle, and the vaginal stump is sutured to the sacrospinous ligament. The range of issues that need to be separated by this surgical procedure is large, and the risk of complications such as injury of ureter, bladder, and obturator nerve, increases at the same time.
Consequently, we attempted to perform posterior sacrospinous ligament fixation. Intraoperative ureteral injury is a perioperative complication in this operation; thus, it is very important to observe the ureter before opening the peritoneum and confirming the course of the ureter. Separation of the ureter can greatly reduce ureteral injury, fistula, and pelvic infection. After the ureter is clearly identified, the peritoneum is opened at the lateral side of the uterosacral ligament, bluntly dissecting the tissue of the pararectal groove and exposing the sacrospinous ligament. Nevertheless, from the perspective of the autopsy, some researchers suggest that bladder is more likely to be injured through anterior approach. At the same time, ureter, rectum, and vascular plexus are more likely to be injured through the posterior approach [8, 9]. In general, the rectum, which can be clearly identified during the laparoscopic approach, is less likely to incur injury. If pelvic adhesion is serious and rectal separation is difficult, a rectal probe is inserted into the rectum to identify the boundary of the rectum during the operation [10]. In surgery, the first stitch of sacrospinous ligament suture is crucial, especially the depth and width of the suture. Tissue tear can easily occur with sutures that are too shallow, while nerve and blood vessels can be easily damaged if the suture is too deep. According to our experience, the suture needle is usually located in the medial half of the sacrospinous ligament so as to avoid the injury of blood vessels and nerves during the operation. When the suture is pulled up, the fixed suture can be felt and cannot be lifted.
Over recent years, numerous studies have reported on the short-term efficacy of the sacrospinous ligament fixation. The cure rates tend to range from 69–100%, with a small number of apical prolapse and a relatively high proportion of anterior vaginal wall prolapse, averaging 18.3% (0–42%)[11]. In this study, apical vaginal prolapse was not observed in patients who underwent hysterectomy simultaneously with surgery, and the recurrence rate of anterior vaginal wall prolapse was 6.5%. The recurrence in the group of patients who retained the uterus was 33.33%, the recurrence of uterine prolapse was 33.33%, while the recurrence of anterior vaginal wall prolapse was 20%. The high recurrent rate of anterior vaginal prolapse could have been caused by the changes of vaginal axial and the backward deviation of the vaginal apex after SSLF, which may predispose to anterior wall descent. This also suggests that the recurrence rate of anterior vaginal prolapse after sacrospinous ligament fixation should be further investigated.
Destruction of ligaments, endopelvic fascia is the direct cause of POP, and the purpose of the operation is to repair the damaged ligaments and fascia and restore its normal anatomical structure. Therefore, most of the key repairable structures of pelvic floor support are pubocervical fascia and uterosacral ligaments, which are located above levator ani muscle level, i.e., level I and II repair. A 3D digital model showed that pubocervical fascia is the most influential structure in the onset of the median cystocele [12]. Accordingly, we attempted to reconstruct the pubocervical fascia and fix it intraoperatively on the vaginal stump. Through the reconstruction of the pubocervical fascia in operation, we wanted to reduce the recurrence rate of anterior vaginal prolapse. Several studies have reported that anterior compartment support defects are largely secondary to apical support loss [13]. Anterior vaginal wall repair was recommended in higher stage prolapse. A study reported a 31% failure rate at 12 months when anterior vaginal wall repair was not performed in higher stage prolapse. In our study, we used pubocervical fascia reconstruction plication that provided better anterior support. Hugo et al reported that pubocervical fascia reconstruction, which was used in robotic-assisted laparoscopic sacrocervicopexy, was feasible and safe. It could improve anterior and apical support, minimize the use of mesh, and improve visualization during surgery [14].
The preservation of the uterus during the operation is also a matter of concern. For women of childbearing age, pelvic floor reconstruction with uterus preservation aims at an anatomical reduction, symptom relief, and fertility preservation. In this study, premenopausal women of childbearing age, combined with partial cervical resection, achieved ideal anatomical reduction without recurrence. However, in postmenopausal women with a preserved uterus, there is an increased risk of postoperative recurrence due to postmenopausal pelvic floor tissue laxity combined with uterine gravity. For postmenopausal women, there is no fertility preservation problem, and reducing the recurrence rate is the main goal of surgery. Therefore, hysterectomy can be performed at the same time during the operation to ensure a satisfactory surgical effect. Some previous studies have also reported no significant difference in the long-term outcome and surgical satisfaction of the sacrospinous ligament fixation with or without preserved uterus [15].
