Textbook Of Gynecology. Dc Dutta’s

Chapter 25. Genital Fistulae

GENITOURINARY FISTULA

DEFINITION

A fistula is an abnormal communication between two or more epithelial surfaces. Genitourinary fistula is an abnormal communication between the urinary and genital tract either acquired or congenital with involuntary escape of urine into the vagina.

The incidence is estimated to be approximately 0.2-1 percent among gynecological admissions in referral hospitals of the developing countries. The incidence is however, much less in the affluent countries.

TYPES: The communication may occur between the bladder, urethra or ureter and genital tract.

VESICOVAGINAL FISTULA (VVF)

DEFINITION: There is communication between the bladder and the vagina and the urine escapes into the vagina causing true incontinence (Fig. 25.2). This is the commonest type of genitourinary fistula.

Fig. 25.1: Types of genitourinary fistula— (1) Vesicovaginal (2) Vesicourethrovaginal (3) Urethrovaginal (4) Vesicocervical (5) Ureterovaginal (6) Vesicouterine

CAUSES: • Obstetrical • Gynecological

Obstetrical: In the developing countries, the commonest cause is obstetrical and constitutes about 80-90 percent of cases, as opposed to only 5-15 percent in the developed countries. The fistula may be due to ischemia or following trauma.

Ischemic: It results from prolonged compression effect on the bladder base between the head and symphysis pubis in obstructed labor → ischemic necrosis → infection → sloughing → fistula. Thus, it takes few days (3-5) following delivery to produce such type of fistula.

Traumatic: This may be caused by:

• Instrumental vaginal delivery such as destructive operations or forceps specially with Kielland. The injury may also be inflicted by the bony spicule of the fetal skull in craniotomy operation.

• Abdominal operations such as hysterectomy for rupture uterus or Cesarean section specially a repeat one or for cesarean hysterectomy. The injury may be direct or ischemic following a part of the bladder wall being caught in the suture.

This type of direct traumatic fistula usually follows soon after delivery.

Gynecological: Although a rarity in the developing countries, it is the commonest type met in the developed ones and accounts for more than 80 percent of fistulae.

• Operative injury likely to produce fistula includes operations like anterior colporrhaphy, abdominal hysterectomy for benign or malignant lesions or removal of Gartner’s cyst.

• Traumatic—The anterior vaginal wall and the bladder may be injured following fall on a pointed object, by a stick used for criminal abortion, following fracture of pelvic bones or due to retained and forgotten pessary.

• Malignancy—Advanced carcinoma of the cervix, vagina or bladder may produce fistula by direct spread.

• Radiation—There may be ischemic necrosis by endarteritis obliterans due to radiation effect, when the carcinoma cervix is treated by radiation. Apart from overdose or malapplication, it may occur even with accurate therapy. It takes usually long time (1-2 years) to produce such fistula.

Fig. 25.2: Midvaginal obstetric fistula (VVF). It was of moderate size to allow a metal catheter which is clearly visible [By courtesy Dr. P. Mukherjee, Professor, Dept of G&O, IPGME&R, Kolkata]

• Infective—Chronic granulomatous lesions such as vaginal tuberculosis, lymphogranuloma venereum, schistosomiasis or actinomycosis may produce fistula.

Thus, the fistula tract may be lined by fibrous, granulation tissue, infective extension or malignant cells.

TYPES: Fistula may be classified as—(i) Simple (Healthy tissues with good access) or (ii) Complicated (tissue loss, scarring, difficult access, associated with RVF).

Depending upon the site of the fistula, it may be:

• Juxtacervical (close to the cervix)The communi-cation is between the supratrigonal region of the bladder and the vagina (vault fistula).

• Midvaginal—The communication is between the base (trigone) of the bladder and vagina.

• Juxtaurethral—The communication is between the neck of the bladder and vagina (may involve the upper urethra as well).

• Subsymphysial—Circumferential loss of tissue in the region of bladder neck and urethra. The fistula margin is fixed to the bone.

CLINICAL FEATURES

Patient profile: In the developing countries, obstetrical fistula being common, the patients are usually young primiparous with history of difficult labor or instrumental delivery in recent past. In others, it is related with the relevant events.

Symptoms

• Continuous escape of urine per vaginum (true incontinence) is the classic symptom. The patient has got no urge to pass urine. However, if the fistula is small, the escape of urine occurs in certain positions and the patient can also pass urine normally. Such history has got a positive correlation with the related events mentioned in the etiology.

