Lower urinary tract fistulas

Historic perspectives

The earliest evidence of gynecologic fistula dates back millennia, to Queen Henhenit, one of the wives of King Mentuhotep II of Egypt (11th Dynasty, c. 2050 bc). In his dissection of the mummy at the Cairo School of Medicine in 1923, Derry noted a large vesicovaginal fistula (VVF) in the presence of a severely contracted pelvis; he concluded that the fistula was a consequence of obstructed labor ( ). In 1663, van Roonhuyse of Amsterdam published Medico-Chirurgical Observations About the Infirmities of Women, commonly thought of as the first textbook on operative gynecology. In it, van Roonhuyse proposed a revolutionary surgical technique for the closure of VVFs based on the following principles: lithotomy position, good exposure of the fistula with a vaginal speculum, marginal denudation of the fistula edge, use of a fine scissors or knife, and approximation of the denuded edges with “stitching needles of stiff swans’ quills” ( ).

Centuries later, J. Marion Sims, advanced the surgical technique to repair vesicovaginal fistula. Sims practiced medicine at a time when treating women was considered distasteful and rarely done. With a modern lens his legacy is both complicated and divisive despite his contributions to the medical field. Sims published his classic paper “On the Treatment of Vesicovaginal Fistula” in 1852 in the American Journal of Medical Sciences , in which he deprecated the use of cautery and advocated for postoperative bladder drainage with a urethral catheter. His technique denuded the fistula edge, closing the defect in one layer with fine silver wire applied with leaden bars and perforated shot. From his work he developed novel surgical instruments including a vaginal speculum with a bent pewter spoon as a vaginal and utilized reflected light from a mirror. ( ). He later designed a silver sigmoid-shaped, self-retaining retractor for this purpose.

Sims is however a controversial figure as his research was conducted on enslaved Black women without anesthesia. This has led medical ethicists and historians to consider his use of enslaved Black bodies as medical test subjects falls into a long, ethically bereft history that includes the Tuskegee syphilis experiment and Henrietta Lacks. The American Medical Association recommends that if unethically acquired data are essential to science, any use or citation of these data should describe the unethical behavior and pay respect to the victims of the experimentation. A candid telling of the history of medicine can apply a new focus on the impact of the women and subjects in the narrative of Sims. Namely, the enslaved women, Lucy, Anarcha, and Betsy, who through their work, fortitude, and even suffering were equally responsible for the contemporaneous advances in surgical care. In this manner acknowledgment builds new ways to understand the history of medical research and to recognize the damage certain practices may continue to have as they reverberate over generations. ( )

The discovery of antibiotics and the development of general and regional anesthesia contributed significantly to the surgical treatment of VVFs in the twentieth century. Other notable milestones included urethral reconstruction using lateral vaginal flaps and labium minus grafts ( ); suprapubic intraperitoneal repair of posthysterectomy, high vesicovaginal and rectovaginal fistulas ( ); partial colpocleisis for posthysterectomy VVFs ( ); urethral reinforcement using pelvic floor muscles ( ); pedicled gracilis muscle flap ( ); bulbocavernosus flaps ( ); abdominal repair technique of VVFs involving bisection of the bladder ( ); pubococcygeus, bulbocavernosus, rectus abdominis, and gracilis flaps ( ); the use of pedicled omental flaps in the repair of extensive VVFs ( ); and urethral reconstruction ( ; ). Knowledge of effective repair of genitourinary fistulas became more widely disseminated with the publication of The Vesico-Vaginal Fistula ( ). Greater international attention was brought to the immense problem of genitourinary fistulas in developing countries with the foundation of the Second Fistula Hospital in Addis Ababa, Ethiopia, in 1975, and the report of 1789 fistulas repaired during an 11-year period from Nigeria ( ).

Epidemiology and etiology

Fistulas, including those in the lower urinary tract, occur secondary to an initial insult followed by a defect or vulnerability in the wound-healing process. Wounded tissue undergoes four phases of healing: coagulation, inflammation, fibroplasia, and remodeling. These phases do not occur independently, but overlap one another. During the fibroplastic phase, collagen is laid down, reaching its peak on the seventh day after injury and continuing for 3 weeks. Between the first and third weeks, healing is most vulnerable to hypoxia, ischemia, malnutrition, radiation, and chemotherapy, so this is the time when most fistulas present. Conditions known to interfere with wound healing are associated with an increased risk of fistula formation, including diabetes mellitus, smoking, infection, peripheral vascular disease, chronic steroid use, malignancy, and previous tissue injury.