The medium-long term efficacy of reconstructive pelvic surgery is an important index used to evaluate the surgical effect. David-Montefiore et al. observed the medium-term and long-term surgical effects in 51 patients, with an average follow-up time of 23.8 ± 8 months; 94.3% of patients had no objective recurrence [16]. Chen et al. analyzed the surgical effect among 94 cases of VSSLF 1 year after the operation, where apical compartment success rate was 94.7%, and recurrence of anterior/ posterior prolapse was 16% [17]. We assume that the success rate of postoperative anatomical reduction is related to the following factors: 1. The severity of POP before the operation is recognized as one of the important factors affecting the outcomes of reconstructive pelvic surgery. POP-Q stage III or IV is a high-risk factor for postoperative POP recurrence [18]; 2. The site of suture: during the operation, vaginal apical fixation should be ensured on the sacrospinous ligament, rather than on the surrounding connective tissue. If feasible, increasing the number of suture needles can make vaginal apical fixation more stable and effective. Besides, the thickness of vaginal stump tissue may also affect the result of surgery, where the suture should be as thick as possible to suture vaginal stump tissue. With the increase in the number of cases, we found that the lowest point of suture should be lower than the Aa point when pubocervical fascia reconstruction was performed, which can significantly reduce the recurrence rate of anterior vaginal prolapse after surgery. 3. The experience of the surgeon: The biggest challenge with laparoscopic surgery is the long learning curve. Compared with opening surgery, the laparoscopic operation is significantly more difficult, especially in the initial learning stage. In our study, we found that most of the patients experienced recurrence in the first two years after the operation. With the increase in the number of cases, the improvement of surgical skills, and the increase of the surgeon's experience, the surgeon is more skilled in laparoscopic suture and knotting, which in turn significantly reduced postoperative recurrence. 4. Anterior colporrhaphy and posterior colporrhaphy: are important factors affecting the overall outcome of the surgery. In our study, we used a one-thread continuous suture on the internal side of the pubocervical fascia with nonabsorbable sutures to provide greater firm and durability. 5. Suture materials: Currently, non-absorbable (Prolene, braided polyester sutures, Ethibond) and absorbable sutures (Vicryl and PDS) are commonly used in reconstructive pelvic surgery. Non-absorable sutures have been associated with lower rates of recurrence compared with absorbable sutures [19, 20].
Previous studies have shown that although the quality of life after reconstructive pelvic surgery has no absolute relationship with the stage of POP, the subjective cure rate of POP is highly correlated with the objective cure rate. The sensation of tissue protrusion into or from the vagina, vaginal or perineal pain, pelvic pressure, pelvic heaviness, low back pain, and other mechanical symptoms are the most troublesome. These are followed by the symptoms of the lower urinary tract, including urinary retention, urinary incontinence, and similar. In this study, we restored the normal anatomical structure of the pelvic cavity, and at the same time, the symptoms of urinary incontinence and dysuria that existed in most patients before the operation was solved. The symptoms of pelvic heaviness, urination, and defecation were significantly relieved and the pelvic floor function was significantly improved. The average age of the patients in this study was 62.70 ± 9.48 years old, and the number of active living patients was small. Therefore, sexual function was not investigated.
The rates of adverse events in the present study are consistent with other clinical studies using native tissue in pelvic floor reconstruction [21]. Compared with the traditional sacrospinous ligament fixation, the advantages of laparoscopic sacrospinous ligament fixation with posterior approach include small incision, small dissection, good exposure, and direct vision. Injuries to the urinary systems are among the most common complications related to this surgery, including bladder injury and ureteral injury. If the injury of the urinary system is suspected during the operation, cystoscopy/ureteroscopy needs to be performed. If examination revealed that sutures penetrated the bladder and ureter obstruction, the sutures should be removed, and in some cases, the ureteral stent should be placed. In the present study, the rate of ureteral injury was 3.2%. Several studies have shown that the rate of ureteral obstructions after SSLF was lower than HUS, while the rate of ureteral obstructions after HUS was 3.7-9% [22]. Jackson [23] et al found that ureteral occlusion was more frequent in those patients undergoing concomitant anterior colporrhaphy. In this study, we used a concomitant pubocervical fascia reconstruction during LSSLF plicated anterior vaginal wall that may pull the ureters toward the anterior vaginal wall, which in turn shortens the distance from the vaginal stump to ureters, and increases the risk of ureteral damage. Consequently, it is very important to distinguish the ureter during the operation.
Acute neuropathic pain is also one of the common postoperative complications, especially buttock pain. Some studies have reported that the incidence of neuropathic pain was 12.4% or even higher [20, 21], while most patients would experience relief 4 to 6 weeks after surgery. The buttock pain after SSLF may be caused by injury to the gluteal nerve and the nerve to levator ani [24]. Nonetheless, Maria [25] found that the nearest structure to the superior margin of the midpoint of the sacrospinous ligament was the S3 nerve (median distance 3 mm, range 0–11 mm), the nearest structure to the ischial spine was the pudendal nerve (median distance 0 mm, range 0–8 mm), and the median distance from inferior gluteal nerve to the ischial spine and to the midpoint of sacrospinous ligament was 28.5 mm and 31.5 mm, respectively in a cadaver study. It seems that buttock pain was caused by the injury to the branches of S3/S4. The surgeon needs to thoroughly understand the complex anatomical structure surrounding the sacrospinous ligament, limit the depth of the insertion of the needle into the ligament, and avoid extending the needle out and into the sacrospinous ligament above the upper segment, which can reduce nerve compression and postoperative acute neuropathic pain.
The impact of bowel function after surgery is also worthy of attention. Some patients tend to develop de novo constipation or de novo anal incontinence after SSLF while having no such symptoms before the surgery. In our study, the incidence of constipation after surgery was 7.3%. David ever reported that the bowel function was unaffected after bilateral SSLF [16]. Hematoma is a serious complication in SSLF. In the present study, there was no blood transfusion and no pelvic hematoma.
There are several limitations to the present study. It was a retrospective study, so we need to be very careful in analyzing the current results and in making recommendations based on those results. Data collection from available medical records was subject to inaccuracies and incomplete data entries, which may result in incomplete data abstraction, ultimately compromising the intended data analysis. Despite the limitations of this study, we believe that reported findings provide new surgical approaches, raise awareness among physicians of the relatively common surgery-related complications, and raise awareness among physicians of the surgical approach and the relentless pursuit of the best surgical procedure. In the future, we plan to design prospective clinical studies to verify the reliability of this approach.