Leakage of urine following surgical injury occurs from the first postoperative day whereas in obstetric fistulae symptoms may take 7-14 days to appear urethral fistulae that are situated high up, often presents with features of stress incontinence.

Women with vesicocervical or vesicouterine fistulae may hold urine at the level of the uterine isthmus and may remain continent. But they complain of cyclical hematuria at the time of menstruation (menouria). Sometimes women may complain of intermittent leakage of urine.

• There is associated pruritus vulvae.

Signs: Vulval Inspection

• Escape of watery discharge per vaginum of ammoniacal smell is characteristic.

• Evidences of sodden and excoriation of the vulval skin.

• Varying degrees of perineal tear may be present.

Internal examination: If the fistula is big enough, its position, size and tissues at the margins are to be noted.

At times, there may be varying degrees of vaginal atresia so as to make the fistula inaccessible.

Speculum examination: A Sims’ speculum in Sims’ position gives a good view of the anterior vaginal wall when the vagina becomes ballooned up by air because of negative suction.

• The size, site and number of fistula.

• Often, the bladder mucosa may be visibly prolapsed through a big fistula (Fig. 25.2).

• A tiny fistula is evidenced by a puckered area of vaginal mucosa.

Associated clinical features that may be present in cases of such fistula are:

• Secondary amenorrhea of hypothalamic origin (Menstruation resumes following successful repair).

• Foot-drop due to prolonged compression of the sacral nerve roots by the fetal head during labor.

• Complete perineal tear or rectovaginal fistula.

CONFIRMATION OF DIAGNOSIS

The diagnosis is most often made from the typical history and local examination. But, sometimes confusion arises in a case of tiny fistula for which additional methods are to be employed (Table 25.2). The confused clinical conditions are stress incontinence, ureterovaginal and urethrovaginal fistula.

To confirm the diagnosis, following are helpful:

• EUA is needed for better evaluation.

• The patient is placed in Sims’ or knee chest position and while examining the anterior vaginal wall, bubbles of air are seen through the small tiny fistula when the woman coughs.

• Dye testA speculum is introduced and the anterior vaginal wall is swabbed dry. When the methylene blue solution is introduced into the bladder by a catheter, the dye will be seen coming out through the opening.

• A metal catheter passed through the external urethral meatus into the bladder when comes out through the fistula not only confirms the VVF but ensures patency of the urethra.

• Three-swab test—The three-swab test not only confirms the VVF but also differentiates it from ureterovaginal and urethrovaginal fistula.

Procedure of Three Swab Test (Fig. 25.3)

Three cotton swabs are placed in the vagina—one at the vault, one at the middle and one just above the introitus. The methylene blue is instilled into the bladder through a rubber catheter and the patient is asked to walk for about 5 minutes. She is then asked

Fig. 25.3 : Three-swab test using methylene blue to lie down and the swabs are removed for inspection (Table 25.1).

TREATMENT OF OLD VVF

♦ Preventive ♦ Operative

PREVENTIVE: Obstetric fistula in the developing world can be prevented with safe motherhood initiative (WHO-1987). Women with obstetric VVF is considered as a ‘near-miss’ maternal death. Gynecological fistula—can be prevented with better anticipation and improved surgical skill.

The following guidelines are prescribed:

● Adequate antenatal care is to be extended to screen out ‘at risk’ mothers likely to develop obstructed labor.

● Anticipation, early detection (partograph) and ideal approach in the method of delivery in relieving the obstruction.

● Continuous bladder drainage for a variable period of about 5-7 days following delivery either vaginally or abdominally in a case of longstanding obstructed labor.

● Care to be taken to avoid injury to the bladder during pelvic surgery—obstetrical or gynecological.

Immediate management: Once the diagnosis is made, continuous catheterization for 6-8 weeks is maintained. This may help spontaneous closure of the fistula tract. Unobstructed outflow tract helps epithelialization, provided the tissue damage is minimum. The management of genitourinary fistula needs a team approach both by the gynecologists, nursing staff and the urologists. These socially ostracized women need realistic counseling. Other-wise treatment failure may cause further devastation.

OPERATIVE: local repair of the fistula is the surgery of choice.