Most of the literature on the etiology, diagnosis, management, and prevention of lower urinary tract fistulas consist of expert opinions, case series, or cohort studies, with few randomized controlled trials. Many of the studies are based on experiences with obstetric fistulas, which primarily occur in women in developing countries. Research in these environments is often limited by resource scarcity and plagued with short-term follow-up periods. It is important to review the information presented in this chapter with these limitations in mind.

Presentation and diagnosis

Patients with genitourinary fistulas present in many ways, but virtually all share the symptom of some form of persistent insensate urinary leakage from the vagina. The timing of symptom onset and the severity of symptoms coincide with the size, location, and nature of the injury. After surgery, radiation, or other inciting insult or injury to the tissue, symptoms may develop after an interval of days, weeks (surgical and obstetric fistulas), months, or even years (radiotherapy-related fistulas). Postsurgical fistulas, the most common type in developed countries, usually present in the first 14 days after surgery. The classic presentation is a patient who describes continuous urinary leakage (day and night) or persistent watery vaginal discharge. If the fistula is very small, leakage may be intermittent, occurring only at maximal bladder capacity or with particular body positions, such as lying supine. Other associated signs and symptoms include unexplained fever, hematuria, recurrent cystitis or pyelonephritis, vaginal pain, suprapubic pain, flank pain, and abnormal urinary stream.

The size, location, and number of fistulous connections should be ascertained to facilitate the best curative measures. Office evaluation, cystourethroscopy, and imaging studies such as intravenous urography permit the localization and characterization of suspected fistula, and additional exclusion or identification other types of urinary tract injury. The initial evaluation of all patients with symptoms of genitourinary fistulas starts with a complete physical examination. In a patient with vaginal leakage, a thorough speculum examination of the vagina may reveal the source. Oftentimes, the first examination finding consistent with fistula is urine pooling in the vaginal vault. Depending on the patient’s anatomy, the fistula may best be seen using a full speculum to retract both the anterior and posterior vaginal wall. This is particularly true when the fistula is located at the vaginal cuff, which is most common for VVFs occurring as a result of hysterectomy. When the fistula is more distal, it is useful to use the bottom blade of a Grave’s speculum to allow careful visualization of the anterior vaginal wall. During examination, the surrounding tissue should be assessed for signs of inflammation, edema, and necrosis, which portend poor wound healing and should be addressed before repair.

If a urethral fistula is suspected but not immediately seen, it may be necessary to place a urethral catheter to elongate the urethra and allow for inspection of the entire vaginal epithelium overlying the urethra. If any portion of the catheter becomes visible on vaginal examination, a sizable fistula is present.

If leakage is seen, and a fistula suspected without certainty based on exam, the fluid may be analyzed for urea or creatinine concentrate to confirm the presence of urine. If leakage is not immediately demonstrated, the bladder may be filled (with saline or methylene blue saline), and provocative maneuvers, such as Valsalva or manual pressure over the bladder, may be used to reproduce and confirm the patient’s symptoms.

Further office-based evaluation to confirm the presence of a small-diameter VVF and/or evaluate for ureteral involvement includes the tampon test. Instillation of methylene blue or indigo carmine into the bladder typically stains a vaginal swab or tampon blue in the presence of a VVF. If instillation volume is inadequate because of urethral leakage, a transurethral Foley catheter should be placed to prevent any staining of the distal tampon from leakage of fluid through the urethral meatus. Unstained but wet swabs may indicate a ureterovaginal fistula. If a ureterovaginal fistula is suspected, oral phenazopyridine can be administered at the time of methylene blue bladder instillation, which will cause orange-colored staining of the tampon. Other options include intravenous indigo carmine, which would stain the tampon blue, and sodium fluorescein. Sodium fluorescein (25 mg of 10% intravenous sodium fluorescein [0.25 mL]) is quickly renally excreted and stains the urine a greenish hue ( ). However, both of these dyes require intravenous access, and may be most appropriate if performing an examination without anesthesia. Intravenous methylene blue must be used with caution because of the risk of methemoglobinemia, a rare but serious complication.

Cystourethroscopy or combined cystoscopy-vaginoscopy is recommended to further characterize the fistula size, number, complexity, and location within the bladder, along with associated lesions and condition of surrounding tissue. Key observations include the fistula’s size and proximity to the bladder neck, urethral sphincter, and ureteral orifices, as well as the presence of tissue edema, slough, infection, induration, stones, foreign material (sutures, mesh), and scarring. An additional benefit is the opportunity to perform retrograde pyelogram in order to assess for ureteral involvement. Cystoscopy can be difficult with large fistulas because of leakage of irrigation; in such cases, a Foley catheter may be placed within the fistula tract to decrease leakage and observe the rest of the bladder. Bladder biopsy should be performed as needed if there is a history or suspicion of malignancy or lesions suspicious for infectious agents, such as tuberculosis, contributing to the development of fistula.

