bubble_chart Overview

A rectovaginal fistula is a connection between the rectum and the vagina. If the fistula is large and allows unobstructed passage of stool, it may be asymptomatic. Most rectovaginal fistulas occur in congenital anorectal malformations.

bubble_chart Clinical Manifestations

The clinical manifestations range from grade I fecal incontinence to significant fecal leakage. When the fistula is small or there is anal stenosis or anal atresia, it presents as chronic incomplete intestinal obstruction. Within days, months after birth, or even at 2-3 years of age, the child may experience difficulty in defecation, with persistent severe constipation that sometimes requires enemas or laxatives to pass stool. If the fistula is large, there are no obstructive symptoms, but symptoms such as abnormal defecation position, painful bowel movements, and stool deformation may occur.

bubble_chart Diagnosis

The diagnosis of rectovaginal fistula can generally be made based on clinical manifestations and pre-existing disease symptoms, but the location of the fistula must be accurately identified to determine the treatment plan. To locate the fistula, a probe can be inserted to trace its path, or it can be observed under a rectal endoscope. If necessary, a fistulography should be performed to confirm the fistula's position. Placing gauze in the vagina and injecting methylene blue into the rectum, then removing the gauze after a few minutes to check for blue staining, can confirm the presence of a vaginal fistula.

bubble_chart Treatment Measures

All types of congenital anorectal malformations require surgical treatment. However, the timing and method of surgery may vary depending on the type of malformation and the size of the fistula. The goal of surgery is to restore normal bowel control function. Rectovaginal fistula, due to its complex causes, diverse types, high postoperative infection and recurrence rates, and significant surgical difficulty, makes the choice of surgical procedure extremely important to achieve success in one attempt.

For congenital anal malformations and rectovaginal fistula, the following should be noted:

1. the surgical method and operative technique;
2. whether the distal rectum is sufficiently mobilized;
3. avoiding severe infection;
4. fully releasing the rectal mucosal end to achieve tension-free suturing.

Imperforate anus combined with low rectovaginal fistula or vestibular fistula: for cases with a very small fistula and difficulty in defecation since birth, a stoma can be created during the neonatal period. If the fistula is very close to the vaginal opening, anoplasty can be performed after 4–5 years of age. If the vaginal fistula is large and feces pass smoothly, early surgery is unnecessary, and surgery at 3–5 years of age is more appropriate.

For acquired rectovaginal fistula, especially iatrogenic rectovaginal fistula, the timing of surgery should be carefully chosen, and immediate surgery should not be performed due to the patient's urgent request. Surgery should wait until all inflammation has subsided and scars have softened, typically 3 months after injury or prior repair surgery. If the fistula is large, wait 6 months. Additionally, all inflammation must be adequately drained.

**Surgical Methods**

**(1) Fistulectomy with Layered Closure**

*Fistulectomy with Layered Closure*

After excising the fistula, layered suturing is performed, which can be done via the vagina or rectum. The advantage is that the procedure is simple and easy to perform. The disadvantage is the high recurrence rate due to tension during suturing and uneven separation of rectal or vaginal tissue. Therefore, the mucosal-muscular flap must have adequate blood supply.

1. **Surgical Technique:** Mobilize the posterior and lateral aspects of the rectal blind end, then dissect around the rectovaginal fistula. After mobilizing and ligating the fistula, use fine absorbable sutures to intermittently close the rectovaginal septum. Then, fully mobilize the rectum to ensure tension-free suturing with the distal mucosal-muscular layer. Postoperatively, keep the wound clean and dry to promote initial healing. Anal dilation should begin 2 weeks postoperatively and continue for no less than 6 months to prevent anal stricture. This procedure is suitable for low imperforate anus, low rectovaginal fistula, or vestibular fistula. The success rate increases with age.
2. **Outcomes:** Reported outcomes vary. Lescher et al. reported an 84% recurrence rate, while Given reported 30%. Hibband reported initial healing in 14 cases. Although some oppose this method for high rectovaginal fistulas, Lawson reported success in 42 out of 53 high rectovaginal fistulas, recommending incision of the rectouterine pouch to facilitate fistula closure. The key points of this procedure are tension-free suturing and ensuring no ischemia at the suture site.