• Preoperative assessment

• Preoperative preparations

• Definitive surgery.

Preoperative Assessment

• Fistula status—Assessment is done as regards the site, size, number, mobility and status of the margins of the fistula.

• Urethral involvement is assessed by introducing a metal catheter through external urethral meatus into the bladder.

• To ascertain the position of the ureteric openings in relation to a big fistula, cystoscopy is indicated. The patient is placed in knee-chest position when the bladder becomes distended with air (Kelly’s air cystoscopy).

• To exclude associated rectovaginal fistula or complete perineal tear.

• Complete hemogram and urea, creatinine (renal function) estimation are done.

Preoperative Preparations

• As the patients are usually from poor socioeconomic status, and socially ostracized the improvement of the general condition is essential prior to surgery.

• Local infection in the vulva should be treated by application of silicone barrier cream or glycerine.

• Urinary infection, if any, should be corrected beforehand. It is difficult to collect urine for culture and sensitivity. It is preferable to collect urine for the same from the indwelling catheter kept following the surgical repair. Preoperative collection is best to be done through ureteric catheterization. Urine collected through vaginal speculum will not serve the purpose because of contamination. It is advised to start urinary antiseptics at least 3-5 days prior to surgery.

Definitive surgery—(Old obstetric VVF).

Time

The ideal time of surgery is after 3 months following delivery. By this time, the general condition improves and local tissues are likely to be free from infection. Further delay is likely to produce more fibrosis and unnecessary prolongs the misery of the patient. Early repair may compromise the success.

Surgical fistula if recognized within 24 hours, immediate repair may be done provided it is small. Otherwise it should be repaired after 10-12 weeks. Radiation fistulae should be repaired after 12 months.

Route of repair: It mostly depends upon the access to the fistula site and the tissue mobility of the vagina. Either the abdominal or vaginal route may be approached according to the choice and expertize of the surgeon.

Suture materials: Polygalactin (Vicryl) 2-0 suture material is preferred for both the bladder and vagina. Polydioxanone (PDS) 4-0 on a 13 mm round bodied needle is used for the ureter. 3-0 PDS on a 30 mm round bodied needle is used for bowel surgery.

Local repair by flap splitting method is the preferred surgery (see Fig. 25.4, Step 1-5).

Principles of surgery

• Perfect asepsis and good exposure of the fistula.

• Excision (minimal) of the scar tissue round the margins.

• Mobilization of the bladder wall from the vagina.

• Suturing the bladder wall without tension in two layers.

First layer is with polygalactin (Vicryl) 2-0 suture (p. 645) on a 30 mm needle is preferred. Interrupted stitches (3 mm apart) excluding the bladder mucosa are done.

Second layer is with interrupted sutures using the same suture material taking the muscle and fascial layer of the bladder wall, burying the first suture line.

• Apposition of the vaginal wall by interrupted sutures using same suture material No. ‘O’ (Fig. 25.4).

• Closure must be water-tight and is tested by dye instillation into the bladder at the end of the operation.

• To maintain continuous bladder drainage by an indwelling catheter (see Fig. 37.6).

Saucerization (Paring and Suturing)

This operation was originally devised by James Marion Sims (1852) of USA. He used to repair (see Fig. 36.2) the fistula in Sims’ position (see p. 103) exposing the fistula with Sims’ speculum and after paring the margins, sutured the fistula with silver wire. Saucerization is the closure of a small fistula using interrupted stitches without dissection of bladder from the vagina. This may be employed in a very small fistula using Vicryl (2-0).

Latzko technique is used to repair a VVF that develops following total hysterectomy operation. Principle of this operation is to produce partial colpocleisis (obliteration of the vagina around the fistula). This procedure is suitable for a fistula which is small and high in the vagina.

Principal steps

• Vaginal mucosa is dissected off the bladder wall around the fistula site.

• The fistula tract is excised.

• Bladder mucosal edges are approximated with interrupted sutures (2-0 Vicryl).

• Two additional suture layers are used to appose the muscle and fascia.

• Vaginal mucosa is closed by interrupted sutures using same suture material. Continuous bladder drainage by indwelling catheter is maintained for 10-14 days.

Modifications of Vaginal Operations (Table 25.3)

● Ureteric openings close to the margins.

To introduce ureteric catheter prior to repair to prevent inclusion of the ureteric opening in suture.

● Involvement of the bladder neck.