There is no clear consensus on the optimal imaging modality that should be performed to diagnose and determine the extent of a urinary tract fistula. In fact, imaging is frequently not required to make a diagnosis and treat a vesicovaginal or UVF, but it may be helpful. In a multiinstitutional study of 226 VVFs diagnosed in the United States, 23% of fistulas were diagnosed and managed based on physical examination alone, while the other 77% were assessed with some form of imaging or cystoscopy ( ).

If one chooses to pursue imaging, the choice of study should be tailored to maximize the likelihood of detecting the fistula based on suspected location. Suspected bladder injuries can be evaluated using retrograde cystourethrography, but for suspected urethral injuries, voiding cystourethrogram is better. However, we prefer intravenous urography with cross-sectional imaging, such as computed tomography (CT) or magnetic resonance urogram, which evaluates not only the bladder but also the ureters for fistula or obstruction ( Fig 38.1 ). However, this technique may not be optimal for suspected concomitant ureteral and bladder fistulas, as they are sometimes difficult to distinguish and, under distension of the bladder, may lead to poor or no visualization of a small VVF. If the fistula is clearly seen on physical exam, imaging may be of less value. In the uncommon setting of vesicouterine fistula, hysterosalpingography may be useful. Other advanced imaging techniques include subtraction magnetic resonance fistulography and endocavitary ultrasound with or without Doppler and contrast ( ; ).

Conservative management

Various conservative or minimally invasive therapies are available for lower urinary tract fistulas, although the true viability and success of these treatment modalities are unknown, as the literature consists mostly of case reports and small retrospective series. The most conservative treatment of a VVF is simply prolonged bladder drainage with a Foley catheter. In a retrospective analysis of 1716 women with obstetric VVF, continuous catheter drainage resulted in spontaneous fistula closure in 15% of patients. Spontaneous closure occurred in 50% to 60% of patients with fistulas that were 2 cm or less and who presented for care no later than 4 to 6 weeks after delivery ( ; ). Because it may be logistically difficult to repair a VVF immediately, and/or there may be tissue factors such as necrosis preventing immediate repair, it is reasonable to proceed with a trial of continuous bladder drainage for 4 weeks in fistulas that are less than 1 cm in diameter and unrelated to malignancy or radiation, as these fistulas may spontaneously resolve in 12% to 80% of cases.

Other less invasive options include curetting, electrofulguration, and laser ablation to deepithelialize the fistula tract and allow it to spontaneously heal while the bladder is continuously drained. Once the fistula tract has been deepithelialized, injection of agents such as fibrin glue and collagen into the fistula tract has been shown to successfully promote closure. Most of these studies report successful treatment in small fistulas (≤5 mm) resulting from gynecologic surgery. There have also been reports of using these methods to successfully close radiation-induced fistulas. Agents such as cyanoacrylic glue administered percutaneously, endoscopically, or vaginally have been used in a series of 13 urinary tract fistulas of differing etiology, with an 85% success rate after a mean follow-up period of 35 months ( ). The failures were in larger fistulas (>1 cm). Nonsurgical fistula closure is best attempted in a patient who has a small fistula, who is a poor surgical candidate, or who desires to first try less invasive options.

Since the 1990s, the recommended initial management of an isolated ureterovaginal fistula has been ureteral stenting when feasible. In 1995, Selzman et al. reported 100% successful curative treatment of ureterovaginal fistula among seven patients in whom stent placement was feasible. More recently, described their 13-year experience with ureteral stent placement. Among 12 patients who underwent conservative management, 11 (92%) were able to be successfully stented (8 retrograde, 3 antegrade). At a median stent duration of 10 weeks, all patients had successful closure of ureterovaginal fistula. Stenting may be more successful when performed sooner rather than later. In a series by , stent failure occurred in two patients who underwent stent placement at 90 and 390 days after initial surgery. However, one patient who was stented 780 days after surgery experienced full resolution of symptoms.

Patients who undergo stent placement should be counseled about the risks of infection, stone formation, and ureteral stricture formation. After 8 to 12 weeks, a retrograde pyelogram can be performed to evaluate for persistence of the fistula. If the fistula has healed, the stent may be removed, and a renal ultrasound, CT urogram, or nuclear renogram may be performed after 4 to 6 weeks to rule out subsequent stricture formation and obstruction.

If stenting is not possible, or the patient fails treatment, interval management with percutaneous nephrostomy may be used until inflammation has subsided and the patient can safely undergo surgery.