Colporrhaphy using elastic tissue continuous with and obscured behind the fibromuscular layer of the vaginal wall

Due to the U.S. Food and Drug Administration's order to cease the use of surgical mesh for transvaginal repair, an improvement of the native tissue repair (NTR) of pelvic organ prolapse (POP) could become important as one of the first‐line operative methods. This study details the surgical technique of an NTR method we developed, with report of our 5 years of experience.


INTRODUCTION
Symptoms related to pelvic organ prolapse (POP) are seen in 44% of women who have given birth, and 11.1% of such women undergo surgery. 1 The current standard treatment, anterior colporrhaphy with complication of the fibromuscular layer (FL) underlying the vaginal epithelium, results in POP recurrence in over 30% of cases. 2 Accordingly, operative methods using synthetic mesh, trans-vaginal mesh surgery (TVM) and laparoscopic sacrocolpopexy (LSC), were developed with much more favorable outcomes than by colporrhaphy. However, the U.S. Food and Drug Administration ordered to cease of the use of the surgical mesh for TVM because of serious complications. 3 The operative burden of LSC seems large in older people, and the long-term effects of using synthetic mesh remain unknown. Improving native tissue repair (NTR) could therefore become an essential issue in this medical field. We present a surgical colporrhaphy technique in which the thick and elastic tissue continuous with and obscured behind the FL of the vaginal wall is pulled out and used to reconstruct the vaginal wall ( Figure 1).
The protocol for this study has been approved by the Takatsuki General Hospital Ethics Committee, and it conforms to the provisions of the Declaration of Helsinki 1995 (as revised in Brazil in 2013). The patients permitted the details of their cases to be reported with signed consent. Patient anonymity has been preserved.

Patients
Between April 2017 and March 2020, we performed our novel repair technique on 87 women with a POP of either POP-Q stage III or IV 4 at Takatsuki General Hospital in Osaka, Japan. The age of the patients was between 52 and 88 years.

Follow-up after surgery
The postoperative examination was done at 1, 3, 6, and 12 months after surgery, and then annually for 5 years where possible.

Definition of recurrence
We defined the criterion of recurrence as POP-Q stage II or higher.

Surgical technique
Six gynecologic surgeons performed all operations, each of whom had been specifically trained in this operative method by the originator of the procedure (F.K.). The attached video shows surgical procedures (Video S1).

Preoperative preparations
With the patient in the lithotomy position, the urinary bladder is emptied and 5 mL of blue dye (indigo carmine) is introduced to reveal any bladder injury during the operation.

Reconstruction of the anterior vaginal wall
Separation of the bladder from the uterine cervix The vaginal wall of the anterior fornix and the underlining bladder pillar are incised transversely. The bladder is then disconnected from the cervical surface.
Separation of the bladder from the vaginal wall [Step 1] The vaginal wall is stretched and the midsection of the bladder is dissected from it. Visual verification of the boundary between the bladder and vaginal FL is key to an accurate procedure. The vaginal wall is then incised vertically, proceeding until a part of the urethra becomes visible (Figure 2a). [ Step 2] Pean forceps grasping the vaginal wall flap are pulled laterally to stretch the vaginal wall and the lateral wall of the bladder is removed from the vaginal wall. At the ureter intrusion, one or two small blood vessels connect the bladder and the vaginal wall ( Figure 2b). Disconnection of these vessels makes separation of the bladder easy.
After completing the same procedure on the contralateral side, the operator can dislocate the whole bladder into the pelvic cavity.

Separation of the FL from the vaginal epithelium
The uterine cervix is pulled downward and the edge of the vaginal flap is pulled laterally to stretch the surface of the vaginal flap. [ Step 1] First, a small portion of the epithelial surface is exposed by grasping the edge of the FL at the vaginal flap with straight tweezers. Then, the exposure of the epithelial surface is extended by inserting Cooper's scissors into the boundary between the FL and the epithelial surface. [ Step 2] Holding the separated FL with Pean forceps, the separation of the FL from the epithelial surface is The fibromuscular layer underlying the vaginal epithelium is thin, but a thick and elastic tissue obscures at the lateral depth (a). This tissue can be pulled up and used to reconstruct the vaginal wall (b). ATFP, arcus tendinous fascia pelvis; FL, fibromuscular layer of the vaginal wall.
The midsection of the bladder is dissected from the vaginal wall and is then incised vertically (a). The side wall of the bladder is easily removed from the vaginal wall by burning off one or two small blood vessels connecting the bladder and the vaginal wall (b). b, bladder; bv, blood vessels connecting the bladder and the vaginal wall; ur, urethra; va, vaginal wall. extended with Cooper's scissors and gauze. The separation of the FL should be done from the entire length of the anterior vaginal wall: from the vaginal fornix to just beneath the urethra (Figure 3). The same procedures are performed on the other side.

Reconstruction of the FL [
Step 1] The separated FL is grasped at both sides with straight and fluted forceps. While winding up the separated FL, the overlaying vaginal epithelium is gently pushed sideways with gauze. Then, elastic, thick tissue continuous with and obscured behind the FL becomes visible (Figure 4). When the forceps on both sides are drawn together, muscular spring-like tension is created between them. [ Step 2] Bilateral rolled-up tissue is sutured using 1-0 absorbable thread. Four to five stitches hold all layers of the rolled-up tissue. The threads are then tied up one by one while withdrawing the forceps ( Figure 5). The pubourethral fascia is sutured using 3-0 thread to prevent hypermobility of the urethra.