**(2) Rectal Advancement Flap Repair**

*Rectal Advancement Flap Repair*

In 1902, Noble first used the rectal advancement flap repair for rectovaginal fistula. Recently, most scholars consider this the preferred method for low rectovaginal fistulas.

After satisfactory anesthesia, place the patient in the prone position. First, identify the internal and external openings, and insert a probe into the fistula tract. The rectal mucosal flap is created with a "U"-shaped incision, with a length-to-width ratio no greater than 2:1 to ensure adequate blood supply. Inject 1:20,000 epinephrine submucosally to reduce bleeding. Dissect the internal sphincter and suture it at the midline. Excise a 0.3 cm rim of mucosal tissue around the fistula to create a fresh wound. Then, advance the flap downward to cover the internal opening and suture it intermittently with 2-0 or 3-0 absorbable sutures, restoring the normal anatomical relationship between the mucosa and skin. The vaginal wound is left open for drainage.

**(3) Abdominoperineal or Sacroperineal Surgery**

Since the levator ani muscle in newborns is only about 1.5 cm away from the anus, it is extremely easy to injure the puborectalis muscle when separating the rectum in the perineal region. The sacrococcygeal incision allows clear identification of the puborectalis muscle, facilitates the mobilization of the rectum, and makes it easier to separate and excise fistulas with higher openings. This surgery is suitable for infants older than 6 months. A longitudinal skin incision of about 3–5 cm is made in the sacrococcygeal region, and the sacrococcygeal cartilage is transversely incised to expose the rectal blind end. A longitudinal incision is made along the rectal blind end to locate the fistula opening within the intestinal lumen. The fistula opening is then separated, cut, and sutured. The rectum is mobilized until it can relax and descend to the level of the anal dimple skin. An X-shaped incision is made in the anal dimple skin to expose the external sphincter. The rectum is gently pulled through the middle of the puborectalis muscle to the anus, ensuring the intestinal segment is not twisted and avoiding forceful digital dilation within the intestinal ring. The rectal wall is sutured to the subcutaneous tissue of the anus with a few silk stitches, and the full thickness of the rectum is intermittently sutured to the anal skin using 3-0 catgut or silk sutures. The sacrococcygeal wound is closed in layers.

In addition, high imperforate anus and rectovaginal fistula can also be treated with abdominoperineal anoplasty, rectovaginal fistula repair, and colostomy during the neonatal period. However, due to practical limitations, the high surgical mortality rate makes it difficult for parents to accept.

The main surgical complications for all high fistulas are infection and fistula recurrence, and reoperation is more challenging. A treatment plan should be formulated for each specific case based on its condition and practical circumstances, selecting the appropriate surgical method.

For acquired rectovaginal fistula, treatment should be tailored to the disease cause. If caused by inflammation, active treatment of enteritis should be followed by selecting repair, bowel resection, or colostomy based on the condition.

For rectovaginal fistulas caused by obstetric surgery or trauma, transrectal or transvaginal repair should be performed after inflammation is controlled. The edges of the rectal and vaginal walls are incised and separated, the rectal wall is closed with transverse invagination, and the submucosal tissue of the vaginal wall is longitudinally approximated while the vaginal mucosa is closed transversely.

Local repair of radiation-induced rectovaginal fistulas is extremely difficult and often impossible, so colostomy should be performed.

For rectovaginal fistulas caused by foreign bodies or electrocautery, an initial stage (first stage) colostomy should be performed when necessary, followed by an intermediate stage (second stage) fistula repair and bowel anastomosis or pull-through procedure.

Currently, there are many surgical methods for rectovaginal fistula, but the optimal approach should be selected for each specific case to minimize injury and achieve the best outcome.