In the developing world, where routine perinatal obstetric care may be limited, VVF most commonly occurs as a result of prolonged obstructed labor resulting from cephalopelvic disproportion, with resulting pressure necrosis to the anterior vaginal wall, bladder, bladder neck, and proximal urethra from the baby.
Typically, these occur in individuals who are young primigravidas with a narrow bony pelvis.
The constellation of problems resulting from obstructed labor is not limited to VVF and has been termed the obstructed labor injury complex.
Obstetric fistulae are more likely to be:
Larger
Located distally in the vagina
Involve large portions of the bladder neck and proximal urethra
Because of their size and extensive ischemia of the surrounding tissues, these fistulae are often difficult to repair.
Cancer
Trauma
Postsurgical: abdominal hysterectomy, vaginal hysterectomy, anti-incontinence surgery, anterior vaginal wall prolapse surgery (e.g., colporrhaphy), vaginal biopsy, bladder biopsy, endoscopic bladder resection, laser therapy in bladder, other pelvic surgery (e.g., vascular, rectal)
In the industrialized world, the most common cause (>75%) is injury to the bladder at the time of surgery, the most common of which is hysterectomy
The rate of iatrogenic bladder injury during abdominal hysterectomy is ≈0.5-1.0%; the rate of incidence of fistula after hysterectomy is ≈0.1-0.2%.
Post-hysterectomy VVFs are thought to result most commonly from an incidental unrecognized iatrogenic cystotomy near the vaginal cuff.
If unrecognized intraoperatively, a pelvic urinoma may develop and ultimately drain out through the vaginal cuff. Ongoing urinary drainage along this tract results in a fistula.
Other potential mechanisms for post-hysterectomy VVF include tissue necrosis from:
Cautery
A suture placed through both the bladder and vaginal wall during closure of the vaginal cuff
An attempt to control pelvic bleeding by suture ligature
Tissue ischemia and then necrosis promotes fibrosis and induration, finally resulting in an epithelial or mucosal lining of the tract and the development of a fistula tract.
Clear vaginal discharge after hysterectomy does not invariably represent a urinary fistula or incontinence. Other than normal vaginal secretions, less common causes include a peritoneovaginal fistula, lymphatic fistula, vaginitis, and fallopian tube fluid
The presence of a VVF may be confirmed by instilling a colored solution, such as methylene blue or indigo carmine into the bladder per urethra and observing whether vaginal drainage is discolored
Small or occult fistulae may be identified in this fashion.
Staining at the introital (distal) end of the packing suggests urinary incontinence or a urethrovaginal fistula, whereas proximal staining suggests a VVF
If the vaginal packing remains dye-free with this maneuver, then the possibility of a ureterovaginal fistula can be investigated with the use of clean vaginal packing, IV indigo carmine (or other vital dye), and a repeat pad test. Blue staining at the proximal end of the pad after this maneuver suggests the presence of a ureterovaginal fistula
A double dye or tampon test may confirm the diagnosis of urinary fistula, as well as suggesting the possibility of an associated ureterovaginal or urethrovaginal fistula. In one variation of the double dye test, a tampon is placed per vagina. Oral phenazopyridine is administered, and vital blue dye is instilled into the bladder. If the tampon is discolored
Yellow-orange at the top, it is suggestive of a ureterovaginal fistula
Green (a combination of blue and yellow) discoloration in the midportion of the tampon suggests VVF
Blue staining at the bottom suggests a urethrovaginal fistula
A trial of indwelling catheterization and anticholinergic medication for at least 2-3 weeks may be warranted in selected patients with newly diagnosed VVF, because spontaneous healing may result (spontaneous closure rate ≈13%)
Drainage of the bladder should start immediately to prevent epithelialization of the fistula tract.
Characteristics associated with favorable outcomes
Size <2-3 mm
Simple injuries to the bladder that do not involve devascularization or thermal injury spread that result in interrupted blood supply to the area
Fistulous tracts that remain open ≥3 weeks after adequate catheter drainage are unlikely to resolve without further intervention
Patients with small epithelialized fistulae, usually <3-5 mm in diameter,may benefit from a minimally invasive treatment involving disruption of the epithelial layer of the fistula tract.