Fixation of the vaginal portion of the cervix to the newly formed FL
The vaginal portion of the cervix is fixed to the newly formed FL with two U-shaped sutures using 1-0 threads ( Figure 6). The purpose of this procedure is to prevent the uterus from slipping down into the vaginal cavity postoperatively. Cervical amputation before the U-shaped suture is helpful in cases of cervical elongation.   Vaginal epithelial closure After the vaginal epithelial closure, the vaginal portion of the cervix is pushed manually into the pelvic cavity. Once moved in, it is difficult and possibly dangerous to pull this out again.

Reconstruction of the posterior vaginal wall
Separation of the rectum from the vaginal wall The perineal skin is excised while maintaining tension at the posterior ostium of the vagina to separate the vaginal wall from the perineal skin. The vaginal wall is then stretched with two sets of Kocher forceps grasping its edge and the rectum is bluntly separated from it. The separated vaginal wall is incised vertically, proceeding to the posterior vaginal fornix. Then, the Pean forceps grasping the vaginal wall flap are pulled laterally to stretch the vaginal wall and the side wall of the rectum is bluntly disconnected from it.

Reconstruction of the FL
In the same manner, as in the anterior vaginal wall, the FL is separated from the vaginal epithelium, and the thick and elastic tissue continuous with and obscured behind the FL is pulled out and sutured. In the posterior vaginal wall, the FL firmly adheres to the epithelium. Thus, in many cases, a sharp dissection using scissors is required in addition to blunt peeling. In the posterior vaginal wall, there is no such elastic thick tissue near the vaginal fornix, so this tissue cannot be used to reinforce the upper part of the posterior wall. The levator ani muscle is sutured, and the vaginal epithelium is closed.

RESULTS
Seven of 87 women dropped out from the follow-up, and 80 were followed up for over 24 months up to 60 months by March 2022 (follow-up rate: 91.2%, 80/87). POP recurred in four patients (recurrence rate 5.0%, 4/80). POP of POP-Q stage IV recurred in two patients with neonatal head-sized POP 3 months after surgery, the anterior vaginal wall prolapse recurred in one patient 6 months after surgery; slipping down of the uterine cervix into the vaginal cavity occurred in one patient.
Operation time was between 49 and 70 min, and the bleeding volume was between 70 and 250 g. There were no intra-or postoperative complications requiring further treatment. Resumption of self-urination took 2 weeks for two patients and 4 weeks for one patient. In all other patients, self-urination resumed within 7 days after surgery.

DISCUSSION
The feature of this surgical procedure is a reconstruction of the FL using a thick and elastic tissue continuous with and obscured behind the FL of the vaginal wall. We discovered this tissue while performing the colporrhaphy method reported by Tsuji ("Saishin Fujinka Shujutsu" 1990, written in Japanese), which recommends to strengthen the thin and fragile FL by layering the rolls. This thick and elastic tissue exists in all women without exception, and can be pulled out at the whole length of the anterior vaginal wall, from just beneath the vaginal fornix to the bladder neck. The newly constructed FL can therefore support the entire length of the anterior vaginal wall. In previously reported anterior colporrhaphy, recurrence rates were over 30%. 2 The reason for this high recurrence rate could be because the FL underlying the vaginal epithelium, which is thin, vulnerable, and sometimes defective, has been used to reconstruct the anterior vaginal wall. 2 Suspension of the vaginal apex (SVA) has therefore been thought to be necessary for colporrhaphy. However, in our operative procedure, we did not perform SVA. We hypothesize that prolapse of the cervix has been prevented due to the following reason in our operative technique: the cervix is anchored to the newly formed FL that connects to the muscle around the arcus tendinous fascia pelvis (ATFP). We speculate that our operative method does not therefore require SVA.
The cause of 33% of cases of POP is detachment of the pubocervical fascia from the ATFP. [5][6][7] It is assumed that this study series also included approximately 25 to 28 similar cases. If the pubocervical fascia completely came off the ATFP, the fascia could be torn off and our operative method was inappropriate. Two of the largest POPs (approximately neonatal-head size) seen in this study series, in whom the timings of recurrence were 3 months after surgery, might be such cases.
The mechanism by which our technique was influential in the remaining 20 or so cases is currently unknown. We believe that the resilient tissue drawn out from the lateral side of the vaginal wall is the pubocervical fascia in the vicinity of the ATFP, which may include some of the muscle groups that attach to the ATFP. MRI reveals lesions on the pelvic floor. [8][9][10] Thus, an investigation by MRI examination for structural change around the ATFP caused by this surgical procedure may reveal the POP repair mechanism of our operative technique. This will be focus of future study.
Operators should be careful to avoid capture of the bladder and especially the ureter while the separated FL is being rolled-up. Complete bladder dissection from the vaginal wall is the key to preventing this complication. Cystoscopy after surgery to check for urine leaking from the bilateral ureteric orifices can help avoid this problem. Pulling out the thick and elastic tissue along the entire length of the anterior vaginal wall is the key to "total repair" of the anterior wall. For this purpose, the FL should be continuously separated from the vaginal fornix to just beneath the urethra.
In this study series, three cases required more than 2 weeks to resume self-urination. We believe this may be a transient phenomenon caused by a change in the bladder-urethra relationship due to surgery. It is not thought to be due to nerve damage or urethral stricture and is 100% normalized.
Our present study was a retrospective cohort study in one institution between 2017 and 2022. The number of patients was too small to allow for meaningful statistical analysis. A randomized controlled trial with enough patients is necessary to determine whether this approach is truly advantageous compared with previously reported colporrhaphy. Nevertheless, we believe that this procedure has the potential to become one of the first-line operative methods for the repair of POP. We consider the results to be good, and most importantly, it is safe, and the operative burden is small for patients. Furthermore, mesh surgery can still be performed if there is a recurrence after this procedure.