Suprapubic or vaginal cystostomy prior hand as temporary urinary diversion to keep the repair area free from getting wet.

● Associated with CPT or RVF.

To repair the VVF first followed by repair of the CPT or RVF in the same sitting.

Use of graft: Repair of a big fistula may need inter position of tissue grafts to fill space and with new blood supply. Different tissues may be used.

Martius graft: Bulbocavernous muscle and labial fat pedicle graft is used for big bladder neck fistula.

Other tissues used are Gracillis muscle, omental pedicle graft (transperitoneal approach) or peritoneal flap.

Advice during Discharge

‣ To pass urine more frequently.

‣ To avoid intercourse for at least 3 months.

‣ To defer pregnancy for at least 1 year.

‣ If conception occurs, to report to the hospital and must have mandatory antenatal check up and hospital delivery. A successful repair should have an abdominal delivery.

If repair fails, local repair should again be attempted after 3 months. The fistula may become smaller when the second attempt may be successful. In cases of repeated failures, before declaring the case as irreparable, it is preferable to have a second opinion or to consult an urologic surgeon. This might avert the last resort to go for urinary diversion — implantation of ureters into the pelvic colon or ileal bladder (preferred).

GRITERIA FOR SUCCESSFUL REPAIR (WHO 2006)

Criteria

Good prognosis

Uncertain prognosis

No. of fistula

Single

Multiple

Site

Vesicovaginal fistula (VVF)

Rectovaginal fistula (RVF), Mixed (VVF and RVF)

Size

<4 cm

>4 cm

Urethral involvement

Absent

Present

Vaginal scarring

Absent

Present

Tissue loss

Minimal

Extensive

Ureter involvement

Ureters are draining inside the bladder, not into the vagina

Ureters are draining into the vagina

Circumferential defect (urethra separated from the bladder)

Absent

Present

 

Principles in the Management of Gynecological VVF

■ Detected during operation: To repair immediately in two layers.

■ Detected in the postoperative period: To put an indwelling catheter for about 10-14 days. If fails, repair is to be done after 3 months.

■ Malignant or postradiation fistula: Any of the following may relief the symptoms—(1) Ileal bladder, (2) Anterior exenteration, (3) Colpocleisis.

■ Infective fistula: Eradication of the specific infection be done first followed by local repair.

URETHROVAGINAL FISTULA

Causes

‣ Part or whole of the urethra is involved along with bladder. The causes are the same as those of VVF.

‣ Small isolated urethrovaginal fistula is caused by:

Injury inflicted during anterior colporrhaphy, urethroplasty, suspension or sling operation for stress incontinence.

Residual fistula left behind following repair of vesicourethrovaginal fistula.

Diagnosis: The patient has got urge to pass urine but the urine dribbles out into the vagina during the act of micturition. A sound or a metal catheter passed through the external urethral meatus when comes out through the communicating urethrovaginal opening confirms the diagnosis. In cases of confusion in diagnosis with VVF or ureterovaginal fistula, three swab test (mentioned earlier) may be employed.

Treatment: Surgical repair in two layers followed by continuous bladder drainage as outlined in repair of VVF is satisfactory. Prior suprapubic or vaginal cystostomy ensures better success. In cases of complete destruction of the urethra, reconstruction of urethra is to be performed.

Success rate of VVF repair following first operation is about 60 to 98 percent. Failure rate is 10 percent and in 10 percent cases there is post fistula stress incontinence. Success rate decreases with increasing number of previous unsuccessful attempts.

URETERIC INJURY IN GYNECOLOGIC SURGERY

Ureteric injury through rare has got considerable morbidity. It is an important cause for litigation.

Causes: ■ Acquired ■ Congenital

Acquired: This is common and usually follows trauma during pelvic surgery. Although commonly associated with difficult surgery like abdominal hysterectomy in cervical fibroid, broad ligament fibroid, endometriosis, ovarian malignancy or radical hysterectomy, it may be injured even in apparently simple hysterectomy—abdominal or vaginal (rare).

Congenital: The aberrant ureter may open into the vault of vagina, uterus or into urethra.

INJURY TO THE URETER DURING GYNECOLOGICAL SURGERY

Because of close anatomical association between ureter and genital organs, ureteric injury is not uncommon during gynecological surgery. Overall incidence is 0.5-1 percent of all pelvic operations. About 75 percent of ureteral injury result from gynecological operations and 75 percent of them occur following abdominal gynecological procedures.