A small cautery electrode is passed into the fistula tract endoscopically as far as possible. The electrode is slowly withdrawn from the tract with the electrode set on coagulation.
Catheterization may be combined with minimally invasive electrocoagulation of the fistula tract.
Fulguration risks failure and the possibility of enlarging the size of the fistula in patients with:
Thin vesicovaginal septum
Large VVF
Non-oblique fistula tract
Significant inflammation around the fistula tract.
Some vaginal procedures, including the Latzko procedure, may result in vaginal shortening and postoperative dyspareunia
Pre-operative estrogen supplementation may be beneficial in the postmenopausal patient with vaginal atrophy; topical estrogen preparations may improve vascularity and local tissue quality
Technique
Approaches (2):
Transvaginal
Transabdominal (transvesical)
Success rates are similar between the two approaches
The most important factor is the experience of the operating surgeon
Advantages of transvaginal approach (3):
Shorter operative times
Shorter hospital stay
Less blood loss
Disadvantages of transvaginal approach (3):
Relative lack of familiarity of the vaginal cuff anatomy to many urologists
Potential for vaginal shortening, especially with the Latzko approach
Difficulty in exposing high or retracted fistulae located near the vaginal cuff, especially in deep, narrow vaginas, or in those without any apical prolapse (though these are not contraindications)
Advantages of abdominal approach (2):
Other intra-abdominal pathology requiring repair
Complicated fistulae including those associated with multiple prior failed attempts at repair, or those that are large (>5cm)
No difference in risk of ureteral injury in transabdominal vs. transvaginal approach
Excision of the fistula tract itself is not always necessary and may even compromise the repair in some patients
Transvaginal approach to VVF repair uses a 3-4 layer closure
Tissue interposition
The interposition of a healthy, well-vascularized tissue flap during VVF repair may be beneficial under certain circumstances, such as (6):
Recurred after a prior attempt at repair
Related to previous radiotherapy
Ischemic or obstetric fistulae
Large fistulae
Associated with a difficult or tenuous closure because of poor tissue quality
Most commonly used flaps for VVF repaired:
Transvaginal repair: Martius flap or peritoneum
Transabdominal: omentum or peritoneum
Other options for a flap include:
Gracilis muscle
Labial myocutaneous flaps
Seromuscular intestinal flaps
Rectum abdominis flaps
Martius flap
Labial fat pad consisting of adipose tissue and connective tissue
Blood supply derives from (3):
Superiorly from the external pudendal artery
Laterally from the obturator artery
Inferiorly from the posterior labial vessels (branch of the internal pudendal artery)
Preferred for low or distal fistulaeinvolving the trigone, bladder neck, and urethra
Peritoneal flap
Preferred for high-lying post-hysterectomy VVF
For post-hysterectomy fistulae, the distance from the labial harvesting site of the Martius flap to the fistula at the apex of the vagina may be considerable. Mobilizing and then tunneling the Martius flap to reach this location may compromise its blood supply and viability.
May also be used as an adjunctive measure during transabdominal repair of VVF, although the approach and technique are vastly different
Omental flap
Blood supply derives from right and left gastroepiploic arteries
Blood supply enters the omentum perpendicular to its origin off the greater curvature of the stomach, enabling vertical incisions and mobilization into the deep pelvis.
In many individuals the flap will reach into the deep pelvis without mobilization and without tension; however, wide mobilization may be necessary to permit the omentum to reach the deep pelvis in some cases; however,
Can be a useful adjunctive measure in the setting of infection or inflammation because of its rich blood supply and lymphatic properties
Postoperative drainage
Can be maintained by single or dual catheters.
Most commonly, both urethral and suprapubic drainage catheters are left postoperatively; the disadvantage to single-catheter drainage is principally that the catheter will malfunction, clog, or kink, resulting in bladder filling, eventual overdistention, and disruption of the suture line.
Timing of repair
Timing of repair is somewhat controversial
Radiation-induced fistula should be repaired after the fistula has matured
Complications
Late post-operative (3):
Vaginal shortening
Vaginal stenosis
Recurrence of the fistula
Follow-up
A postoperative cystogram should include voiding or postvoiding images to ensure that the VVF has been adequately repaired
There is no standard filling volume for cystography.
Generally, 2 to 3 weeks from surgery is an adequate time period for postoperative imaging.
The success rate reported for a simple VVF repair is >90%.
Complicated VVFs, including those resulting from obstetric causes, larger fistulae, and those associated with radiation, generally have a lower success rate.
Radiation-induced fistulae can be repaired vaginally, and adjuvant flaps are used to bolster the repair
In patients with obstetric fistulae associated with loss of the bladder neck and proximal urethra, relatively high rates of persistent severe sphincteric incontinence are noted despite successful repair of the VVF
Stress urinary incontinence may coexist with VVF; however, it is usually not related to the repair.
In some patients, repair of VVF is not possible or multiple surgical attempts have failed. Urinary diversion can be considered.
Fistulae in patients who are not candidates for surgical intervention may be managed by percutaneous ureteral occlusion and permanent nephrostomy.
Surgical injury to the distal 1/3 ureter (below the level of the iliac vessels)
Most common cause: hysterectomy for benign indications
Most common injury to the urinary tract during hysterectomy is a bladder laceration.
Although ureteral injuries are not uncommon, they occur far less frequently than bladder injuries.
The pelvic ureter is intimately related to the female genital tract throughout its course.
In the deep pelvis, the ureter passes at the lateral edge of the uterosacral ligament and ventral to the uterine artery, and then passes just lateral to the cervix and fornix of the vagina.
In females who undergo vaginal surgery (such as hysterectomy) or sustain penetrating pelvic trauma involving the vagina, an initially unrecognized ureteral injury can present in a delayed manner with ureterovaginal fistula.
Other risk factors include: gynecologic surgery (cesarean section, anterior colporrhaphy (cystocele repair)), vascular surgery, urologic surgery including retropubic bladder neck suspensions, colon surgery, locally advanced malignancy, radiation therapy, pelvic trauma, chronic inflammatory diseases (e.g., actinomycosis), endometriosis and obesity
Incidence of iatrogenic ureteral injury during major gynecologic surgery ≈0.5-2.5%
Most common presenting symptom is the onset of constant urinary incontinence 1-4 weeks after surgery.
In direct contrast to VVF, in the setting of continuous urine leakage from a ureterovaginal fistula, patients will continue to report normal voiding habits because bladder filling is maintained from the contralateral, presumably undamaged, upper urinary tract
Imaging
Suspicion of a ureterovaginal fistula should prompt upper tract imaging
Ureterovaginal fistulae may be seen on CT urography or MRI.
CT urogram most commonly will demonstrate some degree of ureteral obstruction and associated caliectasis or ureteral dilation. These findings in the presence of constant vaginal drainage strongly suggest a ureterovaginal fistula.
Alternatively, if the fistula is mature and large, the upper urinary tract may appear completely unremarkable; however, urine will be seen opacifying the vagina before the postvoid image.
If retrograde pyelography demonstrates the fistula, as well as ureteral continuity, then an attempt at stenting is warranted.
Cystography is performed primarily to exclude a coexistent VVF.
A cystogram will not demonstrate the ureterovaginal fistula unless there is preexisting vesicoureteral reflux.
Once the diagnosis is made, prompt drainage of the affected upper urinary tract is essentialbecause partial ureteral obstruction is often present.
An attempt at ureteral stenting or percutaneous nephrostomy tube decompression is warranted as soon as possible if direct open surgical repair is not immediately considered.
Ureteral stenting may be sufficient to promote closure of the fistula in some cases
In some cases, an antegrade stent placement will be successful where a retrograde attempt had failed.
If ureteral stenting is unsuccessful owing to complete ureteral occlusion or if prolonged leakage persists despite stenting, then formal surgical repair is indicated
Timing of the repair of ureterovaginal fistulae is controversial.
Open surgical repair most commonly involves ureteroneocystostomy since most injuries occur to the distal ureter
Unlike other types of urogynecologic fistulae, vesicouterine fistulae may or may not manifest with constant urinary incontinence because of the sphincter-like activity of the cervix:
Exception is in the setting of an incompetent cervix (e.g. post-partum period) wherein urinary leakage is constant
Prolonged indwelling bladder catheterization or fulguration of the fistula tract followed by bladder drainage may be successful in select cases, especially in patients with small, immature fistulae.