Important anatomical locations where ureteric injury is more common.

● At the level of infundibulopelvic ligament— where ureter runs parallel to ovarian vessels at the same place. Ureter forms the posterior boundary of ovarian fossa. Any inflammatory or malignant processes will involve the ureter.

● Deep in the pelvis, below the level of ischial spine, where ureter lies lateral to the peritoneum of uterosacral ligament.

● At the level of internal cervical os, 1.5 cm lateral to the cervix where uterine artery crosses the ureter from above.

● Over the anterior vaginal fornix, within the ureteric tunnel of cardinal ligament (tunnel of Wertheim) where it turns anteriorly and medially to enter the bladder.

● Where it traverses through the musculature of bladder (intravesical part).

● Any congenital malformation (duplex ureter) makes it more vulnerable to injury at any of these sites.

Nature of Ureteral Injury

Severity of ureteric injury may be any of the following types:

● Simple kinking or angulation—causing obstruction.

● Ischemic injury resulting from trauma to ureteric sheath endangering its blood supply.

● Ligature incorporation.

● Crushing injury by clamps followed by necrosis.

● Transection—either partial or complete.

● Segmental resection either accidental or planned.

● Thermal injury during minimally invasive surgical procedure when diathermy (monopolar or bipolar) or laser energy is used (see p. 612).

● Injury by staplers during Laparoscopic surgery.

Gynecological Operations and Ureteric Injury

Risk of injury is more where pelvic anatomy is distorted due to presence of any pelvic pathology. Common pathological conditions are:

● Cervical fibroid or low corporeal fibroid (p. 284)

● Broad ligament tumor (p. 602).

● Pelvic endometriosis (p. 304).

● Gynecological malignancy (p. 576).

● Pelvic hematoma.

● Tubo-ovarian mass, pelvic adhesions.

● Reapplication of a clamp to the pedicle of uterine artery following its initial slip.

● Presacral neuronectomy (endoscopic).

● Ovarian remnant (see p. 559)—when needs removal.

● Radical hysterectomy (p. 605).

● Vaginal hysterectomy (rare) (p. 217).

● Colposuspension (p. 403).

● LAVH (p. 617).

Diagnosis: Signs and symptoms are subtle and often overlooked. Fever, flank pain, hematuria, abdominal distension, urine leakage (vaginally), peritonitis, ileus and retroperitoneal urinoma should raise the suspicion.

a. Escape of urine through vagina following the operative procedure is suspicious.

b. The patient has got urge to pass urine and can pass urine normally.

c. Three swab test differentiates it from VVF (Table 25.1).

d. Intravenous indigo carmine test—if the urine in the vagina is unstained following three-swab test, indigo carmine is injected intravenously. If urine becomes blue (generally within 4-5 minutes) the diagnosis of ureterovaginal fistula is established.

e. Cystoscopy—Should be performed to determine the side of ureterovaginal fistula. There is no spurt of urine from the ureteric orifice of the affected side.

f. When a ureteric catheter is passed under cysto- scopic guidance, obstruction is met when the catheter tip reaches the site of injury.

g. Excretory urography (IVU) confirms the side and site of fistula. The tract of ureterovaginal fistula is also outlined.

h. Renal ultrasound is a noninvasive method. Hydronephrosis and retroperitoneal urinomas when seen, are helpful to the diagnosis (ureteral ligation).

i. Computed tomography (CT) showing contrast extravasation is the most consistent to the diagnosis.

Peroperative detection of ureteral laceration can be made by seeing the leakage of dye at the site, following intravenous injection of indigocarmine. When the ureter is ligated or kinked, gradually increasing ureteric dilatation will be noticed, instead of dye leakage.

MANAGEMENT OF URETERIC INJURY

■ Preventive ■ Operative

PREVENTIVE MEASURES

A thorough knowledge of pelvic anatomy is essential. Where there is any doubt, the following measures may be of help, if taken either during preoperative or intraoperative period.

● Intravenous urography (preoperative)—is helpful in certain situation (e.g. pelvic tumors), to ascertain the course of the ureters. Any congenital abnormality is also revealed.

● Placement of ureteral catheters (preoperative or intraoperative) to facilitate detection and dissection of ureters. Unfortunately in a fibrotic pelvic condition (endometriosis) palpation may be difficult.

● Direct visualization and/or palpation of ureters throughout its pelvic course wherever possible.

● Uriglow —ureteric catheters within built incorporated light source for better localization has been tried.

● Adequate exposure of pelvic organs is a must. Inadequate incision leads to inadequate exposure and dissection. This may lead to blind clamping or suturing.

● Meticulous care during dissection—not to damage the sheath of ureter so that longitudinal vessels are not destroyed.

● To follow the important axiom of surgery— any important structure at risk of inadvertent injury must be carefully dissected and adequately exposed.

● To avoid blind clamping of blood vessels.

OPERATIVE

Management of ureteric injury depends on the following factors—(a) Time of detection: intraoperative or postoperative (b) Type and severity of injury (c) Anatomical level (d) Mobility of the ureter and bladder (e) Pathology leading to ureter injury (f) Patient’s general condition and prognosis.

Principles of Ureteric Repair

• Not to damage the ureteric sheath and its blood supply during dissection.

• Ureteric mobilization and tension-free anastomosis.

• Watertight closure with polydioxanone (PDS) 4-0 on a 13 mm needle is used.

• Sent with a ureteric catheter.

• Passive drain at the anastomotic site to prevent urine accumulation.

Complications Following Repair of Ureteric Injury

(i) Stricture. (ii) Infection. (iii) Ureteric obstruction.

(iv) Reflux of urine. (v) Stent or Boari flap com plications.

RECTOVAGINAL FISTULA

Management When Injury Is Recognized During Operation

Ureteral sheath denudation: No intervention, rarely ureteral stenting (double J or Pig tail), if a long segment is involved.

Ureteral kinking (due to closely placed sutures): Immediate removal of suture.

Ureteral ligation: Deligation immediately → assessment of viability by blood flow and ureteral peristalsis. Ureteral stenting may be needed if any doubt.

Ureteral crushing (clamp injury): Remove the clamp → check the viability → ureteral stenting → extraperitoneal drainage at the site is placed.

URETERIC TRANSECTION

Partial: Primary repair over ureteral stent.

Complete: (i) In the middle-third → end-to-end anastomosis over an ureteral stent (uretero-ureterostomy) following adequate mobilization of both the segments. Otherwise (complicated) ureteroileal interposition is done. (ii) In the lower-third → ureteroneocystostomy with psoas hitch over an ureteral stent.

Thermal injury resection and management according to the length of transection.

Ureteric implantation into the bladder (uretero-neocystostomy) must be done without any tension. High mobilization of bladder is needed and bladder dome is sutured to the psoas muscle on that side (psoas hitch). To prevent vesicoureteric reflux, ureter is implanted through submucosal tunnel in the posterior wall of the bladder.

Bladder flap procedure (modified Boari-Ocker-blad) is an alternative when the ureter is short or the injury is at the level of pelvic brim. An obliquely placed bladder flap is outlined. The flap is rolled into a tube and the ureter is reimplanted in the submucosal tunnel without tension.

Alternatively ureteroileoneocystostomy would be done.

Thermal injury: Depending upon the severity it may need resection and management according to transection.

DEFINITION: Abnormal communication between the rectum and vagina with involuntary escape of flatus and/or feces into the vagina is called rectovaginal fistula (RVF) (see Fig. 25.5).

CAUSES: • Acquired • Congenital

Acquired

Obstetrical

a. Incomplete healing or unrepaired recent CPT is the commonest cause of RVF.

b. Obstructed labor—The rectum is protected by peritoneum of pouch of Douglas in its upper-third, by the perineal body in the lower-third and by the curved sacrum in the middle-third. However, if the sacrum is flat, during obstructed labor the compression effect produces pressure necrosis → infection → sloughing → fistula.

Fig. 25.5: Rectovaginal fistula (RVF) following traumatic forceps delivery. It was of moderate size so as to pass a metal probe through the vagina and it is clearly seen to come out through the anus

c. Instrumental injury inflicted during destructive operation.