Hormonal induction of menopause will induce involution of the puerperal uterus, and this principle has been used with some success in treating this condition.
Surgical therapy for vesicouterine fistulae is often contingent on the specific reproductive wishes of the patient. If there is no further desire for childbearing, then transabdominal hysterectomy and bladder closure should be considered. For the patient who desires preservation of fertility, uterine-sparing surgery can be considered
Symptoms of urethrovaginal fistulae are largely dependent on the size and location of the fistula along the urethral lumen
Proximal fistulae can be associated with stress incontinence, or, if they are located at the bladder neck, continuous incontinence may result, similar to that associated with VVF
Distal fistulae beyond the sphincteric mechanism may be completely asymptomatic or may be associated with a splayed urinary stream.
Can often be made on physical examination and cystourethroscopy; however, VCUG is most useful
An associated VVF will be found in up to 20% of cases, and therefore a thorough evaluation of the entire lower urinary tract is warranted
Foreign material should be excised as widely as possible from the margins of the fistula
Various types of soft-tissue flaps are often an important component of a successful urethrovaginal fistula repair including, most commonly, a Martius labial fat flap, but also gracilis and rectus abdominis muscle
SUI may persist after repair of urethrovaginal fistulae. Whether repair of SUI should be done concomitantly with the fistula surgery or should be deferred until after repair of the fistula is controversial
Classic presentation of vesicoenteric fistula (described as Gouverneur syndrome) consists of (4):
Suprapubic pain
Urinary frequency
Dysuria
Tenesmus
Symptoms of vesicoenteric fistulae may originate from the urinary or GI tract; however, in general, storage LUTS are more common at presentation.
Recurrent UTIs or cystitis refractory to antibiotic therapy may suggest a colovesical fistula
Imaging
Cross-sectional imaging
Modality of choice
CT with contrast
Generally considered to be the most sensitive and specific modality for the diagnosis of colovesical fistulae
Findings on CT that are suspicious for colovesical fistulae (3):
Bladder wall thickening adjacent to a loop of thickened colon
Air in the bladder (in the absence of previous lower urinary manipulation)
The presence of colonic diverticula
CT scan with IV and oral contrast, coronal view, demonstrating bladder wall thickening adjacent to a loop of thickened bowel. 57M with history of diverticulitis, dysuria, urinary frequency, and fecaluria.
Cystography and transrectal contrast studies (e.g., barium enema)
Although commonly used are less likely to demonstrate the fistula
Other
Endoscopy
The finding of bullous edema during cystoscopy is nonspecific; however, in the appropriate clinical setting, this can be very suggestive of a colovesical fistula.
80-100% of cases of colovesical fistulae have an abnormality noted on cystoscopy
Bourne test
Performed after a nondiagnostic barium enema.
The first voided urine after the barium enema is immediately centrifuged and then examined radiographically. Radiodense particles in the urine are considered a positive test result and evidence for a vesicoenteric fistula
Activated charcoal
Oral administration of activated charcoal, which, in the setting of a fistula, will appear in the urine as black particles
Option in selected nontoxic, minimally symptomatic patients with nonmalignant causes with vesicoenteric fistula
Trial of medical therapy including intravenous total parenteral nutrition, bowel rest, and antibiotics may be warranted.
May be the preferred initial approach, especially in patients with Crohn disease, in whom the notion of immediate exploratory laparotomy and bowel resection is often discouraged because of the chronic relapsing nature of the disease
Operative management
Goal is to separate and close the involved organs with minimal anatomic disruption and normal long-term function of both systems.
Both single and multistage procedures have been advocated, depending on the clinical circumstances.
A one-stage procedure involves removal of the fistula, closure of the involved organs, and primary reanastomosis of the bowel after resection of the involved bowel segment.