Gynecological

a. Following incomplete healing of repair of old CPT (commonest).

b. Trauma inflicted inadvertently and remains unrecognized in operations like—perineorrhaphy, repair of enterocele, vaginal tubectomy, posterior colpotomy to drain the pelvic abscess, reconstruction of vagina, etc.

c. Fall on a sharp pointed object.

d. Malignancy of the vagina (common), cervix or bowel.

e. Radiation.

f. Lymphogranuloma venereum or tuberculosis of the vagina.

g. Diverticulitis of the sigmoid colon → abscess → bursts into the vagina.

h. Inflammatory bowel disease: Crohn’s disease involving the anal canal or lower rectum.

CongenitalThe anal canal may open into the vestibule or in the vagina.

DIAGNOSIS

• Involuntary escape of flatus and/or feces into the vagina. If the fistula is small, there is incontinence of flatus and loose stool only but not of hard stool.

• Rectovaginal examination reveals the site and size of the fistula.

• Confirmation may be done by a probe passing through the vagina into the rectum. If necessary, methylene blue dye is introduced into the rectum which is seen escaping out through the fistula into the vagina. Examination under anesthesia may be conducted to facilitate clinical diagnosis (Fig. 25.5).

INVESTIGATIONS

• Barium enema.

• Barium meal and follow through may be needed to confirm the site of intestinal fistula.

Sigmoidoscopy and proctoscopy are helpful for the diagnosis of inflammatory bowel disease or for taking biopsy of fistula edge.

TREATMENT: • Preventive • Definitive

PreventivePreventive aspects include good intranatal care, identification of CPT and its effective repair. Consciousness about the possible injury of the rectum in gynecologic surgery mentioned and its effective and appropriate surgery minimize the incidence of fistula.

Definitive surgery includes:

● Situated low down—to make it a complete perineal tear and repair it as that of CPT.

● Situated in the middle-third—repair by flap method.

Repair by flap method— Repair is commonly done transvaginally. The scar-margin is excised. Vaginal wall separated from the underlying rectal wall. This wide tissue mobilization helps repair without any tension. Repair is done in layers. Suture material used is polydioxanone (PDS) 3-0 on a 30 mm needle. Pre- and postoperative bowel management are similar to that in repair of CPT.

● Situated high up—Preliminary colostomy → local repair after 3 weeks → closure of colostomy after 3 weeks.

● The preoperative preparations of one stage vaginal repair are like those mentioned in repair of CPT.

KEY POINTS

The incidence of genitourinary fistula ranges between 0.2-1 percent among gynecological admissions of the developing countries. Vesicovaginal fistula is the commonest one.

The majority (80-90%) is obstetrical following ischemia due to obstructed labor (p. 418). In the developed countries, the fistula is mostly gynecological (80%).

The fistula is best revealed in Sims' position using Sims' speculum (Sims' triad p. 423). In tiny fistula, diagnosis is made by three swab test. The test also differentiates it from ureterovaginal fistula. Investigations (p. 403) are needed to diagnose it exactly.

Local repair by flap splitting method between 3 months following delivery is the preferred surgery. Continuous bladder drainage for 10-14 days following surgery should be a must (p. 406). Special postoperative care is essential for success (see p. 423). If repair fails, local repair should be attempted after 3 months. In traumatic fistula, specially gynecological, the repair should be done immediately during primary surgery. However, if detected in the postoperative period, the continuous bladder drainage is to be kept for about 10-14 days failing which repair is to be done after 3 months. There are some favorable factors for successful repair (Table on p. 424).

Ureterovaginal fistula is common following difficult abdominal hysterectomy for cervical or broad ligament fibroid, endometriosis, ovarian malignancy or radical hysterectomy (see p. 425). It may also occur following vaginal hysterectomy or otherwise, in a case of simple hysterectomy. There are some anatomical locations as well as pelvic pathologies where ureteric injury is more likely (see p. 425). Nature of ureteric injury may vary from kinking to complete transection. Three swab test differentiates it from a tiny VVF (p. 403). Further investigations are needed to confirm the diagnosis and also to know the side and site of injury (see p. 408). End-to-end anastomosis during surgery or ureteroneocystostomy is the preferred surgery in late cases.

Rectovaginal fistula is common following incomplete healing or unrepaired recent complete perineal tear. Other cause of RVF are obstetric, gynecological or congenital (p. 427).

Diagnosis (p. 428) is important as regard the site and size of fistula.

Definitive surgery for RVF may be as that of a repair of a CPT or by flap method or repair with prior colostomy (p. 428).



If you find an error or have any questions, please email us at admin@doctorlib.info. Thank you!