A two-stage approach advocates removal of the fistula, closure of the involved organs, and creation of a temporary proximal diverting colostomy, with a later return to the operating room for colostomy takedown once the fistula tract has been demonstrated to be closed
Most common cause has historically been chronic inflammatory disease, such as xanthogranulomatous pyelonephritis or other infectious diseases involving the kidney or bowel.However, iatrogenic surgical trauma, especially that related to percutaneous renal surgery and percutaneous nephrolithotomy (PCNL), has been associated with an increasing number of such fistulae
Right-sided pyeloenteric fistulae most often involve the duodenum, whereas left-sided pyeloenteric fistulae most commonly involve the descending colon
A large nephrostomy tube, enteric suction or bowel rest, antibiotics, and removal of any foreign body (e.g., a stone) may be attempted. Internal stenting of the urinary tract may be pursued for maximal drainage.
Fistulae associated with a poorly functioning kidney are best treated by primary closure of the bowel and nephrectomy.
Acquired rectourethral fistula may occur in the male under a variety of clinical circumstances, including those related to prostatectomy for benign or malignant disease, cryotherapy, pelvic radiotherapy, anorectal surgery, external penetrating trauma, urethral instrumentation, locally advanced prostatic or rectal malignancy, infection (e.g., TB), ruptured prostatic abscess, or inflammatory disease (e.g., Crohn disease)
The incidence of rectourethral fistula after radical retropubic prostatectomy is low but owing to the frequency with which the operation is performed, it is the most common cause of rectourethral fistula.
Rectal injury during radical prostatectomy occurs in < 1-2% of patients
Symptoms may include fecaluria, hematuria, UTI, nausea, vomiting, and fever
Imaging
Lower tract imaging
VCUG or retrograde urethrogram usually provides a definitive diagnosis of rectourethral fistula
Upper tract imaging should be performed in patients to exclude a related ureteral injury
Other
In patients with a history of pelvic malignancy, biopsy of the fistula is suggested to evaluate for a local recurrence of the tumour
Cystoscopy and sigmoidoscopy visualize the fistula tract in the vast majority of cases and provide a mechanism for biopsy
Assessment of continence and sphincteric function in patients with rectourethral fistula after radical prostatectomy
Given the location of most rectourethral fistulas at or near the vesicourethral anastomosis and the membranous urethra, there is a risk for persistent severe stress incontinence postoperatively after rectourethral fistula repair
Most rectourethral fistula will require surgical repair, although some will close with conservative management.
Rectourethral fistula that follows open or laparoscopic prostatectomy may heal spontaneously with catheter drainage, bowel rest, and intravenous hyperalimentation.
In some cases, fecal diversion is necessary.
Staged repairs might be considered in (5):
Large fistulae
Associated with radiation therapy
Uncontrolled local or systemic infection
Immunocompromised states
Inadequate bowel preparation at the time of definitive repair
Transrectal approaches with and without division of the anal sphincter have been described for the operative repair of rectourethral fistula.
The York-Mason procedure is a transrectal, transsphincteric approach that has been found to be effective and to have low morbidity
Most common causes are procedures in which percutaneous renal access is required, such as PCNL. Alternatively, a long-term indwelling nephrostomy tube may lead to pyelovascular fistula formation.
Depends on the cause of the fistula and the associated clinical manifestations
Patients with severe hemorrhage on removal of the nephrostomy tube can be temporized in some instances by replacing the tube, or, in large mature tracts, by placing a Foley catheter to tamponade the bleeding.
In patients with ongoing bleeding, transcatheter angiographic embolization of the lacerated vessel is recommended.
≈70% of fistulae occurring after needle biopsy of the kidney close spontaneously within 18 months, thus, expectant management is an appropriate first step
Fistulae due to renal cell carcinoma warrant nephrectomy
In a stable patient with a suspected ureterovascular fistula, radiographic evaluation can be used for diagnostic purposes and treatment planning (reconstructive options or angiographic embolization).
In the unstable patient, surgical intervention must be considered early, especially because radiographic evaluation may be nondiagnostic.
Nephropleural or nephrobronchial fistulae are uncommon; may occur secondary to percutaneous access to the upper urinary tract.
Cutaneous fistulae from the urinary tract may arise from the kidney, ureter, bladder, or urethra. For newly diagnosed urocutaneous fistulae, it is imperative to evaluate for distal urinary obstruction.
